含H2S天然气井溢流动态模拟  

Dynamic Simulation of Overflow in H2S-containing Natural Gas Well

作　　者：毛良杰[1] 蔡明杰 文小勇 夏宏伟 MAO Liang-jie;CAI Ming-jie;WEN Xiao-yong;XIA Hong-wei(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;Chuanqing Drilling Engineering Co.Ltd Sichuan West Drilling Co.,Ltd,Chengdu 610051,China;Southwest Oil and Gas Field Company,Engineering Technology Institute,CNPC,Guanghan 618399,China)

机构地区：[1]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500 [2]川庆钻探工程有限公司川西钻探公司,成都610051 [3]中国石油天然气股份有限公司西南油气田分公司工程技术研究院,广汉618399

出　　处：《科学技术与工程》2020年第25期10219-10224,共6页Science Technology and Engineering

基　　金：四川省科技计划(2019YFS0045)。

摘　　要：考虑H 2S在井筒中的相态变化,建立了含H 2S气井井筒动态溢流模型,同时采用有限差分法对模型进行求解,结合四川某含H 2S天然气井现场数据模拟含H 2S天然气井溢流过程,并将模拟结果与不含H 2S气井进行对比分析。研究结果表明:随着温度和压力的降低,H 2S在上部地层井段发生相变并直接引起气体体积的膨胀。含气率的突增使钻井液池增量迅速增加,且在相同的溢流时间内,关井时刻钻井液池增量增加更明显。含H 2S气井井筒内气体膨胀更迅速,导致环空压力下降更快,环空流型转化更加迅速。此外,井底压力下降更快,关井套压迅速增加,进一步加剧了溢流程度。因此,含H 2S气井井喷预警时间急剧缩短,井控难度和井喷危险大大增加。Considering the change in phase state of H 2S in wellbore,a dynamic overflow model of H 2S-containing gas well was established.The model was solved using the finite difference method in the MATLAB program,and combined with field data to simulate the overflow process of a H 2S-containing natural gas well in Sichuan Province,SW China.The simulation results were compared with H 2S-free gas well.Results show that with the decrease of temperature and pressure,H 2S changed the phase in the upper stratum and directly caused expansion in gas volume.The sudden increase of gas void fraction caused rapid increase of pit gain,and the increase of pit gain was more obvious at the time of shut-in in the same overflow time.The gas expansion in the wellbore of H 2S-containing gas well was accelerated,resulting in faster reduction of annular pressure and faster transformation of annular flow pattern.In addition,the well bottom pressure decreased faster and the shut-in casing pressure increased rapidly,which further promoted the overflow.Therefore,the warning time of H 2S gas well blowout could be shortened sharply,and the difficulty of well control and blowout danger be increased greatly.

关 键 词：H2S 天然气井 溢流 动态模拟 

分 类 号：TE249[石油与天然气工程—油气井工程]