Downhole tool
US5189645A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 1, 1991 |
| Grant date | Feb 23, 1993 |
| Priority date | — |
| Expiry date | Nov 1, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A downhole tool for generating pressure pulses in a drilling fluid comprising an elongated body and a plurality of blades spaced around the body. The blades are each divided into an independent front section and rear section, forming a set of front sections and a set of rear sections, at least one of the set of front sections and the set of rear sections being mounted for rotation such that the front and rear sections are angularly displaceable relative to each other between a first position in which the sections are aligned and a second position in which the rear sections obstruct fluid flow between the front sections to generate a pressure pulse. The tool includes a means for generating a torque on the blade sections, and an escapement means which is radially movable to permit stepwise rotation of the blade sections, and thus to move the blade sections between the first and second positions. Each successive rotation of one of said sets of blade sections relative to the other of said sets of blade sections occurs in the opposite direction to the immediately preceding stepwise rotation of the said one set of blade sections relative to the said other set of blade sections.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.