Thierry Lepage

Stationary system for the active and/or passive monitoring of an underground deposit

Monitoring of an underground effluent deposit (2) and the exploration thereof are performed by installing various devices or user modules : reception arrays (Ri, Rj, Rk) such as geophones or hydrophones, condition sensors (C1, C2) , tools requiring electric power supply, etc, in various locations along one or several wells (1) drilled down into a formation, behind well casings or in the annular space between these casings and tubings, and by connecting these devices to a surface station (4), by means of a particularly simple and reliable multi-channel transmission unit. The surface station adapts the commands thereof according to the device to be controlled in return, of receiving all the signals they transmit whether analog or digital and coded, and adapts to several modes of allocation of the transmission channels. With such a system, long-duration monitoring operations may be carried out on a large scale under satisfactory economic conditions.