The Athabasca oil sands deposit of Axe Lake Discovery is situated T95 R25W3 in Saskatchewan. The Axe Lake oil sand deposit is a highly permeable, extremely coarse grained bitumen accumulation overlain by highly heterogeneous layered Quaternary Till deposits. The variable effective containment of the overburden material demands a unique horizontal well geometry for an optimized bitumen recovery process.
Laboratory and simulation results were combined to develop an optimal plan guiding Phase 1 operations using six fully instrumented closely spaced vertical wells and also Phase 2 operations using three 300m long horizontal wells spaced 50m apart. This paper describes the reservoir simulation models designed for Test Site 1 using geostatistical methods. Presented simulation results provide sensitivity analyses on. geomechanical effects, flow patterns, sweep efficiencies of water and steam, well geometry, monitoring techniques, and possible calibration methods for numerical simulation models. Relevant laboratory experiments are discussed. All wells and facilities for steam / water handling at Test Site 1 have been completed and steam injection is expected in July 2009.
We describe the first steps of a multi-staged approach for the development of a potential in situ recovery process for the Axe Lake bitumen deposit, i.e. how to measure the necessary effective reservoir properties effectively, efficiently and optimally at the appropriate scale.
The Athabasca oil sands deposit of Axe Lake is a highly permeable, extremely coarse grained bitumen accumulation, overlain by highly heterogeneous layered Quaternary Till deposit. Oilsands Quest is currently exploring bitumen in situ extraction of the Axe Lake deposit within Test Site 1. Figure 1 shows Test Site 1 located within Township 95 Range 25 West of the Third Meridian. The main in situ recovery processes reviewed in this paper are Cyclic Steam Stimulation (CSS) and Steam Assisted Gravity Drainage (SAGD). Other in situ recovery processes discussed herein are solvent injection, electro-thermal stimulation (electric current flowing in the reservoir) and electro-magnetic stimulation (electric current in the reservoir induced by magnetic fields). Test Site 1 involves steam/water injection consisting of a cluster of six vertical injector/producer wells three horizontal wells and fourteen planned vertical observation wells.
Results of Test Site I will establish how the reservoir reacts to steam and hot water injection on a field scale. The results will also be used to confirm and evaluate expected swept volumes. drainage volumes and recovery rates for a range or reservoir operating pressures. These results can be compared to existing data from other reservoirs with similar reservoir geometry ascertaining the validity or the results from Test Site I.
The following list outlines the main objectives regarding Test Site I:
Study reservoir (rock + fluid) behavior when injecting cold water. hot water and steam
Determine geo-mechanical effects through a cold water mini-frac test
Evaluate micro-seismic analysis and cross-well seismic measurement methods
Determine steam rise velocities and the effects or shale barriers during steam injection
Determine the rite of fluid penetration and heat propagation into the reservoir as a function or time. using pressures and temperature measurements
