Journal of Oil, Gas and Petrochemical Technology

Journal of Oil, Gas and Petrochemical Technology

Challenges in Well Testing Data from Multi-layered Reservoirs and Improving Nonlinear Regression: A Gas filed case

Document Type : Research Paper

Authors
Shima Soleimani 1
Abdolnabi Hashemi 2
Riyaz Kharrat 3
1 Department of Petroleum Engineering, Science and Research branch, Islamic Azad University, Tehran, Iran.
2 Petroleum University of Technology
3 Professor of PUT
10.22034/jogpt.2017.58087
Abstract
Well test analysis of multi-layer reservoir comprises several parts. The first part concerns the estimation of parameters values and next considers finding an appropriate method to determine the unknown reservoir parameters. If the initial estimations are less accurate and weak, the final assessment may lead to incorrect results, which are totally different from the reality. Utilizing Automated Type-Curve Matching method by means of computers is effective and successful. In addition, it has priority over the ordinary analysis methods, and numerical calculations are performed with higher speed thereby causing fewer errors. In this study, first, a numerical simulation of reservoir was conducted by means of Eclipse 100 software and then its production and pressure results were introduced to Ecrin software of well test analysis. Different states were investigated in the analyzer to obtain the minimum error, and suggestions, including effect of regression point selection, initial guess, and effect of using each layer production were made to minimize the error. The final analysis results were compared with numerical simulation data to determine the performance of Ecrin software, and then a real well test was investigated in the gas field of South Pars by using this method. Furthermore, parameters of each layer were obtained so that applying the mentioned method caused the analyzer error to decrease to a favorable desired value.
Keywords
numerical simulation
Automated Type-curve Matching
Minimizing the Analyzer Error
Multilayer Gas Reservoirs

Full Text

[1]        H. PARK, “well test analysis of a multilayered reservoir with formation crossflow,” 1989.
[2]        H.A. Eskandari Niya M., A. Zareiforoush, “Challenges in Well Testing Data from Multi-Layered Reservoirs; a Field Case,” Int. J Sci. Emerging Tech, vol. 4, 2012.
[3]        P.R. Raghavan R., A.C. Reynolds, “Well Test Analysis for Wells Producing Layered Reservoirs with Crossflow,” Soc. Pet. Eng. J., pp. 407-418, June 1985.
[4]        A.J. Rosa, R.N. Horne, “Automated Type-Curve Matching in Well Test Analysis Using Laplace Space Determination of Parameter Gradients,” presented at the 58th Annual Technical Conference and Exhibition, San Francisco, CA, 1983.
[5]        J.P. Spivey, “Estimating Layer Properties for Wells in Multilayer Low-Permeability Gas Reservoirs by Automatic History-Matching Production and Production Log Data,” presented at the Gas Technology Symposium, Calgary, Alberta, Canada, 2006.
[6]        S.M. Tariq, “A Study of the Behavior of Layered Reservoirs with Wellbore Storage and Skin Effect,” Ph.D. Dissertation, Petroleum Engineering Department, Stanford University, 1977.
[7]        H.O. Jahns, “A Rapid Method for Obtaining a Two-Dimensional Reservoir Description From Well Pressure Response Data,” Soc. Pet. Eng. J., December 1966.
[8]        A. R. A. Lolon E.P., T.A. Blasingame, “New Semi-Analytical Solutions For Multilayer Reservoirs,” p. 8, 2008.
[9]        K. M. Kuchuk F., L. Ayestaran, “Well Testing and Analysis Techniques for Layered Reservoirs,” SPE 13081, August 1986.
[10]      S. P. C. Kuchuk F., L. Ayestaran, B. Nicholson, “Application of multilayer testing and analysis: a field case,” presented at the in Proceedings of the SPE Annual Technical Conference and Exhibition, New Orleans, La, USA, 1986.
[11]      H.G. Haiyang Yu, Y. He, H. Xu, L. Li, T. Zhang, B. Xian, S. Du, Sh. Cheng, “Numerical Well Testing Interpretation Model and Applications in Crossflow Double-Layer Reservoirs by Polymer Flooding,” The Scientific World Journal, 2014.
[12]      Ecrin.Well-Test Analysis Software. User Manual. 2015
Journal of Oil, Gas and Petrochemical Technology
Volume 4, Number 1
December 2017
Pages 85-98