适用于低温地层的纳米复合水泥浆体系研究

Research on a Nano-Composite Cement Slurry System Suitable for Low-Temperature Formations

王胜 谌强 袁学武 华绪 陈礼仪

WANG Sheng CHEN Qiang YUAN Xuewu HUA Xu CHEN Liyi

地质灾害防治与地质环境保护国家重点实验室（成都理工大学），四川成都 610059 四川藏区高速公路有限责任公司，四川成都 610041

State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology), Chengdu, Sichuan, 610059, China Sichuan Tibet Expressway Co., Ltd, Chengdu, Sichuan, 610041, China

为解决低温地层钻探过程中的井壁坍塌和井漏问题，研制了适用于低温地层的纳米复合水泥浆。采用宏观试验与微观分析相结合的方法，研究了低温下纳米Al2O3对硅酸盐–硫铝酸盐复合水泥浆性能和水化过程的影响；以普通硅酸盐水泥与硫铝酸盐水泥复合产生的水化协同效应为基础，结合纳米Al2O3、防冻剂EG、减水剂JS-1和早强剂TEOA，配制了纳米复合水泥浆NAC；采用扫描电镜、X射线衍射和水化放热试验相结合的方法，研究了NAC的低温水化过程及水化机理。试验得知，温度为–9 ℃时，纳米复合水泥浆具有良好的初始流动性，可泵期为57 min，初、终凝时间分别为84和101 min，24 h抗压强度为6.9 MPa。研究结果表明，NAC具有直角稠化效应，低温下性能优越，能够满足钻进低温地层时的护壁堵漏要求。

In order to solve the problems of borehole wall collapse and well leakage in low-temperature drilling, a nano-composite cement slurry system suitable for low-temperature formations was designed. Combining the macroscopic test with microscopic analysis, the influence of nano-Al2O3 at low temperatures on the performance of silicate-sulphoaluminate composite cement slurry and the hydration process was studied. Based on the synergistic effect of hydration generated from the composite of ordinary silicate cement and sulphoaluminate cement, a nano-composite cement (NAC) was developed in conjunction with the nano-Al2O3, antifreeze agent EG, water reducing agent JS-1, and hardening accelerating agent TEOA. In addition, the low-temperature hydration process of NAC and its mechanism were studied through a combination of the scanning electron microscope (SEM), X-ray diffraction (XRD), and exothermic experiments of hydration. Experimental results showed that the nano-composite cement slurry had good initial fluidity at −9 ℃ with a pumpable period of 57 min, a 24-hour compressive strength of 6.9 MPa, and an initial and final setting time of 84 min and 101 min, respectively. The results of the study indicated that NAC had the right-angle thickening effect and superior performance at low temperatures, capable of meeting the requirements of borehole wall protection and loss circulation control in low-temperature formations.

国家自然科学基金项目“纳米复合水泥浆液低温水化过程与流变凝固特性研究”（编号：41672362）和珠峰科学研究计划项目“青藏高原深部找矿快速绿色智能钻进关键技术研究”（编号：80000-2020ZF11411）部分研究内容

https://doi.org/10.11911/syztjs.2021009