Exploring the principle and method for commingled production of coal-measure gas through layered pressure relief in surface wells

Authors

LI Rui, State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; National & Local Joint Engineering Laboratory of Gas Drainage in Complex Coal Seam, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, ChinaFollow
JIN Lihong, School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China
XIA Binwei, State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; National & Local Joint Engineering Laboratory of Gas Drainage in Complex Coal Seam, Chongqing University, Chongqing 400044, China
GE Zhaolong, State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; National & Local Joint Engineering Laboratory of Gas Drainage in Complex Coal Seam, Chongqing University, Chongqing 400044, China; School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China

Abstract

This study aims to gain an in-depth understanding of factors restricting the commingled production of coal-measure gas and boost the contributions of various pay zones to gas production. To this end, it analyzed the essential factors of the dynamic, channel, and gas source conditions in the commingled production. The dynamic conditions for the commingled exploitation of multiple reservoirs can be met by (1) enhancing the flow conductivity of reservoirs by altering the crustal stress state and (2) changing reservoir fluid pressure by layers. Following this principle, this study proposed a method for the commingled production of coal-measure gas through layered pressure relief in surface wells. This method involves directional drilling on the surface and then high-pressure water jet in target reservoirs to artificially create pressure-relief spaces (e.g., fractures, slots, and cavities) and alter the crustal stress state. This can reduce the damage caused by effective stress, increase the number and aperture of diversion channels in reservoirs, and accelerate pressure drop transfer in target reservoirs. Afterward, commingled production can be conducted after the reservoir pressure decreases to the dynamic conditions for the commingled production of coal-measure gas, thus enhancing the contributions of pay zones to gas production. Compared to conventional reservoir stimulation, this method can reduce the damage of effective stress to coal-measure gas reservoirs, improve the transfer efficiency of pressure drop, enhance the desorption and diffusion of coal-measure gas, and decrease the interlayer interference during the commingled production of multiple coal-measure gas reservoirs. Based on these findings, this study proposed that the commingled production of coal-measure gas through layered pressure relief in surface wells is primarily applicable to coal-measure gas reservoirs with high crustal stress and small spacings between pay zones. Furthermore, this method is expected to be widely applied to the stimulation of coal-measure gas reservoirs with thin interbeds for production growth and to the exploitation of superimposed paragenetic coal-measure reservoirs with severe interlayer interference.

Keywords

coal-measure gas, layered pressure relief, commingled production of multiple reservoirs, high-pressure water jet, crustal stress, effective stress

DOI

10.12363/issn.1001-1986.23.10.0701

Recommended Citation

LI Rui, JIN Lihong, XIA Binwei, et al. (2024) "Exploring the principle and method for commingled production of coal-measure gas through layered pressure relief in surface wells," Coal Geology & Exploration: Vol. 52: Iss. 2, Article 18.
DOI: 10.12363/issn.1001-1986.23.10.0701
Available at: https://cge.researchcommons.org/journal/vol52/iss2/18

Reference

[1] OUYANG Yonglin，TIAN Wenguang，SUN Bin，et al. Accumulation characteristics and exploration strategies of coal measure gas in China[J]. Natural Gas Industry B，2018，5(5)：444−451.

[2] QIN Yong. Research progress of symbiotic accumulation of coal measure gas in China[J]. Natural Gas Industry B，2018，5(5)：466−474.

[3] 陈尚斌，侯晓伟，屈晓荣，等. 煤系气叠置含气系统与天然气成藏特征：以沁水盆地榆社–武乡示范区为例[J]. 天然气工业，2023，43(5)：12−22.

CHEN Shangbin，HOU Xiaowei，QU Xiaorong，et al. Superimposed gas–bearing system of coal measure gas and its natural gas accumulation characteristics：A case study of Yushe–Wuxiang demonstration area in the Qinshui Basin[J]. Natural Gas Industry，2023，43(5)：12−22.

[4] LIU Lingli，WANG Jianjun，SU Penghui，et al. Experimental study on interlayer interference of coalbed methane reservoir under different reservoir physical properties and pressure systems[J]. Journal of Petroleum Exploration and Production Technology，2022，12(12)：3263−3274.

[5] JIA Li，PENG Shoujian，XU Jiang，et al. Interlayer interference during coalbed methane coproduction in multilayer superimposed gas–bearing system by 3D monitoring of reservoir pressure：An experimental study[J]. Fuel，2021，304：121472.

[6] WANG Chaowen，JIA Chunsheng，PENG Xiaolong，et al. Effects of wellbore interference on concurrent gas production from multilayered tight sands：A case study in eastern Ordos Basin，China[J]. Journal of Petroleum Science and Engineering，2019，179：707−715.

[7] 胡进奎，杜文凤. 浅析煤系地层“三气合采”可行性[J]. 地质论评，2017，63(增刊1)：83−84.

HU Jinkui，DU Wenfeng. Analysis on feasibility of three gas co–exploration in coal measure strata keywords：Coal measure strata;coalbed methane;shale gas;tight sandstone gas;“three gas co–exploration”[J]. Geological Review，2017，63(Sup.1)：83−84.

[8] 魏虎超，封蓉，张亮，等. 煤系多气合采层间干扰特征数值模拟研究：2020油气田勘探与开发国际会议[C]. 成都，2020.

[9] 许耀波. 煤层气井合层开发层间干扰分析与合采方法探讨：以平顶山首山一矿为例[J]. 煤田地质与勘探，2021，49(3)：112−117.

XU Yaobo. Analysis of interlayer interference in combined development of coalbed methane wells and discussion on combined production methods：A case study of Shoushan No.1 Coal Mine in Pingdingshan[J]. Coal Geology & Exploration，2021，49(3)：112−117.

[10] 李国璋，秦勇. 煤系气合采兼容性物理模拟：以鄂尔多斯盆地临兴区块为例：第十六届全国古地理学及沉积学学术会议[C]. 西安，2021.

[11] DAI Shijie，XU Jiang，LI Jia，et al. On the 3D fluid behavior during CBM coproduction in a multi pressure system：Insights from experimental analysis and mathematical models[J]. Energy，2023，283：129088.

[12] 全方凯. 叠置含煤层气系统合采储层动态及层间干扰量化判识[D]. 徐州：中国矿业大学，2023.

QUAN Fangkai. Reservoir dynamics and interlayer interference quantification during methane co–production from superimposed CBM system[D]. Xuzhou：China University of Mining & Technology，2023.

[13] 张和伟，申建，李可心，等. 鄂尔多斯盆地临兴西区深煤层地应力场特征及应力变化分析[J]. 地质与勘探，2020，56(4)：809−818.

ZHANG Hewei，SHEN Jian，LI Kexin，et al. Characteristics of the in–situ stress field and stress change of deep coal seams in the western Linxing area，Ordos Basin[J]. Geology and Exploration，2020，56(4)：809−818.

[14] 朱光辉，李本亮，李忠城，等. 鄂尔多斯盆地东缘非常规天然气勘探实践及发展方向：以临兴–神府气田为例[J]. 中国海上油气，2022，34(4)：16−29.

ZHU Guanghui，LI Benliang，LI Zhongcheng，et al. Practices and development trend of unconventional natural gas exploration in eastern margin of Ordos Basin：Taking Linxing–Shenfu gas field as an example[J]. China Offshore Oil and Gas，2022，34(4)：16−29.

[15] 苏育飞，宋儒. 沁水盆地榆社武乡区块深部煤层气地质特征研究及可改造性评价[J]. 中国煤炭地质，2023，35(5)：46−57.

SU Yufei，SONG Ru. Study on geological characteristics of deep CBM in Yushewu Block，Qinshui Basin and evaluation of transformability[J]. Coal Geology of China，2023，35(5)：46−57.

[16] LI Rui，WANG Shengwei，LYU Shuaifeng，et al. Geometry and filling features of hydraulic fractures in coalbed methane reservoirs based on subsurface observations[J]. Rock Mechanics and Rock Engineering，2020，53(5)：2485−2492.

[17] 李瑞，卢义玉，葛兆龙，等. 地面井卸压的煤层气开发新模式[J]. 天然气工业，2022，42(7)：75−84.

LI Rui，LU Yiyu，GE Zhaolong，et al. A new CBM development mode：Surface well pressure relief[J]. Natural Gas Industry，2022，42(7)：75−84.

[18] 桑树勋，周效志，刘世奇，等. 应力释放构造煤煤层气开发理论与关键技术研究进展[J]. 煤炭学报，2020，45(7)：2531−2543.

SANG Shuxun，ZHOU Xiaozhi，LIU Shiqi，et al. Research advances in theory and technology of the stress release applied extraction of coalbed methane from tectonically deformed coals[J]. Journal of China Coal Society，2020，45(7)：2531−2543.

[19] 郑司建，桑树勋. 煤层气勘探开发研究进展与发展趋势[J]. 石油物探，2022，61(6)：951−962.

ZHENG Sijian，SANG Shuxun. Progress of research on coalbed methane exploration and development[J]. Geophysical Prospecting for Petroleum，2022，61(6)：951−962.

[20] 田守嶒，黄中伟，李根生，等. 径向井复合脉动水力压裂煤层气储层解堵和增产室内实验[J]. 天然气工业，2018，38(9)：88−94.

TIAN Shouceng，HUANG Zhongwei，LI Gensheng，et al. Laboratory experiments on blockage removing and stimulation of CBM reservoirs by composite pulsating fracturing of radial horizontal wells[J]. Natural Gas Industry，2018，38(9)：88−94.

[21] 李根生，黄中伟，李敬彬. 水力喷射径向水平井钻井关键技术研究[J]. 石油钻探技术，2017，45(2)：1−9.

LI Gensheng，HUANG Zhongwei，LI Jingbin. Study of the key techniques in radial jet drilling[J]. Petroleum Drilling Techniques，2017，45(2)：1−9.

[22] 卢义玉，葛兆龙，陈久福，等. 煤矿井下割缝复合水力压裂增透技术及应用[R]. 重庆：重庆大学，2015.

[23] 郭君. 低透气性松软煤层高压水力割缝增透机理研究及应用[D]. 北京：北京科技大学，2019.

GUO Jun. Research and application on high pressure hydraulic slitting in soft coal seam with low permeability[D]. Beijing：University of Science and Technology Beijing，2019.

[24] 毕彩芹，胡志方，汤达祯，等. 煤系气研究进展与待解决的重要科学问题[J]. 中国地质，2021，48(2)：402−423.

BI Caiqin，HU Zhifang，TANG Dazhen，et al. Research progress of coal measure gas and some important scientific problems[J]. Geology in China，2021，48(2)：402−423.

[25] 桑树勋，郑司建，易同生，等. 煤系叠合型气藏及其勘探开发技术模式[J]. 煤田地质与勘探，2022，50(9)：13−21.

SANG Shuxun，ZHENG Sijian，YI Tongsheng，et al. Coal measures superimposed gas reservoir and its exploration and development technology modes[J]. Coal Geology & Exploration，2022，50(9)：13−21.

[26] 陈世达. 黔西多煤层煤层气储渗机制及合层开发技术对策[D]. 北京：中国地质大学(北京)，2020.

CHEN Shida. Permeable–storage mechanism and the development technical countermeasures for coalbed methane in multi–seams in western Guizhou[D]. Beijing：China University of Geosciences (Beijing)，2020.

[27] 黄华州，桑树勋，毕彩芹，等. 煤层群煤系多套含气系统特征及其合采效果：以铁法盆地阜新组为例[J]. 沉积学报，2021，39(3)：645−655.

HUANG Huazhou，SANG Shuxun，BI Caiqin，et al. Characteristics of multi–gas–bearing systems within coal seam groups and the effect of commingled production：A case study on Fuxin Formation，Cretaceous，Tiefa Basin[J]. Acta Sedimentologica Sinica，2021，39(3)：645−655.

[28] 秦勇，吴建光，李国璋，等. 煤系气开采模式探索及先导工程示范[J]. 煤炭学报，2020，45(7)：2513−2522.

QIN Yong，WU Jianguang，LI Guozhang，et al. Patterns and pilot project demonstration of coal measures gas production[J]. Journal of China Coal Society，2020，45(7)：2513−2522.

[29] 郭晨，秦勇，易同生，等. 煤层气合采地质研究进展述评[J]. 煤田地质与勘探，2022，50(3)：42−57.

GUO Chen，QIN Yong，YI Tongsheng，et al. Review of the progress of geological research on coalbed methane co–production[J]. Coal Geology & Exploration，2022，50(3)：42−57.

[30] SHEN Jian，LI Kexin，ZHANG Hewei，et al. The geochemical characteristics，origin，migration and accumulation modes of deep coal–measure gas in the west of Linxing Block at the eastern margin of Ordos Basin[J]. Journal of Natural Gas Science and Engineering，2021，91：103965.

[31] GAO Deli，BI Yansen，XIAN Baoan. Technical advances in well type and drilling & completion for high–efficient development of coalbed methane in China[J]. Natural Gas Industry B，2022，9(6)：561−577.

[32] TAO Shu，PAN Zhejun，TANG Shuling，et al. Current status and geological conditions for the applicability of CBM drilling technologies in China：A review[J]. International Journal of Coal Geology，2019，202：95−108.

[33] 徐凤银，闫霞，林振盘，等. 我国煤层气高效开发关键技术研究进展与发展方向[J]. 煤田地质与勘探，2022，50(3)：1−14.

XU Fengyin，YAN Xia，LIN Zhenpan，et al. Research progress and development direction of key technologies for efficient coalbed methane development in China[J]. Coal Geology & Exploration，2022，50(3)：1−14.

[34] 杨增强，王琛艳，朱栋，等. 高压水射流钻割一体化防冲机理分析及其数值模拟研究[J]. 矿业安全与环保，2021，48(1)：17−22.

YANG Zengqiang，WANG Chenyan，ZHU Dong，et al. Analysis and numerical simulation of high pressure water jet drilling–cutting integration for rock burst prevention mechanism[J]. Mining Safety & Environmental Protection，2021，48(1)：17−22.

[35] 李瑞. 煤层气排采中储层压降传递特征及其对煤层气产出的影响：以山西沁水盆地为例[D]. 武汉：中国地质大学，2017.

LI Rui. Dynamic characteristics of reservoir depressurization during coalbed methane reservoir depletion and its influences on gas output in the Qinshui Basin，Shanxi Province[D]. Wuhan：China University of Geosciences，2017.

[36] 伊向艺，吴红军，卢渊，等. 寺河煤矿煤岩颗粒解吸–扩散特征实验研究[J]. 煤炭工程，2013，45(3)：111−112.

YI Xiangyi，WU Hongjun，LU Yuan，et al. Experiment study on desorption–diffusion features of coal and rock particles from Sihe Mine[J]. Coal Engineering，2013，45(3)：111−112.

[37] 葛兆龙，卢义玉，周哲，等. 煤层控制水力压裂裂缝导向扩展理论与技术[M]. 北京：科学出版社，2020.

[38] 时亚军，武沛武，王佳，等. 高压水射流卸压增透石门揭煤技术研究[J]. 中国煤炭，2012，38(11)：90−93.

SHI Yajun，WU Peiwu，WANG Jia，et al. Research on rock cross–cut coal uncovering via high–pressure water jet to release pressure and improve permeability[J]. China Coal，2012，38(11)：90−93.

[39] 卢义玉，夏彬伟，葛兆龙，等. 水力化煤层增透理论及技术[M]. 北京：科学出版社，2016.

[40] 秦勇，申建，史锐. 中国煤系气大产业建设战略价值与战略选择[J]. 煤炭学报，2022，47(1)：371−387.

QIN Yong，SHEN Jian，SHI Rui. Strategic value and choice on construction of large CMG industry in China[J]. Journal of China Coal Society，2022，47(1)：371−387.

[41] 郭涛，高小康，孟贵希，等. 织金区块煤层气合采生产特征及开发策略[J]. 煤田地质与勘探，2019，47(6)：14−19.

GUO Tao，GAO Xiaokang，MENG Guixi，et al. Combined CBM production behavior and development strategy of multiple coal seams in Zhijin Block[J]. Coal Geology & Exploration，2019，47(6)：14−19.

[42] 张雷，徐凤银，李子玲，等. 煤层气田单/合层开发影响因素分析及应用：以保德区块为例[J]. 煤田地质与勘探，2022，50(9)：68−77.

ZHANG Lei，XU Fengyin，LI Ziling，et al. Analysis on influencing factors of single/multi–layer development of coalbed methane field：A case study of Baode Block[J]. Coal Geology & Exploration，2022，50(9)：68−77.