WBPC19 Abstract #19
In Canada, especially Saskatchewan, Cold heavy oil production with sand (CHOPS) has been an effective and preferred heavy oil recovery method for the past two decades. However, the CHOPS process recovers only 7-12% of the heavy oil in place, leaving a substantial resource stranded. Wormholes are generated during CHOPS production and grow to extend laterally hundreds of meters away from the wellbore and can be both a benefit and a hindrance to subsequent enhanced oil recovery (EOR) processes. Wormholes are thought to be long thin open-hole sections surrounded by a high permeability dilated sand regions. This structure results in extremely high fluid transmissibility and effectively bypasses most of the oil in place surrounding the well. The structure can also short-circuit injected fluids to production wells making conventional waterflooding and other similar continuous EOR applications unsuccessful. At the Saskatchewan Research Council, we have devised laboratory and field programs to study and test potential post-CHOPS EOR processes. We have developed advanced numerical models to simulate CHOPS and evaluate post-CHOPS process performance. Our mobile units complement the field operations with gas monitoring, analysis and data gathering. This presentation describes laboratory and field work to develop and evaluate post-CHOPS hot water vapour (HWVP), steam plus flue gas, and cyclic solvent injection (CSI) processes. The Lloydminster area of SK contains about 10,000 suspended wells, of which the majority are CHOPS wells. This area also contains the largest share of Saskatchewan’s 25+ billion barrels of heavy oil resource.