Abstract
Steam Assistant Gravity Drainage (SAGD) is widely used to recover heavy oil and bitumen reservoirs. Typical SAGD operations involve a pair of horizontal wells separated vertically. Steam, or a steam-solvent mixture (e.g., Expanding- Solvent SAGD), is injected into the upper well to form a steam chamber and mobilize oil, which drains to the lower production well. Significant mechanical stresses associated with this process can increase the risk of fracturing the reservoir, or cap-rock. We perform a fully-coupled thermal-compositional-mechanical numerical simulation of SAGD and ES-SAGD processes for a typical bitumen reservoir in the Fort McMurray region of Alberta, Canada. A mixed finite-volume approximation for the flow and a Galerkin finite-element approximation for the mechanics are used, and the resulting set of nonlinear equations are solved using a fully implicit formulation. The two discretizations share the same unstructured grid. We demonstrate that thermo-mechanical effects can be quite significant in SAGD operations. The sharper gradients associated with the standard SAGD process increase the risk of damaging of the cap-rock. On the other hand, ES-SAGD operations lead to more dispersed temperature and pressure distributions, which decreases the possibility of damaging the cap-rock.
Original language | English |
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Title of host publication | Society of Petroleum Engineers - SPE Canada Heavy Oil Technical Conference 2015, CHOC 2015 |
Publisher | Society of Petroleum Engineers |
Pages | 1282-1297 |
Number of pages | 16 |
ISBN (Electronic) | 9781510811652 |
Publication status | Published - 2015 |
Externally published | Yes |
Event | SPE Canada Heavy Oil Technical Conference 2015, CHOC 2015 - Calgary, Canada Duration: 9 Jun 2015 → 11 Jun 2015 |
Conference
Conference | SPE Canada Heavy Oil Technical Conference 2015, CHOC 2015 |
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Country/Territory | Canada |
City | Calgary |
Period | 9/06/15 → 11/06/15 |