Based on the non-structural PEBI grid of fractured horizontal well, dusty-gas model is introduced to establish the mathematical model of migration in comprehensive consideration of adsorption/desorption, diffusion and Darcy flow in shale gas reservoirs. On this basis, using both control volume finite difference method and fully implicit method, the production decline mathematical model is derived for the infinitely conductive fractured horizontal well in shale gas reservoirs. Furthermore, shale adsorption/desorption effect is considered to modify material balance pseudotime in the Blasingame modern production decline analysis method. This method is extended to shale gas reservoirs, by which the Blasingame typical production decline curves of infinitely conductive fractured horizontal well are calculated and obtained. The results show that compared with the production decline curves after the modification of material balance, the infinitely conductive fractured horizontal well has smaller production decline curve values prior to modification; the boundary quasi-steady flow appears earlier; the single-well control reserve is smaller. The Blasingame typical production decline curves of infinitely conductive fractured horizontal well are divided into four flow stages, i.e., early fissure linear flow, early radial flow, composite linear flow and pseudo-radial flow. The shale adsorption/desorption has significant influences on the typical production decline curves, such as Langmuir pressure with non-linear effect while Langmuir volume with linear effect.

%U https://www.syxb-cps.com.cn/EN/10.7623/syxb201604010