天然气工业2025，Vol.45Issue(5)：113-123,11.DOI:10.3787/j.issn.1000-0976.2025.05.010
超大尺寸井眼固井关键技术探索与实践
Exploration and practice of key cementing technologies for oversized boreholes:A case study of Well SDCK1,a 10 000-m extra-deep well
摘要
Abstract
As oil and gas exploration and development advances into ultra-deep and 10 000-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 two-phase 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.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Key words
10,000-m extra-deep well/Cementing technology/Oversized borehole/Oversized casing/Hole cleaning/Safe casing running/Pressure control/Curable分类
能源科技引用本文复制引用
陈力力,邹祥富,严海兵,马勇,付强,陈敏,付志,汪瑶,冯予淇,刘强,杨万忠..超大尺寸井眼固井关键技术探索与实践[J].天然气工业,2025,45(5):113-123,11.基金项目
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). （编号:2023ZZ20）
