Bit positioning while drilling system
US4144949A · kind A · utility
Inventor
Key dates
| Filing date | May 2, 1977 |
| Grant date | Mar 20, 1979 |
| Priority date | — |
| Expiry date | May 2, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/42
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method and apparatus for determining the precise position of the drill bit on the bottom of a long drill string in a deep borehole in the earth during a drilling operation, comprising placing a plurality of geophones in an array near the surface of the earth above the expected position of the drill bit in the earth, causing at least a weak seismic wave to be initiated at the drill bit in the earth, repeating the source a great many times and determining at the surface of the earth the times of initiation of each of the seismic waves, determining the incremental movement of the drill pipe in the hole, and responsive to the known times of initiation and the known incremental movement of the drill pipe into the hole, stacking each of the repeated geophone signals from each of the geophones for each of the repetitions of the source, whereby each of the stacked signals will be in phase with those that resulted from earlier and later repetitions of the source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.