Mechanism Research On Hydraulic Fracture Directional Initiation By The Guidance Of Radial Well

In low permeable oil fields,the stimulation effect is not obvious after the radial well technology applied.Therefore hydraulic fracturing on the radial well is essential.But there are some problems about radial well fracturing currently: the mechanism on fracture initiation and propagation for radial well is not clear now,and by kinds of conditions limited,the hydraulic fracture may not propagate along a single radial well,which leading to communicate the target area unsuccessfully.The fracture propagation may be changed on half way,and can not penetrate deep reservoir.Because of above reasons,the stimulation effect is not ideal.Therefore,this paper carry out mechanism study on fracture initiation for multi-vertical radial well.In order to model the fracture initiation for radial well,the wellbore pressure,in-situ stress and fracturing infiltration are taken into account,then space force theory analysis of radial well fracturing is conducted.Then combining with numerical calculation and physical simulation experiment,we study the process of fracture initiation influenced by multi-vertical radial well.Then we analyze the influence of factors included horizontal stress difference,radial well declination angle,diameter,space and number.The results indicate that: the fracture tend to initiate along the radial well under different conditions;radial well declination angle has influence to the fracture initiation process;fracture morphology affectd by many parameters;small diameter and displacement,large space and stress difference can change fracture propagation;initiation pressure has negative correlation relationship with space and stress difference.Those conclusions can be theoretical basis for the radial well fracturing design.