Schlumberger Technology Corporation

Herve Ohmer

Alain G Delpuech

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

An apparatus is described for urging the measuring pad of a well logging sonde into engagement with the wall of a borehole. A relatively long primary arm on which the pad is mounted includes an actuator, and is pivotally connected to the body of the well logging sonde by a member extending therefrom. A backup arm is pivotally mounted on the extension member and biased outward from the logging sonde by suitable resilient means. The backup arm also is positively connected to a displacement member associated with the actuator. The primary and backup arms are cooperatively withdrawn into the body of the logging sonde by operation of the actuator. Moreover, the logging sonde is made eccentric in the borehole by suitable resilient means connected between the extension member and the sonde body.

Arm apparatus for pad-type logging devices

A logging sonde housing includes a stack of ceramic rings (26) surrounded by a first layer (33) of reinforced plastic material. Elastic seals (28) are placed between the rings and kept under compression by the layer of plastic material. A second elastomeric layer (34) is provided around the plastic material to ensure sealing. A third layer (35) of reinforced plastic material protects the elastomer, and a fourth layer (36) of a fabric impregnated with a more resilient plastic material improves the abrasion and shock resistance. The assembly forms a housing (18) resistant to borehole pressure for receiving, for example, electromagnetic transducers of the antenna or coil type.

Growing community of inventors

Antony, France

Herve Ohmer