水合物储层钻井水合物分解及井眼坍塌分析  

Hydrate Dissociation and Wellbore Collapse Analysis in Hydrate Reservoir Drilling

作　　者：李庆超 王威 王义顷 孙晓东 Li Qingchao;Wang Wei;Wang Yiqing;Sun Xiaodong(School of Energy Science and Engineering,Henan Polytechnic University;College of Petroleum Engineering,Guangdong University of Petrochemical Technology;Guangdong Research Center for Unconventional Energy Engineering Technology;Sinopec Petroleum Machinery Co.,Ltd.;College of Continuing Education,China University of Petroleum(Huadong))

机构地区：[1]河南理工大学能源科学与工程学院,河南省454000 [2]广东石油化工学院石油工程学院 [3]广东省非常规能源工程技术研究中心 [4]中石化石油机械股份有限公司 [5]中国石油大学(华东)继续教育学院

出　　处：《石油机械》2021年第6期43-50,共8页China Petroleum Machinery

基　　金：国家重点研发计划项目“海洋天然气水合物试采技术和工艺”(2016YFC0304005);国家重点基础研究发展计划(973计划)项目“海洋深水油气安全高效钻完井基础研究”(2015CB251201);青岛市科技计划项目“天然气水合物开发储层失稳机制及控制技术研究”(15-9-1-55-jch);广东石油化工学院人才引进项目(2018rc08)。

摘　　要：南海泥质细粉砂水合物储层钻井过程极易发生井眼坍塌和扩径,威胁水合物钻采安全。鉴于此,利用Fortran语言并结合水合物分解动力学理论,编写了用以实现水合物钻井过程井周水合物相变分解和分解前缘动态移动的DISSOCIATION子程序,并开展了钻井液扰动效应试验以验证DISSOCIATION子程序的有效性,在此基础上探究了水合物分解对井眼屈服坍塌的影响。研究结果发现:尽管钻井液扰动效应试验中水合物分解到3个探针位置所用时间均小于数值模拟结果,但与模拟结果均相差极小;当考虑水合物分解时井眼扩大率为50.25%,而忽略水合物分解时井眼扩大率则仅为19.23%,为考虑水合物分解时的38.27%。所编制的DISSOCIATION子程序可用于水合物储层钻井井壁失稳的多场耦合数值模拟,且水合物储层钻井井眼稳定性分析务必要考虑水合物相变分解的影响。Wellbore collapse and hole enlargement are easy to occur during drilling argillaceous fine silt hydrate reservoir in the South China Sea,which threatens the safety of drilling and exploitation of hydrate.In order to solve this problem,combined with the hydrate dissociation dynamic theory,the Fortran language was used to compile the DISSOCIATION subroutine for simulating the hydrate phase change dissociation around wellbore and the dynamic movement of the dissociation front during the hydrate drilling process;moreover,the disturbing effect test of drilling fluid was carried out to verify the effectiveness of the DISSOCIATION subroutine;on the basis of which,the influence of hydrate dissociation on the wellbore yield collapse analysis was studied.The study results show that although the time for the hydrate to decompose to the 3 probe positions in the drilling fluid disturbance effect experiment is less than the numerical simulation results,it is very close to the simulation results;when the hydrate dissociation is considered,the borehole enlargement rate is 50.25%,and when the hydrate dissociation is ignored,the borehole enlargement rate is only 19.23%,which is 38.27%of the borehole enlargement rate when the hydrate dissociation is considered.The compiled DISSOCIATION subroutine can be used for multi-field coupling numerical simulation of wellbore instability in drilling hydrate reservoir,and the wellbore stability analysis in drilling hydrate reservoir must consider the effect of hydrate phase change dissociation.

关 键 词：水合物储层 钻井液扰动 井眼坍塌 分解前缘 相变分解 

分 类 号：TE52[石油与天然气工程—油气田开发工程]