A New Analytical Method for Analyzing Linear Flow in Tight/Shale Gas Reservoirs: Constant-Rate Boundary Condition
- Morteza Nobakht (University of Calgary) | Christopher R. Clarkson (University of Calgary)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- February 2012
- Document Type
- Journal Paper
- 51 - 59
- 2012. Society of Petroleum Engineers
- 5.8.2 Shale Gas, 5.8.1 Tight Gas
- Shale Gas, Pseudotime, Linear Flow Analysis, Corrected Pseudotime, Constant Rate
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- 2,293 since 2007
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Hydraulically fractured vertical and horizontal wells completed in shale gas and some tight gas plays are known to exhibit long periods of linear flow. Recently, techniques for analyzing this flow period using (normalized) production data have been put forth, but there are known errors associated with the analysis. In this paper, linear flow from fractured wells completed in tight/shale gas reservoirs--subject to a constant-production-rate constraint--is studied. We show analytically that the square-root-of-time plot (a plot of rate-normalized pressure vs. square root of time that is commonly used to interpret linear flow) depends on the production rate. We also show that depending on production rate, the square-root/time plot may not be a straight line during linear flow; the higher the production rate, the earlier in time the plot deviates from the expected straight line. This deviation creates error in the analysis. To address this issue, a new analytical method is developed for analyzing linear-flow data for the constant-gas-rate production constraint. The method is then validated using a number of numerically simulated cases. As expected, on the basis of the analytical derivation, the square-root/time plots for these cases depend on gas-production rate and, for some cases, the plot does not appear as a straight line during linear flow. Finally, we found that there is excellent agreement between the fracture half-lengths obtained using this method and the input fracture half-lengths entered in to numerical simulation.
|File Size||1 MB||Number of Pages||9|
Agarwal, R.G., Gardner, D.C., Kleinsteiber, S.W., and Fussell, D.D. 1999.Analyzing Well Production Data Using Combined-Type-Curve and Decline-CurveAnalysis Concepts. SPE Res Eval & Eng 2 (5): 478-486.SPE-57916-PA. http://dx.doi.org/10.2118/57916-PA.
Anderson, D.M. and Mattar, L. 2005. An Improved Pseudo-Time for GasReservoirs with Significant Transient Flow. Paper CIPC 2005-114 presented atthe Canadian International Petroleum Conference, Calgary, 7-9 June. http://dx.doi.org/10.2118/2005-114.
Anderson, D.M., Nobakht, M., Moghadam, S., and Mattar, L. 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.
Bello, R.O. and Wattenbarger, R.A. 2008. Rate Transient Analysis inNaturally Fractured Shale Gas Reservoirs. Paper SPE 114591 presented at theCIPC/SPE Gas Technology Symposium, Calgary, 16-19 June. http://dx.doi.org/10.2118/114591-MS.
Carlson, E.S. and Mercer, J.C. 1989. Devonian Shale Gas Production:Mechanisms and Simple Models. J. Pet Tech 43 (4): 476-482.SPE-19311-PA. http://dx.doi.org/10.2118/19311-PA.
Fraim, M.L. and Wattenbarger, R.A. 1987. Gas Reservoir Decline CurveAnalysis Using Type Curves with Real Gas Pseudopressure and Normalized Time.SPE Form Eval 2 (4): 671-682. SPE-14238-PA. http://dx.doi.org/10.2118/14238-PA.
Ibrahim, M. and Wattenbarger, R.A. 2005. Rate Dependence of Transient LinearFlow in Tight Gas Wells. Paper CIPC 2005-057 presented at CanadianInternational Petroleum Conference, Calgary, 7-9 June. http://dx.doi.org/10.2118/2005-057.
Ibrahim, M. and Wattenbarger, R.A. 2006. Analysis of Rate Dependence inTransient Linear Flow in Tight Gas Wells. Paper SPE 100836 presented at the AbuDhabi International Petroleum Exhibition and Conference, Abu Dhabi, UAE, 5-8November. http://dx.doi.org/10.2118/100836-MS.
Mayerhofer, M.J., Lolon, E.P., Youngblood, J.E., and Heinze, J.R. 2006.Integration of Microseismic Fracture Mapping Results with Numerical FractureNetwork Production Modeling in the Barnett Shale. Paper SPE 102103 presented atthe SPE Annual Technical Conference and Exhibition, San Antonio, Texas, USA,24-27 September. http://dx.doi.org/10.2118/102103-MS.
Moghadam, S., Jeje, O. and Mattar, L. 2011. Advanced Gas Material Balance inSimplified Format. J. Can Pet Tech 50 (1): 90-98.SPE-139428-PA. http://dx.doi.org/10.2118/139428-PA.
Nobakht, M. and Clarkson, C.R. 2011a. A New Analytical Method for AnalyzingProduction Data from Shale Gas Reservoirs Exhibiting Linear Flow: ConstantPressure Production. Paper SPE 143989 presented at the North AmericanUnconventional Gas Conference and Exhibition, The Woodlands, Texas, USA, 14-16June. http://dx.doi.org/10.2118/143989-MS.
Nobakht, M. and Clarkson, C.R. 2011b. Analysis of Production Data in ShaleGas Reservoirs: Rigorous Corrections for Fluid and Flow Properties. Paper SPE149404 presented at the Eastern Regional Meeting, Columbus, Ohio, USA, 17-19August. http://dx.doi.org/10.2118/149404-MS.
Wattenbarger, R.A., El-Banbi, A.H., Villegas, M.E., and Maggard, J.B. 1998.Production Analysis of Linear Flow Into Fractured Tight Gas Wells. Paper SPE39931 presented at the SPE Rocky Mountain Regional/Low-Permeability ReservoirsSymposium, Denver, 5-8 April. http://dx.doi.org/10.2118/39931-MS.