Fireflood or steamflood Enhanced Oil Recovery (EOR) processes are commonly used in the recovery of heavy oils or tar sands. To optimize the use of these processes, the operator needs to know the velocity, location, and direction of movement of the thermal flood front. To obtain this information using current technology, sparsely spaced observation wells are drilled. As the depth of production increases, 90 does the cost of drilling. This tends to decrease the economics of drilling an optimum number of observation wells. Thus, it is desirable to develop a surface mapping method to track the location of the flood front without drilling additional wells. One promising method in this area is passive seismic monitoring. Previous observations at a fireflood in Eastern Alberta, Canada, detected, using down-hole sensors, both seismic noise emissions and discrete seismic events being generated from the flood front. Phase I aims to show that these seismic events can be detected by surface or near-surface seismometers and used to map the location of the flood front. Phase II will consist of a longer field monitoring period to show that the velocity and migration pattern of the flood front can be mapped. During Phase II it also would be desirable to build a real-time processor for on-site program execution in the field.Anticipated Results/Potential Commercial Applications as described by the awardee:Successful results of this study would provide an economical method of mapping fire or steamflood fronts in commercial and government EOR projects. This method would also provide higher spatial resolution because the mapping does not require the need for observation wells. Results may also be applicable to mapping hydraulic fractures in geothermal and tight gas sands stimulation projects.
