Study On The Law Of Expansion And Characterization Of Hydraulic Fracture Joint Development By Water Injection

In the low-permeability carbonate reservoir,during the long-term water injection development,the formation near the injection well was held back.When the pressure exceeded the fracture pressure of the rock formation,new fractures were generated in the formation.With the increase of water injection pressure,new cracks continue to extend,which can easily lead to cracked water flooding and seriously affect the development effect.This article aims to use the combination of physical simulation and theoretical methods to carry out the experimental study on the law of hydraulic fracture fracture expansion of injection wells.Firstly,based on the theoretical model,a plate of equivalent permeability-effective fracture length is established.And using radial extrusion method to develop a full-slot core and 1 / 2-slot core.Re-carry out the hydraulic fracture fracture expansion experiment of carbonate rock core,analyze the change relationship of injection pressure and relative fracture length,summarize the dynamic expansion law of hydraulic fracture fracture,and fit the formula to clarify the quantitative characterization of relative fracture length,finally Use uniaxial plus acoustic emission mechanical tests to analyze the stress-strain relationship and acoustic emission events of the test core,to verify the feasibility of crack opening and expansion of carbonate rock during water injection development,and to deeply study the fracture law and expansion of the rock layer The mechanism provides a certain theoretical basis for engineering practice.The research results of this paper have a certain guiding significance for the optimization of high-efficiency water injection development technology policies for carbonate reservoirs.