Automatic control system and method for bottom hole pressure in the underbalance drilling
US7158886B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 29, 2004 |
| Grant date | Jan 2, 2007 |
| Priority date | — |
| Expiry date | Dec 25, 2024 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/085
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
This invention provides an automatic control system and method for bottom hole pressure (BHP) in the underbalanced drilling. It relates to a computer automatic control technology. The automatic control system according to the invention includes a processing module for the BHP based on the mechanisms of hydraulics. The BHP in the underbalanced drilling is calculated from the acquired standpipe pressure (SPP), the calculated circulating pressure loss in the drilling tools, drill bit pressure drop and the fluid colunm pressure in the drill string. The resulting BHP is then compared with the set pressure value of the system. In case that the BHP is higher or lower than the set pressure, an instruction to regulate throttle valve opening will be issued in order to bring the BHP back to the set pressure range and complete BHP monitoring and control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.