Xinjiang Petroleum Geology ›› 2022, Vol. 43 ›› Issue (5): 606-611.doi: 10.7657/XJPG20220514

• RESERVOIR ENGINEERING • Previous Articles     Next Articles

Tri-Porosity and Dual-Permeability Well Test Analysis Model for Inclined Wells in Fractured-Vuggy Reservoirs

JIA Ran1(), NIE Renshi1(), LIU Yong2, WANG Peijun2, NIU Ge2, LU Cong1   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Development Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, China
    2. Hade Oil and Gas Development Department, Tarim Oilfield Company, PetroChina, Korla, Xinjiang 841000, China
  • Received:2022-04-23 Revised:2022-05-17 Online:2022-10-01 Published:2022-09-22
  • Contact: NIE Renshi E-mail:jiaran202204@163.com;nierenshi2000@163.com

Abstract:

In fractured-vuggy reservoirs, there is cross flow between the matrix, fractures and cavities, and the matrix and fractures supply fluid to the wellbore at the same time. Assuming that the reservoir is horizontal, equal in thickness, impermeable at top and bottom, and infinite laterally, a theoretical model of well test analysis for inclined wells was established. The analytical solution of the model in the Laplace space was obtained by means of Laplace transform and variable separation, and the solution of the bottom hole pressure was obtained through Stehfest inversion. Type curves controlled by model parameters for well test analysis were used for flow stage identification and curve sensitivity analysis were conducted. The tri-porosity and dual-permeability well test type curves of inclined wells reflect 8 main flow stages, including early radial flow stage, linear flow stage, cavity-to-fracture cross flow stage, cavity-to-matrix cross flow stage and the matrix-to-fracture stage, etc. The values of parameters such as inclination and fracture-reservoir permeability ratio obviously influence the characteristics of the well test type curves.

Key words: fractured-vuggy reservoir, tri-porosity and dual-permeability, inclined well, well test analysis model, Laplace transform, type curve, flow stage, sensitivity analysis

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