f Use of permanent downhole geophones for microseismic surveying of gas storage reservoir

In most cases, the recording of microseismic activity requires setting the acoustic sensor as close as possible to the emission area. In the oil industry, the depth of the reservoir, the well spacing and the attenuation of the oil and gas saturated layers are the reasons why the acoustic sensors are preferably placed downhole. For hydraulic fracture mapping, an acoustic tool can be run in with a cable. But such a method is not convenient for a long-lasting experiment such as passive surveying of a reservoir.