钙质晶须在高温加砂水泥中的增强性能研究

The Reinforcing Effect of Calcium-Based Whisker in High-Temperature Sand-Cement Mixtures

楼晨阳 姚晓 何德清 于三跃 韩远远 张鹏伟

Lou Chenyang Yao Xiao He Deqing Yu Sanyue Han Yuanyuan Zhang Pengwei

南京工业大学材料科学与工程学院, 江苏南京 210009; 中石化河南石油工程有限公司钻井工程公司, 河南南阳 473132

College of Materials Science and Engineering, Nanjing Tech University, Nanjing, Jiangsu, 210009, China; Sinopec Henan Oilfield Service Corporation, Nanyang, Henan, 473132, China

为满足稠油开采对油井水泥石高温力学性能的要求,探索了钙质晶须在油井水泥及高温加砂水泥中应用的可行性。首先研究了80℃下硫酸钙晶须(CSW)及两种自制钙质晶须(GZWS和GZWL)对油井水泥石的增强增韧效果,并在此基础上,通过干热养护方式(600℃煅烧6 h)考察了5% GZWL对加砂水泥石的增强效果。结果发现,CSW对油井水泥石无增强增韧作用,而GZWL和GZWS的增强增韧效果明显,且长径比大的GZWL优于GZWS。随GZWL加量增大,油井水泥石的抗压强度和冲击韧度增大,当加量为5%时,1,3,7和28 d水泥石的抗压强度较净浆水泥石分别提高了18.7%,42.4%,20.6%和20.7%,冲击韧度较净浆水泥石分别提高了6.8%,7.0%,12.8%和13.0%;该加量下干热养护后的水泥石抗压强度较纯加砂水泥石提高了108.0%。研究结果表明,晶须表面性质(亲水性)是保障其与水泥石基体良好胶结并发挥其作用的前提,晶须长径比越大,增强效果越显著,故GZWL能有效抑制加砂水泥石的高温强度衰退。

To satisfy the requirement of high temperature mechanical properties of oil well cement in heavy oil production,the application of calcium-based whisker in oil well cement as well as in cement with silica sand at high temperatures was investigated. First, the reinforcing and toughening effect of calcium sulfate whisker (CSW) and self-made whiskers (GZWS and GZWL) at 80℃ on oil well cement rock was tested, and then on the base of it, respectively. Compressive of cement with silica sand mixed with 5% GZWL in dry-heat curing at 600℃ was studied as well. The result showed that CSW had no reinforcing and toughening effect on oil well cemented rock, while GZWS and GZWL had obvious reinforcing and toughening effects, and GZWL with greater length diameter ratio was superior to GZWS. With the increased application of GZWL, the compressive strength and impact toughness of oil well cement stone increased, too. When 5% was added, the compressive strengths of cement rocks 1, 3, 7 and 28 d were increased by 18.7%, 42.4%, 20.6% and 20.7% respectively, compared with neat paste. Impact toughness was increased by 6.8%, 7.0%, 12.8% and 13.0% in the curing age. The result of the high temperature experiment showed the compressive strength of cement with silica sand with 5% GZWL was more than twice the contrast. It was demonstrated that GZWL efficiently acts as a high temperature resistance reinforcing admixture. Furthermore, a whisker with hydrophilicity had a good reinforcing effect, and the greater the long diameter ratio of whisker, the higher the reinforcing effect.

中石化石油工程技术服务有限公司先导项目"新型固井材料提高热采井固井质量技术应用研究" 和江苏省高校优势学科建设工程项目资助。

https://doi.org/10.11911/syztjs.201504016