基于节点网络的水平井分段流入剖面预测方法

随着水平井分段完井技术的发展，完井结构变得越来越复杂，为了准确模拟水平井分段完井流入剖面，研究了基于节点网络的水平井分段流入剖面预测方法。将完井结构简化为由地层、井壁与完井工具间的环空、完井工具构成的水平井井筒网络，基于物质守恒原理和动量守恒定理，建立了各类流动桥的压降模型；用桥流动指数来表征流体流动方向，建立了耦合地层、井壁与完井工具间的环空、完井工具三者之间的流体流入剖面预测模型，并采用Newton–Raphson迭代方法进行了求解。算例分析表明，应用该方法可预测水平井复杂完井结构的环空、油管中的压力和流量分布，准确反映完井方式和完井工具对井筒流体流入剖面的影响，且具有较高的预测精度。研究认为，建立的水平井分段流入剖面模型可为完井方式选择、参数优化设计提供理论支撑。 

A Dynamic Prediction Method for Segmental Flow Performance in Horizontal Wells Based on Node Networks

The dynamic prediction of segmental flow performance in horizontal wells is the basis for analyzing the adjustment effect of wellbore fluid inflow in different completion methods and the production performance of different well sections. The completion structure can be simplified into a three-layer node network composed of the formation, the annulus between borehole wall and completion tools, and completion tools. Based on the principle of mass conservation and the theorem of momentum conservation, the pressure drop model of various flow bridges was established. The bridge flow index was used to characterize the direction of fluid flow, and with the performance prediction model of the fluid flow in the coupling formation, the above mentioned annulus and the completion tools were further established. Finally, the Newton–Raphson iterative method was used to find the solution. The analysis on the calculation example showed that this model is able to predict the annulus, pressure and flow distribution in the tubing in horizontal wells with complex completion structure, and it can effectively reflect the impact of completion mode and completion tools on the fluid flow performance of the wellbore, with higher prediction precision. The established model can provide theoretical supports for the selection of segmental completion method and parameters for best practices for the optimization design of horizontal wells.