SU Xiaoyue1, LIU Pingjiang2, ZHANG Ye2, TIAN Baozhen2,GAO Fei2, MEI Kaiyuan1,3, CHENG Xiaowei1
(1. School of New Energy and Materials, Southwest Petroleum University, Chengdu 610000, China;2. Bohai Drilling Engineering Company Limited, CNPC, Tianjin 062552, China; 3. State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China)
Abstract：In order to improve the exploitation efficiency of geothermal energy, cementing materials with high thermal conductivity should be used in the heat recovery section of geothermal wells. Superfine graphite was used as an admixture to improve thermal conductivity, and sodium dodecyl benzene sulfonate was used as a dispersant to improve the dispersion stability of superfine graphite in cement slurry. After the suitable superfine graphite dispersion was selected, superfine graphite composite modified cement stones (referred to as cement stones) were further prepared as the cement materials. The effects of superfine graphite content on compressive strength and thermal conductivity of cement stones were studied. The phase composition, porosity and structural compactness of cement stones were tested and characterized by XRD, TG, MIP and SEM. The effects of different contents of superfine graphite on the thermal conductivity of cement stones were studied. The thermal conductivity mechanism of cement stones under different graphite contents and porosity were discussed also. The results show that with the increase of the content of superfine graphite, the thermal conductivity of cement stones first increases and then decreases. When the content of superfine graphite is 12%, the thermal conductivity of cement stone reaches the maximum value of 2.45 W/(m·K). The high thermal conductivity of superfine graphite, the porosity and the mass fraction of hydration products can affect the thermal conductivity of cement stone. With the increase of superfine graphite content, the compressive strength of cement stones first increases and then decreases. Considering the thermal conductivity and mechanical properties of cement stones, the optimal mass fractions of superfine graphite should be from 10% to 12%.
Keywords：geothermal energy; cementing material; superfine graphite; modification; cement stone; thermal conductivity
Get Citation：SU X Y, LIU P J, ZHANG Y, et al. Thermal conductivity of cement stone modified with superfine graphite[J]. China Powder Science and Technology, 2023, 29(6): 61-71.
DOI：10.13732/j.issn.1008-5548.2023.06.006
Received：2023-04-21,Revised：2023-09-12,Online：2023-10-09 09:51。
Funding Project：国家自然科学基金项目,编号:42207206。
First Author：苏晓悦(1998—),女,硕士研究生,研究方向为固井水泥石的导热性能。E-mail: 675820894@qq.com。
Corresponding Author：程小伟(1977—),男,教授,博士,博士生导师,研究方向为先进胶凝材料与其在固井材料中的应用。E-mail: chengxw@swpu.edu.cn。
CLC No：TB332; TB44
Type Code：A
Serial No：1008-5548(2023)06-0061-11
