The intent of this website is to share my expertise on In-Situ Combustion (ISC), as a method for exploitation/recovery of the oil and gas, and recovery of the energy stored in the underground coal. The most widespread utilization has been as an Enhanced Oil Recovery (EOR) method applied in heavy oil reservoirs. Synonyms for in situ combustion are:
Underground combustion
Fireflooding
"Underground combustion" in other languages:
Spanish:
Combustion subterranea (combustion en sitio o combustion en el yacimiento)
French:
Combustion souterraine (combustion in situ or deplacement par combustion)
Russian:
Внутрипластовое горение (Vnutriplastovoe gorenie)
German:
Unterirdische Verbrennung (In Situ Verbrennungsprozese)
Dutch:
Ondergrondse verbranding
Portuguese:
Combustao in-situ
Chinese:
火烧油层
Hindi:
Bhumigat Jwalan
Arabic:
الاحتراق تحت الأرض
Romanian:
Combustie subterana
Norwegian:
Undergrunn forbrenning (Underjordisk forbrenning)
Similar to the steam-injection based processes, ISC is a thermal Enhanced Oil Recovery (EOR) process. My OBJECTIVE is to provide ISC related knowledge, both basics and essential last-minute advancements, in order to facilitate a quick update for youngsters and/or engineers and scientists, just entering this area of EOR. This is imperative as ISC mechanisms are more complex that those for other thermal processes.
BIO - Alex Turta: CEO of A T EOR Consulting Inc
A T EOR Consulting Inc. is a company specialized in EOR and Heavy Oil Recovery. Alex has a Ph.D. in oil recovery by in situ combustion (ISC), with a subsequent in-depth specialization in ISC applications.
For more than 12 years, Alex was involved in the implementation and management of Suplacu de Barcau commercial project, the world's biggest ISC project.
He has served as an ISC consultant in North and South America, Europe and Asia. He has also been engaged in assignments from the World Bank and the United Nations Development Programs (UNDP). As an UNDP expert he has guided the development of Balol and Santhal ISC projects in India, from pilot to commercial stage operation.
All in all, he has been involved in 8 commercial ISC operations and 16 ISC pilots, worldwide.
Alex is the recipient of 2012 Society of Petroleum Engineers Canada Regional Reservoir Description and Dynamics Award for his contributions in theory and practice of ISC application; he was instrumental in developing the theory and practice of commercial exploitation of heavy oil reservoirs by ISC using the peripheral line drive operation starting from the uppermost part of the structure; this theory has been confirmed by the successful operation of the commercial ISC projects at Suplacu de Barcau (Romania), Glen Humel and Mid-way Sunset, USA, Balol and Santhal (India) and other projects.
Also, Alex is the recipient of 2024 Society of Petroleum Engineers International Reservoir Description and Dynamics Award for his contribution to the foundation and development of the new in-situ combustion process called Toe-to-Heel Air Injection (THAI) along with its theoretical support by the development of the theory of short-distance and long-distance heavy oil displacement.
Alex is the author of the ISC chapter in the USA published book, namely "Enhanced Oil Recovery. Field Case Studies", Elsevier, 2013, Editor James J. Sheng.
Since 1992, Alex has been part of the “split-team”, which has continuously worked on both sides of the Atlantic (in UK and Canada), to develop novel ISC processes for heavy oil recovery, namely Toe-To-Heel Air Injection (THAI) and its version for in-situ upgrading, CAPRI. Since 1996 Alex has also been instrumental in developing the Toe-To-Heel Waterflooding process.
For the use of horizontal wells in heavy oil recovery, he introduced and defined the concept of short-distance oil displacement as opposed to the concept of long-distance oil displacement, used in conventional light oil recovery, when using only vertical wells.
Expertise in the area of oil recovery by ISC
Obtained his Ph.D with a contribution to the development of the wet combustion process
More than 27 year's experience with field, laboratory and analytical modelling of ISC, being instrumental in the design, implementation and evaluation of the biggest world’s ISC process at Suplacu de Barcau, Romania (maximum daily oil production 10,000 bbl/day) and guiding the second biggest world’s ISC processes in Balol and Lanwa, in India
Technical reports on ISC: 37 (for more than 18 projects, both pilots and commercial projects)
Publications on ISC process/projects: 20
ISC international consultancy work: Ecuador, India, Malaysia, Japan, China, Russia, Kazakhstan, Romania, Brazil, USA, Colombia and Argentina; World Bank ISC expert in 1986 for Videle-Balaria commercial ISC projects in Romania; ISC expert for India in the period 1991-1996 and in 2015
Consultancy in North America: Amoco, USA, Oracle Oil, USA, ARC (1993)
ISC related patents: 9
Alex Turta’s top accomplishments related to the development of ISC process:
Instrumental in developing the theory and practice of commercial exploitation of heavy oil reservoirs by ISC using the peripheral line drive operation starting from the uppermost part of the structure; today, this is the preferred mode of exploitation, worldwide.
Instrumental in the development of the short-distance oil displacement (SDOD) processes: Toe-To-Heel Air Injection (THAI), and catalytic THAI (CAPRI), in a long cooperation (1992-2003) with University of Bath, England. THAI and CAPRI are new recovery processes for heavy oil recovery. Also, developed the Toe-To-Heel Waterflooding (TTHW) process and investigated the Toe-To-Heel Steamflooding, which, at this time, is still under development
In year 2000, he introduced the concept of Short-distance oild displacement (SDOD) process, used extensively in conjunction with SAGD, THAI, top-down ISC, etc, which are SDOD processes
Established a more general equation for the calculation of the apparent hydrogen-carbon ratio (H/C ratio) from the composition of the produced gases of an ISC pilot. This takes into account the gases which are non-participating in the combustion but are produced with those participating, such as hydrocarbon gases, hydrogen, some CO2, etc
Highlighted the strong positive effect of high reservoir temperature on the applicability of ISC. This is directly related to the possibility of using small air fluxes (low air injection rates) and to the possibility of using the peripheral line drive operation starting from the uppermost part of the structure
Banner
Identification of the pictures in the Banner (from left to right):
MAJOR CONTRIBUTORS TO THE DEVELOPMENT OF THE ISC PROCESS, INCLUDING THAI PROCESS
MAJOR CONTRIBUTORS TO THE DEVELOPMENT OF THE ISC PROCESS, IN GENERAL
J. Alexander, N.K. Baibakov, John Belgrave, Arkadii Bokserman, Jack Burger, Chieh. Chu, Murat Cinar, D.N. Dietz, Reza Fassihi, Norman Freitag, Claude Gadelle, Byron Gottfried, Malcolm Greaves, Dubert Gutierrez, Wenlong Guan, Berna Haskakir, Pan Jingjun, Tang Junshi, Punitkumar Kapadia, R.L. Koch, Anthony Kovscek, C.S. Kuhn, Victor Machedon, W.L. Martin, Raj Mehta, J.S. McNiel, Gordon Moore, John Moss, T.W. Nelson, Valentin Petcovici, S.K. Sinha, Sidhartha Sur, Alex Turta, Philip White, and Dimitrios Yanimaras.
All other persons having their Ph.D. theses in the area of in-situ combustion investigation (such as: Reza Alamatsaz, Hamid Rahnema, Alex Condrachi, Eider Niz-Velasquez, Keni Adegbesan, Nicolae. Trasca, Zeinab Khansari, Melek Deniz etc)
MAJOR CONTRIBUTORS TO THE DEVELOPMENT OF THE TOE-TO-HEEL AIR INJECTION (THAI)/CAPRI PROCESSES
Ado Muhammad Rabiu, Alex Turta, Malcolm Greaves, Conrad Ayasse, Claude Gadelle, Wenlong Guan, Ankush Kumar, Narayan Rao, Ramesh Pareek, Ravinder Sierra, Konstantin Starkov, Renbao Zhao, Xia TianXiang, Abarasi Hart and Joseph Wood.
All other persons having their Ph.D. theses in the area of THAI investigation (such as: Anbari Hossein, De Araujo E. Andrade, T. Lopeman, Safaei, Mohsen, Wei Wei, etc)
Acknowledgments
Many thanks to all collaborators/reviewers for their support in building this website; especially to:
Dr. Malcolm Greaves - Former Professor, University of Bath, UK
Dr. Joe Wood, Professor at University of Birmingham, UK
Dr. Claude Gadelle, France and USA
Dr. Aleksandra Ushakova, Russia and China
Dr. Yi-Bo Li, Chengdu, China
Dr. Norman Freitag, former Saskatchewan Research Council (SRC) Regina, Canada
Ravinder Sierra, Calgary, Canada
Roy Coates - former Alberta Research Council (ARC), Edmonton, Canada
David McLellan, Former Petrobank Energy and Resources - Calgary, Canada
Dr. Adel Guirgis, Calgary, Canada
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Curriculum Vitae
Alex Turta, Ph.D., P.Eng.
Education
1977 - Ph.D., Petroleum Engineering, Institute of Oil and Gas Bucharest, Romania (thesis: heavy oil recovery by in-situ combustion).
1968 - M.Sc., Petroleum Engineering, Institute of Oil and Gas, Bucharest, Faculty of Drilling of Wells and Exploitation of Oil and Gas Reservoirs.
Summary of Qualifications
Heavy oil reservoir exploitation by thermal methods, waterflooding and primary solution gas drive (foamy oil)
Designing, implementing and evaluating Improved Oil Recovery (IOR) projects
Laboratory testing and research for IOR methods applied to heavy and light oil reservoirs
Reservoir engineering aspects of horizontal wells
Conventional reservoir engineering
Top Acomplishments
Instrumental in the development of the PRIze software, used for the evaluation of EOR potential of oil reservoirs. This software was later improved and its name was changed to SelectEOR. Coordinator of the team
Instrumental in developing the theory and practice of commercial exploitation of heavy oil reservoirs by in-situ combustion (ISC) using the peripheral line drive operation starting from the uppermost part of the structure; today, this is the preferred mode of exploitation, worldwide
Instrumental in the development of the short-distance oil displacement (SDOD) processes: Toe-To-Heel Air Injection (THAI), and catalytic THAI (CAPRI), in a long cooperation (1992-2003) with the University of Bath, England. THAI and CAPRI are recovery processes for heavy oil recovery. Also, developed the Toe-To-Heel Waterflooding (TTHW) process and investigated the Toe-To-Heel Steamflooding, which, at this time, is still under development
In the year 2000, he introduced the concept of the Short-distance oil displacement (SDOD) process, used extensively in conjunction with SAGD, THAI, top-down ISC, etc, which are SDOD processes
Established a more general equation for the calculation of the apparent hydrogen-carbon ratio (H/C ratio) from the composition of the produced gases of an ISC field process. This takes into account the gases that are non-participating in the combustion but are produced with those participating, such as hydrocarbon gases, hydrogen, some CO2, etc. The paper dealing with this subject won the Asia International Research Awards (AIRA) 2023 handed to AIRA winners in October 1st, 2023 in Trichy, Tamil Nadu, India
Highlighted the strong positive effect of high reservoir temperature on the applicability of ISC. This is directly related to the possibility of using smaller air fluxes (lower air injection rates) when using the peripheral line drive operation starting from the uppermost part of the structure, to promote a more stable gravity oil displacement
Employment History
02/2014 - To date
President and CEO of A T EOR Consulting Inc., Calgary
Consultancy firm specialized in Heavy Oil Recovery and EOR
04/2000 - 02/2014
ALBERTA INNOVATES TECHNOLOGY FUTURES / ALBERTA RESEARCH COUNCIL, Calgary
Conducting research in the following areas:
mechanisms of primary recovery of heavy oils (foamy oil)
waterflooding of light heavy oils
thermal recovery methods
asphaltene deposition problems
1990 - 2000
PETROLEUM RECOVERY INSTITUTE, Calgary
Conducted research in the following areas:
mechanisms of primary recovery of heavy oils (foamy oil)
miscible coreflood to asses the efficiency of different schemes
study of wettability changes as induced by miscible displacement
asphaltenes deposition phenomena inside and outside porous media
performed international consultancy work in the area of EOR thermal pilots evaluation, mainly ISC pilots
participated in the development of the PRI software PRIze, for evaluating the EOR potential of oil reservoirs
1988-1990
PETROLEUM RECOVERY INSTITUTE, Calgary
Conducted research on sweep efficiency improvement using foams. Carried out and evaluated:
foam coreflood tests;
micromodel flow tests to visualize the foam interaction with the crude oil.
Research and Development Institute for Oil and Gas, Romania
1985-1988
Deputy Manger - Heavy Oil Department
Responsible for the evaluation of two commercial firefloods in Videle-Balaria basin and two steam injection pilots (cyclic and steam drive) in Moreni Field.
1979-1988
Supervisor EOR Group
Responsible for screening of E.O.R. techniques (thermal, miscible and chemical) for the main oil reservoirs in Romania.
1975-1988
Chief Engineer - Heavy Oil Exploitation
Designing, implementing and evaluating steam injection, fireflood and CO2 immiscible pilot projects.
1971-1974
Senior Research Engineer
Responsible for supervising the research team for the development of the wet combustion at Suplacu de Barcau field.
1968-1970
Resevoir Engineer
Responsible for conducting lab tests on fluid and rock properties and establishing primary and secondary reserves.
International EOR Consulting Activity
Consultancy with Petrobras, Brazil, and JNOC, Japon in the area of in-situ combustion (ISC) application (ISC 2-day course and consultancy relative to feasibility of ISC for several oil fields), 2006-2007.
Consultancy with Staatsolie, Paramaribo, Suriname, in the area of in-situ combustion application, 2005
Review of Eight ECOPETROL (Colombia) Oil Reservoirs in order to assess the potential for EOR and Horizontal Wells. November 1993. The assessment was conducted using PRIze, the software developed by PRI.
Consultancy with United Nations Development Programs for India, 1991-1996 (thermal methods, mainly ISC).
International EOR Consulting Studies
Coates R., and Turta A.: "Feasibility of Applying In-Situ Combustion Process in N-E Reservoir, under-lain by Bottom Water" June 2004, Contract work with Shell, Netherlands
Turta A., and Singhal A.: "Staatsolie IOR/EOR Opportunities: Evaluation of Future IOR/EOR Potential" April 2004, Contract work
Turta A.: "Assessment of the Commercial Steamflood Project in Karazhanbas Field, Kazahstan" March 2003. Contract work
Turta A.: "Evaluation of Possibilities to Improve Post In-Situ Combustion Exploitation of Bellevue Oil Field, Within Oracle Oil Company Lease" Shreveport, Louisiana, USA., November 2000
Turta A.: Review of the Balol and Lanwa In-Situ Combustion Field Tests.; Technical Report Prepared for the United Nations; Development Programs, March 1996
Turta A.: Review of the In-Situ Combustion Laboratory and Field Tests for Balol and Lanwa Oil Reservoir. Technical Report Prepared for the United Nations Development Programs, November 1994
Turta A.: Performance Evaluation of the Balol and Lanwa In-Situ Combustion Pilots and Recommendations for Further Development of the In-Situ Combustion Process on the Santhal-Balol-Lanwa Structure. Technical Report Prepared for the United Nations Development Programs. April 1993
Turta A.: Performance Evaluation of the Balol In-Situ Combustion Pilot and Recommendations for Further Development of the In-Situ Combustion Process in the Balol-Lanwa Reservoir. Technical Report Prepared for the United Nations Development Programs. November 1991
Turta A., Anghel A.: The Feasibility of the Fireflood Application for the Exploitation of Russkoe Reservoir, Siberia, U.S.S.R. Under the Memorandum between Ministry of Petroleum, Romania and Ministry of Petroleum, U.S.S.R. 1987
Machedon V., Panaitescu A., and Turta A.: The Design of a Fireflood for Pampa del Castillo la Guittara, South Argentina. Under Contract Between Ministry of Petroleum, Romania and The Company Perez Companc, Argentina, 1983-1984
Barbalata G., Bennion D., Nichols J. and Turta A.: Appraisal of EOR Study of Videle-Balaria Oil Reservoir. AOSTRA Canada and ROMCONSULT Romania. Bucharest, Sept.1981. Technical Report for the World Bank
Carcoana A., Machedon V., Popescu V. and Turta A.: The Evaluation of the Water Injection on the Um-El-Yusr Reservoir, Egypt.Under Contract between Ministry of Petroleum, Romania and General Petroleum Company,Egypt, December 1981
Turta A., Socol S., Popp V. et al.: The Feasibility of the Application of the Thermal Methods (Steam Injection and Fireflood) for the Rio Hollin Tar Sand Reservoir, Provincia Oriente Ecuador. Under Contract between the Romanian Ministry of Petroleum, and Compania Asphalto del Ecuador, Quito, Ecuador, October 1977
The Guidance section intends to help beginners to acquire very quickly the essential knowledge on the ISC process by using just the most important books and technical papers written in the last 60 years.
In the Conventional ISC section the following sub-sections exist:
The information from these sub-sections is intended to be a very significant help for a novice/neophyte to this area of EOR. It will direct the person to the most important and representative information in that class.
In the New ISC Processes section a brief presentation of the following processes are made:
Out of these four new ISC processes, only THAI has reached the status of field piloting.
Guidance
Since its first application, more than 1000 technical papers have been written on ISC or related to ISC process.
Some very good ISC books and papers are listed here to help the beginners in acquainting them with the basics of the process. The recommended books are written by specialists with hands-on experience on the ISC process.
At the same time, the papers indicated here are the most informative and complete on the subject. For instance, as far as the field application is concerned, they present well instrumented pilots and/or commercial operations, with a reliable evaluation of the
respective processes. In each area of activity some 3-4 papers are indicated; these papers can orient the reader to continue a more in-depth study using the most relevant papers.
The focus of this "Guidance" section was to save significant time for those starting to study ISC process. The following topics can be found:
Review of ISC commercial applications - Heavy Oil Reservoirs
Review of ISC commercial applications - Light Oil Reservoirs (very deep, high temperature, light oil reservoirs)
Review of ISC field pilots (Heavy Oil)
Review of cyclic ISC (burn and turn ISC) operations
Most important papers on routine laboratory testing (in view of field testing)
Most fundamental paper on kinetics of oxidation
Analytical and numerical simulation of ISC process
Ignition operations
Basic design
New ISC process: Toe-To-Heel Air Injection (THAI)
Books for basic ISC understanding
Thermal Recovery Methods by Jon T.Moss and Phillip D. White. PennWell Publishing Co., Tulsa, Ok, USA. , 1983. Presents mainly USA experience. Field oriented.
Thermal Methods of Oil Recovery by J Burger, P Sourieau and M Combarnous. Edition Technip Paris, 1985.
Thermal Methods of Petroleum Production by Baibakov N. K. and Garushev A.R. Elsevier Amsterdam, 1989. Presents mainly the Russian experience.
Enhanced Oil Recovery. Field Case Studies.Editor: James J. Sheng. Chapter 18: In-Situ Combustion (page 447 to 543) by Alex Turta. Gulf Professional Publishing (an imprint of Elsevier), 2013.
ISC PAPERS
Synthesis paper: Ursenbach, M.G.: "Air Injection in Heavy oil Reservoirs - A Process Whose Time Has Come (Again)" In Journ. of Can. Petr. Technology (JCPT), January 2010.
Review of ISC commercial applications - Heavy Oil Reservoirs
Turta A.: In-Situ Combustion - From Pilot to Commercial Application. Proceedings of the Field Applications of In-Situ Combustion - Past Performance/Future Application Symposium, Tulsa, April 21-22, 1994.
Turta, A., Chattopadhyay S.K, Bhattacharya R.N., Condrachi, A., and Hanson, W.: "Current Status of the Commercial In-Situ Combustion (ISC) Projects and New Approaches to Apply ISC". Journal of Canadian Petroleum Technology (JCPT) November 2007
Panait-Patica, A., Serban, D. and Ilie N.: "A Case-History of a Successful In-Situ Combustion Exploitation" Paper SPE 100346 presented at the SPE Europec/EAGE Annual Conference and Exhibition, Vienna, Austria, 12-15 June 2006
Dayal, H.S, Bhushan, B.V et al.: "In-Situ Combustion: Opportunities and Anxieties" Paper SPE 126241 presented at the SPE Oil and Gas India Conference and Exhibition, Mumbai, India, 20-22 January 2010.
Review of ISC commercial applications - Light Oil Reservoirs (very deep, high temperature, light oil reservoirs)
Kumar, V.K. et al.:"Case History and Appraisal of the Medicine Pole Hills Unit Air Injection Project" Soc. of Petr. Eng./DOE Paper No 27792/1994
Fassihi, M.R. and Gillham T.H.: "The Use of Air Injection to Improve the Double Displacement Process". Proceedings of the Field Applications of In-Situ Combustion - Past Performance/Future Application Symposium, Tulsa, April 21-22, 1994. Or Soc. of Petr. Eng. Paper No 26374 /1993
Kumar, V.K. et al.: "Air Injection and Waterflood Performance Comparison of Two Adjacent Units in Buffalo Field: Technical Analysis". Soc. of Petr. Eng. Paper No 99454/2006
Gutierez, D. et al.: "Buffalo Field High-Pressure Air Injection Projects: Technical Performance and Operational Challenges". Soc. of Petr. Eng. Paper No 113254/2008
Review of ISC field pilots - Heavy Oil Reservoirs
Aldea, Gh. Petcovici, V. and Dumitrescu H.: "Aplicarea experimentala a metodei de exploatare prin combustie subterana in Romania" Petrol si Gaze, Vol. 19, No1, 1968 (in Romanian)
Ramey, H.J., et al.: "Case History of South Belridge, California, In-Situ Combustion Oil Recovery" Soc. of Petr.Eng./DOE Paper No 24200/1992
Petcovici V.: "La combustion in-situ assure un taux de recuperation eleve dans un important gisement d'huile lourde de Roumanie: le sarmatien de Balaria" Colloque Internat. sur les Techniques d'Exploitation et d'Exploration des Hydrocarbures, Paris, December 10-12, 1975.
Review of Cyclic ISC (burn and turn ISC) operations
Turta A., Socol S., Trasca N. and Ilie N.: "Application of Cyclic Combustion in Romania", Mine Petrol si Gaze, July 1985 (in Romanian). Note; Translation of this paper in English can be provided at your request
Trasca N. and Paduraru R. "Stimulation of Oil Inflow and Consolidation of the Productive Stratum by Cyclic Combustion" 1993 Joint Canada-Romania Heavy Oil Symposium, Sinaia, Romania, March 7-13, 1993
Most important papers on routine laboratory testing (in view of field testing)
Combustion Tube tests (for both heavy and light oils)
Showalter E.W.: "Combustion - Drive Tests" Soc. of Petr. Eng. Journal, March 1963
Penberthy, K.W and Ramey, H.J.: "The Design and Operation of Laboratory Combustion Tubes: Soc. of Petr. Eng. Paper No. 1290, October 1965
Ursenbach M. et al.: "Laboratory In-Situ Combustion Behavior of Athabasca Oil Sands" Eight Petroleum Conference of the South Saskatchewan Section of CIM, Regina, October 18-20, 1993
Moore, G. et al.: "An Evaluation of the Benefits of Combined Steam and Fireflooding as a Recovery Process for Heavy Oils Proceedings of the Field Applications of In-Situ Combustion - Past Performance/Future Application Symposium, Tulsa, April 21-22, 1994.
Greaves, M et al.: "Improved Residual Light Oil Recovery by Air Injection (LTO Process)". In Journ. of Can. Petr. Technology (JCPT), Vol 39, No.1, January 2000.
Ramped Temperature Oxidation tests
Martin, W, Alexander D. J. and Dew N.J.: "Process Variables of In-Situ Combustion" Trans AIME 1958
Moore, G. et al.: "Ramped Temperature Oxidation Analysis of Athabasca oil Sands Bitumen" In Journ. of Can. Petr. Technology, Vol 38, No.13, Special Edition, 1999
Kovscek, A.R., Castanier, L.M. and Gerritsen M.G.: "Improved Predictability of In-Situ Combustion Enhanced Oil Recovery" In SPE Reservoir Evaluation and Engineering, May 2013
Accelerated Rate Calorimeter tests (mainly for light oils)
Yannimaras, D.V. et al.: "The Case for Air Injection Into Deep Light Oil Reservoirs" Proceedings of the Sixth European Symposium on IOR, 1991
Yannimaras, D.V. and Tiffin, D.L.: "Screening of Oils for In-Situ Combustion at Reservoir Conditions by Accelerating - Rate Calorimetry". In SPE Reservoir Engineering, February 1995
Juan S. et al. "Laboratory Screening for Air Injection-Based IOR in Two Waterflooded Reservoirs" Paper 2003-215, presented at International Petroleum Conf. June 10-12, 2003, Calgary, Canada
Gundogar, A.S. and Kok, M.V. : "Thermal characterization, combustion and kinetics of different origin crude oils" In Fuel, 123, (2014) 59-65
Yi-Bo Li, Ya-Fen Chen, Wan-Fen Pu, and Bing Wei: "Low Temperature Oxidation Characteristics Analysis of Ultra-Heavy Oil by Thermal Analysis" In Journal of Industrial and Engineering Chemistry 48 (2017) 249-258
Most important papers on kinetics of oxidation
Belgrave, J. D. M. et al. "A Comprehensive Approach to In-Situ Combustion Modeling" Soc. of Petr. Engin. /DOE paper 20250 /1990
D. Gutierrez, R.G. Moore, M.G. Ursenbach, S.A. Mehta. "The ABCs of In-Situ-Combustion Simulations: From Laboratory Experiments to Field Scale /SPE- 148754, 2012"
Khansari, Zeinab, Gates, I.D. and Mahinpey, N: "Low-temperature oxidation of Lloydminster heavy oil: Kinetic study and product sequence estimation". In Fuel 115 (2014) 534=538
Cinar, M. and Kovscek, Anthony: "Assessing the Consistency of Measurements and Models for the Kinetics of In-Situ Combustion" Paper presented at the Annual Technical Conference and Exhibition, Houston, USA, 28-30 September 2015. SPE-175141-MS
Freitag N : "Chemical Reaction Mechanisms That Govern Oxidation Rates During In-situ Combustion and High Pressure Air Injection". In SPE Reservoir Evaluation and Engineering November 2016
Note: See also the 2 papers from Point 6 (TGA/PDSC), above.
Analytical and Numerical Simulation of ISC process
Analytical
Thomas, G.W.: "A Study of Forward Combustion in a Radial System Bounded by Permeable Media" In Journ. of Petr. Technology (JPT) October 1963
Chu Chieh : "Two-dimensional Analysis of a Radial Heat Wave" In Journ. of Petr. Technology October 1963
Gotfried, B.S.: "A Mathematical Model of Thermal Oil Recovery in Linear Systems" In Soc. of Petr. Eng. Journal, September 1965
Numerical
Gutierez et al.: "The ABC of In-Situ Combustion Simulations: From Laboratory Experiments to the Field Scale" SPE paper 148754 presented at the Canadian Unconventional Resources Conference, Calgary, Canada, 15-17 November 2011
Kumar, M.A.: "Cross-Sectional Simulation of West Heidelberg In-Situ Combustion Project" SPE Res. Eng. Evaluation Journal, February 1991
Coats K.: "In-Situ Combustion Model" In Soc. of Petr. Eng. Journal, Vol 20, 1980
Rubin, B and Vinsome P.K.W.: "The Simulation of In-Situ Combustion Process in in One Dimension Using A Highly Implicit Finite-Difference Scheme" In Journ of Canadian Petr. Techn Vol 19 ,No. 4, Oct-Dec 1980
Ignition operations
Strange, L.K.: "Ignition: Key Phase in Combustion Recovery" Petroleum Engineer, vol. 36, No. 12 and 13, 1964
Tadema, N.J. and Weijdema, J.: "Spontaneous Ignition of Oil Sands". Oil and Gas Journal December 14, 1970
Turta, A.: "Review of Steam-Based Ignition Operations for Initiation of In-situ Combustion Process". World Heavy Oil Congress, Edmonton Alberta, Canada, March 2011
Basic Design
Nelson, T.W. and McNiel,J.S: "How to Engineer an In-Situ Combustion Project" Oil and Gas Journal June 5, 1961
Gates, C.F. and Ramey H.J.: "A Method for Engineering In-Situ Combustion Oil Recovery Projects" Journ of Petr. Techn., February 1980
Turta A, Wassmuth F., Maini, B. and Singhal A.: "Evaluation of IOR Potential of Petroleum Reservoirs". (as included in the PRIze 3.1 software). Proceedings of the 16th World Petroleum Congress, Calgary , Canada, June 11-15, 2000.
Most important papers regarding Toe-To-Heel Air Injection (THAI)
Greaves M. and Turta A.: Oilfield In-Situ Combustion Process. U.S.Patent No.5,626,191, May 6, 1997. Canadian Patent 2,176,639, August 8, 2000.
Greaves, M., Saghr. A.M. Xia, T.X., Turta, A. and Ayasse, C: “THAI – New Air Injection Technology for Heavy Oil Recovery and In-Situ Upgrading” Journal Of Canadian Petroleum Technology, March 2001, Vol 40, No.3.
Turta, T. A. and Singhal K.A. : "Overview of Short-Distance Oil Displacement Processes". Journal of Canadian Petroleum Technology, February 2004, Vol. 43, No.2, pp 29-38.
Liang Jinzhong, L., Wenlong, G., Youwei, J., Chanfeng, X., Bojun, W. and Xiaoling, L.: “Combustion Front Expanding Characteristic and Risk Analysis of THAI Process”. Petroleum Exploration Development, March 2013.
Renbao Zhao, Shuai Yu, Jie Yang, and Minghao Heng: “Optimization of Well Spacing to Achieve a Stable Combustion During the THAI Process” In Energy 151 (2018) 467-477. Available online March 9, 2018
Pareek, R.C, Prasanna G, Goyal M, Singh P.K and Rao N.S.: "Integration of Toe Up Horizontal Wells (of THAI process) with In Situ Combustion Process" Presented at PETROTECH; 13th International Oil and Gas Conference and Exhibition, 10-12 February 2019, Greater Noida, Delhi, India
Turta, A., Punitkumar, K. and Gadelle, C.: “THAI Process: Determination of the Quality of Burning From Gas Composition Taking Into Account the Coke Gasification and Water-Gas Shift Reactions” Journal of Petroleum Science and Engineering (JSPE) Volume 187, April 2020. Published version available online: 25 Nov-2019 DOI information: 10.1016/j.petrol.2019.106638
Turta, T., Singhal, A., Sierra, R., Greaves, M. and Islam, M.: “Evaluation of the First Field Piloting of the THAI Process: Athabasca Pilot” SPE Canadian Energy Technology Conference and Exhibition, March 15-16, 2023, Calgary, Canada
Kumar.,A., Kumar., R., Kesharwani, A., Mahanta, J., Kumar, N., Khadia, D.S..K. and Dayal H.S.: “Enhancement of oil production in an In-situ combustion process through unconventional and innovative approaches (including THAI): Case study from Lanwa field, Cambay Basin, India.” ”. SPE Canadian Energy Technology Conference, March 13-14, 2024, Calgary
Turta, A., Singhal, A., Greaves M and Islam, M. : “An In-Depth Evaluation of Toe-To-Heel Air Injection Application in a Heavy Oil Reservoir Underlain by Bottom Water. Kerrobert Case” SPE Canadian Energy Technology Conference, March 13-14, 2024, Calgary
Farouq Ali's characterization of ISC: the most tantalizing EOR process.
Dr. Ashok Singhal's characterization of ISC: Too simple to describe in general, but too complex to describe in detail.
My characterization of ISC: In some applications ISC is of a gordian complexity. My two criteria for success (a necessary condition and a sufficient condition must be met): The necessary condition is to burn efficiently (very good oxygen utilization efficiency) and the sufficient condition is to produce oil at an economic air-oil ratio.
The focus of this section was to save significant time for those starting to study ISC process. The following topics can be found:
ISC for Heavy Oil Recovery
ISC for Very Light Oil Recovery – High Pressure Air Injection (HPAI)
Essential information on routine laboratory testing (in view of field testing)
Most important ISC pilots
Most important ISC commercial projects
Special ISC applications [oil sands, gas-over-bitumen (GOB) related applications, underground coal gasification (UCG), etc
ISC for Heavy Oil Recovery
Two phases of the ISC process: Unlike all EOR process, ignition has to be performed first, hence two phases: ignition (generation of the ISC front in the oil reservoir, near the injection well) and the propagation of the ISC front towards the surrounding production wells. Ignition procedures:
Using artificial devices (gas burners and electric heaters)
When choosing the ignition method, the following parameters are taken into account:
Reservoir temperature
Oxidability characteristics of the oil-rock couple
Depth of reservoir
Two kinds of ISC processes:
Forward ISC (which can be dry or wet)
Reverse ISC
Note 1: Only forward ISC is commercially applied. General rule for forward ISC application: Apply pre-heating (if the oil viscosity > 1,500-2,000 cp); pre-heating is usually done by cyclic steam stimulation (CSS).
Fluid saturation and temperature profile for dry forward ISC (picture 1) clearly shows that most of the generated heat remains behind the ISC front and therefore does not contribute to oil heating and its viscosity decrease.
That's why the wet ISC was designed; to transfer some of this heat to the region ahead of the ISC front, as seen in fluid saturation and temperature profile for wet forward ISC (picture 2). In practice, both dry and wet ISC are segregated, hence the term segregated ISC.
Picture 1. Temperature and saturation profiles during dry ISC process (modified after Burguer, 1985)Picture 2. Temperature and saturation profiles during wet ISC process (modified after Burguer, 1985).
Illustrative pictures (3a and 3b) for forward and reverse ISC process are given based on a simple analogy: the cigarette example. The main features of the reverse ISC are:
Ignition takes place at the future production well
ISC front moves counter-current relative to the air flow
Picture 3a. Forward combustion; when inhaling air (inhaling oil and flue gases, if the cigarette is oil saturated!"). Picture 3b. Reverse combustion; when blowing into the cigarette (producing very hot oil, if the cigarette is oil saturated!).
ISC fluid saturation and temperature profile (picture 4) are very different from forward ISC; here oil is flowing through the burned zone, as well, and air is flowing through the virgin/cold zone. Cyclic ISC (burn and turn) or short-term ISC, resembles the Cyclic
Steam Stimulation (CCS) process in the sense that a single well is involved. First, an ISC front is propagated a few meters around the well and then the well is put into production.
Picture 4. Reverse combustion: temperature and saturation profiles (after Burger,1985). The dotted profiles correspond to not strictly one-dimensional conditions, with lateral heat losses.
Generally, the light oils are more reactive than heavy ones. This can be easily seen from a Ramped Temperature Oxidation (RTO) test (pictures 5a and 5b), in which a small amount of oil+rock sample is submitted to a programmed
linear-increasing temperature with a constant air injection and composition for the effluent gases are determined (see point C, at the end of this section/page : comparative RTO for heavy and light oils).
Picture 5. Typical ramped temperature oxidation test (Kisler Shallcross, 1985).
ISC for Very Light Oil Recovery - High Pressure Air Injection (HPAI)
There is a paradox related to the fact that so far ISC has been applied commercially for the very light oils (oil viscosity less than 2 cp), but it has not been proven (applied commercially) for medium oils with viscosity in
the range of 2 to 40 (60cp). ISC has been applied commercially for the high temperature, deep reservoirs having a very low oil recovery in a solution gas drive regime; for reservoirs typical to Williston Basin carbonates in North and South Dakota, USA. Crucial to this application
is the achievement of spontaneous ignition; therefore from the operator side it seems to be just an air injection to produce flue gas in-situ, due to the consumption of the oxygen by oxidation. It is commonly known as High Pressure Air Injection (HPAI).
HPAI process has not been proven yet as a commercial method when applied after water flooding, either natural or water injection
Fluid saturation and temperature profiles, from a laboratory tube test, shows a very long zone in which low temperature oxidation (LTO) takes place (pictures 6a and 6b).
Picture 6. LTO-Immiscible Air Flooding for light oils(Greaves, 1996). Lab tests. Produced gas composition vs. time after gas breakthrough. Schematic diagram of the process.
Essential information on routine laboratory testing (in view of field testing)
For evaluation of applicability of ISC in a certain field, one could consider 3 main laboratory tests, namely: Combustion Tube (CT) tests, Ramped Temperature Oxidation (RTO) tests and Accelerated Rate Calorimetry (ARC) tests. The kinetics of oxidation [high temperature
oxidation (HTO) and low temperature oxidation(LTO)] is investigated using RTO and ARC tests.
What is each test simulating and what information is providing: ARC and RTO tests provide information on chemical reactivity of oil in porous medium. The oxidation (more generally the chemical/physical transformations) of an infinitesimal volume of oil
reservoir when the ISC approaches, intercepts and completely traverses that volume. Simulation of the complex displacement processes is not the main goal of ARC and (most of) RTO tests.
CT tests provide quantitative, complete representation of phenomena: hydrodynamic, thermal, and chemical; an ISC front is generated and propagated along the combustion tube,
while the temperatures inside the CT and at its wall are recorded, along with the properties of produced fluids. Simulation of the complex displacement phenomena (one-, two- and three-phase immiscible
displacement), miscible displacement, heat transfer due to mass transfer between phases(vaporization / condensation) chemical phenomena of distillation, cracking, fuel formation and burning, etc. is the
objective. Heat losses are not simulated (quasi-adiabatic operation), they are just minimized!
Comparative RTO curves for heavy and light oils show that, for very light oils, the reactivity of oil at low temperatures (up to 300 0C) is high enough to ensure the self-sustainability of the process.
On the contrary, for heavy oil this is a lot lower and it is not enough such that the self-sustainability of the process can be ensured only if the oxidation takes place at high temperatures, in the range of
400-600 0C. In simpler words, self-sustainability of the process occurs when the peak temperature is up to 300 0C for light oils while for heavy oil the peak temperature have to be higher than 400 0C; in other words, the ISC can function properly in the LTO regime for light oils.
MOST IMPORTANT PILOTS
These pilots have been conducted in typical conditions, they used to have a very good instrumentation and a good evaluation was possible. All of them - except North Asphalt
Ridge, which is reverse ISC - are forward ISC operations. Most unique and difficult (to obtain data) are specified here for each pilot.
Suplacu de Barcau, Romania
7 inverted 5-five-spot patterns (arranged in line) located up-dip on structure - operated for 7 years; leading to a line drive commercial operation
3 observations wells; maximum temperature recorded: 620 0C
17 coring wells have been drilled in the burned out zone, behind the ISC front, for post-mortem evaluation; the conformance factor (ratio between burned out thickness and total thickness of the oil layer) was found to be less than 35%
Oxygen utilization efficiency: 90%-93%
South Belridge, Ca, USA
Isolated pattern operated for a very long period of time.
5 observations wells; maximum temperature recorded: 5100C
6 coring wells drilled in the burned out zone, behind the ISC front; the conformance factor was found to be in the range of 30% to 90%
Oxygen utilization efficiency: 100%
Balaria, Romania
4 inverted 5-five-spot patterns forming a confined pattern around the common production well
3 observations wells
3 coring wells have been drilled in the burned out zone, behind the ISC front for post-mortem evaluation; the conformance factor was found to be less than 35%???
Oxygen utilization efficiency: 80-90%
Pressure-Cycling In-Situ Combustion (PC-ISC) at Morgan Oil Field, Alberta, Canada
Morgan pilot encompassed:
primary production with sand (Cold Heavy Oil Production with Sand -CHOPS), cyclic steam stimulation (CSS), cyclic steam-air stimulation (CASA) & PC-ISC
8 inverted large contiguous patterns operated from 1980 to 1992
CSS (1980-1984): 7 to 10 cycles per well AND 1 or 6 cycles air-steam stimulations per well
ISC (1984-1992) operated with long cycles (7-12 months) of pressurization by air injection (with all producers closed) and 10-14 months of no air injection and just producers being ON
Outstanding upgrading of the ISC oil (up to 10 API degrees) produced during non-air injection periods, but totally unexplained
Oxygen utilization efficiency almost 100% and a very low air-incremental oil ratio (450 sm3/m3)
Marguerite Lake Pilot
The test was conducted by BP Canada and AOSTRA at Marguerite Lake, Wolf Lake region of Alberta, in the period 1979-1988.
Extremely high viscous oil (100,000 mPa.s at the reservoir temperature of 15 0C)
Process tested in a 3-well very small pattern first, and then in 4 adjacent patterns of 4ha/pattern; more than 14 observations wells
Tested process was called “Pressure Up Blowdown Combustion - PUBC) but in reality was very similar to PC-ISC, described for Morgan Pilot in the previous section. In both cases sustainability of ISC was based on very intensive preheating (by cyclic steam stimulation or other means) of a man-fractured (for Marguerite Lake) or CHOPS channeled (for Morgan project) rock before starting ISC pilot/li>
Moderate wet ISC with alternate air-water injection was carried out
O2-enriched air ISC was tested in the last phase
Very high peak temperatures recorded on-trend during the process; 900 0C during ISC with air and 1250 0C during the O2-enriched air ISC
For the first time, the production of hydrogen in the produced gases was documented:2-3.5% during ISC with air and 10-12% (up to 20%) during ISC with O2-enriched air. It was believed to be the result of coke gasification and water shift reactions, induced by high peak temperatures
Due to the very high complexity of this process (in a channeled reservoir), associated with substantial challenges in the control of the process, there was a continuous decline of the oil production, therefore there were difficulties in maintaining a sustained oil production
North Tisdale, Wyoming, USA
Application in the presence of bottom water
2 observations wells; maximum temperature recorded: 247 0C
2 coring wells have been drilled in the burned out zone; the conformance factor was less than 27%
Oxygen utilization efficiency: 72% (O2 % = 6% in the produced gases)
North Asphalt Ridge (NAR), Utah, USA
There are two very well instrumented reverse ISC pilots: Bellamy, Montana USA and N Asphalt Ridge (NAR). The preference was given to the second one as the first one was conducted in a very shallow reservoir -depth 20m and the spacing between wells
was extremely low -5m. In the NAR pilot, the reservoir depth was 107 m and the spacing between well rows was 20m. After ignition, the whole NAR pilot lasted 180 days, being intentionally converted from reverse to forward ISC after approx. 90
days, when the advancing reverse ISC front reached the injection wells; therefore there was a half-half period of reverse and forward ISC.
13 observations wells; maximum temperature recorded: 150 0C to 400 0C for the reverse ISC phase and 540 0C to 1,100 0C for forward ISC phase
7 coring wells drilled in the burned out zone; the conformance factor was in the range of 30% to 90%
Some results; average upgrading 6 degrees API and extremely high air-oil ratio ( 25,000 sm3/m3)
COMMERCIAL PROJECTS
In the last 6 decades of ISC application there have been more than 20 large-scale ISC operations worldwide, operated for a long period of time and containing a large number of wells. The most important ones are presented here.
Suplacu de Barcau, Romania
Shallowest ISC operation; depth of reservoir in the range of 35m to 250m
Commercial dry ISC operation with a very low well spacing is being used, less the 2.5 acre/patterns: low pressure process (injection pressure less than 200 psi). The process displays the longest ISC front (5.3 miles), associated with the line drive
operation, having 150 injection wells at the peak.
Oil production approx. 1,500 m3/day
Air-oil ratio (AOR) approx. 2,500 sm3/m3
Operational difficulty: mud volcanoes at surface in the area with lowest depth (35m)
Balol and Santhal, India
Highest-pressure wet ISC operation in a heavy oil reservoir containing some coal laminations; depth of reservoir approx. 1,000m; strong lateral water drive
Line drive operation
Oil production approx. 1,500 m3/day from 2 commercial operations
Air-Oil Ratio (AOR) approx. 1,000 sm3/m3
Bellevue, Lu, USA
Typical dry and wet ISC, applied in small patterns (1ha / 2.5 acres). Low pressure process (injection pressure less than 1724 kPa/250psi). Getty Oil Co used to have the biggest exploitation, then
small companies - such as Bayou Oil State Co. - continued exploitation on other areas.
Midway Sunset, Ca, USA
The non-selective oil production by ISC of a multilayer formation comprising 6 layers was feasible and successful.
Although the reservoir temperature was only 52oC, initiation of ISC by spontaneous ignition was possible. This was the major key-factor of success for this project. A second factor for success was the crest air injection.
Heidelberg, USA
The deepest ISC process (3,447m / 11,300 ft). All three injectors were located up-dip.
Buffalo, N Dakota
The first ISC commercial application in a high-temperature, carbonate reservoir with very low permeability, containing a very light oil; the process was initiated at a very low current oil recovery.
Large scale operations of both ISC and steam drive, on the same heavy oil pool, were conducted for:
Piloting of novel ISC process, Toe-To-Heel Air Injection (THAI)
Piloting in the period 2006 - 2011
More details on the results are found under the “New ISC Processes” section, under THAI Field testing, WhiteSands Pilot
1.2 Gregoire Lake Pilot, Athabasca:
Reservoir (located South of McMurray City, Alberta, Canada):
Tar sand; bitumen of 8 0API; viscosity=2,000,000 cps at reservoir temperature of 110C. Depth: 350m. Very fine sand, prone to sand influx.
Before ISC tests, very extensive pre-heating was carried out; almost like heating the whole region submitted to the testing; either by cyclic steam stimulation or dry ISC, both via horizontal-induced fracture (s)
ISC tests were conducted in the period 1955-1981 by Amoco Canada and AOSTRA
6 phases of testing for different procedures (with and without fracturing) and pattern sizes
Main displacement process: moderate wet ISC; air-water co-injection.
ISC application for re-pressurization of gas-over bitumen reservoirs (GOB situation) in order to facilitate exploitation of oil sands (located underneath) via Steam Assisted Gravity Drainage (SAGD)
At the field piloting stage (EnCAID and AIDROH tests). The EnCAID (Encana Air Injection and Gas Displacement) test was started in 2006 in Kirby Wabiskaw K-3 Pool, close to Christina Lake SAGD Project in Athabasca region, Canada. The EnCAID consisted in using the combustion gases (flue gases) produced by an ISC front generated and sustained within the gas cap. Later on, in 2011, on the fly, It was converted in the AIDROH pilot by drilling a horizontal producer under the gas-bitumen interface; the intention was to test the recovering of bitumen underlying the gas cap. This was dictated by the fact that the ISC front designed to be propagated within the gas-cap penetrated and heated the bitumen zone underneath.
Inspired by Encana test, a similar test (but more elaborate) was conducted by Husky Energy under the name of McMullen Thermal Conduction Pilot in the period 2011-2015. This time it was designed from the beginning as a process to recover bitumen underlying a depleted gas cap.
The lack of THAI knowledge precluded both tests in having a happy end; both tests were suspended without clear conclusions
ISC in reservoirs with extensive bottom water
Not feasible at the current stage of development of ISC process.
ISC in reservoirs with extensive fractures
Not feasible at the current stage of development of ISC.
Self-sustaining Treatment for Active Remediations (STAR) Technology
STAR is a relatively new technology to remediate Non-Aqueous Phase Liquids (NAPLs), including coal tar and hydrocarbons from the soils/aquifers. It uses ISC to burn these hazardous liquid contaminants.
The STAR process resulted from collaboration between the University of Edinburgh, the University of Western Ontario, the University of Strathclyde, and SiREM.
Patent: Gerhard, J.I. and Torero, J. L ; 2005, STAR In-Situ Subsurface Remediation Technology, UK Patent Office, GB 0525193.9, filed 10/12/2005.
Underground coal gasification (UCG)
UCG makes use of the reverse ISC.
Note: So far, only UCG is a proven technology; it has been commercially applied (using a line drive configuration) in former Soviet Union.
UCG references:
Skafa P.V. Underground Coal Gasification. Gostoptehizdat Nauko-Tehnicescoe Izdatelstvo po Gornomu Delo, Moskow, 1960 (book written in Russian)
Davis, B.E. and Jennings J.W. : "State-of-the-Art Summary for Underground Coal Gasification" In Journ of Petr Techn, January 1984
Novel Process: Toe To Heel Air Injection (THAI) brochure
Combines ISC process with horizontal wells in a Short Distance Oil Displacement (SDOD) process. Therefore, similar to Steam Assisted Gravity Drainage (SAGD) process, THAI is an SDOD process.
Short history: THAI was discovered in 1992 via a cooperation by Prof. Malcolm Greaves of University of Bath, UK and Dr. Alex Turta, formerly of the Petroleum Recovery Institute (PRI); later on PRI was incorporated in Alberta Research Council /Alberta Innovates-Technology Futures/Innotech Alberta, Alberta, Canada USA patent: 5,626, 191/May 6, 1997; expired in 2015. Canadian patent 2,176, 639/August 2, 2000; expired in May 2016.
As seen in the bird's-eye view (picture 1 and picture 2), specific to the process is the location of the vertical injector in the proximity of the toe of the horizontal producer. As seen in the section view (picture 3), the ISC front is upright, leaning forward and propagates from the toe to the heel of horizontal producer. Upgrading of the oil occurs because the oil displaced by the in-situ combustion front is flowing through a relatively high temperature region called Mobile Oil Zone (MOZ).
Picture 1. Schematic of Toe-To-Heel Air Injection in a Direct Line Drive Configuration. Bird's Eye View.Picture 2. Schematic of Toe-to-Heel Air Injection in a Staggered Line Drive Configuration. Bird's Eye View.
An important feature of the process is its self-healing feature as far as the complete oxygen consumption is concerned. This is related to the existence of a local blockage (coke-plug) at the intersection of the ISC front with the horizontal section of the horizontal producer. This local intensive coking of the borehole of horizontal producer (inside and around it), occurs on a limited distance; it moves along with the ISC front (picture 4). This feature was confirmed in the laboratory, by three organizations, independently. However, the existence of the coke-plug is not a condition "sine qua non" for the process, as the gravity segregation (controlled gravity over-ridding of the ISC front) also plays an important role as a self-healing feature. The effect of this local blockage on the advancement of the ISC front, close to the horizontal well and laterally, away from it, needs more investigations.
Related information from the attempts to apply the steamflooding in a toe-to-heel (TTH) configuration tends to confirm that although both direct line drive and staggered line drive gave good results in the laboratory 3-D THAI tests, in the field, the application in a staggered line drive is strongly recommended; this is related to its considerably better chances for a better areal sweep efficiency (otherwise expressed, for a better lateral development of the ISC front). This seems to be even more important in case of TTH application of ISC as compared to TTH application of steamflooding. THAI application in a staggered line drive will requires more preparatory work for the generation of an appropriate initial hot communication tightly correlated with ignition operations in order to create an initial large burning area; that preparatory work is a crucial condition for success.
Picture 3. Schematic of Toe-to-Heel Air Injection.Picture 4. The Self-healing Feature for Thermal Front Advancement.MOZ = Mobile oil zone
As seen in picture 4, oil is heated and mobile inside the MOZ, flowing down in the borehole of horizontal well (HW); some oil flows through the hot zone (thermal upgrading). MOZ itself moves along the HW towards the heel.
The THAI process is the first EOR process in which a consistent upgrading of the oil (by 4-7 API degrees in the laboratory tests) is obtained.
So far, more than 100, 3-D model laboratory tests have been conducted at University of Bath, UK. Also, numerical simulations were conducted by at least ten different organizations/companies.
An illustrative temperature profile of the process on a horizontal plane and integrated into a THAI geometric configuration is shown in Picture 5a. This picture was obtained by slightly modifying the temperature profile in the conventional in-situ combustion (ISC); the original temperature profile was that given in Advanced Reservoir Management and Engineering book (page 564) by Ahmed Tarek & D.N. Meehan, 2012. The main problem of this temperature profile is that does not suggest that the largest fraction of the heat generated is stored in the burned zone; the distortion is also related to the acceptance of a too long steam plateau, which is not justified for THAI that is a dry ISC and not a wet ISC process.
A much better representation of the temperature profile and zonation in the THAI process is provided in Picture 5b, which still remains illustrative (and distorted) as the temperature profile extends on an exaggerated large distance (between injection and heel of production) and the original reservoir temperature is not shown for a by far larger distance; the comparison of the zones and their temperatures was the main goal of the illustration. From this picture, please note that in THAI the combustion zone and coke zone are more developed than in the normal dry ISC process; combustion reactions occur at higher temperature on an extended zone and allow an almost full oxygen consumption. Particularly, the coke zone extends on a by far larger temperature range than in conventional ISC. Unlike conventional ISC, the vaporization-recondensation zone of light oil fractions and water may be less developed as there is not a lot of time to grow because THAI is a short-distance displacement process and therefore the fluids are produced relatively quickly; however in this zone, the light oil fractions (from cracking and vaporization) exist and they mix with original oil resulting in a globally upgraded oil. Hydrogen generation seems to be related to coke gasification and water-gas shift reactions; as Picture 5b may not offer full explanations for these reactions, the flow of air/gases along the coke zone and the mobile oil zone (MOZ) would help in a better understanding of full oxygen consumption and then its long journey via a very hot zone.
For the reasons discussed above, the water bank also extends on a shorter distance and it is less defined compared to that in the conventional ISC.
Picture 5b can be correlated with Pictures 3 and 4. Depending on the horizontal plan considered for temperature profile, the sizes of various zones would differ; mainly the distance on which coke zone exists will become larger as this horizontal plane is considered closer to the bottom of oil layer. Also, the position of the peak temperature would be slightly different depending on the vertical position of the horizontal plane considered; the propagation of the ISC front is clearly suggested. The profile does not necessarily apply to the plane containing the horizontal section of producer.
Picture 5a. Temperature profile across all zones formed during application of THAI process
(Wei, Wei – Journal of Petroleum Science and Engineering 197 / 2021). Not at scale.Picture 5b. Temperature profile and the sizes of the zones formed during application of THAI process.
Not at scale. Note: Mobile oil zone (MOZ) is located imemdiately ahead of the coke zone and may comprise 3 zones. Oil belonging to original reservoir zone may or may not flow pending on its mobility at original reservoir temperature
THAI Field testing:
1) WhiteSands Pilot, Conklin, Alberta, Canada Athabasca, oil sands region
Three patterns - all of them in direct line drive (DLD) configuration - were operated 5 years (2006-2011). Easy initiation and sustaining of the process; no oxygen breakthrough occurred. Easy to resume after a very long air injection interruption (3-4 months). Propagation of the in-situ combustion fronts along the horizontal section of producers was clearly seen in all the patterns. There has been in situ upgrading of the produced oil (approx. 4 API degrees). Also, hydrogen production in the produced gas was recorded (3%-6%).
Some operational problems:
Sand influx
Some oil lifting problems
Note: Oil rate lower than in SAGD
For more details see the paper: Turta, T., Singhal, A., Sierra, R., Greaves, M. and Islam, M.: “Evaluation of the First Field Piloting of the THAI Process: Athabasca Pilot” SPE Canadian Energy Technology Conference and Exhibition, March 15-16, 2023, Calgary, Canada
2) Kerrobert Pilot and Semi-Commercial Project, Saskatchewan, Canada
Conventional heavy oil (oil viscosity - 33,000cp-54000cp); reservoir underlain by bottom water having a thickness 0.3 to 0.9 of the thickness of the oil layer, therefore a relatively thick bottom water zone. The THAI piloting was initiated after primary recovery, when the water cut was in the range of 85%-95%, at an oil recovery of around 1.2%. Both vertical and horizontal wells were utilized in primary production; horizontal wells had their horizontal section located toward the top of the formation.
The pilot: Two pairs (modules), using the direct line drive (DLD) configuration, were operated for 3.5 years (2009-2012) with good results; no premature oxygen breakthrough and oil production up to 22 m3/day/well (average 10 m3/day/well).
Semi-commercial project: It consisted of the extension from 2 pairs to 12 pairs (24 wells); It also used the DLD configuration. It started in 2012; as of November 2022 it is still ongoing, but with low air injection. The performance is lower than that of the pilot. After 14 years of THAI operation, in principle, the mechanisms of THAI application in the presence of bottom water (of this kind) have been deciphered and the knowledge necessary for the optimization of the process in similar situations has been obtained. The presence of the bottom water precluded the increase of the air injection rate towards the projected values. There has been substantial day-by-day upgrading of the produced oil (3-4 API degrees), while produced gas contained some hydrogen (1%-1.5%).
For more details see the paper: Turta, A., Singhal, A., Greaves M and Islam, M.: “An In-Depth Evaluation of Toe-To-Heel Air Injection Application in a Heavy Oil Reservoir Underlain by Bottom Water. Kerrobert Case” SPE Canadian Energy Technology Conference, 13-14 March 2024, Calgary, Canada.
The gas composition and oil viscosity data from the Kerrobert THAI project, released by Petrobank Energy and Resources to the public, they can be found on
https://petrobank.ca. Gradually, this site will provide more data, including injection and production data, and other useful information.
3) THAI Pilots outside Canada
There have been 6 more THAI pilots, with three in China and three in India. In China, the pilot Shuguang (started in 2012) has been completed, while the Fengcheng Pilots (started in 2014-2015) in Xinjiang Province, probably, are underway (at least one pilot). For more details see:
- Guan, Wenlong: "Field Control Technologies of Combustion Assisted Gravity Drainage (CAGD/THAI)" Presentation at the Thermal EOR Workshop, Chengdu, China, 15-18 October 2018
- Renbao Zhao, Shuai Yu, Jie Yang, and Minghao Heng: "Optimization of Well Spacing to Achieve a Stable Combustion During the THAI Process" In Energy 151 (2018) 467-477. Available online March 9, 2018
The first THAI pilot (one pattern-pilot) in India has been taking place on the Balol heavy oil reservoir since December 2016; given the good results of this first pattern, during 2017 the piloting in Balol was extended to four more patterns; one pattern adjacent to the first pattern and three more in a different region. At the end of 2017, a second THAI pilot (one pattern) on the second heavy oil reservoir (Lanwa Reservoir) was initiated; later on (in 2021), on the same reservoir, a second pattern was added. As of November 2021, all 5 THAI patterns in Balol are in operation. Very recently (probably in 2022-2023), the THAI testing was expanded to the third reservoir, the Santhal reservoir having a lower oil viscosity. The recent results of the two-pattern pilot in Lanwa are detailed in the reference below. In general, for more technical details on THAI field application in India, please see the following three presentations at international conferences in India and Canada, namely:
- Rakundla, S., Mishra, N., Das, S. and Singh, S.K.: "First Ever Successful Execution of Gravel Packing in Toe to Heel Air injection (THAI) K Wells in a THAI Project" Presented at PETROTECH; 13th International Oil and Gas Conference and Exhibition, 10-12 February 2019, Greater Noida, Delhi, India
- Pareek, R.C, Prasanna G, Goyal M, Singh P.K and Rao N.S.: "Integration of Toe Up Horizontal Wells (THAI producers) with In Situ Combustion Process" Presented at PETROTECH; 13th International Oil and Gas Conference and Exhibition, 10-12 February 2019, Greater Noida, Delhi, India. Note: Toe Up producers are the producers in the THAI pilots having specially designed new (or existing old ones) vertical injectors located up-structure
- Kumar.,A., Kumar., R., Kesharwani, A., Mahanta, J., Kumar, N., Khadia, D.S..K. and Dayal H.S.: “Enhancement of oil production in an In-situ combustion process through unconventional and innovative approaches (including THAI): Case study from Lanwa field, Cambay Basin, India.” SPE Canadian Energy Technology Conference, March 13-14, 2024, Calgary
THE SIX CRITICAL CONDITIONS FOR SUCCESSFUL APPLICATION OF THAI (OR A GENERALIZED PROCESS SIMILAR TO THAI):
High permeability (K) pathway at the bottom of the layer: horizontal production well, or "simple wormhole", or disk-fracture, or even a thin sublayer of extremely high permeability
Vertical air injector (s) has to be located within the drainage area of the toe of the horizontal producer
Proper anchoring of the ISC front to the toe of the corresponding horizontal producer (s) or high permeability (K) pathway
Advancement of the ISC front along the horizontal section of the horizontal producer; if the advancement is stalled, a combustion chamber forms around the toe of the producer
Existence of self-healing features in the advancement of the displacement front (along the high K pathway); local plugging being the one and controlled gravity segregation being the second one
Existence of a hot region of high fluid mobility behind the displacement front and a relatively low temperature region of low fluid mobility ahead of the displacement front (along or parallel to the high permeability pathway) with a tilting forward of the separation between these two regions
CAPRI Process
An enhanced upgrading can be obtained by applying the catalytic version of THAI, named CAPRI (CAtalytic upgrading PRocess In-situ).
In CAPRI, the horizontal section of the THAI horizontal producer is surrounded by a catalyst-activated gravel packing (picture 6). Therefore, CAPRI is a THAI-add-on process.
All the phenomena (thermal, hydrodynamic, etc) are the same for THAI and CAPRI; the only difference is the second upgrading occurring when oil is flowing into the bottom-hole of the horizontal
producer. In laboratory testing, the process was able to achieve an upgrading of up to 14 API degrees.
Compared to THAI, CAPRI is much less investigated and developed. In addition, there are many challenges in the simulation of the process; at this time it is practically impossible to reflect the upgrading process in its entirety.
Short history: CAPRI was discovered in 2002 by Dr. Conrad Ayasse and Dr. Alex Turta, formerly of the Petroleum Recovery Institute (PRI), with PRI later incorporated in Alberta
Innovates-Technology Futures/Innotech Alberta, Calgary, Canada. Prof. Malcolm Greaves of University of Bath, UK is also a co-author of this novel process.
USA patent: 6,412,557/July 2, 2002
Canadian patent 2,176,639/July 8, 2003
Current status: So far, CAPRI process has not been systematically piloted. It has seen just a very limited testing within the frame of the THAI Whitesands Pilot in Athabasca.
10-year investigations conducted in UK at the University of Birmingham succeeded to clarify many aspects of CAPRI process. These laboratory investigations aimed at selecting the most efficient catalysts for the CAPRI process, combating of catalyst fouling and other important aspects; a fixed-bed catalyst was used in these investigations. Catalyst nano-particles were also investigated.
Picture 5. Catalytic THAI - CAPRI Process.
COSH/COGD Process
COSH Combustion Override Split-Production Horizontal Well) is intended for application in reservoirs containing oil with some mobility at reservoir condition. COGD (combustion overhead gravity
drainage) is a version of COSH intended for the application in oil sands. In addition to COSH it specifies the means for obtaining the initial communication between injectors and producers, therefore is
intended for higher viscosity oil reservoirs, even without mobility at reservoir conditions.
Both processes combine the ISC with horizontal wells in a short distance oil displacement (SDOD) process for most of the their project life. As seen in the general schematics (picture 6) and
crossection views (picture 7), there are several vertical injectors located immediately above the horizontal producer, which is located at the bottom of the thick oil layer. Laterally, there are some vent
wells for gas production, mainly.
Short history: COSH was proposed in 1994 by Ken Kinsman, Edmund Lau and Bill Good of AOSTRA, Alberta, Canada.
Canadian patent 2096034; see Journ of Can Petr. Techn, March 1994
The most important feature of both processes is the existence of vent wells; their role is to produce most of the combustion gases. My comments on these processes:
The control of several ISC fronts intercepting the same horizontal producer well is extremely difficult
Requires special gas collection wells (more expensive)
Current status: COSH and COGD processes have not been field tested.
Picture 6. Schematic of COSH process (After Kisman and Lau,1994).Picture 7. Schematic COSH Process Diagram.
Top-Down ISC Process
The process was directly inspired from the peripheral (top-down), line drive commercial ISC exploitation at Suplacu de Barcau.
To some extent, the process is similar to COSH process. However, unlike COSH, the process does not have any vent wells (picture 8).
There are two versions of top-down ISC: one is intended for application when there is some mobility of oil, and the second one is intended for application in oil sands; second one assumes the existence of a man-made initial communication. The first one was studied in more detail by simulation, while the second one was investigated in the laboratory.
Short history: First, the process was proposed in 1993 by David Redford of AOSTRA and later on investigated by Roy Coates and John Ivory of Alberta Research Council (ARC); ARC later became Alberta Innovates - Technology Futures (AITF)/ Innotech. Alberta, currently. Recently (by 2011) the same process was re-proposed by Conrad Ayasse under the name of multi-THAI.
Current status: the process has not been field tested.
Picture 8. Conceptual Application of a TD-ISC Process (late phase of the process).
Consultancy
I am offering consultancy services either by themselves or in conjunction with courses/workshop.
The consultancy can be carried out either “in person” or remotely. The remote consultancy work - via emails, phone conversations, Dropbox work and Zoom virtual meetings - has been practiced with good results for the last 3 years.
The most efficient system is to have a course/workshop of three to five days followed by another two to five days of consultancy work. When ISC consultancy is involved, generally, there is an initial ISC course/workshop followed by the selection of an oil reservoir for ISC, and finishing with an analysis of how one can design the ISC pilot and go from pilot to commercial operations for that specific reservoir. When EOR consultancy is involved, generally, there is an initial course on evaluation of EOR potential, followed by the hands-on use of a software for choosing the most appropriate EOR/IOR methods for several reservoirs belonging to the participants; in this case the data for those reservoirs have to be prepared in advance by the participants and checked by the instructor.
Selection criteria for choosing the appropriate oil reservoir for application of ISC process will be provided separately for heavy oils, very light oils (HPAI process) and for THAI process. Please note that THAI process is not commercially proven yet. So far 6 field THAI pilots/projects have been conducted in 3 countries and very important lessons have been learned. Based on that, consultancy services for selection of the reservoir and design/monitoring/evaluation of a field THAI pilot are offered; this is also done for a potential application of THAI as a follow up to SAGD.
Past ISC consulting work: India, Malaysia, Colombia, Brazil, Ecuador, Surinam, Russia, Netherlands, USA, Romania, Canada, China and Japan.
Highlight-India: Guidance from pilot to commercial development for Balol-Santhal ISC projects. Design of the THAI pilot in Balol Field.
Past consulting work on evaluation of EOR potential: Malaysia, Iran, Albania, Canada, USA, Colombia, Surinam, Gabon and Sudan.
How the consultancy services can be conducted:
Turn-key projects (from A to Z)
Time-based consultancy work as per your needs
Guidance on how-to-do and/or review of your final work regarding the selection of the ISC as an EOR method and the design of the ISC pilot for a certain oil reservoir OR guidance on how-to-do and/or review of your final work on evaluation of EOR/IOR potential for your reservoirs
of interest; (review of your SelectEOR reports)
The team of Mehsana Asset (in Gujarat State, India) managing the Santhal-Balol in-situ combustion (ISC) projects. The picture was taken during my consultancy work (2015) relative to the review of the Balol and Santhal commercial ISC Projects and the pre-design of the Toe-to-Heel Air Injection (THAI) pilot in Balol.Visit to the spectacular landscape of Red Beach during ISC consultancy in Panjin, Liaoning Province, China
A working session (2015) in Villavicencio, Colombia for the preparation of the Chichimene in-situ combustion pilot.Working with Field operators (2019) during the implementation of the ignition operation for Chichimene in-situ combustion pilot.
Courses / Training
I am providing two categories of courses: A) General courses and B) Specialized In-Situ combustion courses.
A) GENERAL courses:
Heavy Oil Recovery Methods
General In-situ Combustion (ISC) Course
Understanding Toe-To-Heel Air Injection (THAI)- Clues for Developing New ISC Technologies
Toe-to-Heel Oil Displacement of Heavy Oils. Application to Waterflooding, Steamdrive and Fireflooding
Evaluating the EOR Potential of Oil Reservoirs
Oil Recovery by CO2 Injection
B) Specialized in-situ combustion (ISC) courses:
Air Injection for Light Oil Recovery, including High Pressure Air Injection (HPAI) Process - 8 hrs course
In-situ combustion (ISC) in a bottom water (BW) situation (4 hr course)
Feasibility of in-situ combustion (ISC) application in naturally fractured rocks (NFR) and hydraulically fractured rocks (HFR) - 4hr/8hr course
Application of Oxygen-Enriched Air In-Situ Combustion (O2-ISC) in Heavy Oil Reservoirs - 4hr/8hr - course
Potential post-SAGD applications of ISC in general and THAI in particular (4 hr-course)
All courses can be conducted/delivered either "in person" or "live" online. For online courses the software MS Teams is used, for which there is already a subscription. If for virtual meetings the client wants to use Zoom or Google Meet or other apps (for virtual meeting), then the client Is supposed to possess a subscription for the respective application in order to host the meeting.
A short description of each of the courses in (A) category, follows:
Heavy Oil Recovery Methods
This is a five-day full course but it can be reduced to 2-3 days. The use of horizontal wells in combination with thermal processes is a focus of this course.
Therefore, the course also covers the Steam Assisted Gravity Drainage (SAGD) process and the essential elements on using in situ combustion (ISC) with horizontal wells;
some information on the toe-to-heel air injection (THAI) process will be provided. Essential aspects of cold heavy oil production (CHOPS), focusing on production mechanisms
(foamy oil and sand production), as well as stimulation of these mechanisms, will be discussed. The course will also cover the various applications of steam injection involving
Cyclic Steam Stimulation (CSS), steam drive, and hot water flooding. Various design details, implementation and field implementation will be reviewed.
Participants to the Heavy Oil Course (October 2014) for National University of Colombia at Medellín.A bit of touristic program: Sculpture by famous Colombian sculptor/painter Fernando Botero in Botero Park of Medellín.
A perusal of the HO Recovery Table of Contents may help you to decide if you are interested in this course. So far, the course has been presented four times, twice in Canada and once in Colombia and Oman (Petroleum Development Oman).
a General ISC Course
As short course, this is a 2-3 day course; when intended for ISC application to heavy oil reservoirs it is a two day course, while when additionally presenting the ISC for light oil reservoirs, it is a 3-day course. For a detailed and in-depth ISC course, the material will be presented in 4-5 days.
A perusal of the ISC Table of Contents and of the
instructor's bio may help you to decide if you are interested in this course; we also provide a one-day course and a 0.5 day course with approximately the same Table of Contents but reduced according, to the time available for the course.
So far the ISC course has been presented in Brazil, Ecuador, Colombia, Russia, Japan, China, Canada and Romania
Chinese participants to the in-situ combustion course held in Calgary, Canada in 2013.
Understanding Toe-To-Heel Air Injection (THAI) - Clues for Developing New In Situ Combustion Technologies
This is a one-day course. The use of horizontal wells in combination with ISC is the main focus of this course. Both uses of horizontal wells in old fields (where an ISC was implemented) and uses of horizontal wells in newly developed ISC processes are covered.
These new processes comprise of COSH, top-down ISC, THAI and CAPRI processes. Details are provided on Toe-to-Heel Air Injection (THAI) as an evolving technology involving short-distance oil displacement. A critical mass of information has emerged after more than 8 years of field testing. So far, the course has been presented twice.
This course involves discussion of these lessons pertaining to THAI in the following areas:
Development of the process
Basic mechanisms
Laboratory testing
Field testing: piloting and semi-commercial operations
Consistent in-situ upgrading of the produced oil
Status of current development and limitations
Criteria for application
A perusal of the THAI Table of Contents may help you to decide if you are interested in this course.
Toe-to-Heel Oil Displacement of Heavy Oils. Application to Waterflooding, Steamdrive and Fireflooding (THAI/CAPRI)
This is a one-day course, with the following OUTLINE:
Introduction.
Long-distance and short-distance oil displacement (LDOD & SDOD) methods; SAGD and toe-to-heel (TTH) displacement methods.
Steam drive in a toe-to-heel (TTH) configuration; improvement by adding solvent. Its limitations as compared to THAI. Laboratory tests and some simulations. Why no field tests, so far?
Toe-to-Heel Waterflooding (TTHW). Details on laboratory tests and simulations. Results of limited field testing (2 field tests; USA and Canada).
THAI Process and its upgrading potential (laboratory, simulation and extensive field piloting). A parallel THAI-SAGD, as SAGD is another SDOD method.
Further possible developments.
Evaluating the EOR Potential of Oil Reservoirs
This workshop is based on using the software SelectEORTM for this purpose. The duration is flexible, between three days and five days.
A perusal of the SelectEOR Table of Contents and of the instructor's expertise may help you to decide if this is right for you. So far this course has been presented in Canada, Colombia, Malaysia, Sudan and Dubai.
I am conducting this workshop as an Alberta Innovates Technology Futures (AITF) consultant; AITF owns the SelectEORTM software. Therefore, the job will be carried out based on a
contract between your business and AITF; for more information and details please email to Alex Turta.
Sudapet (Sudan) participants at the course "Evaluating the EOR Potential of Oil Reservoirs" held in Dubai in 2015.
Note: As mentioned, these courses can be presented in conjunction with consultancy services occurring immediately after the course. When the courses are presented separately, they are charged as courses – higher daily charge – while when presented with consultancy services they are charged as normal consultancy activity.
Oil Recovery by CO2 Injection
This is a two-days course. It covers mostly miscible flooding for light oils, with an emphasis on the robustness of the method; it also deals with extension of this method to fractured rocks. CO2 injection as an immiscible method for heavy oil recovery is also discussed.
For more details please see the Biographical Sketch of the instructor and outline of the course.
A short description of each of the courses in (B) category (specialized in-situ combustion courses), with a simplified Table of Contents, follows:
Air Injection for Light Oil Recovery, including High Pressure Air Injection (HPAI) Process - 8 hrs course
ISC mechanisms, dry and wet ISC
Kinetics of oxidation for heavy and light oils
Laboratory work specific for light oil ISC
Spontaneous ignition
Oil miscibility of the mixtures of N2 and CO2. Nitrogen injection performance as an EOR process
Commercial application of ISC in the Williston Basin, USA (HPAI process). Use of vertical wells, ONLY
Commercial application of ISC in the Williston Basin, USA (HPAI process). Use of horizontal wells, ONLY
Attempts to extend ISC in light oil reservoirs outside Williston Basin, USA; why did they failed
Application of HPAI in naturally fractured rocks (NFR) containing light oil
In-situ combustion (ISC) in a bottom water (BW) situation (4 hrs course)
ISC mechanisms, dry and wet ISC
Laboratory work specific for bottom water ISC
Summary on simulation of bottom water and its effect/influence
Analysis of field tests of conventional ISC in a bottom water situation
Analysis of a field test of novel ISC Toe-to-Heel Air Injection (THAI) in a BW situation; Kerrobert THAI piloting
Discussion. Favorable and unfavorable factors related to existence of bottom water
Some guiding screening criteria
New directions
Feasibility of in-situ combustion (ISC) application in naturally fractured rocks (NFR) and hydraulically fractured rocks (HFR) - 4hrs/8hrs
ISC as a commercially proven EOR process for exploitation of heavy and light oils. Screening criteria for ISC application
ISC mechanisms, dry and wet ISC
Summary of laboratory testing for ISC
Analytical and numerical simulation of ISC
Naturally fractured rocks (NFR); their characterization in view of thermal oil recovery /ISC application
Hydraulically fractured rocks (HFR); their characterization in view of thermal oil recovery /ISC application
Field experience with application of ISC in NFR, heavy oil reservoirs
Field experience with application of ISC in NFR, light oil reservoirs
Oil miscibility of the mixtures of N2 and CO2. Nitrogen injection performance as an EOR process for light oil recovery
Field experience with application of ISC in HFR, heavy oil reservoirs
Some lessons regarding feasibility of ISC application in fractured rocks
Future work/trends to develop fractured rocks by ISC
Application of Oxygen-Enriched Air In-Situ Combustion (O2-ISC) in Heavy Oil Reservoirs - 4hr/8hr - course
Conventional ISC mechanisms, dry and wet ISC; essential on simulation of conventional ISC
Introduction. Theoretical advantages of O2-enriched air ISC over conventional ISC
Laboratory work specific to O2-enriched air ISC
Generation of O2-enriched air; ways to separate O2 from the air
Economic factors and conditions favoring O2-enriched air ISC over conventional ISC
Lessons from field testing of O2-enriched air ISC and O2-ISC
Favorable factors due to CO2 solubilization and pseudo-miscible effects
Possibilities to apply Toe-to-Heel Air Injection (THAI) process with O2 injection as an efficient process to produce in-situ upgraded oil and hydrogen
Possibility of combining O2-ISC with SAGD
Next possible developments
Post-SAGD application of ISC in general and THAI in particular
Basic information on conventional in-situ combustion (ISC)
Short-distance oil displacement (SDOD) and long-distance oil displacement (LDOD); Steam Assisted Gravity Drainage (SAGD) and Toe-To-Heel Air Injection (THAI) as SDOD processes
Basic information on THAI and steamflood in a toe-to-heel (TTH) configuration
Successful new areas of ISC application; heavy oil reservoirs with high reservoir temperature and post-steamflood ISC deployment
Laboratory testing of post-SAGD ISC/THAI application
Golden opportunities for post-SAGD field testing in Canada
Opportunities for post-SAGD field testing outside Canada
Future work/trends to develop post-SAGD ISC application
Cooperations
AskEOR Tech Hydrocarbon Pvt Ltd. Registered in India as a private incorporated company AskEOR was launched in Aug 2020, to fill the knowledge gap in the areas of Exploration and IOR/EOR by adopting collaborative business model with industry and academia as preferred Knowledge Partners. The team formed by experienced Geo-scientists & Reservoir Engineers, aims to provide expert services in Exploration and Production of Hydrocarbon both within and outside India.
Petro Management Group Ltd. Petro Management Group Ltd. (PMG) has been established in Calgary, Alberta in 1994. PMG has been offering petroleum engineering consulting and training services in North America and Internationally for the past 26 years. The services are mainly in the following areas:
Field development plan and integrated reservoir simulation studies
Production optimization and well stimulation
Horizontal well applications
Multi-stage Frac of Horizontal Wells (MFHW’s); frac design, optimization, and performance monitoring
Well test analysis (PTA) and Rate Transient Analysis
Customized training; online and classroom
U of B has conducted more than 10 years of investigations in the area of CAPRI development process. It has succeeded to clarify many aspects of the process. These laboratory investigations aimed at selecting the most efficient catalysts for the CAPRI process, combating of catalyst fouling and other important aspects; a fixed-bed catalyst was used in these investigations. Catalyst nano-particles were also investigated.
Conducting simulation studies for THAI application in heavy oil reservoirs with bottom water.
Offering petroleum engineering consulting and training services internationally, with a focus on China.
Website Links
Thanks for visiting us! Here are a few of the sites around the web that we recommend.
SiREM Lab Self-sustaining Treatment for Active Remediation (STAR) Technology.
University of Edimburgh, University of Western Ontario, University of Strathclyde, and SiREM
How reliable is it to use the automatic translation of the website in a non-English language?
This is possible and via the menu you have instructions on how to use the Google Chrome browser to this effect.
The translation will be very useful, but not perfect, as some specific technical terms may be mistranslated; sometimes, the comparison with the original English language content is necessary.
What are the most difficult conditions for ISC application?
When the reservoir has extensive bottom water or is naturally, extensively fractured.
Observation: There is some experience that in case of man-made fractures, or after a CHOPS exploitation, ISC is still applicable if a very intensive pre-heating (usually by cycling steam stimulation-CSS) is applied; CSS should be applied for at least 3-4 years corresponding to the operation of at least 3-4 cycles per each well CHOPS=Cold Heavy Oil Production with sand
The advancement of ISC front in the dry forward ISC can be related directly to the deficiency of?
Deficiency of fuel (in the burned zone).
The advancement of ISC front in the reverse ISC can be related directly to the deficiency of?
Deficiency of oxygen (in the burned zone).
Why the reverse ISC process is not feasible in a reservoir with high temperature (>40-50 0C)?
Because the ISC front cannot be supplied with oxygen; the oxygen is consumed by low temperature reactions (LTO) before reaching the ISC front.
Is the ISC process applicable after CHOPS (Cold Heavy Oil Production with Sand)?
There is no field evidence suggesting that conventional ISC is applicable after CHOPS. Also, THAI process may not be applicable; more investigations are necessary to establish its feasibility. The main barrier is the mapping of the “wormhole network” with the view of designing/tailoring the appropriate THAI application.
Which are the conditions for a successful in-situ combustion (ISC) process application in the field?
Using a similarity with what is frequently used in Mathematics, we can state that there are two conditions (and both are to be fulfilled); the necessary condition (NC) and the sufficient condition (SC); the NC and SC are:
NC: To have a good quality burning, as expressed by the oxygen utilization efficiency and/or peak temperature and/or apparent hydrogen-carbon ratio (H/C), etc.
SC: To record a value of the air-oil ratio (AOR) less than 3,000-4,000sm3/m3, depending on injection pressure. This AOR is calculated as air injected per incremental oil, obtained above the pre-existing mechanism. Also, in general, an increase in oil production by at least 50-60% is a must, mainly for oil reservoirs having wells with low oil production.
Is in-situ combustion (ISC) proven as a tertiary commercial process for waterflooded heavy oil reservoirs?
Not totally proven yet.
What are the prospects of application of in-situ combustion (ISC) in the heavy oil reservoirs located at high depths and having a high reservoir temperature (>60-70 0C)?
The prospects of application of ISC are good. This is so due to the fact that the peak temperature in the ISC front may not be excessively high and the damaging of the production wells (including their cementation) is almost eliminated. For more details please see the first Technical Note on this website.
What are the prospects of application of ISC as a tertiary process after steamflood?
The prospects of application of ISC are good. This is so due to the fact that the premature breakthrough of oxygen in the production wells is almost eliminated. For more details please see the following technical documents (papers/presentations):
Guan Wenlong, Xi Chanfeng, Huangjihong, Tang Junshi: “Fire-flood Technologies in Post-Steam Heavy Oil Recovery: A successful Example of CNPC”. Paper Presented at the SPE Heavy Oil Conference, Calgary, Canada 11-13 June 2013. SPE 165436
Pan Jingjun: “Pilot test of In-situ combustion in heavy oil reservoir after steam injection”. Presentation at the Thermal EOR Workshop, Chengdu, China, 15-18 October 2018
What are the prospects of ISC application as a follow up to SAGD?
The prospects of application of ISC are not straightforward. On the one hand, as a negative factor, it is difficult to follow a gravity segregation process, such as SAGD, with another gravity segregation, such as ISC, and, on the other hand, as a positive factor, the huge amount of heat stored, respectively increased reservoir temperature is favorable; the premature breakthrough of oxygen in the production wells is almost eliminated. For more details please see the course "Post-SAGD application of ISC in general and of THAI in particular" in the Section Services/Courses on this website.
FAQ’s related to the THAI process
What are the critical conditions to be respected in order to apply correctly the THAI process?
For successful application of THAI (or a kind of a generalized process similar to THAI) the following general principles/requirements should be strictly respected:
A high permeability pathway at the bottom of the layer; horizontal production well, or “simple wormhole”, or a disk-fracture to collect the produced oil.
A vertical air injector(s) located within the drainage area of the toe of the horizontal producer.
Anchoring of the ISC front to the toe region of the corresponding horizontal producer, and then, preserving the stable anchoring
Existence of self-healing features during the advancement of the displacement front (along the horizontal section of the horizontal producer); local plugging being the one and controlled gravity segregation being the second one
Existence of a hot region of high fluid mobility behind the displacement front and a relatively low temperature region of low fluid mobility ahead of displacement front (along or parallel to the high permeability pathway), with a tilting forward of the separation between these two regions.
What are the best conditions for the application of THAI process?
When it is possible to graft the THAI process on an existing commercial in-situ combustion project developed in a line drive operation started updip.
Why a horizontal producer drilled as an infill well in a commercial exploitation by in-situ combustion (ISC) - using vertical air injectors and producers - does not automatically constitute a THAI pattern?
In the ISC exploitations where some horizontal producers are drilled as infill wells, they do not qualify to form a THAI pattern(s), if none of the existent vertical air injector(s) from the region falls within the drainage area of the toe of the horizontal well(s), and if not all the critical conditions listed at the FAQ 1 ( responses to the question 1) are respected.
Why the short-circuit of oxygen (premature O2 break-through) does not occur in the THAI process?
Due to a pronounced over-riding tendency of the air/flue gases and existence of a mobile, coke local plugging, located in the proximity of the intersection of the ISC front with the horizontal section of horizontal producer. The over-riding intensity can be controlled via an appropriate design of the configuration (including the size of the start-up region) and completions.
What is the major difference between the cracking-oxidation reactions in classic ISC process and in THAI process?
It is believed that the major difference is the value of residence time in the hot reaction region of each process. The residence time is considerably longer in the THAI process. As a consequence of that and of the short-distance oil displacement feature of THAI, the oil upgrading and hydrogen production are obtained. A second consequence seems to be the total lack of any LTO reactions during the normal propagation of the ISC front along the horizontal section of horizontal producer.
What is the first EOR process to produce upgraded oil and hydrogen in the produced gases?
Underground upgrading of the produced oil while being recovered from the heavy oil reservoir has been fully validated for the first time ever by the novel ISC process, Toe-to-Heel Air Injection (THAI). Also, in this process fully validated is the production of hydrogen in the recovered gases.
Observation: The field validation as described above may not exist for oils with viscosities less than 500 cp; this limit has not been established firmly, yet.
What is the quasi-THAI process?
Quasi-THAI process is a kind of generalized THAI process. While THAI uses vertical injectors and horizontal producers, quasi-THAI uses only vertical wells for both injection and production. However, quasi-THAI can occur only for a very specific permeability distribution on the vertical of oil layer [either existing naturally or man-made (disk-fracture close to the bottom of formation)
Quasi-THAI process: How it was possible to produce upgraded oil in a classic, conventional ISC process (using only vertical wells)?
Examples: West New Port Project, Ca, USA, and Morichal and Tia Juana Projects, Venezuela. See the technical presentation about quasi-THAI from the hyperlink on Landing Page.
Due to a potential very high permeability thin layer at the bottom of oil formation
Can THAI applied in a bottom water (BW) situation be assimilated with a quasi-THAI process? Can it be favorable?
To some extent, it can be assimilated with a quasi-THAI process, but it is a very complicated process, as there are two high mobility pathways (one is the horizontal section of the producer and the second one is in the bottom water, under the interface water-oil); its efficiency is not totally proven. This is so because the interaction of bottom water can be negative both for the trapping of some of the displaced oil and for the production of excessive amounts of water. More investigations are necessary to properly understand this process and make it more controllable, therefore efficient. Nevertheless, at this time its application is not ruled out.
What is the essential difference between THAI and quasi-THAI process?
Quasi-THAI process is by far less investigated and understood. In general, it should be considered more challenging to control than THAI. Its performance may be better or lower than that of THAI depending on the control possible to exercise.
What is the current status of the process CAtalytic upgrading PRocess In-situ (CAPRI) development?
In principle, CAPRI is a THAI-add-on process, in which the horizontal section of the THAI horizontal producer is surrounded by a catalyst-activated gravel packing. All the phenomena (thermal, hydrodynamic, etc) are the same for THAI and CAPRI; the only difference is that a second upgrading occurs when oil is flowing into the horizontal section of the horizontal producer. In laboratory testing, the process was able to achieve an upgrade of up to 14 API degrees. So far, CAPRI process has not been systematically field piloted. It has seen just very limited testing within the frame of the THAI Whitesands Pilot in Athabasca. More than 11-year investigations conducted in the UK, at the University of Birmingham, succeeded in clarifying many aspects of the CAPRI process. These laboratory investigations aimed at selecting the most efficient catalysts for the CAPRI process, combating catalyst fouling and other important aspects. Catalyst nanoparticles were also investigated.
Is it possible to get in-situ upgrading of the produced oil in a conventional in-situ combustion (ISC) process?
In general, there is no in-situ upgrading in the conventional lSC process. However, in some particular cases of stratification displaying a very high permeability sublayer at the bottom of oil formation, it may occur. Examples of in-situ upgrading in conventional ISC projects: West Newport CA, USA, and ISC processes in Tia Huana Field and Morichal Field of Venezuela. Possible explanation: A quasi-THAI process can be developed naturally when the permeability of the bottom sublayer of oil formation is (comparatively) very high as compared to that of the rest of the layer (thief sublayer for a fast flow at the bottom of formation).
What modifications to an in-situ combustion (ISC) process have to be operated in order to promote hydrogen (H2) generation and its production?
H2 generation is intensified at temperatures higher than around 700 0C. Therefore, one of the conditions is that the ISC process has to be operated in such a way that peak temperatures in the combustion front are as high as, or higher than 700 0C. Other conditions may apply, such as the use of a short-distance oil displacement configuration, a large combustion surface with almost no oxygen presence (downstream), very short hydrogen residence time in high-temperature regions (until is produced), etc.
In what steam-injection methods did in-situ catalytic upgrading start to show some results during the field testing?
When tested in cyclic steam stimulations (CSS). Unlike the non-cyclical steam injection processes, in CSS operations it is more feasible to spread the supported catalyst uniformly in the stimulated volume of the well under CSS operation. The research is still in an incipient form but it is promising. To get more details, please see the recent publication (a collection of recent papers on the subject): Catalytic In-Situ Upgrading of Heavy and Extra-Heavy Crude Oils, Wiley Editor, 2023, edited by Mikhail Varfolomeev, Chengdong Yuan and Jorge Ancheyta. Also, browse the paper “Current Status and Future Trends of In Situ Catalytic Upgrading of Extra Heavy Oil”, where some field results are presented. The paper is authored by Zhengbin Wu et al. in Energies, June 2023. This article belonged to the Special Issue Oil and Gas Reservoir Stimulation Theory and Technology of the Energies magazine.
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