Enhanced CHOPS Using SuperSump to Reduce Environmental Footprint and Increase Oil Recovery

摘要

The two key challenges of primary heavy oil production using the process of Cold Heavy Oil Production with Sand (CHOPS) are limited recovery and the environmental footprint. With estimated remaining heavy oil in Western Canada of up to 300 billion barrels there is a significant opportunity for industry. Recovery of this oil using CHOPS is generally limited to 15% maximum brought on by high operating costs due to sand handling and interruption of the reservoir production process due to sand related workovers. The large CHOPS environmental footprint is driven by the significant surface disturbance due to close well spacing, greenhouse gas emissions from the use of heated lease tanks and handling and the long term disposal of produced sand. Ongoing evaluations show that the SuperSump System has the potential to reduce the environmental footprint and increase recovery of typical CHOPS operations both in new heavy oil fields and in revitalizing existing fields. The technology uses a gravity stable process to drain oil through multiple wells from an upper viscous oil reservoir into a small fit for purpose cavern washed from underlying salt formations. Oil, water, and sand separate in the cavern and clean oil is produced from a single wellbore to surface. The environmental footprint is reduced by eliminating sand handling, reducing lease sizes, and reducing fluid storage and processing on surface. The SuperSump technology also has the potential to reduce operating costs, allowing increased recovery by prolonging the economic well life as production rates decline. In addition, early well failures due to sudden, massive sand influx may be virtually eliminated, encouraging the uninterrupted development of the sand production mechanism in the reservoir. Plugging problems and pump failures may also be eliminated as the wells mature because sand, oil and water are allowed to drain into the cavern below, where sand settles, water separates and sand- free, clean oil is produced to surface. Simulation work has demonstrated that the SuperSump System could improve CHOPS operations in the following ways: Recovery factors are 50% higher; Operating costs are 30% lower; Energy efficiency is better by 75%; and Greenhouse Gas Emissions are lower by 95%. Estimated costs indicate very favourable economics compared to conventional CHOPS operations. The analysis of SuperSump System currently focuses on CHOPS operations in the Western Canadian Sedimentary Basin, but could be used anywhere CHOPS is applied. It appears to be especially effective for developing new small fields where the cost of surface facilities constitute a significant portion of the field development cost. SuperSump could also be beneficial in applications where high density drilling is required but there are sensitivities to surface footprint. SuperSump could also be a cost effective precursor to EOR/IOR.