摘要
针对超深井长封固固井中,顶部底部水泥浆温差大,顶部低温段水泥浆超缓凝、水泥石强度发展缓慢的问题,采用水溶液聚合法制备了一种MgAl-EDTA-LDH(EDTA插层型水滑石)大温差早强剂,并配套形成了一套大温差水泥浆体系。实验结果表明,该大温差早强剂具有一定的缓凝效果,当其加量为2.0%,复配4.0%缓凝剂时,在240℃下其稠化时间可达509 min。该水泥浆在60℃养护1 d和30℃下养护6 d的抗压强度均大于7 MPa,最大温差为210℃。大温差早强剂在不影响水泥浆稠化可调性的前提下,有利于低温段水泥浆柱的强度发展,耐热温度达300℃以上,适用于大温差固井需求。
In cementing operation in ultradeep wells with long cementing sections,there is a large difference between the temperature at the top of the cement slurry and that at the bottom of the cement slurry.The low temperature at the top of the cement slurry retards the development of the strength of the set cement.To solve this problem,an early strength additive named EDTA-LDH(EDTA intercalated hydrotalcite)was developed through water solution polymerization.A cement slurry for working at big temperature difference conditions was formulated with EDTA-LDH.Laboratory experimental results show that this early strength additive has retarding effect to some extent;at a concentration of 2.0%EDTA-LDH and 4.0%retarder,a cement slurry has thickening time of 509 min at 240℃.After aging at 60℃for 1 d or at 30℃for 6 d,the cement slurry has compressive strengths of both greater than 7 MPa,and experiences maximum temperature difference of 210℃.The use of EDTA-LDH is beneficial to the development of the strength of the cement slurry column in low temperature without affecting the adjustability of the thickening time of the cement slurry.This early strength additive can work normally at temperatures above 300℃,and is suitable for cementing wells with large temperature differences.
作者
刘景丽
刘平江
任强
刘岩
彭松
曹洪昌
张文阳
程小伟
LIU Jingli;LIU Pingjiang;REN Qiang;LIU Yan;PENG Song;CAO Hongchang;ZHANG Wenyang;CHENG Xiaowei(Bohai Drilling Engineering Technology Research Institute,Tianjin 300451;Bohai Drilling First Cementing Company,Renqiu,Hebei 062552;State Key Laboratory of Reservoir Geology and Development Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500)
出处
《钻井液与完井液》
CAS
北大核心
2023年第6期778-786,共9页
Drilling Fluid & Completion Fluid
基金
中国石油天然气集团有限公司科技重大项目“万米超深层钻探关键工程技术与装备研制”(2023ZZ20)。
关键词
大温差
固井
水泥浆
早强剂
万米深井
Large temperature difference
Well cementing
Cement slurry
Early strength for large temperature difference
Well of ten thousand meter deep
