Title:
METHODS TO DETECT FORMATION PRESSURE
Document Type and Number:
WIPO Patent Application WO2004025079
Kind Code:
A3
Abstract:
Methods for estimating formation pressure from data taken during the drawdown cycle are presented. In one aspect, a method of determining a formation pressure during drawdown of a formation comprises sampling fluid from a formation using a downhole tool having a sample volume and a fluid sampling device. At least one time dependent parameter of interest related to the fluid is determined during the drawdown. The at least one time dependent parameter is analyzed using a plurality of calculation techniques to determine the formation pressure. The techniques include (i) a first pressure derivative technique; (ii) a second pressure derivative technique; (iii) a formation rate analysis technique; (iv) a dp/dt-ratio technique; and (v) a stepwise drawdown technique.
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Inventors:
KRUEGER SVEN
NIEMEYER EICK
MEISTER MATTHIAS
LEE JAEDONG
NIEMEYER EICK
MEISTER MATTHIAS
LEE JAEDONG
Application Number:
PCT/US2003/028726
Publication Date:
May 13, 2004
Filing Date:
September 12, 2003
Export Citation:
Assignee:
BAKER HUGHES INC (US)
International Classes:
E21B49/00; E21B49/10; (IPC1-7): E21B49/00; E21B49/10
Foreign References:
| US5708204A | 1998-01-13 | |||
| US20030167834A1 | 2003-09-11 | |||
| US5803186A | 1998-09-08 | |||
| US5233866A | 1993-08-10 | |||
| US5377755A | 1995-01-03 |
Other References:
ONUR M ET AL: "Nonlinear Regression: The information Content of Pressure and Pressure-derivative Data", SOCIETY OF PETROLEUM ENGINEERS JOURNAL, DALLAS, TX, US, no. SPE 71579, 30 September 2001 (2001-09-30), pages 1 - 9, XP002256559, ISSN: 0197-7520
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