Schlumberger Technology Corporation

Prad Research and Development Nv

Services Petroliers Schlumberger

Schlumberger Holdings Limited

Alain G Delpuech

Eric P Donzier

Bruce W Boyle

Emmanuel Tavernier

Bronislaw Seeman

Philippe F Salamitou

Claude Stanisiere

David C Hoyle

Alan J Sallwasser

Herve Ohmer

Jean-Luc Decorps

A well logging apparatus adapted to be moved inside a borehole includes an elongate body, a measuring pad adapted to contact the wall of the borehole, a support device for the pad mounted pivotally on one side of the body, and a counter arm which causes the pad to be applied against the wall of the borehole. The support device includes an arm which carries the weight of the pad and is connected to the pad substantially in the central part thereof.

Well logging apparatus comprising a measuring pad and a combinaton

The invention concern a combination well logging device adapted to be moved inside a borehole to measure the properties of geological formations through which the borehole passes. The device according to the invention comprises a series of elongate logging sections mounted end to end, including a first section adapted to be maintained with a generatrix applied against the wall of the borehole, a second section comprising a body and a measurement pad adapted to be spaced radially from the body for application against said wall, a third section adapted to be kept space from said wall, and first and second hinges connecting the second section to the first and third sections respectively in order to allow respective angles of inclination between the second section and the first and third sections.

Combination well logging device

A sonde for acquiring seismic signals in a borehole, the sonde comprising: a detector module (30) enclosing at least one seismic sensor (G); an elongate body (21) having a lateral cavity (22) suitable for receiving the detector module (30); a resislient suspension (40, 50) connecting said module to said body; and an anchor member (12, 13) disposed on the opposite side of said body to the side in which said cavity is disposed. The sonde is characterized by the fact that the resilient suspension exerts a force on said module suitable for displacing it out from the cavity and for pressing it against the wall of the borehole so as to couple it to said wall, together with means (41, 43, 51, 53, 60) which are provided to retract the module into said cavity against the force exerted by the resilient suspension.

Method of coupling a seimic detector module to the wall of a borehole,

A sonde for aquiring seismic signals in a borehole, the sonde comprising: a detector module (30) enclosing at least one seismic sensor (G); an elongate body (21) having a lateral cavity (22) suitable for receiving the detector module (30); a resilient suspension (40, 50) connecting said module to said body; and an anchor member (12, 13) disposed on the opposite side of said body to the side in which said cavity is disposed. The sonde is characterized by the fact that the resilient suspension exerts a force on said module suitable for displacing it out from the cavity and for pressing it against the wall of the borehole so as to couple it to said wall, together with means (41, 43, 51, 53, 60) which are provided to retract the module into said cavity against the force exerted by the resilient suspension.

Method of coupling a seismic detector module to the wall of a borehole

A logging sonde for evaluating underground formations traversed by a borehole is disclosed. The sonde contains a frame which is free to rotate relative to the cylindrical body of the sonde. The frame supports a plurality of detector means including at least one detector which is free to rotate relative to the frame. Also attached to the frame are locking means including braking means and a solenoid for disengaging the braking means from their engaged surfaces. In a rest position, the braking means are arranged in such a manner as to lock the detector means relative to the cylindrical body. The invention is applicable, in particular, to geophones intended to detect seismic waves along three orthogonal axes, including a vertical axis, regardless of the tilt of the sonde.

Device for locking a set of gimbal-mounted detectors

The present invention relates to the acquisition of seismic signals at different levels in a borehole, in response to the generation of seismic waves by a source placed on the surface or in the vicinity of the surface. The acquisition is carried out by means of a sonde suspended in the borehole from a cable and equipped with an anchoring pad. At each acquisition level, the pad is anchored in the borehole wall to couple the sonde to the formation, and then the pad is released from the wall once the acquisition is over. The signals acquired are then sent to the surface by means of the cable. The force with which the pad is anchored in the wall is controlled by means of a feedback arrangement which includes a sensor arranged in the pad itself. During the sonde movements from one level to another, the pad is kept in contact with the wall.

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Le Plessis Robinson, France

Alain G Delpuech