纤维/晶须材料对固井水泥石的增韧机理研究  

Research on The Toughening Mechanism of Fiber/Whisker on Oil Well Cement Stone

作　　者：李明[1] 邓双[1] 严平[2] 靳建洲 于永金 LI Ming;DENG Shuang;YAN Ping;JIN Jianzhou;YU Yongjin(School of Material Science and Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China;College of Chemistry and Environmental protection Engineering,Southwest University for Nationalities,Chengdu,Sichuan 610041,China;CNPC Drilling Research Institute,Changping,Beijing 102206,China)

机构地区：[1]西南石油大学材料科学与工程学院,四川成都610500 [2]西南民族大学化学与环境保护工程学院,四川成都610041 [3]中国石油钻井工程技术研究院,北京昌平102206

出　　处：《西南石油大学学报（自然科学版）》2016年第5期151-156,共6页Journal of Southwest Petroleum University(Science & Technology Edition)

基　　金：中国石油集团重大科技项目(2014A-4213)

摘　　要：扫描电子显微镜(SEM)用于水泥基材料研究,可以准确、快速、直观地提供水泥石断面的微观形貌等信息。固井水泥环这一水泥基材料在井下工况受复杂应力影响易产生微裂缝与微环隙,造成水泥环封固能力下降。高弹模纤维、低弹模纤维、晶须等材料有助于降脆增韧水泥环。为了弄清高弹模纤维、低弹模纤维、晶须等材料对水泥环的降脆增韧机制,用扫描电镜对水泥石微观形貌进行了观察分析,探讨了增韧机制。实验结果表明,高弹模纤维、低弹模纤维、晶须等材料降脆增韧水泥环的机制包括拔出、桥连和裂纹偏转。相对于单掺纤维或单掺晶须,将二者混杂使用的增韧效果更好,其原理在于晶须属于微米级材料,可以阻止微米级微裂纹的产生和扩展;纤维属于毫米级材料,可以阻止毫米级微裂缝的产生与扩展;二者混杂使用可以起到多层次阻裂和增韧的目的。Information such as the microstructure of cement stone cross section can be accurately,speedily and intuitively,provided by SEM when used in the research of cement-based materials. Oil well cement stone easily caused the micro-fracture and micro-annulus under the complex downhole stressed to decrease the sealing integrity between the cement sheath and the casing or formation. Whisker,fiber,and hybrid fiber are incorporated to strengthen and toughen the cement stone. Microstructures and micromechanical behaviors are investigated using scanning electron microscopy. The experimental results show that the toughness of the hybrid fiber cement stone was better than that of the single fiber cement stone. The toughening mechanisms of cement stone contains bridging,crack deflection and fiber pull out and the improvement could be correlated to energy-dissipating processes at the crack tips for different size and structure between the whisker and fibers and different load phases.

关 键 词：油井水泥石 扫描电镜 纤维 增韧 微观形貌 

分 类 号：TE348[石油与天然气工程—油气田开发工程]