MOBILE SYSTEM FOR SEISMIC EMISSION WITH FIXED COUPLING DEVICES, AND METHOD THEREFOR

摘要

Each activation point (S1,...Sn) has a coupling (1) with at least one anchor (12) directly coupled to the formation at a certain depth and at least one transmission element (10, 13) fixed to the anchor. The seismic source (V) is moved successively to the different points and has means of bolting onto the transmission element The coupling contains at least two anchors buried in the ground, each connected by transmission elements to the seismic source on or near the surface. The first and second anchors are buried at different depths. A first transmission element is connected to the anchor nearer the surface and a second transmission element. The first transmission element surrounds the second transmission element and is connected at one end to the second deeper anchor. The seismic source is rigidly connected to the two transmission elements during operation. The first transmission element is tubular and the seismic source sits on a seating (17) at its top end. The coupling contains an anchor at a certain depth, with the seismic source coupled to operate with the transmission element fixed to this anchor and pressing on the ground directly or via pressure elements. The transmission elements are isolated from the formation by at least one sleeve (20). The bolts are accessible in a pit (6) formed in the ground at each activation point. The pressing surface on which the seismic source sits is inside or outside the pit. The seismic source is a piezoelectric, electromagnetic, electrohydraulic or magnetostrictive vibrator, or a vibrator containing a motor (16) between a plate (15) pressed on the ground and an opposing plate (14) designed in operation to be bolted to the transmission element. The seismic source can be integrated into a vehicle with means of maneuvering it into place and coupling it, or it can be transported by a vehicle independent of it. In addition the system includes a seismic source fixed in a position with a coupling. An Independent claim is included for seismic prospecting or surveying of an underground formation by putting in place seismic receivers and their coupling with the formation, by installing a number of set positions, each with at least one coupling as described above, moving a seismic source to different positions and bolting it to the transmission elements of the corresponding coupling, setting off the seismic source in each position and collecting the corresponding seismic data from the receivers. An additional seismic source is fixed in a position with a coupling.