Method and system for real-time estimation of at least one parameter linked with the displacement of a drill bit
US5852235A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1997 |
| Grant date | Dec 22, 1998 |
| Priority date | — |
| Expiry date | Jun 23, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B45/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The present invention relates to a system and to a method designed to estimate the effective displacement of a drill bit fastened to the end of a drill string and driven into rotation in a well by surface driving means. A non-linear physical model of the drilling process based on general mechanics equations is used in the invention. The following stages are performed in the method: PA1 the parameters of said model are identified by talking account of the parameters of said well and of said string, PA1 said model is linearized about a working point, PA1 said linearized model is reduced while keeping only some of the specific modes of the state matrix of said model, PA1 the displacement of the drill bit is computed in real time by means of the reduced model and of at least one parameter measured at the surface. PA1 FIG. 4 to be published.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.