Schlumberger Technology Corporation

Pierre C Escaron

Joachim A Hoppe

A method and apparatus for conducting logging or perforating operation in a borehole, particularly a deviated borehole, includes lowering a length of drill pipe having the well-logging tool, or well bore perforator, releasably mounted thereon into the borehole. An extension member, which is also lowered through the drill pipe, is secured to the well-logging tool, or well bore perforator, and releases it from the drill pipe, whereupon the extension member and well-logging tool or well bore perforator are moved through the borehole. The apparatus includes a latching sub mounted to the end of the length of drill pipe, and a latching head releasably mounted within the latching sub for releasably holding a well-logging tool or well bore perforator within the latching sub.

Method and apparatus for conducting logging or perforating operations in

A rigid extension member, for use with a well-logging cable in a borehole, has a means for protecting the well-logging cable disposed along the length of, and on the outer surface of, a cylindrical tube. Means for detachably securing the well-logging cable within the protection means is also provided.

Extension member for well-logging operations

An apparatus for measuring the downhole force applied to a cable suspending a well-logging apparatus in a borehole according to the invention is connected between the cable and the well-logging apparatus. An elongated sensitive element has a strain gauge integrally bonded upon it for measuring the downhole force, and the strain gauge includes at least one sputter deposited strain gauge. The apparatus is provided with elements for compensating for pressure and temperature changes in the borehole, wherein an envelope is sealingly disposed about the strain gauge means and is formed to allow the sides of the envelope to deflect inwardly and outwardly from the strain gauge in response to changes in pressure and temperature in the borehole. The envelope is filled with oil.

Downhole force measuring device

In the representative embodiment of the new and improved apparatus disclosed herein for positioning acoustic well-logging tools, outwardly-bowed elongated spring members of a wear-resistant metal are cooperatively spaced around the body of an acoustic-logging tool and arranged as required for maintaining the tool substantially centered within a well bore. To at least minimize or significantly attenuate the acoustic noise inherently generated by the rubbing of the outward faces of the spring members along the well bore walls which noise may otherwise unduly interfere with the reception of the acoustic logging signals, the inward faces of at least the mid portions of the several spring members are respectively covered with a composite material including an elastomer containing a substantial number of small embedded particles or interspersed balls of a sound-absorbing material such as lead.

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Houston, TX, United States of America

Pierre C Escaron