New methods for computing stress field around refracturing cracks

Refracturing is the main method to stimulate and beneficiate low permeability oilfields.The reservoir fairway will be easily opened with cracks by refracturing.The extended track of new refracturing cracks is always the key problem in fracture designing and is hard to be calculated.From the perspective of mechanics,fracture extension is mainly controlled by surrounding stress.Then the fluid compressibility in initial crack is taken into account,the compressibility factor is introduced,and the induced stress field model of initial artificial crack is created.Based on the superposition principle of potential,the model of pore pressure around refracturing wells is built.Induced stress field of pore pressure is calculated according to the Wright's poro-elastic theory.The model of temperature induced stress field is created considering the effect of temperature.The total stress field is calculated before refracturing on the basis of the linear superposition principle.All mechanical quantities of fracture diversion are figured out.Stress around one oil well is calculated,which is affected by three water wells.There is well coincidence between computational solution and measured results.