Sensitivity analysis of geometry for multi-stage fractured horizontal wells with consideration of finite-conductivity fractures in shale gas reservoirs

• Established a new model for multi-stage fractured horizontal well in shale gas reservoirs.
• Adsorption, stress sensitivity and fracture conductivity are considered in this new model.
• Type curves are plotted and the relevant flow regimes are identified as well.
• Validating the new well testing model compared with an existing model and numerical simulation.
• Relevant parameters and geometry of fracture are significantly analyzed based on this model.

A new analytical solution of pressure and rate transient analysis is proposed for MFHW with finite-conductivity transverse hydraulic fractures in shale gas reservoirs. Meanwhile, desorption, adsorption, viscous flow, stress sensitivity of natural fractures, skin damage and wellbore storage are simultaneously considered as well in this paper. Laplace transformation, line source function, perturbation method, and superposition principle are employed to solve this new model. The pressure and rate transient responses are inverted into real time space with stehfest numerical inversion algorithm. Based on this new solution, the transient pressure distribution of MFHW with multiple finite-conductivity transverse hydraulic fractures was obtained, type curves are plotted, and different flow regimes in shale gas reservoirs are identified, the effects of relevant parameters are analyzed as well. The innovation and essence of this paper is combining transient gas flow in finite-conductivity hydraulic fractures, the geometry of hydraulic fractures and dual-porosity character of shale gas reservoirs. Compared with some existing models for shale gas reservoirs, this new model is more comprehensive and can provide a relative practical analysis of the relevant parameters. Besides, the conclusions involving in the geometry of hydraulic fractures can greatly match with the previous conclusions from numerical simulation and are more persuasive than that. To sum up, this new model provides some relative real evaluation results for multi-stage fracturing horizontal well technology in shale gas reservoirs.