Method and apparatus for optimizing determination of the originating depth of borehole cuttings
US4708212A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 1986 |
| Grant date | Nov 24, 1987 |
| Priority date | — |
| Expiry date | Mar 4, 2006 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B49/005
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Lag-determining method and apparatus which provides for determination of and an indication of when borehole cuttings from preselected depths arrive at the surface of the earth is disclosed and includes devices for inputting the value of the lag strokes and the predetermined drilling depth increments. A signal representative of the actual drilling depth is provided to a computer circuitry. Counter circuitry accumulates a count of the strokes of the positive displacement mud pump. Adder circuitry sums the lag strokes and the accumulated count of the mud pump. Comparator circuitry provides an output when the compared values of the accumulated number of strokes of the positive displacement mud pump equals the sum of the lag strokes and the strokes of the positive displacement mud pump at a predetermined depth plus the depth increment. Visual and audio indications provide notification of the arrival of borehole cuttings from preselected depths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.