Method for determining drilling conditions while drilling
US4852399A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 13, 1988 |
| Grant date | Aug 1, 1989 |
| Priority date | — |
| Expiry date | Jul 13, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B44/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Downhole torque and rate of penetration are utilized to develop indications of formations that are porous, argillaceous or tight. This information is useful as an aid in selecting drilling practices and drilling bits. The method separates bit effects from lithology effects when drilling with roller cone or PDC bits by utilizing surface and subsurface wellsite sensors to determine averaged values of real time penetration rate and downhole torque. Changes in bit torque are used to broadly classify the lithology into three categories: porous, argillaceous and tight formations while trends in bit torque and rate of penetration in shale are used to separate wear of the bit from changes in formation strength.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.