地面氮气抽吸作业气体流动规律研究  

Study on the Gas Flow Law of Ground Nitrogen Extraction Operation

作　　者：许期聪 李中权 姚舜 XU Qicong;LI Zhongquan;YAO Shun(Drilling and Production Engineering Technology Research Institute,CNPC Chuanqing Drilling Engineering Co.,Ltd.,Guanghan,Sichuan 618300,China;National Energy Research and Development Center for High Sour Gas Reservoir Exploitation,Chengdu,Sichuan 610051,China;China Petroleum Underbalance and Gas Drilling Test Base,Guanghan,Sichuan 618300,China;Downhole Operation Company,CNPC Chuanqing Drilling Engineering Co.,Ltd.,Chengdu,Sichuan 610051,China)

机构地区：[1]中国石油川庆钻探工程有限公司钻采工程技术研究院 [2]国家能源高含硫气藏开采研发中心 [3]中国石油欠平衡与气体钻井试验基地 [4]中国石油川庆钻探工程有限公司井下作业公司

出　　处：《钻采工艺》2023年第3期1-8,共8页Drilling & Production Technology

基　　金：中国石油天然气集团有限公司科学研究与技术开发项目“水平井优质高效钻完井技术研究”课题“气体钻水平井/侧钻水平井技术研究”(编号:2021DJ4205)。

摘　　要：储层氮气钻完井是致密砂岩等低渗气藏储量有效动用和产能释放的革命性技术之一。储层氮气钻完井作业期间,起下钻及下完井管串过程中,井口处于敞开状态,此时采用地面氮气抽吸技术,有控制地“引导”地层产出的天然气流向排砂管线出口进行处理。为此,文章基于数值仿真方法,系统研究了敞井条件下地面氮气抽吸作业时的气体流动规律,考虑天然气的扩散现象,建立了气体流动模型,并定量分析了影响氮气抽吸效果的主要因素。研究表明,氮气抽吸效果主要受注入方式、氮气抽吸气量、抽吸装置安装位置、排砂管线长度和天然气产量的影响。同心注气方式相较于斜插注气方式具有更好的抽吸效果;低抽吸气量下,氮气注入量越大,抽吸率越高,随着抽吸气量持续增加,抽吸率达到峰值后有所下降;抽吸装置距离排砂管线出口越近、排砂管线越短、地层产气量越低,抽吸效果越好,实现完全抽吸所需的临界抽吸气量越低。文章研究成果为优化氮气抽吸工艺设计、保障储层氮气钻完井敞井条件下的安全作业提供了理论支撑,并在四川大塔场气田进行了现场应用,实现了储层氮气钻完井作业敞井条件下地层产出天然气100%的抽吸,确保了作业安全。Nitrogen drilling and completion of reservoirs is one of the revolutionary technologies for effectively utilizing reserves and releasing production capacity in low-permeability gas reservoirs such as tight sandstones.During the nitrogen drilling and completion operation of the reservoir,the wellhead is in an open state during the tripping and completion of the well string.At this time,it is necessary to use the wellhead nitrogen suction technology to control the flow of natural gas produced by the formation to the outlet of the sand discharge pipeline for treatment.Therefore,based on numerical simulation methods,the article systematically studied the gas flow law during nitrogen suction operation under open well conditions,considered the diffusion phenomenon of natural gas,established a gas flow model,and quantitatively analyzed the main factors affecting the nitrogen suction effect.Research has shown that the effectiveness of nitrogen suction is mainly influenced by injection method,nitrogen suction volume,installation position of suction device,length of sand discharge pipeline,and natural gas production.The concentric injection method has better suction effect compared to the oblique insertion injection method;under low suction volume,the larger the nitrogen injection volume,the higher the suction rate.As the suction volume continues to increase,the suction rate reaches its peak and then decreases;the closer the suction device is to the outlet of the sand discharge pipeline,the shorter the sand discharge pipeline,and the lower the gas production of the formation,the better the suction effect,and the lower the critical suction volume required to achieve complete suction.The research results provide theoretical support for optimizing the design of nitrogen suction process and ensuring safe operation under open well conditions for nitrogen drilling and completion in reservoirs.They have been applied on-site in Sichuan Datachang Gas Field,achieving 100%suction of natural gas produced in the formation under open we

关 键 词：氮气钻完井 起下钻 完井管串 氮气抽吸技术 抽吸装置 抽吸注气量 

分 类 号：TE37[石油与天然气工程—油气田开发工程]