基于ABAQUS的径向井井壁稳定性分析

Stability analysis of ultra-short radius radial wells using ABAQUS finite element method

 刘晓强¹ 张习斌¹ 许鹏¹ 常琨² 苏程³ 朱金鑫⁴

中国石油大学（华东）石油工程学院，山东 青岛 266580 中国石化华北油气分公司石油工程监督中心，河南 郑州 450000 中国石化华北油气分公司勘探开发研究院，河南 郑州 450000 中国石油青海油田公司钻采工艺研究院，甘肃 敦煌 736200）

College of Petroleum Engineering, China University of Petroleum, Qingdao 266580, China Petroleum Engineering Supervision Center, Huabei Company, SINOPEC, Zhengzhou 450000, China Research Institute of Exploration and Development, Huabei Company, SINOPEC, Zhengzhou 450000, China Drilling and Production Research Institute, Qinghai Oilfield Company, PetroChina, Dunhuang 736200, China)

 基于岩石力学相关理论，依据Mohr?鄄Coulomb准则，建立了多分支径向井井壁稳定力学模型，并采用有限元数值模拟方法对力学模型进行了验证，结果表明该模型具有较高的准确度。基于ABAQUS有限元数值模拟，依次研究径向井方位角、地层最大主应力与最小主应力压差（地应力差）、弹性模量、泊松比、径向井孔径等因素对三分支径向井井壁稳定性的影响。研究结果表明：多分支径向井井壁稳定性受地应力差和径向井孔径的影响较大；径向井眼的跟端和中段易存在明显的应力集中，是井眼防塌的关键区域；径向井方位角、弹性模量和泊松比对径向井井壁稳定性的影响较小，在一定范围内径向井井壁处于力学稳定状态。

 Based on the theory of rock mechanics and principle of Mohr-Coulomb, a mechanical model for bore stability of multi-branch ultra-short radius radial well is established. Compared with the model deduced by the finite element method simulation, the mechanical model for bore stability has a high accuracy. Based on ABAQUS finite element numerical simulation, azimuthal angle of the ultra-short radius radial well, pressure difference between the maximum principal stress and the minimum principal stress, Young′s modulus, Poisson′s ratio and the hole diameter are taken into consideration to analyze the effects on the stability of ultra-short radius radial wells. According to the results, the stability of the borehole is dramatically affected by the pressure difference and the hole diameter. The end and the central of the ultra-short radius radial well have distinctly stress concentration, which are the key zones of anti-collapse. Azimuthal angle, Young′s modulus and Poisson′s ratio have relatively little influence on the stability of the hole.

10.6056/dkyqt201604025