Factors affecting casing equivalent stress in multi-cluster fracturing of horizontal shale gas wells: finite element study on Weirong Block, southern Sichuan Basin, China

Abstract Multi-cluster fracturing technology was often used in horizontal well reservoir reconstruction to achieve production increase, which also affected casing equivalent stress distribution. This paper focuses on multi-cluster and establishes a model line with the reality. The three-dimensional finite element of fracture-formation-cement sheath-casing proposed, influence cluster spacing number studied. On this basis, single segment 8-cluster developed. rock elastic modulus, inner wall pressure, geostress change modulus cement sheath simulated from two aspects uniform non-uniform extrusion wellbore. Actual data analyzed for section Weirong Block, southern Sichuan Basin, China. results showed that decreased increase fracture dip angle. increased spacing; however, it modulus. pressure. Also, cracks extrude evenly did not affect stress. It found that, when uniformly squeezed by multiple fractures, difference ground had little effect stress, while greater Further, there no wellhead pumping sheath, contrary. lower than research certain guiding significance prevention control damage section.