APPLICATIONS OF TECHNOLOGY:
Continuous crosswell seismic monitoring of
- Oil and gas reservoirs
- Aquifers for CO2 sequestration
- Monitoring stress changes near earthquake faults
- Monitoring hydraulic fracturing and enhanced oil recovery
ADVANTAGES:
- Aids in optimizing oil recovery by providing real time and continuous data on reservoir dynamics
- Enables detection of reservoir trends that would be missed by intermittent monitoring
- Eliminates labor costs and production inefficiencies caused by switching between borehole monitoring and production
- Eliminates the need for dedicated boreholes for wireline deployment
- Minimizes the likelihood of borehole damage caused by retracting and reinserting production tubing
- Allows monitoring of hydraulic fracturing
ABSTRACT:
Tom Daley and colleagues at Berkeley Lab have invented Continuous Active Source Seismic Monitoring, (CASSM), a novel combination of experimental methodology, geometry, and instrumentation enabling virtually continuous monitoring of subsurface seismic properties within a defined area (typically 100s of m2). Application with crosswell geometry has allowed CASSM to achieve a precision in measurement far beyond previous field-scale experiments. As opposed to the “snapshots” provided by present time-lapse imaging methods, CASSM’s continuous monitoring produces real-time information indicating trends often missed by present methods. Also, because CASSM can be operated while fluid is being injected into or withdrawn from a well, it eliminates the substantial labor costs and inefficiencies resulting from switching between borehole monitoring and production.
