Downhole heaters for in-situ pyrolysis of tar-rich coals：A review and prospects

Authors

WANG Zhendong, Key Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Natural Resources, Xi’an 710021, China; Shaanxi Coal Geology Group Co., LTD., Xi’an 710021, ChinaFollow
DUAN Zhonghui, Key Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Natural Resources, Xi’an 710021, China; Shaanxi Coal Geology Group Co., LTD., Xi’an 710021, China
YANG Fu, Key Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Natural Resources, Xi’an 710021, China; Shaanxi Coal Geology Group Co., LTD., Xi’an 710021, China
MA Li, Key Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Natural Resources, Xi’an 710021, China; Shaanxi Coal Geology Group Co., LTD., Xi’an 710021, China

Abstract

Significance China boasts abundant tar-rich coal resources, which prove to be potential coal-based oil and gas resources capable of ensuring China's energy security. Extracting hydrogen while preserving carbon through the in-situ pyrolysis of tar-rich coals has developed into a trend in the clean and low-carbon utilization of coal resources. Downhole heaters serve as critical equipment for the efficient in-situ pyrolysis of tar-rich coals. Advances Based on investigations and the systematic collection of relevant information and data, this study offers a brief introduction of the currently used methods for in-situ convection heating, focusing on the present situation of the research and development (R&D) of heaters for in-situ convection heating. Finally, this study briefly explores the application of downhole electric heaters, as well as providing future prospects for making breakthroughs. Relatively mature surface heaters are only suitable for shallow strata and strata requiring low heating temperatures (< 350 ℃). Downhole combustion heaters face challenges in effectively enhancing the stability of combustion reactions and the reliability of secondary ignition under extreme working conditions. Downhole electric heaters, which combine an enhanced heat transfer structure with electric heating rods, allow for reducing the surface temperatures of electric heating rods while decreasing the sizes of heaters, thereby effectively enhancing the heating efficiency and prolonging the service life. Additionally, employing seal structures can effectively improve the adaptability of downhole electric heaters to complex working conditions. Using a self-developed downhole electric heater with a closed double-shell structure, Shaanxi Coal Geology Group Co., Ltd. has successfully extracted the world's first barrel of coal tar from tar-rich coals through the in-situ pyrolysis in the Dabaodang mine field of the Yushen mining area in the Jurassic coalfield in northern Shaanxi. Prospects To boost the heating rate and efficiency of tar-rich coal seams, subsequent research on downhole electric heaters can center around high-power downhole electric heaters and composite heating. However, composite heating suffers certain heat loss during medium transport, especially with an increase in heating well number and coal seam depth. Hence, it is recommended that high-power downhole electric heaters should be highlighted. This study is expected to provide technical support for the R&D and industrial application of the in-situ pyrolysis technology for tar-rich coals in China.

Keywords

tar-rich coal, in-situ underground pyrolysis, convection heating, downhole electric heater, enhanced heat transfer

DOI

10.12363/issn.1001-1986.24.01.0009

Recommended Citation

WANG Zhendong, DUAN Zhonghui, YANG Fu, et al. (2024) "Downhole heaters for in-situ pyrolysis of tar-rich coals：A review and prospects," Coal Geology & Exploration: Vol. 52: Iss. 7, Article 5.
DOI: 10.12363/issn.1001-1986.24.01.0009
Available at: https://cge.researchcommons.org/journal/vol52/iss7/5

Reference

[1] 丁鹏，王迪. 我国油气资源进口安全问题及应对策略[J]. 中国能源，2023，45(5)：56−63.

DING Peng，WANG Di. Research on the security problems and countermeasures for China’s oil and gas resources import[J]. Energy of China，2023，45(5)：56−63.

[2] 张勇，李超. 国内油气对外依存度发展趋势[J]. 中国石油和化工标准与质量，2023，43(17)：124−126.

ZHANG Yong，LI Chao. Development trend of domestic oil and gas dependence on foreign countries[J]. China Petroleum and Chemical Standard and Quality，2023，43(17)：124−126.

[3] 李瑞忠，郗凤云，杨宁，等. 2010年世界能源供需分析：《BP世界能源统计2011》解读[J]. 当代石油石化，2011，19(7)：30−37.

LI Ruizhong，XI Fengyun，YANG Ning，et al. The analysis of world energy supply & demand in 2010：An explanation of BP statistical review of world energy 2011[J]. Petroleum & Petrochemical Today，2011，19(7)：30−37.

[4] 许勤华，李文琪. 全球碳中和背景下的中国能源安全方略[J]. 南通大学学报(社会科学版)，2023，39(1)：117−129.

XU Qinhua，LI Wenqi. China’s energy security strategy in the context of global carbon neutrality[J]. Journal of Nantong University (Social Sciences Edition)，2023，39(1)：117−129.

[5] 纪玉山. 我国非常规油气资源的开发利用与能源安全的经济分析[J]. 社会科学家，2016(10)：10−16.

JI Yushan. Economic analysis on the development and utilization of unconventional oil and gas resources and energy security in China[J]. Social Scientist，2016(10)：10−16.

[6] 付德亮，段中会，杨甫，等. 富油煤钻井式地下原位热解提取煤基油气资源的几个关键问题[J]. 煤炭学报，2023，48(4)：1759−1772.

FU Deliang，DUAN Zhonghui，YANG Fu，et al. Key problems in in situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resources[J]. Journal of China Coal Society，2023，48(4)：1759−1772.

[7] 刘朝全，姜学峰. 2020年国内外油气行业发展报告[M]. 北京：石油工业出版社，2021.

[8] 马丽，拓宝生. 陕西富油煤资源量居全国之首 榆林可“再造一个大庆油田”[J]. 陕西煤炭，2020，39(1)：220−222.

MA Li，TUO Baosheng. Shaanxi’s oil-rich coal resources rank first in China，and Yulin can “rebuild a Daqing oilfield”[J]. Shaanxi Coal，2020，39(1)：220−222.

[9] 马丽，王双明，段中会，等. 陕西省富油煤资源潜力及开发建议[J]. 煤田地质与勘探，2022，50(2)：1−8.

MA Li，WANG Shuangming，DUAN Zhonghui，et al. Potential of oil-rich coal resources in Shaanxi Province and its new development suggestion[J]. Coal Geology & Exploration，2022，50(2)：1−8.

[10] 汪友平，王益维，孟祥龙，等. 美国油页岩原位开采技术与启示[J]. 石油钻采工艺，2013，35(6)：55−59.

WANG Youping，WANG Yiwei，MENG Xianglong，et al. Enlightenment of American’s oil shale in situ retorting technology[J]. Oil Drilling & Production Technology，2013，35(6)：55−59.

[11] JU Yang，ZHU Yan，ZHOU Hongwei，et al. Microwave pyrolysis and its applications to the in situ recovery and conversion of oil from tar-rich coal：An overview on fundamentals，methods，and challenges[J]. Energy Reports，2021，7：523−536.

[12] KANG Zhiqin，ZHAO Yangsheng，YANG Dong，et al. A pilot investigation of pyrolysis from oil and gas extraction from oil shale by in situ superheated steam injection[J]. Journal of Petroleum Science and Engineering，2020，186：106785.

[13] JEREMY B. Oil shale：is now the time?[C]//Garfield County Energy Advisory Board Meeting. Colorado：2011.

[14] 高攀明. 鄂尔多斯盆地吴起地区长7页岩油烃源岩特征及生排烃潜力[J]. 非常规油气，2024，11(3)：10−18.

GAO Panming. Characteristics and hydrocarbon generation and expulsion potential of Chang7 shale oil source rocks in Wuqi Area，Ordos Basin[J]. Unconventional Oil & Gas，2024，11(3)：10−18.

[15] 韩婧. 水氧协同作用对油页岩热解特性影响研究[D]. 长春：吉林大学，2019.

HAN Jing. Study on the effect of synergy of water and oxygen on pyrolysis characteristics of oil shale[D]. Changchun：Jilin University，2019.

[16] 孙友宏，郭威，邓孙华. 油页岩地下原位转化与钻采技术现状及发展趋势[J]. 钻探工程，2021，48(1)：57−67.

SUN Youhong，GUO Wei，DENG Sunhua. The status and development trend of in situ conversion and drilling exploitation technology for oil shale[J]. Drilling Engineering，2021，48(1)：57−67.

[17] ALLIX P，BURNHAM A，FOWLER T，et al. Coaxing oil from shale[J]. Oilfield Review，2010，22(4)：4−15.

[18] KANG Zhiqin，ZHAO Yangsheng，YANG Dong. Review of oil shale in situ conversion technology[J]. Applied Energy，2020，269：115121.

[19] 邓孙华. 近临界水对块状油页岩中有机质的提取研究[D]. 长春：吉林大学，2013.

DENG Sunhua. Sub-cirtical water extraction of organic matter from oil shale lumps[D]. Changchun：Jilin University，2013.

[20] 王洪艳，邓孙华，李俊锋，等. 一种地下原位提取油页岩中烃类化合物的方法：CN101871339B[P]. 2013-03-27.

[21] 王振东. 油页岩原位开采连续螺旋折流板式电加热器传热性能和加热效率研究[D]. 长春：吉林大学，2021.

WANG Zhendong. Study on heat transfer performance and heating efficiency of electric heater with continuous helical baffles for oil shale in-situ conversion[D]. Changchun：Jilin University，2021.

[22] GUO Wei，WANG Zhendong，SUN Zhongjin，et al. Experimental investigation on performance of downhole electric heaters with continuous helical baffles used in oil shale in situ pyrolysis[J]. Applied Thermal Engineering，2019，147：1024−1035.

[23] 刘争芬，彭杰，闫吉曾，等. 基于油气开发工程的深部煤炭地下气化关键技术[J]. 油气与新能源，2023，35(1)：77−81.

LIU Zhengfen，PENG Jie，YAN Jizeng，et al. Key deep underground coal gasification technology based on oil and gas development projects[J]. Petroleum and New Energy，2023，35(1)：77−81.

[24] 张杰，张轮亭，杨中成，等. 稠油热采用注汽锅炉现状及展望[J]. 工业加热，2016，45(3)：61−63.

ZHANG Jie，ZHANG Lunting，YANG Zhongcheng，et al. Status and development tendency of steam injection boiler to heavy oil thermal recovery[J]. Industrial Heating，2016，45(3)：61−63.

[25] 方兵. 稠油热采注汽锅炉清灰技术研究与应用[J]. 油气田环境保护，2014，24(5)：21−22.

FANG Bing. Research and application of soot cleaning technology of steam injection boiler for heavy oil thermal recovery[J]. Environmental Protection of Oil & Gas Fields，2014，24(5)：21−22.

[26] DONALDSON A B，HOKE D E，MULAC A J. Downhole steam generator with improved preheating/cooling features：US4411618[P]. 1983-10-25.

[27] MUIR J F，WEIRICK L J，PETTIT F S. Field test of two high-pressure，direct-contact downhole steam generators. Volume I. Air/diesel system[R]. United States：Sandia National Lab. (SNL-NM)，Albuquerque，NM(U.S.)，1983. doi:10.2172/6289352.

[28] 徐进良，陈听宽. 井下蒸汽发生器装置及燃烧特性的研究[J]. 动力工程，1992，12(2)：9−14.

XU Jinliang，CHEN Tingkuan. Uuder-ground steam ganarators and their combustion characteristics[J]. Power Engineering，1992，12(2)：9−14.

[29] 徐进良，陈听宽. 井下蒸汽发生器燃烧室壁冷却传热特性的研究[J]. 动力工程，1993，13(4)：6−10.

XU Jinliang，CHEN Tingkuan. Research on combustion chamber’s wall cooling heat transfer characteristics of under-ground steam generators[J]. Power Engineering，1993，13(4)：6−10.

[30] SCHICKS J，SPANGENBERG E，GIESE R，et al. A counter-current heat-exchange reactor for the thermal stimulation of hydrate-bearing sediments[J]. Energies，2013，6(6)：3002−3016.

[31] FRIEDLE U，VESER G. A counter-current heat-exchange reactor for high temperature partial oxidation reactions I. Experiments[J]. Chemical Engineering Science，1999，54(10)：1325−1332.

[32] ALBERT H S. Engineering and economics of enhanced oil recovery in the Canadian oil sands[D]. Austin：University of Texas at Austin，2014.

[33] 赵帅，孙友宏，李强，等. 一种用于油页岩原位裂解的超燃加热器：CN208619096U[P]. 2019-03-19.

[34] 刘鹏宇，康维国，刘黎，等. 用于石油稠油开采的蒸汽发生器：CN203547694U[P]. 2014-04-16.

[35] 谢青，李宁，姚征，等. 黄陵矿区富油煤焦油产率特征及主控地质因素分析[J]. 中国煤炭，2020，46(11)：83−90.

XIE Qing，LI Ning，YAO Zheng，et al. Research on the tar yield characteristics and main control factors of tar-rich coal in Huangling mining area[J]. China Coal，2020，46(11)：83−90.

[36] SOEDER D J. The successful development of gas and oil resources from shales in North America[J]. Journal of Petroleum Science and Engineering，2018，163：399−420.

[37] 王盛鹏，刘德勋，王红岩，等. 原位开采油页岩电加热技术现状及发展方向[J]. 天然气工业，2011，31(2)：114−118.

WANG Shengpeng，LIU Dexun，WANG Hongyan，et al. Current situation and development potential of electric heating process of in situ oil shale conversion[J]. Natural Gas Industry，2011，31(2)：114−118.

[38] OJEDA S S，PARMAN D G. Use of electric downhole heaters to improve production and recovery of heavy，viscous oil in California and Venezuela[C]// SPE Kuwait Oil and Gas Show and Conference，Kuwait City，Kuwait，2013. DOI: 10.2118/167347-MS.

[39] YANG Hao，GAO Xiaoqiao，XIONG Fansheng，et al. Temperature distribution simulation and optimization design of electric heater for in situ oil shale heating[J]. Oil Shale，2014，31(2)：105.

[40] BYBEE K. Electrical downhole heaters for faja heavy-oil reservoirs[J]. Journal of Petroleum Technology，2009，61(3)：77−79.

[41] ZHU Zuojing，ZENG Fanhua，ZHAO Gong，et al. Evaluation of the hybrid process of electrical resistive heating and solvent injection through numerical simulations[J]. Fuel，2013，105：119−127.

[42] HASSANZADEH H，HARDING T. Analysis of conductive heat transfer during in-situ electrical heating of oil sands[J]. Fuel，2016，178：290−299.

[43] CASTROGIOVANNI A G，VOLAND R T，WARE C H，et al. Downhole steam generator and method of use：US9617840[P]. 2017-04-11.

[44] 匡韶华，王宝权，张建军，等. 井下电加热蒸汽发生器：CN203810358U[P]. 2014-09-03.

[45] 董社霞，张海龙，张保康，等. 一种蒸汽热采稠油的设备及其方法：CN103114836A[P]. 2013-05-22.

[46] 谢小辉. 井下电磁感应加热器理论分析及实验研究[D]. 成都：西南石油大学，2017.

XIE Xiaohui. Theoretical analysis and experimental study of underground electromagnetic induction heater[D]. Chengdu：Southwest Petroleum University，2017.

[47] 郭威，王振东，孙友宏，等. 一种井下涡流加热器：CN108343415B[P]. 2023-09-22.

[48] 郭威，王振东，孙友宏，等. 一种井下流体电加热器：CN108505971B[P]. 2023-09-22.

[49] 郭威，王振东，孙友宏，等. 一种非常规能源用井下流体加热器：CN108301817B[P]. 2023-09-15.

[50] 王振东，郭威，李强，等. 一种串联式变螺距井下流体电加热器：CN207093039U[P]. 2018-03-13.

[51] 王振东，杨甫，付德亮，等. 一种井下电加热器：CN215718629U[P]. 2022-02-01.

[52] 王振东，杨甫，付德亮，等. 一种双壳体井下电加热器：CN216305871U[P]. 2022-04-15.

[53] GUO Wei，WANG Zhendong，SUN Youhong，et al. Effects of packer locations on downhole electric heater performance：Experimental test and economic analysis[J]. Energies，2020，13(2)：377.

[54] WANG Zhendong，LÜ Xiaoshu，LI Qiang，et al. Downhole electric heater with high heating efficiency for oil shale exploitation based on a double-shell structure[J]. Energy，2020，211：118539.

[55] WANG Zhendong，YANG Fu，FU Deliang，et al. Economic and heating efficiency analysis of double-shell downhole electric heater for tar-rich coal in situ conversion[J]. Case Studies in Thermal Engineering，2023，41：102596.

[56] 郭威，王振东，李强，等. 一种油页岩用井下电缆高温高压密封接头：CN109861162B[P]. 2023-10-24.

[57] 自然资源部煤炭资源勘查与综合利用重点实验室成功提取全球第一桶富油煤焦油. https://www.iziran.net/news.html?aid=5296081.

[58] 郭威，刘召，孙友宏，等. 富油煤原位热解开发地下体系封闭方法探讨[J]. 煤田地质与勘探，2023，51(1)：107−114.

GUO Wei，LIU Zhao，SUN Youhong，et al. Discussion on underground system sealing methods in in-situ pyrolysis exploitation of tar-rich coal[J]. Coal Geology & Exploration，2023，51(1)：107−114.