The productivity evaluation model and its application for finite conductivity horizontal wells in fault block reservoirs

It is very difficult to evaluate the productivity of horizontal wells in fault block reservoirs due to the influence of fault sealing. On the basis of the method of images and source-sink theory, a semianalytical model coupling reservoir and finite conductivity horizontal wellbore flow dynamics was built, in which the influence of fault sealing was taken into account. The distribution of wellbore flow and radial inflow profiles along the horizontal interval were also obtained. The impact of the distance between the horizontal well and the fault on the well productivity was quantitatively analyzed. Based on this analysis, the optimal distance between the horizontal well and the fault in banded fault block reservoirs could be determined. According to the field application, the relative error calculated by the model proposed in this paper is within ±15%. It is an effective evaluation method for the productivity of horizontal wells in fault block reservoirs. The productivity of the horizontal well increases logarithmically as the distance between the horizontal well and the fault increases. The optimal distance between the horizontal well and the fault is 0.25–0.3 times the horizontal well length.