Experimental study on fracture initiation and propagation characteristics caused by pressure drive in low-permeability sandstone reservoirs

In view of the difficulties in formation energy replenishment and failed injection and production by water drive in low-permeability reservoirs， Shengli Oilfield proposed a water injection technology based on pressure drive for low-permeability reservoirs according to the technical requirements for increasing liquid production and stable oil production in the oilfield. Pressure drive could effectively increase the water injection volume through high-pressure water injection. Field tests showed that a certain scale of fractures was formed in the reservoir during the pressure drive. However， the breakdown pressure and fracture propagation law caused by pressure drive were still unclear. Five pressure drive experiments were carried out using natural sandstone and true triaxial hydraulic fracturing platforms to optimize field construction parameters. The influence of injection rate on breakdown pressure and fracture geometry caused by pressure drive was studied， and that of injection modes on fracture geometry wa