摘要
针对CCUS/CCS井高浓度CO_(2)环境下传统硅酸盐水泥体系易腐蚀、强度衰减、环空密封失效等问题,开发了一种低碳型地质聚合物水泥浆体系。该水泥浆体系以粉煤灰、矿渣等固体废物为基材,通过草酸钠与氢氧化钙反应生成的缓释型激活剂替代传统氢氧化钠,构建出具有稠化性能可调控、抗腐蚀能力强的新型胶凝体系。通过筛选外加剂,优化了水泥浆的流变性和耐腐蚀性。实验表明,该水泥浆体系在70℃~120℃下稠化时间可控,密度为1.85 g/cm^(3),24 h抗压强度可达40 MPa,弹性模量为6.5 GPa。经30 d CO_(2)腐蚀后水泥石强度无衰退,渗透率增长仅为9%。现场应用于5口CCUS井,固井质量全部达标。研究成果为高腐蚀环境下的固井体系优化提供了新思路和工程实践依据。
Conventional silicate cement in CCUS/CCS wells is easy to be corroded by the high concentration of CO_(2),resulting in cement strength deterioration and failure of sealing in annular spaces.To deal with this problem,a low-carbon geopolymer cement slurry was developed.This cement slurry was formulated with solid wastes such as fly ash and slag as the basic materials,and a controlled-release activator produced by the reaction of sodium oxalate and Ca(OH)2 was used in the cement slurry to replace the commonly used NaOH.This new cement slurry has adjustable thickening performance and strong resistance to corrosion.The rheology and the corrosion resistance of the cement slurry are optimized with carefully selected additives.Experimental results show that this cement slurry,with its density being 1.85 g/cm^(3),has controllable thickening time at temperatures between 70℃and 120℃,24 h compressive strength of 40 MPa and elastic modulus of 6.5 GPa.After corrosion by CO_(2) for 30 d,the strength of the set cement does not decline,and the permeability of the set cement increases only by 9%.Five CCUS wells were cemented with this cement slurry,and the job quality all met the standards.The results of this study provide new ideas and engineering practice bases for optimizing the well cementing system used in a highly corrosive environment.
作者
高飞
任孟
郭宇程
田宝振
费中明
郭胜来
董三宝
GAO Fei;REN Meng;GUO Yucheng;TIAN Baozhen;FEI Zhongming;GUO Shenglai;DONG Sanbao(The First Cementing Branch of CNPC Bohai Drilling Engineering Company Limited,Renqiu,Hebei 062552;School of Petroleum Engineering,China University of Petroleum(East China),Qingdao,Shandong 266580;College of Chemistry and Chemical Engineering of Xi'an Shiyou University,Xi'an,Shaanxi 710065)
出处
《钻井液与完井液》
北大核心
2025年第5期665-671,共7页
Drilling Fluid & Completion Fluid
基金
中国石油集团渤海钻探工程有限公司项目“CCUS/CCS井配套低碳型地质聚合物水泥浆体系研究”(2022D53F)。
