Flow Modeling of Well Test Analysis for a Multiple-fractured Horizontal Well in Triple Media Carbonate Reservoir

摘要

Carbonate reservoir is one kinds of important reservoir in the world. Because of the characteristics of carbonate reservoir, horizontal well, and acid fracturing became a key technology for efficiently developing carbonate reservoir. Establishing corresponding mathematical models and analyzing transient pressure behaviors of this type of well-reservoir configuration can provide a better understanding of fluid flow patterns in formation as well as estimations of important parameters. A coupling mathematical model for a fractured horizontal well in triple media carbonate reservoir with three kinds of reservoir outer boundaries by conceptualizing vugs as spherical shapes is presented in this article, in which the infinite conductivity of the acid fractures is taken into account. A semi-analytical solution is obtained in the Laplace domain by using source function theory, Laplace transformation, discretization of fracture, and superposition principle. Analysis of transient pressure responses indicates that several characteristic flow periods of fractured horizontal wells in triple media carbonate reservoir can be identified. Parametric analysis shows that fracture half-length, fracture number, fracture spacing, conditions of reservoir outer boundary, and so on can significantly influence the transient pressure responses of fractured horizontal wells in triple media carbonate reservoir. The model presented in this article can be applied to obtain important parameters pertinent to reservoir or fracture by type curve matching, and it can also provide useful information for optimizing fracture parameters.