超临界CO_2钻井井筒流动规律  

Study on wellbore flow field of supercritical carbon dioxide drilling

作　　者：宋维强 倪红坚 景英华 王瑞和 沈忠厚 李斌 SONG Weiqiang;NI Hongjian;JING Yinghua;WANG Ruihe;SHEN Zhonghou;LI Bin(School of Petroleum Engineering in China University of Petroleum, Qingdao 266580, China;Research Institute of Unconventional Petroleum and Renewable Energy in China University of Petroleum Qingdao 266580, China;CNPC Xibu Drilling Engineering Company Limited (XDEC), Urumqi 830011, China)

机构地区：[1]中国石油大学石油工程学院,山东青岛266580 [2]中国石油大学非常规油气与新能源研究院,山东青岛266580 [3]中国石油西部钻探工程有限公司,新疆乌鲁木齐830011

出　　处：《中国石油大学学报（自然科学版）》2017年第6期101-107,共7页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家"973"重大专项(2014CB239202);国家博士后基金项目(2017m622315);国家自然科学基金项目(51504281);山东省自然科学基金项目(ZR201709190087)

摘　　要：考虑井筒轴向传热以及井壁围岩的温度变化对流场的影响,建立CO_2井筒循环流动模型,实现对流场压力参数、温度参数与CO_2物性参数的耦合计算与分析。结果表明:实验条件下连续管内CO_2由液态转变为超临界态的临界井深为780 m,环空中CO_2可始终处于超临界态;环空中压力剖面与井深近似呈线性相关,CO_2的压降比水的小36.7%;连续管内物性参数的变化主要由温度的变化决定,环空中则取决于压力的变化;环空中雷诺数高达106,处于较强的紊流状态;超临界CO_2钻井在窄密度窗口储层应用中具有优势。A wellbore circulation flow model was proposed to couple calculate and analyze the flow field pressure parameter,temperature parameter and physical parameter of CO2,in consideration of the influence of the axial heat transfer and the tem-perature change of sidewall rocks on the flow field.The results show that CO2turns into supercritical state at the depth of780m in the tubing and it maintains the supercritical state in the annulus under experimental conditions.The pressure in the an-nulus is approximately in linear correlation with depth.The pressure change of CO2is36.7%smaller than that of water.Inthe tubing,the temperature change dominates the changes of properties of CO2.However,the pressure change becomes thedominating factor in the annulus.The Reynolds number is as high as106in the annulus,which is in violent turbulence.Thesupercritical CO2drilling shows advantages in the exploitation of reservoirs with narrow pressure windows.

关 键 词：超临界CO2 井筒流动 传热 压力剖面 雷诺数 

分 类 号：TE242[石油与天然气工程—油气井工程]