CCUS井工况下不同引晶材料对水泥石裂缝自愈合过程的影响  

Comparative Study on Effects of Different Crystallographic Materials on Self-healing of Fractures in Set Cement under CCUS Well Work Conditions

作　　者：饶志华 邓成辉 马倩芸 武广瑷 武治强 程小伟[4] RAO Zhihua;DENG Chenghui;MA Qianyun;WU Guang'ai;WU Zhiqiang;CHENG Xiaowei(CNOOC Shenzhen Company,Shenzhen,Guangdong 518052;Engineering Technology Research Institute BHDC,Tianjin 300450;CNOOC Research Institute Co.,Ltd.,Beijing 100028;School of New Energy and Materials,Southwest Petroleum University,Chengdu,Sichuan 610500)

机构地区：[1]中海石油(中国)有限公司深圳分公司,广东深圳518052 [2]中国石油集团渤海钻探工程技术研究院,天津300450 [3]中海油研究总院有限责任公司,北京100028 [4]西南石油大学新能源与材料学院,成都610500

出　　处：《钻井液与完井液》2023年第4期495-501,共7页Drilling Fluid & Completion Fluid

基　　金：中海油科技项目“CO_(2)封存与利用钻采关键技术研究”(KJGG-2022-12-CCUS-0104)。

摘　　要：为了尽快实现碳中和的目标,二氧化碳捕获、利用和封存(Carbon Capture,Utilization and Storage——CCUS)技术不可或缺。由于CCUS高温高压的环境引起较大的应力和温度波动,水泥环易形成裂缝对CO_(2)的安全封存造成威胁。以碳酸钙晶须和氧化石墨烯作为引晶材料诱导水泥石裂缝表面碳化结晶,并研究其对水泥石裂缝自愈合进程的影响。实验结果表明,经过碳化自愈合反应不同的龄期后,分别掺入碳酸钙晶须和氧化石墨烯水泥石的抗压强度均高于空白水泥石。μ-CT的结果分析表明,掺入碳酸钙晶须和氧化石墨烯的水泥石裂缝体积的自愈率分别为55.24%和74.60%,要高于空白水泥石的18.32%;水泥石裂缝表面物相分析表明,随着碳化时间的增加,掺入引晶材料水泥石裂缝表面的CaCO_(3)晶体含量高于空白水泥石。由此说明碳酸钙晶须和氧化石墨烯作为引晶材料可提高水泥石裂缝在CCUS工况下的碳化自愈合能力。To achieve the goal of carbon neutrality as soon as possible,carbon capture,utilization and storage(CCUS)is an indispensable technology.High temperature high pressure environment in CCUS operations causes large stress and temperature fluctuations which in turn result in fractures in cement sheaths.These fractures in cement sheaths are a threat to the safe sequestration of CO2.To deal with this problem,calcium carbonate whisker and graphene oxide are used as crystallographic materials to induce carbonization crystallization on the surface of the fractures developed in set cement,and the effects of the crystallographic materials on the self-healing of the fractures in the set cement were studied.Experimental results show that after different periods of carbonization self-healing reaction,the compressive strengths of the set cement samples from cement slurries treated with calcium carbonate whisker and graphene oxide separately are all higher than the compressive strength of the blank set cement sample.μ-CT results show that the set cement samples containing calcium carbonate whisker and graphene oxide have percent self-healing of the volume of the fractures of 55.24%and 74.60%,respectively,higher than the percent self-healing of the volume of the fractures in the blank set cement sample,which is only 18.32%.Phase analyses of the substances at the surfaces of the fractures in the set cement samples show that as the time for the carbonization increases,the CaCO_(3)crystal contents at the surfaces of the fractures of the set cement samples containing crystallographic materials are higher than that of the blank set cement sample.From the experiment results it can be seen that the calcium carbonate whisker and the graphene oxide can be used as crystallographic materials to improve the carbonization self-healing ability of the fractures in cement sheath under CCUS work conditions.

关 键 词：裂缝 碳化自愈合 CCUS 碳酸钙晶须 氧化石墨烯 μ-CT 

分 类 号：TE256[石油与天然气工程—油气井工程]