Water breakthrough problems occur frequently during water injection in the mid-to-late stages of developing low-permeability reservoirs in Xinjiang, resulting in a sharp rise in water cut and reduced oil displacement efficiency. Development of a high-quality, injection-mouldable and sealing-performance-excellent, break-resistant system is required. Optimize the formulation of polyurethane resin in this study and examine how different temperatures, mineralisation, etc., affect the rheological properties and compressive strength of the system as well as its sealing performance. Based on the above results, the best curing composition is 40% polyurethane resin and 2% curing agent, at 80 ° C for 1 hour; this achieved a crack-free effect. High Mineralisation Reduced the Curing Period. Increase the proportion of curing agent and reduce deformation. Sealing performance tests showed that the 40%+2% polyurethane system had a maximum sealing rate of 96% and a breakthrough pressure gradient of 4.2 MPa·m⁻¹. Therefore, a new route will be developed to address water infiltration in the low-permeability reservoirs of Xinjiang.
