Abstract
Most of the problems associated with conventional gas well tests are related to the nonlinearity of the equations describing real gas flow, the presence of the rate dependent (non-Darcy) skin, and the long shut-in time periods required to collect the data for the analysis in tight reservoirs in which the wellbore storage period can be excessively long. This paper presents a new pressure buildup technique that reduces the wellbore storage effects, eliminates the long shut-in periods experienced with conventional tests by using afterflow rate and pressure data, and most importantly provides a direct method to estimate non-Darcy skin. The proposed technique uses normalized pseudofunctions to avoid the nonlinearities of the governing equations and involves using two different plots. The formation permeability is obtained from the slope of the first plot. The mechanical and non-Darcy skin factors are obtained respectively from the slope and intercept of the second plot. A field example and two simulated cases are presented to illustrate the application of the new technique.
Original language | English |
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Pages | 623-636 |
Number of pages | 14 |
Publication status | Published - Jan 1 1995 |
Event | Proceedings of the 9th Middle East Oil Show & Conference. Part 2 (of 2) - Duration: Mar 11 1995 → Mar 14 1995 |
Other
Other | Proceedings of the 9th Middle East Oil Show & Conference. Part 2 (of 2) |
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Period | 3/11/95 → 3/14/95 |
ASJC Scopus subject areas
- Geotechnical Engineering and Engineering Geology
- Geology