Discussion of Permeability Anisotropy Effect in Transformation
- Authors
- James Sheng (Consultant)
- DOI
- https://doi.org/10.2118/139430-PA
- Document ID
- SPE-139430-PA
- Publisher
- Society of Petroleum Engineers
- Source
- Journal of Canadian Petroleum Technology
- Volume
- 49
- Issue
- 07
- Publication Date
- July 2010
- Document Type
- Journal Paper
- Pages
- 42 - 46
- Language
- English
- ISSN
- 0021-9487
- Copyright
- 2010. Society of Petroleum Engineers
- Disciplines
- 5.6.4 Drillstem/Well Testing, 5.5 Reservoir Simulation
- Keywords
- well testing, anisotropy, equivalent permeability, coordinate transformation, equivalent isotropic model
- Downloads
- 2 in the last 30 days
- 471 since 2007
- Show more detail
- View rights & permissions
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Summary
To solve an anisotropic flow problem, the problem is transformed into an equivalent isotropic problem. It is expected that an anisotropic solution can be readily obtained from the equivalent isotropic solution. However, sometimes that is not the case. Using the drawdown equation of a fully penetrated vertical well test and the drawdown and buildup equations for a probe test, this paper discusses when it is both possible and impossible to directly obtain an anisotropic solution from an isotropic solution. Because of the fact that transformation causes the changes in flow geometry and the shape of the wellbore or probe, the equivalent isotropic solution must be modified to obtain the anisotropic solution. Finally, a case of how horizontal well productivity was incorrectly derived in a published paper --caused by the misuse of the concept of anisotropy--is presented.
File Size | 170 KB | Number of Pages | 5 |
References
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