On SAGD in Oil Sands Reservoirs With No Caprock and Top Water Zone
- Ali A. Al-Turki (University of Calgary) | Ian D. Gates (University of Calgary) | Brij B. Maini (University of Calgary)
- Document ID
- Society of Petroleum Engineers
- Journal of Canadian Petroleum Technology
- Publication Date
- March 2011
- Document Type
- Journal Paper
- 21 - 33
- 2011. Society of Petroleum Engineers
- 1.7.5 Well Control, 5.5 Reservoir Simulation, 5.4.6 Thermal Methods, 5.3.9 Steam Assisted Gravity Drainage, 5.8.5 Oil Sand, Oil Shale, Bitumen
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The ever-increasing world demand for energy to satisfy current needs and future economic growth has forced the oil and gas industry to exploit challenging energy resources. Heavy oil and oil sands are challenging because of the complexity of reservoirs together with high-oil viscosities, which are often greater than hundreds of thousands to millions of centipoise. Most steam-based recovery processes, such as cyclic steam stimulation (CSS) and steam-assisted gravity drainage (SAGD), require a competent caprock to prevent excessive steam losses and maintain good thermal efficiency and production rates, as well as preventing steam flow to surface. However, there exist significant amounts of oil sands resources, which have little or no caprock; thus, at this point, these resources are considered inaccessible. This research examines the feasibility of using SAGD in oil sands reservoirs with no caprock with detailed thermal reservoir simulation. The results of this research provide guidelines that explain how to implement the SAGD process in shallow oil sands reservoirs with no caprock. This could unlock a resource that is currently considered inaccessible. The results show that vertical chamber growth can be controlled to some extent by using variable pressure operating strategies and coinjection of a noncondensable gas, such as methane. In oil sands reservoirs without caprocks, pressure control is critical, especially if there is to be minimal fluid invasion from the oil sands formation into the water zone above. However, the pressure must be sufficient to delay or prevent flow of water into the steam chamber. This study is important because in Alberta, Canada alone there are billions of barrels of shallow oil sands resources without sufficient caprock to operate conventional high-pressure steam recovery processes, such as CSS and SAGD. The results of the study provide a technical basis to design feasible low-pressure steam processes for such reservoirs.
|File Size||1 MB||Number of Pages||13|
Butler, R.M. 1997. Thermal Recovery of Oil and Bitumen. Calgary,Alberta: GravDrain Inc.
Doan, L.T., Baird, H., Doan, Q.T., and Farouq Ali, S.M. 1999. An Investigation of theSteam-Assisted Gravity-Drainage Process in the Presence of a Water Leg.Paper SPE 56545 presented at the SPE Annual Technical Conference andExhibition, Houston, 3-6 October. doi: 10.2118/56545-MS.
Gates, I.D., Kenny, J., Hernandez-Hdez, I.L., and Bunio, G.L. 2007. Steam-Injection Strategy andEnergetics of Steam-Assisted Gravity Drainage. SPE Res Eval &Eng 10 (1): 19-34. SPE-97742-PA. doi: 10.2118/97742-PA.
Good, W.K., Rezk, C., and Felty, B.D. 1997. Possible Effects of Gas Caps onSAGD Performance. Technical Report, Alberta Energy Utilities Board, Calgary,Alberta (March 1997).
Heron, C., Thimm, H., Sullivan, L., and Atkinson, I. 2008. NCG Behavior in SAGD--A NumericalSimulation Analysis. Paper SPE 117647 presented at the InternationalThermal Operations and Heavy Oil Symposium, Calgary, 20-23 October. doi:10.2118/117647-MS.
Ito, Y., Ichikawa, M., and Hirata, T. 2001. The Effect of Gas Injection on OilRecovery During SAGD Projects. J Can Pet Technol 40(1). JCPT Paper No. 01-01-03. doi: 10.2118/01-01-03.
Law, D.H.S., Nasr, T.N., and Good, W.K. 2003a. Lab-Scale Numerical Simulation ofSAGD Process in the Presence of Top Thief Zones: A Mechanistic Study. JCan Pet Technol 42 (3): 29-35. JCPT Paper No. 03-03-02. doi:10.2118/03-03-02.
Law, D.H.S., Nasr, T.N., and Good, W.K. 2003b. Field-Scale Numerical Simulation ofSAGD Process with Top-Water Thief Zone. J Can Pet Technol 42 (8): 32-38. JCPT Paper No. 03-08-01. doi: 10.2118/03-08-01.
Nasr, T.N., Law, D.H.S., Beaulieu, G., Golbeck, H., Korpany, G., and Good,W.K. 2003. SAGD Application in GasCap and Top Water Oil Reservoirs. J Can Pet Technol 42(1): 32-38. JCPT Paper No. 03-01-02. doi: 10.2118/03-01-02.