Research On Prolongation Law Of Hydraulic Fracture For Directional Well

In recent years,The mining of low permeability reservoirs of proportion increases year by year,For low permeability reservoir high yield and high efficiency development has the vital significance。Now,Hydraulic fracturing technology is to improve the low permeable reservoir of the main means mining effects。Artificially fracturing directly influenced the fracture existence of fracturing fluid flow state。Crack geometry size significantly impact on crack diverting capacity and fracturing effect of increase after,Therefore understand the developing regularity of crack for fracturing,improve production guiding deviated fracturing effect to have the important meaning。This paper use of indoor true triaxial simulation experiment system the fracturing of hydraulic fracturing crack up crack and crack propagation simulation experiment。Preparation of a certain perforating phase laboratory conditions,different Wells bevel azimuth of the core samples,Using real triaxial equipment for these samples hydraulic fracturing。Observe the core sample after fracturing of cracks form, get after pressing crack geometry shape and fracturing process pressure variation law with time。The results of the study show that,vertical fracturing,along the maximum horizontal cracks always the principal stress direction on crack。The casing by perforating phase affect fracturing vertical Wells,perforating phase size affect crack craze pressure。Deviated orientation and the maximum horizontal wellbore principal stress direction,fracture cracks up crack and extended rules and vertical fracturing is similar,the principal stress along the maximum horizontal cracks up crack,and the direction deflection does not happen;Deviated borehole azimuth and minimum level when the principal stress direction,well, the greater the inclined Angle to the more complex the cracks,when well beyond a certain value,inclined produced along the vertical up to cracking, and happen deflection。Deviated maximum horizontal cracks along not fracturing principal stress direction on crack,Generally more crack, but will still be turned down the maximum horizontal principal stress direction expansion。...