Numerical well test for well with finite conductivity vertical fracture in coalbed.pdf

Appl. Math. Mech. -Engl. Ed., 35(6), 729–740 (2014) Applied Mathematics DOI 10.1007/s10483-014-1825-6 and Mechanics c Shanghai University and Springer-Verlag Berlin Heidelberg 2014 (English Edition) Numerical well test for well with finite conductivity vertical fracture in coalbed∗ 1 1 2 Yue-wu LIU ( ) , Wei-ping OU-YANG () , Pei-hua ZHAO () , 2 3 Qian LU ( ) , Hui-jun FANG () (1. Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, P. R. China; 2. PetroChina Coalbed Methane Company Limited, Beijing 100028, P. R. China; 3. Well Test Department of Geermu Oil Factory of Qinghai Oil Field, Geermu 816000, Qinghai Province, P. R. China) Abstract A new well test model is developed for the hydraulic fractured well in coalbed by considering the following aspects: methane desorption phenomena, finite conductivity vertical fractures, and asymmetry of the fracture about the well. A new parameter is introduced to describe the storage of the fracture, which is named as a combined fracture storage. Another new concept called the fracture asymmetry coefficient is used to define the asymmetry of the fracture about the well. Finite element method (FEM) is used to solve the new mathematical model. The well test type curves and pressure fields are obtained and analyzed. The effects of the com