Schlumberger Technology Corporation

Andre Landaud

Yves Nicolas

Jean C Lavigne

In the representative embodiment of the new and improved apparatus disclosed herein, a so-called 'stuck-point indicator' or 'freepoint-indicator' tool includes a unique deformation-responsive sensor tandemly arranged between upper and lower hydraulically-operated tool anchors which, in the preferred embodiment of the tool, are cooperatively arranged to be sequentially engaged with longitudinally-spaced wall portions of a string of well pipe believed to be stuck in a well bore. In the disclosed embodiment of the tool, the new and improved sensor is arranged as an elongated body tandemly interconnecting the tool anchors and having upper and lower portions thereof cooperatively arranged for being preferentially deformed in response to tensional forces and torsional forces acting on the body. Separate strain gages are arranged on the upper and lower portions of the sensor body as required for producing distinctive electrical signals respectively representative of tensional forces and torsional forces acting on the body.

Methods and apparatus for determining the stuck point of a conduit in a

In the representative manner of practicing the new and improved method disclosed herein, a so-called 'stuck-point indicator' or 'freepoint-indicator' tool including a unique deformation-responsive sensor tandemly arranged between unique upper and lower tool anchors is positioned in a string of well pipe believed to be stuck in a well bore. The tool is then moved to a selected depth location in the pipe string and, in keeping with the principles of the present invention, operated so that the upper anchor is engaged with the pipe string wall before the lower anchor is engaged. Thereafter, upon application of forces to the upper end of the pipe string, independent measurements are produced by the sensor which are respectively representative of tensional forces and torsional forces acting on that portion of the pipe string between the upper and lower anchors.

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Maisons Alfort, France

Andre Landaud