Pressure transient behavior of a fractured well in multi-region composite reservoirs

Although there has been some research on the pressure transient behavior of fractured wells in radial composite reservoirs, the analysis and modeling of such systems remain limited. Most existing solutions only consider the case of a fractured well located at the center of an infinite bi-zonal radial composite reservoir. In addition, corresponding research on a partially penetration fractured well in a radial composite reservoir is also rare. In this paper, we present an analytical three-dimensional solution for a point source located at an arbitrary position in the first circular region of a multi-region radial composite reservoir with three side boundary conditions. Then, using the principles of discretization and superposition, a general pressure transient solution of a fully penetrating fractured well or a partially penetrating fractured well in reservoirs is obtained. The standard log-log type curves of the transient pressure are plotted. Sequentially, the main flow regimes are identified and the effects of relevant parameters are analyzed. There is a special flow regime (the first transition flow regime) in the type curves due to the well not being at the center of the circular region. The well location has a significant effect on the mid-term response of the transient pressure. The presented solution can also be used in well testing to obtain reservoir parameters.