Optimized completion design for triggering a fracture network to enhance horizontal shale well production

摘要

Horizontal well drilling accompanied by multicluster fracturing is unlocking shale gas resources. It is essential to create a large-scale fracture network connecting the reservoir to the wellbore by activating the preexisting natural fractures (NFs) through well completion optimization. Coupling the geomechanical characteristics of a shale formation to achieve the maximum stimulated reservoir volume (SRV), we develop a new completion optimization pattern for a single horizontal wellbore called modified alternate fracturing. The new model is a combination of conventional simultaneous and alternate fracturing. Unlike the previous studies that mainly concentrated on predicting the quasistatic dilation of NF failure, the presented paper assesses the dynamic evolution progression of NF growth under different failure criteria. Additionally, an analysis of how the modified alternate fracturing influences the fracture network is performed. The results demonstrate that a NF may be crossed, opened or slipped by an approaching hydraulic fracture (HF), depending on the tensile or shear stresses exerted on the NF. The combination of perforation parameter optimization and injection rate real-time control is able to utilize induced stresses to form a complex fracture network. A field application reveals that the modified well completion pattern performed better than conventional simultaneous fracturing due to increasing the near-wellbore and far-field fracture complexity. In addition, no additional equipment such as bridge plugs or coiled tubingis needed during operation, reducing potential issues.