Abstract:
Within the scope of operations of long-term regular monitoring of an underground area, a seismic emission-reception device is installed in a fixed position on the production site, so as to have time stable operating conditions of identical emission-reception locations, identical quality of coupling with the formations, etc. The device includes a plurality of seismic sources (S1 . . . Sn) in fixed places at the surface or buried beneath the surface, on either side of a production well (1), and at least one array of receivers (R) set in a fixed position at the surface or in at least one well. Explosive sources, hydraulic overpressure sources, electromechanical sources, etc, can be used and connected to a plant (3) providing energy using an explosive gaseous mixture, which may be a constituent taken from the monitored area, fluid under pressure transmitting hydraulic shocks or vibrations, etc, by means of buried pipes or cables (2). The feeding and the triggering thereof are controlled by a central control and recording station (4). The method and device can for example be used for the filling of an underground gas storage reservoir.
Abstract:
The invention centralizes data acquired through active or passive monitoring equipments installed permanently in contact with a geologic formation and notably in wells, under the control of one or several permanent stations (PCL) comprising microcomputers. The signals collected by these stations including spontaneous or induced seismic signals, parameters measured by condition sensors, etc., are converted and transferred onto a communication network managed by a server. The signals are translated into a common format more easily accessible for a seismic laboratory taking part in the processing of the data collected by the various monitoring equipments.
Abstract:
The seismic source (5) according to the invention is associated with a drill string (1) linking a drill bit to a surface installation close to the bit. It comprises a closed chamber (6) fastened inside a drill cellar (4) of the drill string. The section thereof is smaller than the inner section of the drill string, so as to allow free circulation of the drilling fluid. A reactive mass (8) may move within this chamber (6) and along the axis of drill string (1). Hydraulic or electro-mechanical means allow a strong alternating force of controlled frequency and duration to be applied to this mass. The energy necessary to the operating thereof is taken from the fluid current. This source requires no substantial modification in the usual drilling equipments. Drilling a well and performing seismic measurings may be achieved at the same time by means of the source by arranging sensors at the surface and/or in one or several adjacent wells.
Abstract:
A sound wave receiving device associated with a probe lowered into a well at the end of a cable and applied against the wall of the well by opening anchorage arms. In the part of the probe in contact with the wall of the well there is disposed at least one receiver assembly comprising a sensor case connected by a resilient sheath and a sleeve, movable along a cylinder integral with the body, to the rod of a piston sliding in said cylinder. A hydraulic and/or pneumatic system is provided for placing the case in contact with the wall and increasing the force of application of said case.
Abstract:
A system is provided for transmitting energy to an apparatus, such as a pulsed or vibratory seismic source, lowered inside a well or drill hole. It includes a structure anchorable in a well, mobile means whose linear displacement with respect to the anchorable structure causes the creation of energy and means for accumulating the energy created, a rigid column connected to said mobile means and drive means disposed outside the well for moving the rigid column linearly. The mobile means and the accumulation means may be formed by a weight and a device for raising this latter or else by a hydraulic system including a linear pump.
Abstract:
Device for generating seismic impulses for, for example, seismic prospecting, inside a hole or drilling well by impact of a weight or mass falling onto a target element coupled with a wall of the hole or drilling well. The target element is bound up with a variable volume anchorage element capable of being expanded so that it strikes against the wall of the hole or drilling well and is surmounted by a guiding column along which slides a hammer or weight forming the mass. A cable lifting system and magnetic devices enable the hammer or weight to be hoisted to a particular height above the target element.
Abstract:
A device for generating sound pulses in a well by a mobile mass striking against a target element integral with an elongate body anchored in a well by retractable shoes actuated by hydraulic cylinders. The mobile mass which slides in a first chamber in the body is moved away by a piston moving in a second chamber of the body and intermittently locked in the moved away position by a valve. The piston, the valve and also the hydraulic cylinders acting on the anchorage shoes are actuated by a hydraulic system which may be remote controlled from the surface.
Abstract:
Adjustment device for the locking jack 9 of a molding press comprising, on a base 1, a mold 4 held by a fixed plate 2 and a movable plate 3 controlled by a rapid movement mechanism 10-13, itself connected to a fixed plate 5 via a movable plate 8 subjected to the action of the locking jack. The adjustment device includes a stem 17 which frictionally slides in relation to the base 1 and which is fitted with arms 18, 19 situated between two control contactors 15 and 16 of the locking jack and connected to the movable plate 8. The device provides automatic adjustment of the control of the locking jack 9 in accordance with the thickness of the mold.
Abstract:
Receiver of continuous structure adapted to be laid on the ground surface or underground, for seismic prospecting on land, comprising at least one support member for geophones, made of a flexible material having an elongated central portion and two lateral portions defining therewith at least one recess, said geophones being fastened to the central portion of the support member and coupled to the earth therethrough and said lateral portions being provided with longitudinal channels housing conductor cables.