Time-lapse seismic interpretation of a heavy oil field producing from cold heavy oil production with sand (CHOPS)

Abstract

Heavy oil reservoirs in Western Canada have been producing using many extraction methods since their discovery. In the right conditions these reserves may be produced using cold heavy oil production with sand (CHOPS), where sand, oil, formation water, and any other gases and fluids, are all pumped out simultaneously. This causes changes in the reservoir that may be examined through time-lapse (4D) seismic methods. Feasibility of this method will be examined using 1D ray trace modeling. Rock property calculations and estimations of the reservoir properties from well log data guided the starting model. Ray tracing is used to test the feasibility of time-lapse effects as well as resolution limitations for a thin sand reservoir. PP-Compressional wave time-lapse seismic analysis is used to investigate the production footprint from CHOPS well production. Interpreting the data and modeling allows determination of future infill well location decisions, by understanding the lateral extent of wormhole influenced regions, the higher permeability zones radiating out from well locations, created during the extraction process of unconsolidated sand and heavy oil together. Time-lapse 4D seismic is a powerful tool for reservoir investigation that may be utilized to monitor reservoirs where changes in the zone of interest are measurable using surface reflection methods.