Methods and apparatus for determining the stuck point of a conduit in a borehole
US4105071A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 1977 |
| Grant date | Aug 8, 1978 |
| Priority date | — |
| Expiry date | Sep 19, 1997 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B23/042
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.