Patent ID: 6049758
Filing Date: 2000-04-11
Classification: G01V

Abstract:
A method of gathering seismic information of a geometry of an underground oil reservoir over time, comprising the steps of:determining from a prior survey information, including previously received signals, a velocity field and a structural geometry of the underground oil reservoir overburden,selecting locations by precalculating positions of seismic sources and seismic sensors using said velocity field and said structural geometry,determining a minimum number of seismic sensors required to fully map the geometry of the underground oil reservoir.identifying a first one of the selected locations for firing a seismic source to excite a number of seismic sensors.placing at least one seismic source at the first one of the selected locations,fixing at least one seismic sensor to a solid surface of the earth at at least a second one of the selected locations,firing said at least one seismic source,receiving signals at said at least one seismic sensor in response to the firing,comparing said received signals to previously received signals, andmapping a changing geometry of oil in the underground oil reservoir.