Compressibility characteristics and modification effect of coal reservoirs in Longtan Formation, Nanchuan area, southeast Chongqing

LIU Jinxian; GUO Tao; ZHOU Yatong; LI Dongyang; JIN Xiaobo

doi:10.11781/sysydz2025010077

Volume 47 Issue 1

Jan. 2025

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LIU Jinxian, GUO Tao, ZHOU Yatong, LI Dongyang, JIN Xiaobo. Compressibility characteristics and modification effect of coal reservoirs in Longtan Formation, Nanchuan area, southeast Chongqing[J]. PETROLEUM GEOLOGY & EXPERIMENT, 2025, 47(1): 77-88. doi: 10.11781/sysydz2025010077

Citation:

LIU Jinxian, GUO Tao, ZHOU Yatong, LI Dongyang, JIN Xiaobo. Compressibility characteristics and modification effect of coal reservoirs in Longtan Formation, Nanchuan area, southeast Chongqing[J]. PETROLEUM GEOLOGY & EXPERIMENT, 2025, 47(1): 77-88. doi: 10.11781/sysydz2025010077

Citation:

LIU Jinxian, GUO Tao, ZHOU Yatong, LI Dongyang, JIN Xiaobo. Compressibility characteristics and modification effect of coal reservoirs in Longtan Formation, Nanchuan area, southeast Chongqing[J]. PETROLEUM GEOLOGY & EXPERIMENT, 2025, 47(1): 77-88. doi: 10.11781/sysydz2025010077

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Compressibility characteristics and modification effect of coal reservoirs in Longtan Formation, Nanchuan area, southeast Chongqing

doi: 10.11781/sysydz2025010077

LIU Jinxian^{1, 2
,},
GUO Tao^{1, 2},
ZHOU Yatong^{1, 2},
LI Dongyang^{1, 2},
JIN Xiaobo^{1, 2}

1.
Exploration and Development Research Institute of SINOPEC East China Oil & Gas Company, Nanjing, Jiangsu 210019, China
2.
SINOPEC Key Laboratory of Deep Coalbed Methane Exploration and Development, Nanjing, Jiangsu 210019, China

Received Date: 2024-08-29
Rev Recd Date: 2024-12-10
Publish Date: 2025-01-28

Abstract

Abstract

Fracturing modification is an important method for enhancing the permeability and conductivity in coalbed methane (CBM) wells. To better guide the development and production of CBM wells in Longtan Formation of Nanchuan area, southeast Chongqing, the study comprehensively applied various experimental methods including well logging data, industrial analysis, scanning electron microscopy, polished section observation, and whole-rock analysis. Based on the characteristics of coal rock porosity, roof and floor plate distribution, and gas content, it analyzed the compressibility characteristics of coal reservoirs and their impact on reservoir modification. The study shows that: (1) The coal rocks exhibit characteristics of medium to high evolution degree, medium to high vitrinite content, and medium to low ash content. The primary storage spaces in coal rocks are micropores and fractures, which facilitates gas adsorption. The coal seams are stably distributed, with the floor plate consisting of aluminous mudstone and the roof plate composed of mudstone, which locally transitions to argillaceous limestone and limestone. The assemblage patterns of the coal reservoir and its roof and floor plates, as well as the variations of mineral composition in roof plate, indicate a transitional sedimentary environment between land and sea. (2) Significant differences in mechanical parameters and in-situ stress of coal seams and roof and floor plates were observed, preliminarily indicating good compressibility. Triaxial stress experiments revealed that under high pressures, mechanical parameters of coal seams could exceed those of roof plate, thereby increasing the risk of fracturing. (3) Controlled by the variations of sedimentary conditions in coal measures, the lithological assemblage of the coal seams with the roof plate, and the mineral composition of the roof plate directly affect wellbore stability during horizontal drilling. Mudstone roof plates with high clay mineral content are brittle, prone to fracturing, and susceptible to swelling upon water contact, which are the major causes for spalling risks and impact horizontal well drilling rate. (4) Irregular natural fractures can lead to fracture propagation and fracture height control failure, while regular fractures that align with the direction of maximum principal stress facilitate artificial fracture propagation and contribute to effective reservoir modification.
- deep coalbed methane,
- coal reservoir compressibility,
- coal reservoir modification,
- Longtan Formation,
- Nanchuan area,
- southeast Chongqing,
- Sichuan Basin

All authors declare no relevant conflict of interests.
LIU Jinxian participated in the research, writing, and revision of the paper. GUO Tao and ZHOU Yatong participated in experimental design and paper revision. LI Dongyang participated in seismic attribute extraction. JIN Xiaobo participated in experimental data analysis. All authors have read the final version of the paper and consented to its submission.

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References(40)

References

[1]	明盈, 孙豪飞, 汤达祯, 等. 四川盆地上二叠统龙潭组深—超深部煤层气资源开发潜力[J]. 煤田地质与勘探, 2024, 52(2): 102-112. MING Ying, SUN Haofei, TANG Dazhen, et al. Potential for the production of deep to ultrdeep coalbed methane resources in the Upper Permian Longtan Formation, Sichuan Basin[J]. Coal Geology & Exploration, 2024, 52(2): 102-112.
[2]	姚红生, 肖翠, 陈贞龙, 等. 延川南深部煤层气高效开发调整对策研究[J]. 油气藏评价与开发, 2022, 12(4): 545-555. YAO Hongsheng, XIAO Cui, CHEN Zhenlong, et al. Adjustment countermeasures for efficient development of deep coalbed methane in southern Yanchuan CBM Field[J]. Petroleum Reservoir Evaluation and Development, 2022, 12(4): 545-555.
[3]	魏志福, 王永莉, 吴陈君, 等. 四川盆地上二叠统龙潭组烃源岩的地球化学特征及对有机质来源和沉积环境的指示意义[J]. 天然气地球科学, 2015, 26(8): 1613-1618. WEI Zhifu, WANG Yongli, WU Chenjun, et al. Geochemical characteristics of source rock from Upper Permian Longtan Formation in Sichuan Basin[J]. Natural Gas Geoscience, 2015, 26(8): 1613-1618.
[4]	秦胜飞, 白斌, 袁苗, 等. 四川盆地中部地区海相储层煤成气来源[J]. 天然气地球科学, 2019, 30(6): 790-797. QIN Shengfei, BAI Bin, YUAN Miao, et al. Sources of coal-derived gas in marine strata in central Sichuan[J]. Natural Gas Geoscience, 2019, 30(6): 790-797.
[5]	张洪亮. 四川盆地东部重庆长寿地区早二叠世龙潭组(P₃l)地层、古地理及聚煤特征研究[C]//第十五届全国古地理学及沉积学学术会议摘要集. 成都: 中国矿物岩石地球化学学会岩相古地理专业委员会, 2018: 1. ZHANG Hongliang. Research on the geological strata, paleogeography, and coal-accumulation characteristics of the Longtan Formation (P₃l) in Chongqing Changshou area, eastern Sichuan Basin[C]// Abstracts of the 15th National Symposium on Paleogeography and Sedimentology. Chengdu: China Mineral Geology and Geochemistry Society Subcommittee on Stratigraphy and Paleogeography, 2018: 1.
[6]	宋文燕, 梁仲, 杨靖, 等. 重庆地区二叠系龙潭组煤系地层非常规气地质特征分析[J]. 能源与环保, 2024, 46(2): 118-125. SONG Wenyan, LIANG Zhong, YANG Jing, et al. Analysis of unconventional gas geological characteristics of Permian System Longtan Formation coal measure strata in Chongqing area[J]. China Energy and Environmental Protection, 2024, 46(2): 118-125.
[7]	薛冈, 郭涛, 张烨, 等. 渝南地区二叠系龙潭组C₂₅煤层煤层气基础地质条件分析[J]. 油气藏评价与开发, 2024, 14(3): 492-503. XUE Gang, GUO Tao, ZHANG Ye, et al. Analysis of general geological conditions of coalbed methane in coal seam C₂₅ of Permian Longtan Formation, south Chongqing[J]. Petroleum Reservoir Evaluation and Development, 2024, 14(3): 492-503.
[8]	胡雄, 邬长武, 杨秀春, 等. 低渗透煤层微观孔隙结构与煤层气解吸规律[J]. 特种油气藏, 2024, 31(2): 129-135. doi: 10.3969/j.issn.1006-6535.2024.02.015 HU Xiong, WU Changwu, YANG Xiuchun, et al. Microscopic pore structure and coalbed methane desorption law in low-permeability coal seams[J]. Special Oil & Gas Reservoirs, 2024, 31(2): 129-135. doi: 10.3969/j.issn.1006-6535.2024.02.015
[9]	王伟, 王成旺, 季亮, 等. 大宁—吉县河西区块深部煤层破裂压力预测及分布特征[J]. 断块油气田, 2024, 31(4): 669-675. WANG Wei, WANG Chengwang, JI Liang, et al. Prediction and distribution characteristics of deep coal seam fracture pressure in Hexi block of Daning-Jixian[J]. Fault-Block Oil & Gas Field, 2024, 31(4): 669-675.
[10]	LI Qian, ZHANG Rui, CAI Yidong, et al. CH4 adsorption capacity of coalbed methane reservoirs induced by microscopic differences in pore structure[J]. Unconventional Resources, 2024, 4: 100097. doi: 10.1016/j.uncres.2024.100097
[11]	梁龙军, 陈捷, 颜智华, 等. 六盘水煤田大倾角地层煤层气L型水平井钻完井技术[J]. 断块油气田, 2023, 30(4): 616-623. LIANG Longjun, CHEN Jie, YAN Zhihua, et al. Drilling and completion technology of L-shaped horizontal wells for coalbed methane in high-dip formation in Liupanshui coalfield[J]. Fault- Block Oil & Gas Field, 2023, 30(4): 616-623.
[12]	李小刚, 秦杨, 刘紫微, 等. 微波强化煤层气井压裂开采的物性规律[J]. 特种油气藏, 2024, 31(3): 70-77. LI Xiaogang, QIN Yang, LIU Ziwei, et al. Physical property law of coalbed methane well fracturing development enhanced by microwave[J]. Special Oil & Gas Reservoirs, 2024, 31(3): 70-77.
[13]	陈杨. 沁水盆地南部煤储层水力压裂改造的地质与力学约束机制[D]. 北京: 中国地质大学(北京), 2022. CHEN Yang. Geological and mechanical constraints on hydraulic fracturing reconstruction of coal reservoir in southern Qinshui Basin[D]. Beijing: China University of Geosciences (Beijing), 2022.
[14]	姚红生, 陈贞龙, 郭涛, 等. 延川南深部煤层气地质工程一体化压裂增产实践[J]. 油气藏评价与开发, 2021, 11(3): 291-296. YAO Hongsheng, CHEN Zhenlong, GUO Tao, et al. Stimulation practice of geology-engineering integration fracturing for deep CBM in Yanchuannan Field[J]. Petroleum Reservoir Evaluation and Development, 2021, 11(3): 291-296.
[15]	李可心, 张聪, 李俊, 等. 沁水盆地南部煤层气水平井射孔优化[J]. 新疆石油地质, 2024, 45(5): 581-589. LI Kexin, ZHANG Cong, LI Jun, et al. Optimization of perforation in CBM horizontal wells in southern Qinshui Basin[J]. Xinjiang Petroleum Geology, 2024, 45(5): 581-589.
[16]	唐书恒, 朱宝存, 颜志丰. 地应力对煤层气井水力压裂裂缝发育的影响[J]. 煤炭学报, 2011, 36(1): 65-69. TANG Shuheng, ZHU Baocun, YAN Zhifeng. Effect of crustal stress on hydraulic fracturing in coalbed methane wells[J]. Journal of China Coal Society, 2011, 36(1): 65-69.
[17]	田丰华, 李小刚, 朱文涛, 等. 大宁—吉县区块8号煤裂缝三维特征评价及压裂段优选[J]. 能源与环保, 2023, 45(9): 88-95. TIAN Fenghua, LI Xiaogang, ZHU Wentao, et al. Evaluation of 3D characteristics and optimization of fracturing sections for No. 8 coal seam crack in Daning-Ji County block[J]. China Energy and Environmental Protection, 2023, 45(9): 88-95.
[18]	高向东, 孙昊, 王延斌, 等. 临兴地区深部煤储层地应力场及其对压裂缝形态的控制[J]. 煤炭科学技术, 2022, 50(8): 140-150. GAO Xiangdong, SUN Hao, WANG Yanbin, et al. In-situ stress field of deep coal reservoir in Linxing area and its control on fracturing crack[J]. Coal Science and Technology, 2022, 50(8): 140-150.
[19]	边利恒, 张亮, 刘清. 天然裂隙对煤层气压裂效果的影响: 以鄂尔多斯盆地韩城区块为例[J]. 天然气工业, 2018, 38(S1): 129-133. BIAN Liheng, ZHANG Liang, LIU Qing. The effect of natural fractures on coal seam hydraulic fracturing: a case study of Hancheng block in Ordos Basin[J]. Natural Gas Industry, 2018, 38(S1): 129-133.
[20]	梅廉夫, 刘昭茜, 汤济广, 等. 湘鄂西—川东中生代陆内递进扩展变形: 来自裂变径迹和平衡剖面的证据[J]. 地球科学(中国地质大学学报), 2010, 35(2): 161-174. MEI Lianfu, LIU Zhaoqian, TANG Jiguang, et al. Mesozoic intra-continental progressive deformation in western Hunan-Hubei- eastern Sichuan Provinces of China: evidence from apatite fission track and balanced cross-section[J]. Earth Science (Journal of China University of Geoscience), 2010, 35(2): 161-174.
[21]	何希鹏, 张培先, 任建华, 等. 渝东南南川地区东胜构造带常压页岩气勘探开发实践[J]. 石油实验地质, 2023, 45(6): 1057-1066. doi: 10.11781/sysydz2023061057 HE Xipeng, ZHANG Peixian, REN Jianhua, et al. Exploration and development practice of normal pressure shale gas in Dongsheng structural belt, Nanchuan area, southeast Chongqing[J]. Petroleum Geology & Experiment, 2023, 45(6): 1057-1066. doi: 10.11781/sysydz2023061057
[22]	冯动军. 川东南二叠系龙潭组海—陆过渡相页岩气甜点评价及意义[J]. 石油与天然气地质, 2023, 44(3): 778-788. FENG Dongjun. Sweet spot assessment and its significance for the marine-continental transitional shale gas of Permian Longtan Fm. in southeastern Sichuan Basin[J]. Oil & Gas Geology, 2023, 44(3): 778-788.
[23]	王运海, 贺庆, 朱智超, 等. 渝东南南川地区常压页岩气示范井应用评价及推广效果[J]. 石油实验地质, 2023, 45(6): 1160-1169. doi: 10.11781/sysydz2023061160 WANG Yunhai, HE Qing, ZHU Zhichao, et al. Application evaluation and promotion effect of normal pressure shale gas demonstration well in Nanchuan area in southeastern Chongqing[J]. Petroleum Geology & Experiment, 2023, 45(6): 1160-1169. doi: 10.11781/sysydz2023061160
[24]	高令宇, 陈孔全, 陆建林, 等. 构造作用对常规—非常规油气连续聚积耦合成藏控制机制: 以川东南平桥地区为例[J]. 石油实验地质, 2024, 46(3): 565-575. doi: 10.11781/sysydz202403565 GAO Lingyu, CHEN Kongquan, LU Jianlin, et al. Control mechanism of tectonic action on continuous accumulation and coupling of conventional-unconventional oil and gas reservoirs: a case study of Pingqiao area, southeastern Sichuan Basin[J]. Petroleum Geology & Experiment, 2024, 46(3): 565-575. doi: 10.11781/sysydz202403565
[25]	汤济广, 汪凯明, 秦德超, 等. 川东南南川地区构造变形与页岩气富集[J]. 地质科技通报, 2021, 40(5): 11-21. TANG Jiguang, WANG Kaiming, QIN Dechao, et al. Tectonic deformation and its constraints to shale gas accumulation in Nanchuan area, southeastern Sichuan Basin[J]. Bulletin of Geological Science and Technology, 2021, 40(5): 11-21.
[26]	李昌昊, 时志强, 闫长辉, 等. 川东南地区上二叠统龙潭组沉积相新认识[C]//第十七届全国古地理学及沉积学学术会议摘要集——专题3 : 河流—三角洲—大陆架体系沉积过程、记录及模拟. 青岛: 中国矿物岩石地球化学学会岩相古地理专业委员会, 2023: 2. LI Changhao, SHI Zhiqiang, YAN Changhui, et al. New insights into sedimentary facies of the Longtan Formation in the Upper Permian of the Chuanbeizong area[C]//Abstracts of the 17th National Symposium on Paleogeography and Sedimentology-Topic 3: Sedimentation processes, records, and simulation of river-deltas-continental shelf systems. Qingdao: Committee on Paleostratigraphy and Paleogeography of the Chinese Mineralogical Society, 2023: 2.
[27]	刘尽贤. 渝东南南川地区深层煤层特征与煤层气赋存状态研究[J]. 中国煤炭地质, 2024, 36(6): 18-26. LIU Jinxian. Characteristics of deep coal seam and occurrence state of coalbed methane in Nanchuan, southeast Chongqing[J]. Coal Geology of China, 2024, 36(6): 18-26.
[28]	姜洪丰, 柳兵, 高永德, 等. 涠西南流沙港组页岩储层地质特征及可压性评价[J]. 科学技术与工程, 2024, 24(15): 6241-6253. doi: 10.12404/j.issn.1671-1815.2304624 JIANG Hongfeng, LIU Bing, GAO Yongde, et al. Geological characteristics and evaluation of fracturability of Weixinan Liushagang Formation shale reservoirs[J]. Science Technology and Engineering, 2024, 24(15): 6241-6253. doi: 10.12404/j.issn.1671-1815.2304624
[29]	余坤, 屈争辉, 余可龙, 等. 淮南矿区新集矿1001井煤系泥岩脆性矿物及其沉积控制[J]. 煤田地质与勘探, 2017, 45(6): 14-21. doi: 10.3969/j.issn.1001-1986.2017.06.003 YU Kun, QU Zhenghui, YU Kelong, et al. Brittle minerals and depositional control of mudstone in coal measures form in well 1001 in Huainan mining area[J]. Coal Geology & Exploration, 2017, 45(6): 14-21. doi: 10.3969/j.issn.1001-1986.2017.06.003
[30]	DAI Shifeng, ZHANG Weiguo, WARD C R, et al. Mineralogical and geochemical anomalies of Late Permian coals from the Fusui Coalfield, Guangxi Province, southern China: influences of terrigenous materials and hydrothermal fluids[J]. International Journal of Coal Geology, 2013, 105: 60-84. doi: 10.1016/j.coal.2012.12.003
[31]	CHEN Jian, LIU Guijian, LI Hui, et al. Mineralogical and geochemical responses of coal to igneous intrusion in the Pansan Coal Mine of the Huainan coalfield, Anhui, China[J]. International Journal of Coal Geology, 2014, 124: 11-35. doi: 10.1016/j.coal.2013.12.018
[32]	杜佳宗, 蔡进功, 谢忠怀, 等. 泥岩埋藏成岩过程中绿泥石的演化途径及意义[J]. 高校地质学报, 2018, 24(3): 371-379. DU Jiazong, CAI Jingong, XIE Zhonghuai, et al. Chloritization sequences in mudstone during diagenesis and its geological significance[J]. Geological Journal of China Universities, 2018, 24(3): 371-379.
[33]	冯兴凯. 煤储层破裂压力对压裂改造的影响与工程应用[J]. 煤矿安全, 2024, 55(3): 84-90. FENG Xingkai. Influence of coal reservoir fracture pressure on fracturing reconstruction and its engineering application[J]. Safety in Coal Mines, 2024, 55(3): 84-90.
[34]	LIU Jun, YAO Yaobin, LIU Dameng, et al. Experimental simulation of the hydraulic fracture propagation in an anthracite coal reservoir in the southern Qinshui Basin, China[J]. Journal of Petroleum Science and Engineering, 2018, 168: 400-408. doi: 10.1016/j.petrol.2018.05.035
[35]	赵志刚, 朱学申, 王存武, 等. 基于资源性与可压性的深部煤层气"甜点"预测[J]. 煤田地质与勘探, 2024, 52(8): 22-31. ZHAO Zhigang, ZHU Xueshen, WANG Cunwu, et al. Predicting the 'sweet spot' of deep coalbed methane based on resource conditions and fracability[J]. Coal Geology & Exploration, 2024, 52(8): 22-31.
[36]	李金平, 潘军, 李勇, 等. 基于流动物质平衡理论的煤层气井定量化排采新方法[J]. 天然气工业, 2023, 43(6): 87-95. doi: 10.3787/j.issn.1000-0976.2023.06.008 LI Jinping, PAN Jun, LI Yong, et al. A new CBM well quantitative production method based on the flow material balance theory[J]. Natural Gas Industry, 2023, 43(6): 87-95. doi: 10.3787/j.issn.1000-0976.2023.06.008
[37]	姚艳斌, 王辉, 杨延辉, 等. 煤层气储层可改造性评价: 以郑庄区块为例[J]. 煤田地质与勘探, 2021, 49(1): 119-129. doi: 10.3969/j.issn.1001-1986.2021.01.012 YAO Yanbin, WANG Hui, YANG Yanhui, et al. Evaluation of the hydro-fracturing potential for coalbed methane reservoir: a case study of Zhengzhuang CBM field[J]. Coal Geology & Exploration, 2021, 49(1): 119-129. doi: 10.3969/j.issn.1001-1986.2021.01.012
[38]	李文博. 碎软煤层井下顶板长钻孔分段水力压裂瓦斯抽采技术研究[D]. 北京: 煤炭科学研究总院, 2023. LI Wenbo. Study on gas drainage technology of long borehole staged hydraulic fracturing in underground roof of broken and soft coal seam[D]. Beijing: China Coal Research Institute, 2023.
[39]	刘晓. 不同压裂规模下煤储层缝网形态对比研究: 以延川南煤层气田为例[J]. 油气藏评价与开发, 2024, 14(3): 510-518. LIU Xiao. Comparison of seam network morphology in coal reservoirs under different fracturing scales: a case of Yanchuannan CBM Gas Field[J]. Petroleum Reservoir Evaluation and Development, 2024, 14(3): 510-518.
[40]	孔祥伟, 谢昕, 王存武. 基于综合可压指数的煤层气水平井压裂分段参数优化[J]. 油气藏评价与开发, 2024, 14(6): 925-932. KONG Xiangwei, XIE Xin, WANG Cunwu. Optimization of segmented fracturing parameters for coalbed methane horizontal wells based on comprehensive fracability index[J]. Petroleum Reservoir Evaluation and Development, 2024, 14(6): 925-932.

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Compressibility characteristics and modification effect of coal reservoirs in Longtan Formation, Nanchuan area, southeast Chongqing

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