2010 Honorary Lecturer Europe | Aldo Vesnaver Italian National Institute of Oceanography
and Experimental Geophysics (OGS)
Trieste, Italy
Talking and Listening to Reservoirs:
Production Monitoring by Active and Passive Seismic | | Abstract  Time-lapse seismic technology matured in the current decade, achieving major successes in offshore fields. On land, repeatability and noise remain hard issues, when production changes only marginally the seismic response of the reservoir. This is the challenge of onshore carbonate fields, for example, which are a large share of hydrocarbon reserves worldwide. Microseismicity is a viable tool that works best in hard rocks as carbonates, so it is an ideal complement to 3D seismic surveys. Active seismic data provides a 3D macromodel for the earth by reflection tomography and migration velocity analysis. A good 3D model for P and S velocities in depth is critical for locating the hypocenters of microearthquakes. The latter ones become new illumination sources of the reservoir, so improving further its tomographic imaging. The hypocenter pattern in space and time gives us clues about local permeability and detects fluid pathways not resolvable by active seismic but very relevant for reservoir simulation and production. The integration of active and passive seismic data, acquired both at surface and in boreholes, provides us information about local stress changes due to injection–not only for hydrocarbon production, but also for gas storage and CO2 sequestration. In conjunction with well core analysis, this information paves the way for a further level of integration in reservoir simulation, i.e., including geomechanics, whose relevance is proven by subsidence and uplift effects at several producing fields. | | | | | | |
