Performance Evaluation of a Horizontal Well With Multiple Fractures by Use of a Slab-Source Function

Abstract

Summary A novel slab-source function was formulated and successfully applied to accurately evaluate performance of a horizontal well with multiple fractures in a tight formation. More specifically, such a slab-source function in the Laplace domain has assigned a geometrical dimension to the source, whereas pressure response of a rectangular reservoir with closed outer boundaries can be determined. A semianalytical method is then applied to solve the newly formulated mathematical model by discretizing the fracture into small segments, each of which is treated as a slab source, assuming that there exists unsteady flow between the adjacent segments. The newly developed function was validated with numerical solution obtained from a reservoir simulator and then its application was extended to a field case. The pressure response together with its corresponding derivative type curves was reproduced to examine effects of number of stages, fracture conductivity, and fracture dimension under various penetration conditions. The fracture conductivity is found to mainly influence early-stage bilinear-/linear-flow regime, whereas a smaller conductivity will force more fluid to enter the toe of the fracture than its heel. The penetrating ratio will impose a significant impact on the pressure response at the early stage, forcing the bilinear/linear flow to become radial flow.