济阳坳陷油页岩力学性能特征实验  

Experimental on Mechanical Properties Characteristics of Oil Shale in Jiyang Depression

作　　者：王爱民[1] 王发明 贺文卿 王帅 刘厚彬[2] Wang Aimin;Wang Faming;He Wenqing;Wang Shuai;Liu Houbin(Sinopec Shengli Oilfield Company,Dongying,Shandong 257000,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China)

机构地区：[1]中国石化胜利油田分公司,山东东营257000 [2]西南石油大学油气藏地质及开发工程国家重点实验室,四川成都610500

出　　处：《特种油气藏》2023年第5期144-150,共7页Special Oil & Gas Reservoirs

基　　金：国家自然科学基金“干热岩型地热泡沫钻井流体相变行为下井筒温度压力响应特性研究”(52174008)。

摘　　要：济阳坳陷页岩油勘探开发成效显著,但大斜度水平井井壁垮塌异常突出,多次引发井下阻卡,甚至埋钻事故。针对上述问题,通过岩石力学室内系列实验研究油页岩力学性能与崩塌破坏规律,剖析油页岩水平井井壁失稳机理与主控因素。研究表明:油页岩岩体裂缝极为发育,主要为近平行低角度层理缝,伴有高角度交叉缝,岩体破碎程度高;油页岩力学参数各向异性特征明显,当井壁最大主应力与层理缝垂直时,井壁整体力学强度最大,随着井壁最大主应力与层理缝面夹角减小,井壁力学强度呈减小趋势,当夹角为60°左右时力学强度最低,井壁稳定性最差;济阳坳陷油页岩整体力学强度低,井下应力环境下抗压强度最大值为165 MPa,最低仅为52 MPa;油页岩岩体破坏方式存在差异,当井壁最大主应力与层理缝面夹角较小时,以沿层理缝间剪切滑移破坏为主,反之为油页岩基岩剪切破坏。济阳坳陷油页岩井壁失稳作用机理研究成果可为油页岩大斜度水平井井壁稳定性预测及工程参数优化设计提供支撑。The exploration and development of shale oil in Jiyang Depression had achieved remarkable results,but the wall collapse of highly deviated horizontal wells was extremely prominent,which has repeatedly caused downhole jamming and even drilling accidents.In response to the problems above,the mechanical properties of oil shale and collapse damage law were studied through a series of indoor experiments on rock mechanics,and the mechanism and main control factors of oil shale horizontal wellbore destabilization were analyzed.The study shows that the oil shale rock fractures are extremely developed,mainly of the subparallel low-angle bedding fractures,accompanied by high-angle cross fractures,and the rock fragmentation is high;the mechanical parameters of oil shale have obvious anisotropy characteristics.When the maximum principal stress of the wellbore is perpendicular to the bedding fractures,the overall mechanical strength of the wellbore is the highest,and as the angle between the maximum principal stress and the bedding fractures decreases,the mechanical strength of the wellbore tends to decrease,and when the angle is about 60°,the mechanical strength is the lowest,and the wellbore stability is the worst.The overall mechanical strength of the oil shale in Jiyang Depression is low,and the maximum compressive strength under downhole stress is 165 MPa,and the lowest is only 52 MPa;there is a difference in the damage mode of the oil shale rock,when the angle between the maximum principal stress and the bedding fracture surface in the wellbore is small,the main damage is the shear slip damage along the bedding fracture,otherwise,the main damage is the oil shale bedrock shear damage.The study results of the destabilization mechanism of oil shale wellbore in Jiyang Depression can provide support for the prediction of wellbore stability and the optimal design of engineering parameters for the highly deviated horizontal wells in oil shale.

关 键 词：济阳坳陷 油页岩 力学强度各向异性 钻井液浸泡作用 

分 类 号：TE311[石油与天然气工程—油气田开发工程]