水平井地质模型-数值模型-FSD耦合分段压裂优化研究

为解决水平井分段改造和均衡层间产气差异的难题,从岩石细观力学角度出发,建立了岩石渗流-应力-损伤耦合模型(FSD模型);考虑岩石的非均质性,应用弹性有限元法作为应力分析工具,计算分析岩石的应力场和位移场,对水压裂缝的萌生、扩展过程中渗透率演化规律及其渗流-应力耦合机制和渗流与损伤耦合机制进行模拟分析。采用基于储层特征、完井方式、流体性质及油藏数值模拟等综合信息的Multi Well Simulator开放式软件平台,通过定义损伤断裂延伸准则和FSD模型方程,可以实现油藏数值模拟和FSD动态耦合分析。以D403-2H井为例,建立地质模型-数值模型-FSD模型,对射孔参数、措施层段、分段工具位置等进行优化,对合理划分措施井段和调整产气剖面进行研究。现场应用结果表明,该技术能够有效解决层间矛盾突出的水平井的层间储量动用不均衡的问题。

Research on the Optimization of Staging Hydraulic Fracturing in Horizontal Wells through Geological Model-Numerical Model-FSD Coupling

A fluid flow-stress-damage coupling model solve the difficulty of staging reformation and making （FSD） is built on meso-meehanics of rock in order to the difference of gas production at interlamination balance.By considering the heterogeneity of the rocks,elastic finite element method,a stress field modeling tool, may be applied to calculation and analysis on rock stress field and migration field and to stimulation on the process of permeability field evolution and the mechanism of fluid flow-stress coupling and that of rock damage-fluid flow coupling during fracture initiation and propagation.The opening simulation platform Multi Well Simulator based on the comprehensive information of reservoir characteristics,well completion system,fluid properties and reservoir numerical simulation is developed.Reservoir numerical simulation and FSD dynamic coupling analysis may be realized if the fracture propagation criterion and FSD model equations have been defined.A field well D403-2H is taken as example to illustrate the workflow of building up a synthetic Geological-Numerical-FSD （GNF） model.Perforation parameters,simulated layer selection and fracturing tool locations and other key fracturing parameters are optimized in order to stage the horizontal well and adjust gas rate profile.The practical application demonstrates that this technology can solve the problem of unbalancing gas production from different layers in the horizontal wells.