层理性页岩油储层井壁坍塌失稳区域研究  

Research on Wellbore Collapse Instability Areas in Stratified Shale Oil Reservoirs

作　　者：张海军[1] 王立辉[1] 张立刚[2] 景海全 杨衍云 曲永林[1] 刘照义 刘跃秋 Zhang Haijun;Wang Lihui;Zhang Ligang;Jing Haiquan;Yang Yanyun;Qu Yonglin;Liu Zhaoyi;Liu Yueqiu(PetroChina Dagang Oilfield Company,Tianjin 300280,China;Northeast Petroleum University,Daqing,Heilongjiang 163318,China)

机构地区：[1]中国石油大港油田分公司,天津300280 [2]东北石油大学,黑龙江大庆163318

出　　处：《特种油气藏》2024年第5期168-174,共7页Special Oil & Gas Reservoirs

基　　金：国家自然科学基金“地层岩石对钻头磨损机理及研磨性评价标准研究”(51874098)。

摘　　要：层理性页岩油储层钻井过程中井壁稳定性差,易发生井壁坍塌、卡钻等事故。为揭示层理面对页岩油储层井壁坍塌扩径的影响规律,基于MG-C强度准则和多弱面准则,构建了页岩油储层钻井井周受力数值模型和坍塌区域预测方法,计算了单一弱面和多弱面在不同应力机制下的坍塌扩径规律。研究表明:多弱面的存在使基质和弱面破坏同时发生,引发井壁坍塌形态复杂化,弱面诱发的井壁坍塌扩径要显著高于基质;相较于走滑应力机制,正应力机制下井壁坍塌随应力比变化更显著,坍塌风险更高;正应力机制下,当应力比超过1.5,井壁扩径率超过100%,且急剧增大。研究成果可为在不同区域应力机制的钻井过程中,预防页岩油储层井壁垮塌提供理论指导。During the drilling process of stratified shale oil reservoirs,if the wellbore stability is not well enough,it is prone to frequent incidents such as wellbore collapse and stuck pipe.A numerical model for the stress around the wellbore and a collapse zone prediction method in shale oil reservoir is developed to reveal the influence of bedding plane on wellbore collapse and enlargement of shale oil reservoir in accordance with MG-C strength criterion and multi-weak plane criterion.Also,the collapse and enlargement patterns for single and multiple weak planes under different stress mechanisms are calculated.The results show that the presence of multiple weak planes causes simultaneous damage to the matrix and weak planes,leading to more complex wellbore collapse patterns.While collapse expansion induced by weak planes is significantly higher than that of the matrix.Compared to the strike-slip stress mechanism,the collapse of wellbore under normal stress mechanisms shows a more significant change with stress ratio,and the collapse risk is higher.Under normal stress mechanisms,when the stress ratio exceeds 1.5,the wellbore expansion rate exceeds 100%and wellbore increases sharply.The research findings provide theoretical guidance for preventing wellbore collapse during drilling in shale oil reservoirs under different regional stress mechanisms.

关 键 词：页岩油 层理 破坏准则 井壁 坍塌卡钻 弱面 

分 类 号：TE249[石油与天然气工程—油气井工程]