Drill pipe measuring tool
US4454655A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1982 |
| Grant date | Jun 19, 1984 |
| Priority date | — |
| Expiry date | Mar 18, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B5/0002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A distance measuring tool is provided for measuring the length of a drill pipe maintained under tension within a well. The tool includes a unitary instrumentation and instrument drive module which is sealed within an instrument housing and which may be removed and replaced as a single unit when malfunction occurs. The moving parts of the module are sealed in lubricating fluid, and a pressure equalization system is provided to equalize the pressure of the lubricating fluid relative to the external drilling mud pressure. The instrumentation and instrument drive module includes a mechanical distance counter and a drive mechanism which drives the counter only when the tool is descending into a drill pipe. The instrumentation within the tool is protected against impact by a shock absorbing nose assembly which includes both mechanical spring and hydraulic shock absorbing units. The shock absorbing nose assembly is mounted for limited universal movement on the tool housing to guide the tool over obstructions in the pipe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.