Experimental Evaluation on the Conductivity of Branch Fracture with Low Sand Laying Concentration and Its Influencing Factors in Shale Oil Reservoirs

Abstract The productivity of shale oil reservoirs is mainly determined by the hydraulic fractured reservoir volume. branch fractures with low sand laying concentration are main channels connecting matrix and fractures. Maintaining fracture conductivity significant to production oil. In this study, a series soaking experiments were conducted using core flooding device small reactor, influences different factors on evaluated. results show that when in less than 3 kg/m2, present stress sensitivity. Particularly 1 closure pressure greater 15 MPa, there will be risk proppant embedded closed. antiswelling agent has an inhibitory effect swelling. When gel-breaking fluid 2%, swelling factor powder only 1.84%. Comparatively, 0.5% poor which can cause rock crack effective decreases. It decline 70-90% flows back associated probability breaking embedding increase. frequent shut-in rapid open-flow for accelerate damage conductivity. necessary optimize fracturing open flow scheme prevent reservoirs.