多分支井连接段有限元流固耦合建模与分析  

The fluid-solid coupling modelling and analysis of the connecting section in multilateral wells

作　　者：吴欣袁[1] 练章华[1] 江文[2] 任荣坤[1] 

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室 [2]北京康布尔石油技术发展有限公司

出　　处：《石油机械》2011年第12期28-31,99,共4页China Petroleum Machinery

基　　金：国家自然科学基金项目"基于数值模拟的复杂地层地应力反演研究"(50774063)

摘　　要：侧钻分支井会对原有地层应力造成扰动,改变2个分支之间连接段的应力分布。以岩石力学为基础,考虑了各向异性的地层应力以及稳态达西渗流的影响,建立了连接段的流固耦合模型。通过对所建模型的计算得出侧钻扰动后连接段附近的应力、位移和渗流场分布规律;采用摩尔-库仑准则图形化了连接段井壁的破坏情况,并且分析了模型中各种几何参数对连接段井壁稳定性的影响。分析结果表明,由所建模型得出的井壁破坏图可以正确地预测井眼周围哪些区域会出现井壁失稳现象;改变分支井眼直径对改善分支井连接段的应力集中作用不大,对连接段的力学稳定性影响很小。The sidetracking lateral well may disturb the original formation stress, thus changing the stress distribution of the juncture, namely the connecting section between two lateral wells. On the basis of rock mechanics, the effect of the anisotropic formation stress and the steady-state Darcy flow were considered and the fluid-solid coupling model of the juncture was established in this paper. The distribution law of stress, displacement and seepage field near the juncture after sidetracking disturbance was obtained by calculating the model established. The Mohr-Coulomb criterion was adopted to diagrammatize the damage of the well wall of the juncture. The effect of the geometric parameters in the model on the stability of the juncture wall was analyzed. The findings show that the diagram of the wall damage derived by the model established can correctly predict the places around the borehole where the wall instability will occur. The effect of alteration of the lateral borehole diameter on the improvement of the stress concentration at the juncture is not remarkable and its effect on the mechanical stability of the juncture is very small.

关 键 词：分支井 井壁失稳 耦合模型 地应力 渗流场 有限元 

分 类 号：TE243[石油与天然气工程—油气井工程]