oa Reservoir Characterization by Using Permanent Downhole Geophones in 4D Seismic and Micro-Seismic Monitoring Applications

Two types of Permanent Downhole Geophones (PDG) [1,2] have been developed for use in a permanent way (several years) in oil or gas wells. These geophones were designed to be installed between the casing and the tubing (Figure 1) or, if needed, behind the casing of new wells. They can be adapted to different well completions. PDGs are suitable for two types of applications: 4D seismic measurements and microseismic monitoring.