A New Fracture Network Swept Volume Prediction Approach for Multi-Fractured Horizontal Wells in Shale Oil Reservoirs

Abstract

The continental shale oil reservoirs usually have strong heterogeneity, which make the law of fracture propagation extremely complex, and the quantitative characterization of fracture network swept volume brings great challenges. In this paper, firstly, the facture shape of volume fracture is described preliminarily. Secondly, the volume fitting model of seam mesh transformation was established by coupling the key geological engineering parameters by multiple nonlinear regression method, and the productivity numerical simulation method was used to correct the reconstruction volume. Finally, a new concept of fracture network swept coefficient is put forward to quantitatively evaluate the fracturing effect. The study results shown that fractures created during the volume fracturing of shale oil reservoir appear as a belt network made up of main fractures primarily and branch fractures secondarily in the shape of cactus, and the main factors affecting the fracture network swept volume are fracturing fluid volume, fracture density, brittleness index, pump rate, horizontal stress difference, net pay thicknessand proppant amount. The prediction method is verified by the typical platform in the field to be accurate and reliable. It can provide scientific basis for the evaluation of volume fracturing effect of horizontal wells in shale oil reservoirs.