A New Coal Permeability Prediction Method Based on Experiment and Dimension Analysis
- Zhiming Wang (China University of Petroleum) | Gang Yang (China University of Petroleum) | Jian Zhang (China United Coalbed Methane Co., Ltd)
- Document ID
- Society of Petroleum Engineers
- SPE Journal
- Publication Date
- June 2014
- Document Type
- Journal Paper
- 356 - 360
- 2013. Society of Petroleum Engineers
- 5.6.1 Open hole/cased hole log analysis, 1.6.9 Coring, Fishing, 5.3.4 Integration of geomechanics in models
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- 418 since 2007
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This paper aims to investigate the effect of temperature and effectivestress on coal permeability. Through the experiment, we find a reversalphenomenon in which the coal permeability presents different change trends astemperature increases at two sides of the reverse point.
The term "critical effective stress" refers to the effective stress at thereverse point. When effective stress is lower than the critical effectivestress, the outward expansion effect of the coal block caused by grain and gasswell is greater than compaction effect as temperature increases under loweffective stress condition. Therefore, the coal expands primarily outward,which results in fissure opening and permeability increase. When effectivestress is higher than the critical effective stress, high effective stresslimits the coal?s outward expansion. The coal expands inward with increasingtemperature, thus causing fissure closure and permeability decrease.
On the basis of dimension analysis and regression analysis, combined withexperimental data, this paper develops a high-precision semitheoretical coalpermeability model of Qinshui basin in China. Simultaneously, what this paperpresents is a permeability prediction method: measuring coal core permeabilityand performing dimension analysis and regression analysis. With this work done,we can establish a similar permeability model suitable for other target zones.Thus, the analytical method presented in this paper provides a basis for coalpermeability prediction.
|File Size||384 KB||Number of Pages||5|
Civan, F. 2008. Correlation of Permeability Loss by Thermally-InducedCompaction due to Grain Expansion. Petrophysics 49 (4):351-361.
Guo, R., Mannhardt, K., and Kantzas, A. 2008. Laboratory Investigation onthe Permeability of Coal During Primary and Enhanced Coalbed MethaneProduction. J Can Pet Technol 47 (10): 27-32. JCPT Paper No.08-10-27. http://dx.doi.org/10.2118/08-10-27.
Li, Z.Q. and Rong, Q. 2009. Coal permeability experiment research under thecondition of different temperature and stress (in Chinese). Journal of ChinaUniversity of Mining and Technology 38 (4): 523-527.
Robertson, E.P. and Christiansen, R.L. 2007. Modeling LaboratoryPermeability in Coal Using Sorption-Induced Strain Data. SPE Res Eval &Eng 10 (3): 260-269. SPE-97068-PA. http://dx.doi.org/10.2118/97068-PA.
Wang, Z.M. 2010. The Completion Optimization Theory and Application ofComplex Well (in Chinese), 134-159. Beijing, China: Petroleum IndustryPress.
Wang, Z.M. and Zhang, J. 2010. Critical Thickness of a Low Permeable CoalBed for Horizontal Well Production in China. Energy Sources Part A33 (4): 307-316. http://dx.doi.org/10.1080/15567030903030641.
Wang, Z.M., Cui, H., and He, G. 2006. Fluid Mechanics (in Chinese).Beijing, China: Petroleum Industry Press.
Zhu, W.C., Wei, C.H., Liu, J. et al. 2011. A model of coal-gas interactionunder variable temperatures. Int. J. Coal Geol. 86 (2-3):213-221. http://dx.doi.org/10.1016/j.coal.2011.01.011.