Similar structure of solution for triple media shale gas reservoir

In view of the limitations of the traditional shale gas reservoir model when used in describing the process of shale gas flow, this paper establishes the seepage model of a triple media shale gas reservoir, and takes the adsorption and desorption process into account. By combining the use of Laplace transforms with similar structure theory, pseudo pressure solutions under three different outer boundary conditions having similar structures are obtained in Laplace space. The pseudo pressures are then inverted into real space with the Stehfest numerical inversion logarithm. In addition, the characteristic curves are drawn, and impact of the variation of the main parameters on them are analyzed. The results show that three different outer boundary conditions of the pseudo pressures are only different at the kernel functions. Furthermore, under the similar structure theory, portraying the characteristic curves of three different outer boundary conditions only requires a change to the kernel functions. Therefore, the similar structure theory replaces the complex calculation process of seepage equations in the simple algebraic calculation. At the same time, the similar structure theory tremendously simplifies the drawing process of the characteristic curves. This will have a profound influence on the development of well testing analysis software in the future as well.