Rate-Transient Analysis Based on the Power-Law Behavior for Permian Wells
- Wei-Chun Chu (Pioneer Natural Resources) | Nimish D. Pandya (Pioneer Natural Resources) | Ray W. Flumerfelt (Pioneer Natural Resources) | Chih Chen (Kappa Engineering)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- November 2019
- Document Type
- Journal Paper
- 1,360 - 1,370
- 2019.Society of Petroleum Engineers
- decline curve analysis, anomalous diffusion, Chow pressure group, rate-transient analysis, power-law behavior
- 20 in the last 30 days
- 214 since 2007
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In unconventional reservoirs, the application of many rate-transient-analysis (RTA) techniques relies heavily on the identification and analysis of the linear flow regime, which is characterized by a ½-slope on a log-log plot of Δp vs. t. Through our analysis of more than 400 wells with downhole pressure gauges in the Wolfcamp Shale of the Permian Basin, we observed power-law behavior, but with slopes much different from ½ over long periods of time. In many cases, the duration of the straight line with a slope different from ½ lasts for years, without ever converging to ½. In some cases, the slope changes over time but is rarely the characteristic ½-slope observed over long periods. Rate forecasts would be in error if we were to assume that the slope would converge to a ½-slope at a later time.
In this work, we present examples of Permian Wolfcamp horizontal wells each with a measured bottomhole pressure (BHP) to demonstrate the characteristic power-law behavior with slopes different from ½. Power-law behaviors are typical in heterogeneous systems and are identified using the Chow pressure group (CPG).
On the basis of the concept of power-law behavior, we developed a workflow to analyze single-phase rate-transient data with highquality measured BHP. Ultimately, the new workflow for RTA uses power-law characteristics to evaluate well performance and is a complementary tool to traditional methods such as the Arps decline-curve analysis (Arps 1945). In this paper, we outline a power-law analysis workflow scheme and demonstrate that the CPG is a convenient means for identifying the exponents of straight lines. In addition, we present case studies to demonstrate the application of this technique to predict the long-term well performance from choked-back wells, to evaluate long-term performance changes associated with offset fracture hits, and to estimate the hyperbolic-decline-curve b-factor.
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Arps, J. J. 1945. Analysis of Decline Curves. Trans AIME 160 (1): 228–247. SPE-945228-G. https://doi.org/10.2118/945228-G.
Bello, O. R. and Wattenbarger, A. R. 2010. Multi-Stage Hydraulically Fractured Horizontal Shale Gas Well Rate Transient Analysis. Presented at the North Africa Technical Conference and Exhibition, Cairo, 14–17 February. SPE-126754-MS. https://doi.org/10.2118/126754-MS.
Chen, C. and Raghavan, R. 2013. On Some Characteristic Features of Fractured-Horizontal Wells and Conclusions Drawn Thereof. SPE Res Eval & Eng 16 (1): 19–28. SPE-163104-PA. https://doi.org/10.2118/163104-PA.
Chow, V. T. 1952. On the Determination of Transmissibility and Storage Coefficients From Pumping Test Data. Trans Am Geophys Union 33: 397–404. https://doi.org/10.1029/TR033i003p00397.
Chu, W-C., Scott, K. D., Flumerfelt, R. W. et al. 2018. A New Technique for Quantifying Pressure Interference in Fractured Horizontal Shale Wells. Presented at the Annual Technical Conference and Exhibition, Dallas, 24–26 September. SPE-191407-MS. https://doi.org/10.2118/191407-MS.
Clarkson, C. R. and Beierle, J. 2010. Integration of Microseismic and Other Post-Fracture Surveillance With Production Analysis: A Tight Gas Study. Presented at the SPE Unconventional Gas Conference, Pittsburgh, Pennsylvania, 23–25 February. SPE-131786-MS. https://doi.org/10.2118/131786-MS.
Clarkson, C. R. and Qanbari, F. 2015. A Semianalytical Forecasting Method for Unconventional Gas and Light Oil Wells: A Hybrid Approach for Addressing the Limitations of Existing Empirical and Analytical Methods. SPE Res Eval & Eng 18 (1): 94–108. SPE-170767-PA. https://doi.org/10.2118/170767-PA.
Deen, T., Shchelokov, V., Wydrinski, R. et al. 2013. Horizontal Well Performance Prediction Early in the Life of the Wolfcamp Oil Resources Play in the Midland Basin. Presented at the Unconventional Resources Technology Conference, Denver, 12–14 August. URTEC-1582281-MS. https://doi.org/10.1190/urtec2013-081.
Duong, A. N. 2011. Rate-Decline Analysis for Fracture-Dominated Shale Reservoirs. SPE Res Eval & Eng 14 (3): 377–387. SPE-137748-PA. https://doi.org/10.2118/137748-PA.
Mohan, K., Scott, K. D., Monson, G. D. et al. 2013. A Systematic Approach to Understanding Well Performance in Unconventional Reservoirs: A Wolfcamp Case Study. Presented at the Unconventional Resources Technology Conference, Denver, 12–14 August. URTEC-1579514-MS. https://doi.org/10.1190/urtec2013-051.
Ozkan, E. 1988. Performance of Horizontal Wells. PhD dissertation, University of Tulsa, Tulsa, Oklahoma.
Palacio, J. C. and Blasingame, T. A. 1993. Decline-Curve Analysis With Type Curves—Analysis of Gas Well Production Data. Presented at the Low Permeability Reservoirs Symposium, Denver, 26–28 April. SPE-25909-MS. https://doi.org/10.2118/25909-MS.
Raghavan, R. 1993. Well Test Analysis. Englewoods Cliffs, New Jersey: Prentice Hall.
Raghavan, R., Chen, C., and Agarwal, B. 1997. An Analysis of Horizontal Wells Intercepted by Multiple Fractures. SPE J. 2 (3): 235–245. SPE-27652-PA. https://doi.org/10.2118/27652-PA.
Raghavan, R. and Chen, C. 2017. Addressing the Influence of a Heterogeneous Matrix on Well Performance in Fractured Rocks. Transp Porous Med 117 (1): 69–102. https://doi.org/10.1007/s11242-017-0820-5.
Raghavan, R. and Chen, C. 2018. A Conceptual Structure to Evaluate Wells Producing Fractured Rocks of the Permian Basin. Presented at the Annual Technical Conference and Exhibition, Dallas, 24–26 September. SPE-191484-MS. https://doi.org/10.2118/191484-MS.
Raghavan, R. and Chen, C.-C. 2019. Evaluation of Fractured Rocks Through Anomalous Diffusion. Presented at the SPE Western Regional Meeting, San Jose, California, USA, 23–26 April. SPE-195305-MS. https://doi.org/10.2118/195305-MS.
Seshadri, J. and Mattar, L. 2010. Comparison of Power Law and Modified Hyperbolic Decline Methods. Presented at the Canadian Unconventional Resources and International Petroleum Conference, Calgary, 19–21 October. SPE-137320-MS. https://doi.org/10.2118/137320-MS.
Scott, K. D., Chu, W.-C., and Flumerfelt, R. W. 2015. Application of Real-Time Bottom-Hole Pressure to Improve Field Development Strategies in the Midland Basin Wolfcamp Shale. Presented at the Unconventional Resources Technology Conference, San Antonio, Texas, 20–22 July. URTEC-2154675-MS. https://doi.org/10.15530/URTEC-2015-2154675.
Thomas, O. O., Raghavan, R., and Dixon, T. N. 2005. Effect of Scaleup and Aggregation on the Use of Well Tests to Identify Geological Properties. SPE Res Eval & Eng 8 (3): 248–254. SPE-77452-PA. https://doi.org/10.2118/77452-PA.
Uzun, I., Kurtoglu, B., and Kazemi, H. 2016. Multiphase Rate-Transient Analysis in Unconventional Reservoirs: Theory and Application. SPE Res Eval & Eng 19 (4): 553–566. SPE-171657-PA. https://doi.org/10.2118/171657-PA.
Wattenbarger, R. A., El-Banbi, A. H., Villegas, M. E. et al. 1998. Production Analysis of Linear Flow Into Fractured Tight Gas Wells. Presented at SPE Rocky Mountain Regional/Low-Permeability Reservoirs Symposium and Exhibition, Denver, 5–8 April. SPE-39931-MS. https://doi.org/10.2118/39931-MS.
Winestock, A. G. and Colpitts, G. P. 1965. Advances in Estimating Gas Well Deliverability. J Can Pet Technol 4 (3): 111–119. PETSOC-65-03-01. https://doi.org/10.2118/65-03-01.