渤中火成岩井壁失稳因素研究  

Study on Wellbore Instability Factors of Igneous Rock Formation in Bozhong

作　　者：任鹏举 刘峰 韩东东 李大伟 向良炜 吕广 赵海建 REN Pengju;LIU Feng;HAN Dongdong;LI Dawei;XIANG Liangwei;LYU Guang;ZHAO Haijian(CNOOC Energy Development Co.,Ltd.,Engineering Technology Branch,Tianjin 300452,China;CNOOC(China)Co.,Ltd.,Tianjin 300452,China)

机构地区：[1]中海油能源发展股份有限公司工程技术分公司 [2]中海石油(中国)有限公司天津分公司

出　　处：《钻采工艺》2024年第3期23-32,共10页Drilling & Production Technology

基　　金：国家科技重大专项“渤海油田高效钻完井及配套技术示范”(编号:2016ZX05058-002)。

摘　　要：渤中A油田位于渤海油田渤中区块,是渤海油田首次开发火成岩发育地层的油田。但由于火成岩地层在钻进过程中易塌、易漏,严重制约钻井时效,文章基于测井数据、物理实验和钻井复杂现象,对渤中A油田的火成岩地层进行了精细划分与详细描述,对不同火成岩地层的复杂现象进行了对应分析;并通过有限元分析,分析了弹性模量、泊松比、钻井液密度和井斜角等对井壁稳定性的影响。研究发现,该区域的玄武岩、凝灰岩和凝灰质砂泥岩均存在黏土矿物,且多充填于岩石裂缝中;玄武岩多发育闭合裂缝,凝灰岩和凝灰质砂泥岩发育为开启缝,凝灰岩和凝灰质砂泥岩发育的裂缝较宽,且连通性更好,这也导致玄武岩以坍塌掉块为主,凝灰岩和凝灰质砂泥岩以漏失为主;数值模拟证明,玄武岩弹性模量较大,泊松比较小,在钻井液浸泡下更倾向于发生坍塌,凝灰岩和凝灰质砂泥岩更容易诱发漏失。最后,基于上述分析提出了对应的技术措施,并在现场应用中取得了良好的生产效果。Bozhong A Oilfield,located in the Bozhong Block of Bohai Oilfield,is the first oilfield to develop igneous rock formation in Bohai Oilfield.The igneous rock formation is prone to collapse and leakage during drilling,which seriously restricts drilling aging.Based on well logging data,physical experiments and drilling complex phenomena,the igneous strata of Bozhong A oilfield are finely divided and described in detail,and the complex performance of different igneous strata is analyzed accordingly in this article.Through finite element analysis,the influences of elastic modulus,Poisson′s ratio,drilling fluid density and well inclination angle on wellbore stability are analyzed.The results show that there are clay minerals in basalt,tuff and tuffaceous sand and mudstone,and most of them are filled in rock fractures.Among them,basalt mostly developed closed fractures,tuff and tuffaceous sand-mudstone developed as open fractures,tuff and tuffaceous sand-mudstone developed wider fractures and better connectivity,which also resulted in basalt mainly collapsed block,tuff and tuffaceous sand-mudstone mainly leakage;Numerical simulation also proves that basalt has a large elastic modulus and a small Poisson ratio,so it is more likely to collapse under drilling fluid immersion,and tuff and tuffaceous sand mudstone are more likely to induce leakage.Finally,corresponding technical measures are put forward based on the above analysis,and good production results have been achieved in field application.

关 键 词：火成岩 渤中区块 井壁稳定性 力学机理 钻进措施 

分 类 号：TE5[石油与天然气工程—油气田开发工程]