Calculation Method of Productivity for Shale Oil in Volumetric Fractured Horizontal Wells

In order to evaluate quantitatively the productivity of shale oil in fractured horizontal wells and in view of the influence of non-Darcy seepage and pressure sensitivity on shale oil productivity, the methods of conformal transformation and superposition theory of complex potential are used to deduce the productivity formula in volumetric fractured horizontal wells with start-up pressure gradient and pressure sensitivity and to calculate quantitatively the productivity of each fracture. In addition, the influence factors on productivity, such as the fracture length, number of fractures, pressure sensitivity coefficient, starting pressure gradient, and other factors, have been analyzed as well. The study results indicate that the productivity of horizontal wells decreases with the increase of the start-up pressure gradient and pressure sensitivity coefficient. With the increase of the half-length and number of fractures, the productivity of fractured horizontal wells will increase, but the amplitude of increase decreases gradually. This method can be used for productivity calculation and optimization design of the fracturing parameter in volumetric fractured horizontal wells.