Key problems in in-situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resources

Tar-rich coal is a special coal resource with the property of oil and gas resources. Developing the oil and gas resources contained in the tar-rich coal is of great significance for ensuring energy security and realizing the goal of "dual carbon". In-situ pyrolysis of tar-rich coal is a ne...

Full description

Bibliographic Details
Main Authors: Deliang FU, Zhonghui DUAN, Fu YANG, Li MA, Zhendong WANG, Tao TIAN, Dan HE
Format: Article
Language:zho
Published: Editorial Office of Journal of China Coal Society 2023-04-01
Series:Meitan xuebao
Subjects:
Online Access:http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.0183
_version_ 1797793784415649792
author Deliang FU
Zhonghui DUAN
Fu YANG
Li MA
Zhendong WANG
Tao TIAN
Dan HE
author_facet Deliang FU
Zhonghui DUAN
Fu YANG
Li MA
Zhendong WANG
Tao TIAN
Dan HE
author_sort Deliang FU
collection DOAJ
description Tar-rich coal is a special coal resource with the property of oil and gas resources. Developing the oil and gas resources contained in the tar-rich coal is of great significance for ensuring energy security and realizing the goal of "dual carbon". In-situ pyrolysis of tar-rich coal is a new coal resource development technology. Through some artificial cracks in coal seams, multiple wells can be connected. The coal seam is then heated using some technologies such as electric heating or fluid heating to generate oil and gas resources from the pyrolysis of tar-rich coal. At present, some problems such as coal seam heating mode, optimal pyrolysis temperature, reservoir reconstruction technology and efficient extraction of pyrolysis oil and gas need to be urgently solved. ① There are some defects in the application of reaction heating, conduction heating, and radiation heating in the underground in-situ heating of tar-rich coal. Convection heating based on injection fluid heating is more suitable for the in-situ heating of tar-rich coal. According to different geological conditions, it is still necessary to carry out targeted research work for optimizing the economical and safe heat carrying fluid and creating an efficient pyrolysis atmosphere. The combination of various heating methods is expected to be the breakthrough direction of the underground in-situ heating method of tar-rich coal. ② At present, 350−450 ℃ is generally recognized as the efficient pyrolysis temperature. With different coal characteristics and different pyrolysis atmospheres, the corresponding dominant pyrolysis temperature range is slightly different. The methods of chemical thermodynamics and kinetics for the pyrolysis of tar-rich coal are effective means to predict pyrolysis temperature scientifically. ③ Hydraulic fracturing, supercritical CO2 fracturing, and liquid nitrogen fracturing have some limitations for the in-situ pyrolysis of tar-rich coal. For different geological conditions, it is necessary to select the appropriate reservoir reconstruction scheme through specific objective evaluation. Controllable shock wave technology has the advantage of high efficiency and control in rock fracturing and is expected to be widely used in the in-situ pyrolysis process in the future. ④ The combustible gases produced by the pyrolysis of tar-rich coal are mainly CH4, H2, and CO, accompanied by a high content of CO2, which is easy to be directly extracted. The oil produced by pyrolysis is coal tar with high density and high viscosity, which will condense in large quantities below 180 ℃. There is a risk of wellbore clogging and the key to improving the extraction efficiency of pyrolysis products is to formulate the temperature and pressure maintenance scheme of the extraction well. In addition, the systematic issues such as integrated geological engineering evaluation, in-situ pyrolysis reaction process monitoring, and the whole-process numerical simulation of tar-rich coal should also be focused on in the future research work.
first_indexed 2024-03-13T02:53:18Z
format Article
id doaj.art-3364e246c5824279b864d2262f2a1180
institution Directory Open Access Journal
issn 0253-9993
language zho
last_indexed 2024-03-13T02:53:18Z
publishDate 2023-04-01
publisher Editorial Office of Journal of China Coal Society
record_format Article
series Meitan xuebao
spelling doaj.art-3364e246c5824279b864d2262f2a11802023-06-28T08:10:19ZzhoEditorial Office of Journal of China Coal SocietyMeitan xuebao0253-99932023-04-014841759177210.13225/j.cnki.jccs.2022.01832022-0183Key problems in in-situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resourcesDeliang FU0Zhonghui DUAN1Fu YANG2Li MA3Zhendong WANG4Tao TIAN5Dan HE6Key Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Nature and Resources, Shaanxi Coal Geology Group Co., Ltd., Xi’an 710026, ChinaKey Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Nature and Resources, Shaanxi Coal Geology Group Co., Ltd., Xi’an 710026, ChinaKey Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Nature and Resources, Shaanxi Coal Geology Group Co., Ltd., Xi’an 710026, ChinaKey Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Nature and Resources, Shaanxi Coal Geology Group Co., Ltd., Xi’an 710026, ChinaKey Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Nature and Resources, Shaanxi Coal Geology Group Co., Ltd., Xi’an 710026, ChinaKey Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Nature and Resources, Shaanxi Coal Geology Group Co., Ltd., Xi’an 710026, ChinaKey Laboratory of Coal Exploration and Comprehensive Utilization, Ministry of Nature and Resources, Shaanxi Coal Geology Group Co., Ltd., Xi’an 710026, ChinaTar-rich coal is a special coal resource with the property of oil and gas resources. Developing the oil and gas resources contained in the tar-rich coal is of great significance for ensuring energy security and realizing the goal of "dual carbon". In-situ pyrolysis of tar-rich coal is a new coal resource development technology. Through some artificial cracks in coal seams, multiple wells can be connected. The coal seam is then heated using some technologies such as electric heating or fluid heating to generate oil and gas resources from the pyrolysis of tar-rich coal. At present, some problems such as coal seam heating mode, optimal pyrolysis temperature, reservoir reconstruction technology and efficient extraction of pyrolysis oil and gas need to be urgently solved. ① There are some defects in the application of reaction heating, conduction heating, and radiation heating in the underground in-situ heating of tar-rich coal. Convection heating based on injection fluid heating is more suitable for the in-situ heating of tar-rich coal. According to different geological conditions, it is still necessary to carry out targeted research work for optimizing the economical and safe heat carrying fluid and creating an efficient pyrolysis atmosphere. The combination of various heating methods is expected to be the breakthrough direction of the underground in-situ heating method of tar-rich coal. ② At present, 350−450 ℃ is generally recognized as the efficient pyrolysis temperature. With different coal characteristics and different pyrolysis atmospheres, the corresponding dominant pyrolysis temperature range is slightly different. The methods of chemical thermodynamics and kinetics for the pyrolysis of tar-rich coal are effective means to predict pyrolysis temperature scientifically. ③ Hydraulic fracturing, supercritical CO2 fracturing, and liquid nitrogen fracturing have some limitations for the in-situ pyrolysis of tar-rich coal. For different geological conditions, it is necessary to select the appropriate reservoir reconstruction scheme through specific objective evaluation. Controllable shock wave technology has the advantage of high efficiency and control in rock fracturing and is expected to be widely used in the in-situ pyrolysis process in the future. ④ The combustible gases produced by the pyrolysis of tar-rich coal are mainly CH4, H2, and CO, accompanied by a high content of CO2, which is easy to be directly extracted. The oil produced by pyrolysis is coal tar with high density and high viscosity, which will condense in large quantities below 180 ℃. There is a risk of wellbore clogging and the key to improving the extraction efficiency of pyrolysis products is to formulate the temperature and pressure maintenance scheme of the extraction well. In addition, the systematic issues such as integrated geological engineering evaluation, in-situ pyrolysis reaction process monitoring, and the whole-process numerical simulation of tar-rich coal should also be focused on in the future research work.http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.0183tar-rich coalin-situ pyrolysisoil and gas resourcespyrolysis processcomprehensive evaluation
spellingShingle Deliang FU
Zhonghui DUAN
Fu YANG
Li MA
Zhendong WANG
Tao TIAN
Dan HE
Key problems in in-situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resources
Meitan xuebao
tar-rich coal
in-situ pyrolysis
oil and gas resources
pyrolysis process
comprehensive evaluation
title Key problems in in-situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resources
title_full Key problems in in-situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resources
title_fullStr Key problems in in-situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resources
title_full_unstemmed Key problems in in-situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resources
title_short Key problems in in-situ pyrolysis of tar-rich coal drilling for extraction of coal-based oil and gas resources
title_sort key problems in in situ pyrolysis of tar rich coal drilling for extraction of coal based oil and gas resources
topic tar-rich coal
in-situ pyrolysis
oil and gas resources
pyrolysis process
comprehensive evaluation
url http://www.mtxb.com.cn/article/doi/10.13225/j.cnki.jccs.2022.0183
work_keys_str_mv AT deliangfu keyproblemsininsitupyrolysisoftarrichcoaldrillingforextractionofcoalbasedoilandgasresources
AT zhonghuiduan keyproblemsininsitupyrolysisoftarrichcoaldrillingforextractionofcoalbasedoilandgasresources
AT fuyang keyproblemsininsitupyrolysisoftarrichcoaldrillingforextractionofcoalbasedoilandgasresources
AT lima keyproblemsininsitupyrolysisoftarrichcoaldrillingforextractionofcoalbasedoilandgasresources
AT zhendongwang keyproblemsininsitupyrolysisoftarrichcoaldrillingforextractionofcoalbasedoilandgasresources
AT taotian keyproblemsininsitupyrolysisoftarrichcoaldrillingforextractionofcoalbasedoilandgasresources
AT danhe keyproblemsininsitupyrolysisoftarrichcoaldrillingforextractionofcoalbasedoilandgasresources