Method for seismic monitoring of an underground zone under development

Abstract

The invention is a method for facilitating discrimination and identification of seismic or microseismic events by means of permanent pickups in an underground zone under development. The method comprises permanent installation of, in one or more wells, elastic wave receivers, geophones and hydrophones leaving the wells clear for development of the zone, at least one reference pickup with direct acoustic coupling with the technical zone development equipment (pickup pressed against a production string for example) for detection of events directly connected with the operation of the wells (valve opening and closure, etc.), acquisition of the signals coming from the various receivers and from each reference pickup in response to the waves received, and comparative analysis of the signals associated with the receivers and with the reference pickup(s), in order to classify the records into different families according to whether the events in the underground zone are independent of the events detected by each reference pickup or depend directly or indirectly thereon, and for each family, application of specific processings. The method can be used for long-term monitoring of fluid production of storage reservoirs, such as hydrocarbons, various waste products, geothermics, etc.