A Novel Semi-Analytical Model for the Multiwell Horizontal Pad with Stimulated Reservoir Volume

Abstract Recently, there have been many attempts to model the stimulated reservoir volume in unconventionls. However, most researches only focused on the intersecting hydraulic or natural fractures and the effects of stimulated reservoir volume are ignored. In this study, we developed a new method that uses an effective semi-analytical method to model the stimulated reservoir volume in unconventional reservoirs. Large-scale hydraulic fracturing not only forms hydraulic fractures but also activates a large number of natural fractures in the near-well region. To the best of our knowledge, most of the multiwell horizontal pad modeling methods ignore the physics of stimulated reservoir volume. Our semi-analytical model has the ability to simulate the behaviors of a multiwell horizontal pad with irregular shaped stimulated reservoir volume and impermeable boundary. Results show that the transient pressure behavior of the multiwell horizontal pad with stimulated reservoir volume is significantly different from that of a single isolated well. The linear flow among wells, the pseudo radial flow of multiwell in stimulated reservoir volume, and transitional flow, and final pseudo radial flow of multiwell correspond to completely different transient pressure response. The high flow ability in stimulated reservoir volume means a faster rate of pressure diffusion and it lead to the appearance of these flow regions in advance. The results also confirm that as the scale of stimulated reservoir volume increase, the flow duration influenced by the stimulated reservoir volume is longer. The stimulated reservoir volume and offsetting wells makes the pseudo-radial flow feature insignificant. The pressure and the pressure derivative exhibit a gradual rise feature. For the pseudo-radial flow in stimulated reservoir volume, the horizontal line value is related to the total production of the well pad. For the unstimulated region, this value is also related to the mobility ratio.