Passive Seismic Monitoring of a Heavy Oil Field

A pilot project was designed to monitor induced seismic activity in a relatively shallow heavy oil reservoir located in a low permeability, high porosity, silicious shale. Several hundred microseismic events have been located over the past two years using data recorded at two borehole seismic arrays. Microseismic activity occurs predominantly in two separate depth zones: one within the reservoir and one in the shallow overburden. Larger events are located at the top of the reservoir close to the injection well; shallow clusters of smaller events could identify fluid migration pathways in the overburden.