底水油藏水平井分段完井产能预测

Productivity Prediction of Bottom-Water Drive Reservoir in Partially Completion Horizontal Well

在分析分段完井渗流机理的基础上,根据质量守恒原理及动量定理推导出了水平井分段完井井筒压降计算模型,并引入了一个修正的壁面摩擦系数,可以准确计算分段后各微元段的压降。针对底水油藏类型,根据势的叠加原理导出了单相原油三维稳态渗流的压力分布公式,再结合分段压降模型,建立了油藏渗流与井筒流动耦合产能预测模型。实例计算表明:用此模型计算水平井分段完井产能,精度高,通过迭代求解可获得沿井筒长度的流率分布和压降分布,从而为生产段和盲管组合方案的优化设计和水平井长度优化等方面提供理论依据。

This paper deduced a pressure drop calculation model based on the analysis ot the percolation mechanism and the principle of conservation of mass and momentum theorem. It also introduced a modified skin friction coefficient to calculate accurately the pressure drop of each infinitesimal section after partition. In addition, it deduced the three-dimensional steady-state seepage potential distribution and stress distribution formula according to the type of the bottom-water drive reservoir and the potential of superposition principle and mirror image principle. Then it established the three-dimensional steady-state hydromechanical coupling productivity prediction model. The actual calculation of the horizontal wells after the partially completion proves that this model can be more precise in calculating the production capability. The distribution of the flux and pressure along the well in the constant rate production can be obtained by iterative solution. The model provides a basis for partially completion and horizontal well length optimization.