莺琼盆地高温高含CO_(2)环境水泥石腐蚀规律及机理研究  

Study on the Corrosion Pattern and Mechanism of Cement in High Temperature and High CO_(2) Environment in Yingqiong Basin

作　　者：邱康 崔强 熊振宇 王颖 范鸿飞 BasinQIU Kang;CUI Qiang;XIONG Zhenyu;WANG Ying;FAN Hongfei(SINOPEC Offshore Oilfield Services Company,Shanghai 200120,China;Southwest Petroleum University,Chengdu Sichuan 610500,China)

机构地区：[1]中石化海洋石油工程有限公司,上海200120 [2]西南石油大学,四川成都610500

出　　处：《海洋石油》2024年第2期80-83,88,共5页Offshore Oil

摘　　要：莺琼盆地部分井高压井段地层的CO_(2)含量高,针对高温高含CO_(2)条件下,水泥环强度衰退和CO_(2)腐蚀导致的水泥石强度降低规律和机理不清楚等问题。采用实验方法分析了腐蚀时间、温度、压力及CO_(2)分压等因素对水泥石的腐蚀规律的影响并分析了腐蚀机理。结果表明:随着腐蚀时间、温度、CO_(2)分压、地层压力的增加,水泥石的腐蚀深度增加,同时抗压强度降低,产生这种现象主要原因是CO_(2)溶于水后会腐蚀水泥石中的雪硅钙石和硬硅钙石,生成在潮湿的CO_(2)环境下易溶的碳酸氢钙,使得水泥石孔隙度和渗透率增大,强度降低。该研究为后续高温高压井固井水泥浆体系选择及改进提供了依据。Due to the high CO_(2) content in high-pressure sections of some wells in Yingqiong Basin,the strength degradation of cement sheath and the mechanism of strength reduction of cement caused by CO_(2) corrosion are not clear under the condition of high temperature and high CO_(2) content,the effects of corrosion time,temperature,pressure and CO_(2) partial pressure on the corrosion of cement were analyzed by experimental method,and the corrosion mechanism was analyzed.The results show that with the increase of corrosion time,temperature,CO_(2) partial pressure and formation pressure,the corrosion depth of cement increases,while the compressive strength decreases.The main reason for this phenomenon is that CO_(2) dissolved in water corrodes tobermorite and xonorite in cement,generating calcium bicarbonate which is easily soluble in moist CO_(2) environment,so that the porosity and permeability of cement increase and the strength decrease.This study provides a basis for the selection and improvement of cement slurry system for subsequent high temperature and high pressure wells.

关 键 词：水泥石 高温 高含CO_(2) 晶体转变 碳酸钙 

分 类 号：TE256[石油与天然气工程—油气井工程]