高温二氧化碳环境水泥石水化产物演化对其性能的影响  

Evolution Effect of Hydration Products on the Properties of Cement in High Temperature CO_(2)Environment

作　　者：温达洋 肖伟[1] 冯青豪 陈志鸣 于新虎 袁彬[2] WEN Dayang;XIAO Wei;FENG Qinghao;CHEN Zhiming;YU Xinhu;YUAN Bin(Oilfield Chemicals R&D Institute,COSL,Langfang,Hebei 065201,P R of China;National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(Southwest Petroleum University),Chengdu,Sichuan 610500,P R of China)

机构地区：[1]中海油田服务股份有限公司油田化学研究院,河北廊坊065201 [2]油气藏地质及开发工程全国重点实验室(西南石油大学),四川成都610500

出　　处：《油田化学》2025年第1期30-37,共8页Oilfield Chemistry

基　　金：国家自然科学基金青年科学基金项目“CCUS地质封存井磷铝酸盐水泥固井提高水泥环耐碳化腐蚀机理研究”(项目编号52204014);四川省青年基金项目“废弃高温气藏注超临界CO_(2)开采地热井水泥环劣化机理及控制研究”(项目编号2023NSFSC0926)。

摘　　要：硅酸盐水泥中添加石英砂可以防止其在高温下由于晶体转变导致的力学性能衰退。然而,180℃高温和超临界CO_(2)共同作用下加砂水泥的水化产物组成和形貌变化更加复杂,导致高温CO_(2)对水泥石力学性能的影响机理尚不清楚。因此,采用扫描电镜、压汞法、热重分析、X射线衍射测试、红外光谱表征等,分析180℃超临界CO_(2)环境中水泥石的腐蚀深度、孔径分布、力学性能、物相组成、官能团及微观结构。结果表明,随着腐蚀时间的增加,水泥石的腐蚀深度增大,抗压强度降低,孔隙度先减小后增大。水化产物由针状的硬硅钙石(C_(6)S_(6)H)、柱状的针硅钙石(C_(2)SH)、片状和棒状的碳酸钙(CaCO_(3))以及疏松多孔的无定形SiO_(2)组成。在180℃超临界CO_(2)条件下,水泥的水化产物演化对其性能的影响机理为:腐蚀早期,大量的C_(2)SH和少部分C_(6)S_(6)H被腐蚀生成CaCO_(3)和无定形SiO_(2),CaCO_(3)(主要为文石和球霰石)填充部分孔隙的同时C-S-H凝胶聚合度增大,减缓碳化腐蚀速率。腐蚀后期,虽然方解石含量增大对强度发展有一定的促进作用,但随着腐蚀的进行,球霰石与文石溶解,C_(6)S_(6)H被大量腐蚀且形貌朝着片状和块状转变,造成水泥石的孔隙度增大,C-S-H凝胶的聚合度降低,导致抗压强度降低,加速碳化。180℃超临界CO_(2)条件下,C-S-H凝胶(C_(6)S_(6)H和C_(2)SH)与碳酸钙(方解石、文石和球霰石)的演化决定了水泥石力学性能的变化。Addition of quartz sand to Portland cement can prevent its mechanical properties from declining due to crystal transformation at high temperatures.However,the composition and morphology changes of hydration products of sand-coated cement under the combined action of 180℃and supercritical CO_(2)are more complex,so the effect of high temperature CO_(2)on the mechanical properties of cement is still unclear.Therefore,the corrosion depth,pore size distribution,mechanical properties,phase composition,functional groups and microstructure of cement stone in supercritical CO_(2)environment at 180℃were analyzed by means of scanning electron microscopy,mercury injection,thermogravimetric analysis,X-ray diffraction test and infrared spectrum characterization.The results showed that with the increase of corrosion time,the corrosion depth of cement stone increased,the compressive strength decreased,and the porosity decreased first and then increased.The hydration products were composed of acicular xonotlite(C_(6)S_(6)H),columnar hillebrandite(C_(2)SH),sheet and rod-shaped calcium carbonate(CaCO_(3))and loose porous amorphous SiO_(2).Under the condition of supercritical CO_(2)at 180℃,the influence mechanism of hydration product evolution of cement on its performance was obtained as follows.In the early stage of corrosion,a large amount of C_(2)SH and a small part of C_(6)S_(6)H were corroded to generate CaCO_(3)and amorphous SiO_(2).CaCO_(3)(mainly aragonite and vaterite)would fill part of the pores,while the polymerization degree of C-S-H gel increased,slowing down the carbonization corrosion rate.In the later stage of corrosion,the increase of calcite content could promote the development of strength to a certain extent.But with the progress of corrosion,the vaterite and aragonite dissolved,a large number of C_(6)S_(6)H were corroded and then the morphology changed toward flake and block,resulting in the increase of porosity of cement stone,the decrease of polymerization degree of C-S-H gel and compressive strength,and

关 键 词：高温 超临界二氧化碳 水泥石 水化产物 碳酸钙 聚合度 

分 类 号：TE256[石油与天然气工程—油气井工程]