海泡石纤维表面包覆二氧化硅增强油井水泥的力学性能  

Mechanical properties of oil well cement reinforced by silica-coated surface of sepiolite fiber

作　　者：胡陈 张春梅[1] 苏晓悦 梅开元[1] 李锟 程小伟[1] HU Chen;ZHANG Chunmei;SU Xiaoyue;MEI Kaiyuan;LI Kun;CHENG Xiaowei(School of New Energy and Materials,National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学新能源与材料学院,油气藏地质及开发工程全国重点实验室,四川成都610500

出　　处：《中国粉体技术》2024年第4期51-61,共11页China Powder Science and Technology

基　　金：国家自然科学基金项目,编号:42207206;文昌9-7油田多分支复杂结构井固井方案及工作液体系研究项目,编号:CCL2022RCPS0702PSN;四川省科技厅自然科学基金面上项目,编号:24NSFSC1580。

摘　　要：【目的】降低天然海泡石纤维的吸水性,提高海泡石纤维水泥浆的流动性能,改善水泥石的力学性能。【方法】通过酸-水热法对天然海泡石纤维进行除杂提纯,并采用正硅酸乙酯(tetraethyl orthosilicate,TEOS)水解在海泡石纤维表面包覆二氧化硅降低海泡石纤维的吸水性,探究海泡石纤维对油井水泥的浆体性能、力学性能影响;运用X射线衍射分析、热分析和扫描电子显微镜分析等方法表征水泥石的物相组成、水化程度及微观形貌。【结果】改性水泥的海泡石纤维最优质量分数为5%,固化7 d的水泥石抗压、抗拉强度较未改性的分别提高了10.98%、10.58%;海泡石纤维质量分数为5%的改性水泥石的峰值应力为35.76 MPa,峰值应变为3.97×10^(-2)。海泡石纤维表面包覆SiO_(2)后,在较低质量分数下(5%)就能够促进水泥水化。【结论】改性海泡石纤维水泥浆的流动性优于未改性的;在纤维掺量和养护时间相同的情况下,改性海泡石纤维水泥石的抗压强度和抗拉强度均高于未改性的;改性海泡石纤维对水泥石的增韧强化能力高于未改性海泡石纤维。Objective Fiber reinforcement proves to be an effective approach in enhancing the mechanical properties of oil well cement.Sepiolite fibers,known for their remarkable dispersibility in cement slurry and strong bonding to the cement matrix,are promising candidates.However,the presence of high impurity levels and significant water absorption in natural sepiolite fibers not only hinder the fluidity of cement slurry but also compromise the compressive and tensile strengths of cement paste,thereby constraining the broader utilization of sepiolite fibers in cement-based materials.To overcome these challenges,this study employed a hydrochloric acid-hydrothermal purification method to refine natural sepiolite fibers,followed by surface coating with SiO_(2) using tetraethyl orthosilicate(TEOS).The impact of modified sepiolite fibers on the properties of cement slurry,mechanical strength,and microstructure of oil well cement was systematically investigated.The findings and methodologies presented in this study offer valuable insights into harnessing sepiolite fibers in various applications involving cement-based materials.Methods This study focused on the purification of natural sepiolite fibers using the HCl-hydrothermal method,followed by the coating of SiO_(2) on the purified sepiolite surface using TEOS to produce modified sepiolite fibers.Scanning electron microscopy(SEM)was employed to characterize both unmodified and modified sepiolite fibers.Subsequently,these fibers were separately incorporated into cement slurry to evaluate their impact on flowability and rheological properties.Additionally,the mechanical properties of the resulting cement paste,including compressive strength,tensile strength,and stress-strain curves,were examined to evaluate the influence of sepiolite fibers.The reinforcement mechanism of both unmodified and modified sepiolite fibers in oil well cement was analyzed using X-ray diffraction(XRD),thermal analysis(TGA),and SEM.Results and Discussion Unmodified sepiolite fibers exhibited a needle-lik

关 键 词：海泡石纤维 油井水泥 力学性能 二氧化硅 

分 类 号：TU528[建筑科学—建筑技术科学] TB4[一般工业技术]