摘要
随着油气向超深层和万米特深领域进军,超大尺寸井眼固井将面临套管安全下入难、易井漏、固井质量难以保证等众多难题。为此,针对万米科学探索井SDCK1井三开固井开展了系列技术攻关,攻克了超大尺寸井眼清洁困难、超大超重套管下入艰难、超大环空水泥环密封完整性难以保证等技术瓶颈,形成了万米特深井超大尺寸井眼固井成套技术。研究结果表明:①基于大尺寸井眼岩屑运移液固两相流模型优化钻井液性能和循环排量,形成的重稠浆与可降解携砂纤维多效协同井眼清洁技术可显著改善携砂效果,有效保障井筒清洁;②厚壁超重大尺寸套管的安全下入要充分考虑井眼扩大率和套管串下入阻力对通井能力和套管下入影响,模拟通井井底钻具组合(BHA)与套管柱刚度比需大于1.3;③固井施工实时模拟监测和精细控制关键层位的井筒动当量密度(ECD),优化地面回收流程返浆管线,可防止注替过程井下垮塌和漏失;④在套管居中度不高的情况下,可通过优化前置液浆柱结构,梯级匹配固井工作液流变性形成高流变级差,采用韧性水泥浆配套可固化冲洗液体系,提高顶替效率与一、二界面胶结质量。结论认为,该技术成功实现了全球首次超大井眼、超大套管、超大体量的优质固井作业,不仅为未来特深井超大尺寸套管固井提供了借鉴,而且还为特深层油气资源高效勘探开发提供了技术储备。
As oil and gas exploration and development advances into ultra-deep and 10000-m extra-deep strata,oversized borehole cementing faces multiple challenges from safe casing running,easy lost circulation and cementing quality assurance.To address these issues,this paper carries out a series of technical researches on the third-stage cementing of the 10,000-m scientific exploration well SDCK1,breaks the bottlenecks like inefficient cleaning of oversized borehole,difficult running of oversized overweight casing,and difficult seal integrity guarantee of oversized annulus cement sheath,and forms a set of cementing technologies for oversized boreholes in 10,000-m extra-deep wells.The following results are obtained.First,the performance and circulating displacement of drilling fluid are optimized based on the liquid-solid twophase flow model of cuttings migration in oversized boreholes,and the collaborative hole cleaning technology of heavy viscous slurry and degradable sand-carrying fiber can improve the sand carrying effect significantly,and thus ensure clean hole effectively.Second,to ensure the safe running of the thick-walled super-heavy large-size casing,it is necessary to give full consideration to the influences of borehole enlargement rate and casing string running resistance on drifting capacity and casing running,and the simulated stiffness ratio of drilling BHA to casing string shall be greater than 1.3.Third,simulating,monitoring and precisely controlling the wellbore equivalent circulating density(ECD)of key horizons in real time during cementing construction,and optimizing the mud return pipeline of surface recovery process can prevent downhole collapse and leakage in the process of injection and displacement.Fourth,in the case of low casing centralization,the optimization of prepad column structure can realize rheological gradient matching of cementing fluid,so as to achieve high rheological contrast,and the application of tough cement slurry with curable flush fluid system can improve the displacement efficiency and the bonding quality at the first and the second interfaces.In conclusion,this technology has successfully achieved the world's first high-quality cementing operation in oversized boreholes with oversized casing and massive cement volume,and provides valuable references for future extra-deep well cementing with oversized casing,as wells technical reserves for the efficient exploration and development of extra-deep oil and gas resources.
作者
陈力力
马勇
付强
陈敏
付志
汪瑶
冯予淇
刘强
杨万忠
邹祥富
严海兵
CHEN Lili;MA Yong;FU Qiang;CHEN Min;FU Zhi;WANG Yao;FENG Yuqi;LIU Qiang;YANG Wanzhong;ZOU Xiangfu;YAN Haibing(PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;CNPC Chuanqing Drilling Engineering Co.,Ltd.,Chengdu,Sichuan 610051,China;CCDC Downhole Service Company,Chengdu,Sichuan 610052,China;CCDC Chuanxi DrillingCompany,Chengdu,Sichuan 610051,China)
出处
《天然气工业》
北大核心
2025年第5期113-123,共11页
Natural Gas Industry
基金
中国石油天然气集团有限公司科技项目“万米超深层钻探关键工程技术与装备研制”(编号:2023ZZ20)。
关键词
万米特深井
固井技术
超大井眼
超大尺寸套管
井眼清洁
套管安全下入
压力控制
可固化
10,000-m extra-deep well
Cementing technology
Oversized borehole
Oversized casing
Hole cleaning
Safe casing running
Pressure control
Curable
