Optimal installation of horizontal wells in the low-permeable anisotropic oil reservoirs

Abstract

Purpose. Investigation of the optimal placement of horizontal wells in the low-permeable anisotropic oil reservoirs to increase oil production. The method of investigation. Thenumerical modeling of pressure distribution around a horizontal wells in the low-permeable anisotropic oil reservoirs is carried out using a combined finite-element-difference method. Results. Analysis of the obtained results shows for effective using of anisotropic hard reaching oil reservoirs, it is necessary to place horizontal production wells in the areas with relatively low anisotropy of the reservoir permeability, especially avoiding places with the presence of reservoir’s shear permeability. At the placing of horizontal wells in the low-permeable anisotropic reservoirs, the most effective is the diagonal installation near themainaxes of the reservoir’s permeable anisotropy. The originality. Based on numerical modeling using the combined finite-element-difference method, we have firstly established that, for effective use of low-permeable anisotropic, hard-reaching oil reservoirs, it is necessary to avoid places with the presence of reservoir’s shear permeability and place horizontal production wells in the diagonal direction relatively the main axes of the reservoir’s permeable anisotropy. This ensures a uniform approach of oil to the well from all possible directions and contributes to increasing the oil recovery from the reservoir. Practical implementation. Theresults obtained show that the intensity of the filtration processes around horizontal wells and, accordingly, the increase in oil production significantly depends on its location in the low-permeable anisotropic oil reservoir. The combined finite-element-difference method can solve various practical problems in hard-reaching heterogeneous low-permeable oil reservoirs.