Effect of Discontinuous Microfractures on Ultratight Matrix Permeability of a Dual-Porosity Medium
- Osman G. Apaydin (EOG Resources) | Erdal Ozkan (Colorado School of Mines) | Rajagopal Raghavan (Phillips Petroleum Company (Retd.))
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- August 2012
- Document Type
- Journal Paper
- 473 - 485
- 2012. Society of Petroleum Engineers
- 3.2.3 Hydraulic Fracturing Design, Implementation and Optimisation, 1.6.9 Coring, Fishing
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- 1,138 since 2007
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This paper examines the effects of matrix microfractures on the effective matrix permeability of a dual-porosity medium. An analytical model is presented, with composite matrix blocks consisting of a core in which unconnected microfractures do not contribute considerably to flow capacity and a surface layer where the microfractures connected to the matrix surface (resembling wormholes) cause a stimulation effect. The composite matrix flow is coupled with the flow in a network of macrofractures, as in the conventional dual-porosity idealizations of fractured media. This paper investigates the effect of matrix-surface stimulation and demonstrates improved fluid transfer from the matrix medium to the fracture network because of matrix microfractures. It is shown that matrix microfractures accelerate production by providing earlier and more-effective contribution of the matrix into flow rates. This contribution of the matrix because of microfractures cannot be simulated by enhanced matrix permeability because the microfractured surface layer of the matrix causes flow characteristics different from those of a homogeneous (unfractured) matrix. The effect of the microfractured surface layer of the matrix cannot be taken into account by a triple-porosity model used to incorporate two sets of connected natural fractures or connected fractures and vugs.
|File Size||3 MB||Number of Pages||13|
Agarwal, R.A. 1979. "Real Gas Pseudo-Time"--A New Function for PressureBuildup Analysis of MHF Gas Wells. Paper SPE 8279 presented at the SPE AnnualTechnical Conference and Exhibition, Las Vegas, Nevada, USA, 23-26 September.http://dx.doi.org/10.2118/8279-MS.
Al-Hussainy, R., Ramey, H.J. Jr., and Crawford, P.B. 1966. The Flow of RealGases Through Porous Media. J Pet Technol 18 (5): 624-636.SPE-1243-A-PA. http://dx.doi.org/10.2118/1243-A-PA.
Anderson, D.M., Nobakht, M., Moghadam, S. et al. 2010. Analysis ofProduction Data from Fractured Shale Gas Wells. Paper SPE 131787 presented atthe SPE Unconventional Gas Conference, Pittsburgh, Pennsylvania, USA, 23-25February. http://dx.doi.org/10.2118/131787-MS.
Barenblatt, G.I., Zheltov, I.P., and Kochina, I.N. 1960. Basic concepts inthe theory of seepage of homogeneous liquids in fissured rocks. J. Appl.Math. Mech. 24 (5): 1286-1303. http://dx.doi.org/10.1016/0021-8928(60)90107-6.
Brown, M., Ozkan, E., Ragahavan, R. et al. 2009. Practical Solutions forPressure Transient Responses of Fractured Horizontal Wells in UnconventionalReservoirs. Paper SPE 125043 presented at the SPE Annual Technical Conferenceand Exhibition, New Orleans, 4-7 October. http://dx.doi.org/10.2118/125043-MS.
Cluff, R.M., Shanley, K.W., and Miller, M.A. 2007. Three Things WeThought We Knew about Shale but Were Afraid to Ask. Poster presentation givenpresented at the AAPG 2007 Annual Conference, Long Beach, California, USA, 1-4April.
de Swaan O., A. 1976. Analytical Solutions for Determining NaturallyFractured Reservoir Properties by Well Testing. SPE J. 16(3): 117-122. SPE-5346-PA. http://dx.doi.org/10.2118/5346-PA.
Hyman, L.A., Malek, D.J., Admire, C.A. et al. 1991. The Effects ofMicrofractures on Directional Permeability in Tight Gas Sands. Paper SPE 21878presented at the Low Permeability Reservoirs Symposium, Denver, 15-17 April. http://dx.doi.org/10.2118/21878-MS.
Kazemi, H. 1969. Pressure Transient Analysis of Naturally FracturedReservoir with Uniform Fracture Distribution. SPE J. 9 (4):451-462. SPE-2156-PA. http://dx.doi.org/10.2118/2156-PA.
Mukherjee, H. and Economides, M.J. 1991. A Parametric Comparison ofHorizontal and Vertical Well Performance. SPE Form Eval 6 (2):209-216. SPE-18303-PA. http://dx.doi.org/10.2118/18303-PA.
Najurieta, H.L. 1980. A Theory of Pressure Transient Analysis in NaturallyFractured Reservoirs. J Pet Technol 32 (7): 1241-1250.SPE-6017-PA. http://dx.doi.org/10.2118/6017-PA.
Ozkan, E., Brown, M.L., Raghavan, R.S. et al. 2009. Comparison ofFractured Horizontal-Well Performance in Conventional and UnconventionalReservoirs. Paper SPE 121290 presented at the SPE Western Regional Meeting, SanJose, California, USA, 24-26 March. http://dx.doi.org/10.2118/121290-MS.
Ozkan, E., Raghavan, R.S., and Apaydin, O.G. 2010. Modeling of FluidTransfer from Shale Matrix to Fracture Network. Paper SPE 134830 presented atthe SPE Annual Technical Conference and Exhibition, Florence, Italy, 19-22September. http://dx.doi.org/10.2118/134830-MS.
Serra, K.V., Reynolds, A.C., and Raghavan, R. 1983. New Pressure TransientAnalysis Method for Naturally Fractured Reservoirs. J Pet Technol 35 (12): 2271-2283. SPE-10780-PA. http://dx.doi.org/10.2118/10780-PA.
Slatt, R.M. and O'Brien, N.R. 2011. Pore types in the Barnett and Woodfordgas shales: Contribution to understanding gas storage and migration pathways infine-grained rocks. AAPG Bull. 95 (12): 2017-2030. http://dx.doi.org/10.1306/03301110145.
Stehfest, H. 1970. Algorithm 368: Numerical inversion of Laplace transforms.Commun. ACM 13 (1): 47-49. http://dx.doi.org/10.1145/361953.361969.
Wang, J. and Liu, Y. 2011. Simulation Based Well Performance Modeling inHaynesville Shale Reservoir. Paper SPE 142740 presented at the SPE Productionand Operations Symposium, Oklahoma City, Oklahoma, USA, 27-29 March. http://dx.doi.org/10.2118/142740-MS.
Warren, J.E. and Root, P.J. 1963. The Behavior of Naturally FracturedReservoirs. SPE J. 3 (3): 245-255. SPE-426-PA. http://dx.doi.org/10.2118/426-PA.