川渝地区天然气井深井固井工程复杂案例分析  

Cementing complexity in deep natural gas wells,Sichuan-Chongqing area

作　　者：伍葳 刘成[1] 蒲俊余[1] 夏连彬 李斌[2] 吴坷[1] Wu Wei;Liu Cheng;Pu Junyu;Xia Lianbin;Li Bin;Wu Ke(Exploration Division,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China;Engineering Technology Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610017,China)

机构地区：[1]中国石油西南油气田公司勘探事业部 [2]中国石油西南油气田公司工程技术研究院

出　　处：《天然气勘探与开发》2020年第4期98-105,共8页Natural Gas Exploration and Development

基　　金：中国石油天然气股份有限公司重大科技专项"西南油气田天然气上产300亿立方关键技术研究与应用——四川盆地高温高压含硫深井超深井钻井、完井及试油技术研究与应用"(编号:2016E-0608)。

摘　　要：深井固井作业面临岩性复杂、井筒高温、油气水显示活跃、同裸眼段多压力系统等诸多挑战。针对川渝深井固井复杂案例展开全过程梳理剖析,表明应从4个方面予以重视:①工程设计时应优选井身结构,必要时启用非标套管层次,充分考虑复杂地质条件下的载荷与腐蚀,合理套管选型,利用软件模拟预判摩阻及屈曲可能性并制订措施;②套管下入要重视通井作业,强化井眼准备,简化套管串及附件,保证尾管送入钻具的可靠性,摩阻扭矩过大时考虑油基钻井液;③固井工艺方面,长裸眼段需设计多凝水泥浆体系,多压力系统地层采用精细控压技术,"三高"气井需加装管外封隔器,加强候凝失重机理研究;④固井工作液需加强水泥浆韧性改造,提高水泥石防气窜能力,尾管悬挂器及套管鞋井段应采用常规密度水泥浆体系,注重水泥石的高温力学稳定性,合理控制固井工作液及污染情况下的稠化时间、凝固时间。结论认为:深井固井作业需紧密结合地质与工程特点,系统性考虑固井工程相关环节,避免固井复杂以确保固井施工安全及封隔有效。Cementing practices in deep wells are faced with many challenges,e.g.complex lithology,high wellbore temperature,active oil,gas,and water show,and multiple pressure systems co-existing in the same interval.So,the whole process of cementing complexity in deep wells in Sichuan-Chongqing area were analyzed.And it is indicated that attention shall be paid from the following four aspects.First,casing program shall be optimized during engineering design.And if necessary,the non-standard casing program can be adopted.It is necessary to give full consideration to load and corrosion in the condition of complex geology,select the casing type reasonably,simulate and predict the friction and yield possibility by using some software,and formulate the measures.Second,in the process of casing running,it is necessary to pay attention to well drifting,strengthen borehole preparation,simplify casing string and its accessories,and ensure the reliability of drill string during liner cementing.And if both drag and torque are too high,it is recommended to adopt oil-based drilling fluid.Third,speaking of cementing process,it is necessary to design multi-setting cement slurry system for long interval,adopt fine managed pressure technology to certain formation with multiple pressure systems,install an external casing packer in"three-high"gas wells,and strengthen a study on wait-on-cement weight loss mechanisms.Fourth,as for cementing fluid,it is necessary to strengthen the modification of slurry toughness,improve the anti-gas channeling capacity of set cement,adopt the conventional-density cement slurry system in the intervals of liner hanger and casing shoe,pay attention to the mechanical stability of set cement under high temperature,and reasonably control the cementing fluid and its thickening time and wait-on-cement time under contamination.In conclusion,these cementing practices in deep wells shall be closely based on geological and engineering characteristics,and it is also necessary to systematically consider the related links of

关 键 词：深井 固井 下套管 钻具刺漏 超缓凝 环空带压 

分 类 号：TE256[石油与天然气工程—油气井工程]