Annulus pressure setpoint correction using real time pressure while drilling measurements
US8240398B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 2011 |
| Grant date | Aug 14, 2012 |
| Priority date | — |
| Expiry date | May 26, 2031 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/085
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method of controlling pressure in a wellbore can include determining a real time wellbore pressure PwbRT1 at a pressure sensor in the wellbore, calculating hydrostatic pressure Ph1 at the pressure sensor, determining a real time annulus pressure PaRT, calculating friction pressure Pf due at least to circulation of the fluid through the wellbore and depth in the wellbore, calculating a friction pressure correction factor CFPf1 equal to (PwbRT1−Ph1−PaRT)/Pf, and controlling operation of a pressure control device, based on the friction pressure correction factor CFPf1. The method can further include determining a desired wellbore pressure PwbD1 at the pressure sensor, calculating an annulus pressure setpoint PaSP1 equal to PwbD1−Ph1−(Pf*CFPf1), and adjusting the pressure control device as needed to maintain PaRT equal to PaSP1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.