Patent ID: 8041510
Filing Date: 2011-10-18
Classification: G01V

Abstract:
1. A system for monitoring fluid pathways in a producing hydrocarbon reservoir of the type in which injected water replaces extracted oil, thereby generating passive microseismic events, wherein the reservoir includes at least one borehole associated with the reservoir, the system comprising: a first sensor array comprising a number of 3-component seismic sensors physically secured to the ground within a sensor area surrounding the borehole; a second sensor array comprising a number of 3-component seismic sensors installed permanently at various levels in the well borehole; and a computer coupled to each of said seismic sensors for receiving signals detected by said seismic sensors, wherein said computer is programmed to apply a predetermined data analysis program to signals representing microseismic data corresponding only to passive microseismic events due to production activities, for determining and outputting a mapping of failure surfaces which define pathways for preferential fluid movement in the reservoir; wherein the size of said sensor area, and the number of sensors contained in said sensor area, together with the number and spacing of sensors in said second sensor array, are sufficient to provide meaningful passive microseismic data to said computer.