Influencing factors of thermal conductivity of cementing materials for geothermal wells

Authors

ZHANG Hao, China Coal Research Institute, Beijing 100013, China;Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
XU Shuanhai, Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China;
YANG Yu, China Coal Research Institute, Beijing 100013, China;Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
HAN Yongliang, Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China;
ZHANG Weidong, Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China;
LI Yongqiang, China Coal Research Institute, Beijing 100013, China; Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China

Abstract

The thermal conductivity of cementing materials is one of the factors that affect the heat removal effect of geothermal wells. In order to improve the thermal conductivity of cementing materials for geothermal wells, orthogonal test was used to study the thermal conductivity of cementing materials based on the AHP-CRITIC mixed weighting method and range analysis. The results show that the thermal conductivity of cementing materials can be improved by adding natural flake graphite, iron powder and quartz sand. The content of graphite and the ratio of water to solid are the primary and secondary factors that affect the comprehensive properties of cementing materials. With the increase of graphite content, the thermal conductivity, the 48 hours compressive strength and the fluidity decreased. The results show that the optimal mix ratio of high thermal conductivity cementing materials is: water solid ratio is 0.44, the amount of graphite, iron powder and quartz sand accounted for 7.5%, 3%, and 2% of the cement mass, respectively, its thermal conductivity can reach 1.87 W/(m·K), which is about 70% higher than conventional cementing materials. It can provide reference for the efficient development and utilization of geothermal energy.

Keywords

geothermal energy, cementing material, thermal conductivity, orthogonal test, AHP-CRITIC mixed weighting method, range analysis

DOI

10.3969/j.issn.1001-1986.2020.02.029

Recommended Citation

ZHANG Hao, XU Shuanhai, YANG Yu, et al. (2020) "Influencing factors of thermal conductivity of cementing materials for geothermal wells," Coal Geology & Exploration: Vol. 48: Iss. 2, Article 30.
DOI: 10.3969/j.issn.1001-1986.2020.02.029
Available at: https://cge.researchcommons.org/journal/vol48/iss2/30

Reference

[1]WANG Kai,YUAN Bin,JI Guomin,et al. A comprehensive review of geothermal energy extraction and utilization in oilfields[J]. Journal of Petroleum Science and Engineering,2018,168:465-477.

[2] 多吉. 钻获干热岩体推进地热发电[J]. 科技导报,2015,33(19):1. DUO Ji. Drilling dry hot rock to promote geothermal power generation[J]. Science & Technology Review,2015,33(19):1.

[3] 自然资源部中国地质调查局等. 《中国地热能发展报告(2018)》[R]. 北京:中国石化出版社,2018. China Geologic Survey,et al. China geothermal energy development report[R]. Beijing:China Petrochemical Press,2018.

[4] 王贵玲,张薇,梁继运,等. 中国地热资源潜力评价[J]. 地球学报,2017,38(4):449-459. WANG Guiling,ZHANG Wei,LIANG Jiyun,et al. Evaluation of geothermal resources potential in China[J]. Acta Geoscientica Sinica,2017,38(4):449-459.

[5] 张明昌. 固井工艺技术[M]. 北京:中国石化出版社,2016. ZHANG Mingchang. Cementing technology[M]. Beijing:China Petrochemical Press,2016.

[6] 杨世铭,陶文铨. 传热学[M]. 北京:高等教育出版社,2006. YANG Shiming,TAO Wenquan. Heat transfer[M]. Beijing:Higher Education Press,2006.

[7] KOHL T,SALTON M,RYBACH L. Data analysis of the deep borehole heat exchanger plant Weissbad(Switzerland)[C]//Proceedings World Geothermal Congress. Kyushu,Japan:ResearchGate,2000:3459-3464.

[8] 李瑞霞,王高升,宋先知,等. 固井水泥对同轴型换热系统取热效果影响数值分析[J]. 建筑科学,2018,34(4):36-40. LI Ruixia,WANG Gaosheng,SONG Xianzhi,et al. Numerical analysis of the effect of cement sheath on the heat extraction performance of coaxial borehole heat exchangers geothermal system[J]. Building Science,2018,34(4):36-40.

[9] 刘崇建,黄柏宗,徐同台,等. 油气井注水泥理论与应用[M]. 北京:石油工业出版社,2001. LIU Chongjian,HUANG Baizong,XU Tongtai,et al. Theory and application of cementing for oil & gas well[M]. Beijing:Petroleum Industry Press,2001.

[10] 齐奉忠,刘硕琼,沈吉云. 中国石油固井技术进展及发展建议[J]. 石油科技论坛,2017,36(1):26-31. QI Fengzhong,LIU Shuoqiong,SHEN Jiyun. Suggestion on CNPC cementing technological development[J]. Oil Forum, 2017,36(1):26-31.

[11] 丁士东,陶谦,马兰荣. 中国石化固井技术进展及发展方向[J]. 石油钻探技术,2019,47(3):41-49. DING Shidong,TAO Qian,MA Lanrong. Progress,outlook,and the development directions at Sinopec in cementing technology progress[J]. Petroleum Drilling Techniques,2019,47(3):41-49.

[12] 王楚峰,王瑞和,杨焕强,等. 煤层气泡沫水泥浆固井工艺技术及现场应用[J]. 煤田地质与勘探,2016,44(2):116-120. WANG Chufeng,WANG Ruihe,YANG Huanqiang,et al. Cementing technology of foam cement slurry for coalbed methane well and its application[J]. Coal Geology & Exploration,2016,44(2):116-120.

[13] 陈春,钱春香,陈惠苏,等. 水泥基保温材料导热系数的模型研究[J]. 建筑材料学报,2009,12(3):348-351. CHEN Chun,QIAN Chunxiang,CHEN Huisu,et al. Model study of thermal conductivity of cement based thermal insulation materials[J]. Journal of Building Materials,2009,12(3):348-351.

[14] 张伟平,童菲,邢益善,等. 混凝土导热系数的试验研究与预测模型[J]. 建筑材料学报,2015,18(2):183-189. ZHANG Weiping,TONG Fei,XING Yishan,et al. An investigation of thermal conductivity of cement-based composites with multi-scale micromechanical method[J]. Journal of Building Materials,2015,18(2):183-189.

[15] 赵育. 高导热性混凝土细观数值模拟与工程应用[D]. 西安:长安大学,2017. ZHAO Yu. Mesosopic numerical simulation and engineering application of high thermal conductivity concrete[D]. Xi'an:Chang'an University,2017.

[16] 周仕明,李根生,王其春. 超高密度水泥浆研制[J]. 石油勘探与开发,2013,40(1):107-110. ZHOU Shiming,LI Gensheng,WANG Qichun. Research and preparation of ultra-heavy slurry[J]. Petroleum Exploration and Development,2013,40(1):107-110.

[17] 袁燊. 高密度水泥浆体系研究[D]. 青岛:中国石油大学(华东),2013. YUAN Shen. Research on high density cement slurry system[D]. Qingdao:China University of Petroleum(East China),2013.

[18] 刘竞妍,张可,王桂华. 综合评价中数据标准化方法比较研究[J]. 数字技术与应用,2018,36(6):84-85. LIU Jingyan,ZHANG Ke,WANG Guihua. Comparative study on data standardization methods in comprehensive evaluation[J]. Digital Technology & Application,2018,36(6):84-85.