AM  Vol.4 No.1 A , January 2013
Seepage Mechanism and Transient Pressure Analysis of Shale Gas
Abstract: The current research of nonlinear seepage theory of shale-gas reservoir is still in its infancy. According to the characteristics of shale gas in adsorption-desorption, diffusion, slippage and seepage during accumulation, migration and production, a mathematical model of unstable seepage in dual-porosity sealed shale-gas reservoir was developed while considering Knudsen diffusion, slip-flow effect and Langmuir desorption effect. By solving the model utilizing the Stehfest numerical inversion and computer programming in Laplace space, several typical curves of bottomhole pressure were obtained. In this paper, we discussed the effects of several parameters on the pressure dynamics, i.e. storativity ratio, Langmuir volume, Langmuir pressure, adsorption-desorption, tangential momentum accommodation coefficient, flow coefficient, boundary. The results show that the desorbed gas extends the time for fluid to flow from matrix system to fracture system; the changes of Langmuir volume and Langmuir pressure associated with desorption and adsorption effect are the internal causes of the storativity ratio change; when the tangential momentum accommodation coefficient decreases, the time for pressure wave to spread to the border reduces; interporosity flow coefficient determines the occurrence time of the transition stage; boundary range restricts the time for pressure wave to spread to the border.
Cite this paper: X. Guo and W. Wang, "Seepage Mechanism and Transient Pressure Analysis of Shale Gas," Applied Mathematics, Vol. 4 No. 1, 2013, pp. 197-203. doi: 10.4236/am.2013.41A030.

[1]   Z. L. Ping and P. R. Fang, “Accumulation and Transformation of Shale Gas Reservoir,” China Petroleum Exploration, Vol. 3, 2009, pp. 20-23;

[2]   D. Y. Gang, W. M. Qiang and L. J. Qiu, “Shale Gas Seepage Mechanism and Fractured Wells Production Evaluation,” Journal of Chongqing University, Vol. 34, No. 4, 2011, pp. 62-66.

[3]   G. S. Sheng, Y. X. He and L. H. Xun, “Impact of Slippage on Shale Gas Well Productivity,” Natural Gas Tndustry, Vol. 31, No. 4, 2011, pp. 55-58.

[4]   F. Javadpour, “Nanopores and Apparent Permeability of Gas Flow in Mudrocks (Shales and Siltstone),” Journal of Canadian Petroleum Technology, Vol. 48, No. 8, 2009, pp. 16-21. doi:10.2118/09-08-16-DA

[5]   V. Shabro, C. Torres-Verdín and F. Javadpour, “Numerical Simulation of Shale-Gas Production: From Pore-Scale Modeling of Slip-Flow, Knudsen Diffusion, and Langmuir Desorption to Reservoir Modeling of Compressible Fluid,” SPE North American Unconventional Gas Conference and Exhibition in The Woodlands, Texas, 14-16 June 2011, pp. 2-4. doi:10.2118/144355-MS

[6]   D. Tzoulaki, L. Heinke and H. Lim. “Assessing Surface Permeabilities from Transient Guest Profiles in Nanoporous Host Materials,” Angewandte Chemie International Edition, Vol. 48, No. 19, 2009, pp. 3525-3528. doi:10.1002/anie.200804785

[7]   M. H. M. Hassan and J. D. Way, “Gas Transport in A Microporous Silica Membrane,” SPE Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 13-16 October 1996, pp. 2-3. doi:10.2118/36226-MS

[8]   E. Ozkan and R. Raghavan, “Modeling of Fluid Transfer From Shale Matrix to Fracture Network,” SPE Annual Technical Conference and Exhibition, Florence, 19-22 September 2010, pp. 10-13. doi:10.2118/134830-MS

[9]   C. M. Freeman, G. Moridis, D. Ilk and T. A. Blasingame. “A Numerical Study of Performance for Tight Gas and Shale Gas Reservoir Systems,” SPE Annual Technical Conference and Exhibition, New Orleans, 4-7 October 2009, pp. 9-12. doi:10.2118/124961-MS

[10]   G. J. Moridis, T. A. Blasingame and C. M. Freeman, “Analysis of Mechanisms of Flow in Fractured Tight-Gas and Shale-Gas Reservoirs,” SPE Latin American & Caribbean Petroleum Engineering Conference Lima, Peru, 1-3 December 2010, pp. 20-22. doi:10.2118/139250-MS

[11]   H. Stehfest, “Algorithm 368 Numerical Inversion of Laplace Transforms,” Communications of ACM, Vol.13, No.1, 1970, pp. 47-49. doi:10.1145/361953.361969

[12]   F. Javadpour, D. Fisher and M. Unsworth, “Nanoscale Gas Flow in Shale Gas Sediments,” Canadian Petroleum Technology, Vol. 46, No. 10, 2007, pp. 55-61.

[13]   S. Roy, R. Raju and F. H. Chuang, “Modelling Gas Flow through Microchannels and Nanopores,” Journal of Applied Physics, Vol. 93, No. 8, 2003, pp. 4870-4879. doi:10.1063/1.1559936

[14]   P. G. Brwon, A. Dinnado and K. G. Cheng, “The Flow of Gas in Pipes at Low Pressures,” Journal of Applied Physics, Vol. 17, No. 10, 1946, pp. 802-813. doi:10.1063/1.1707647

[15]   A. E. Schrodinger, “The Physics of Flow through Porous Media,” University of Toronto Press, Toronto, 1974.