Method for measuring formation properties with a formation tester
US7328610B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 2006 |
| Grant date | Feb 12, 2008 |
| Priority date | — |
| Expiry date | Mar 7, 2026 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B49/008
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method is disclosed for estimating a formation pressure using a formation tester disposed in a wellbore penetrating a formation, said method comprising: (a) establishing fluid communication between a pretest chamber in the downhole tool and the formation via a flowline, the flowline having an initial pressure therein; (b) moving a pretest piston in a controlled manner in the pretest chamber to reduce the initial pressure to a drawdown pressure during a drawdown phase; (c) terminating movement of the piston to permit the drawdown pressure to adjust to a stabilized pressure during a build-up phase and measuring simultaneously in relation to time, pressure P(t) and temperature T(t) in the pretest chamber; (d) extracting an index i(t) dependent of the pressure P(t) and the temperature T(t) informing on the build-up phase; (e) analyzing index i(t) and repeating steps (b)-(d) or going to step (f); (f) determining the formation pressure based on a final stabilized pressure in the flowline. And more generally a method could be used for estimating type of a build up pressure phase, the build up pressure phase being done after a drawdown pressure phase, said both drawdown and build up phas…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.