Characteristics of the shale gas reservoirs and evaluation of sweet spots in Wufeng Formation and Longmaxi Formation in Jingmen exploration area

Authors

LI Xiaoming, Safety Engineering Center, North China Institute of Science and Technology, Beijing 101601, China
LIU Jirong, Safety Engineering Center, North China Institute of Science and Technology, Beijing 101601, China
LIN Wen, Department of Shale Gas, Research Institute of Petroleum Exploration and Development, Beijing 100083
MA Lihong, Safety Engineering Center, North China Institute of Science and Technology, Beijing 101601, ChinaFollow
LIU Dexun, Department of Shale Gas, Research Institute of Petroleum Exploration and Development, Beijing 100083
CHEN Yujie, Safety Engineering Center, North China Institute of Science and Technology, Beijing 101601, China

Abstract

In order to further clarify the resource potential of shale gas from Wufeng Formation to Longmaxi Formation in Jingmen exploration area, sweet spots were selected. The shale in Wufeng Formation and 1th Member of Longmaxi Formation of the well X was taken as the research object in this study. Using sliced kerogen, X-ray diffraction, nuclear magnetic resonance, micro nano CT scanning, geochemical analysis and other testing methods, combined with logging interpretation results, based on the petrology, organic geochemical and mineral composition, physical properties, pore types and structure characteristics and hydrocarbon content, the reservoir characteristics of Wufeng-1^th Member of the Longmaxi Formation were evaluated, and the longitudinal shale gas sweet spots were optimized. The results show that: (1) Wufeng-1^th Member of the Longmaxi Formation is mainly composed of siliceous shale mainly forming the reduction environments in the deep shelf facies. The natural gas in the high-quality shale section has high natural gas quality and excellent organic geochemical characteristics; (2) There is a positive correlation between porosity and permeability measured by various methods. The NMR T2 spectrum of water -saturated shale can be divided into 2 types and 5 types. The pore size distribution of shale reflected by different types of T2 spectrum is different. The isolated pores mainly exist in micropores smaller than 2 nm, which accounts for a very small proportion; (3) Based on the comprehensive evaluation of reservoir characteristics Long \begin{document}$_1^1$\end{document}- Long \begin{document}$_1^2$\end{document} layer were selected as type I reservoir, the upper Wufeng Formation and Long \begin{document}$_1^3$\end{document} layers were classified as type Ⅱ reservoirs, and Long \begin{document}$_1^4$\end{document} layer as type Ⅲ reservoir. The upper Wufeng Formation-Long₁³ small layer (about 17.7 m thick) namely carbon-rich high silicon shale section is a shale gas sweet spot. The research results can provide a reference for determining the horizontal well target segments for shale gas exploration and development in Jingmen exploration area.

Keywords

Jingmen exploration area, Wufeng Formation and Longmaxi Formation, reservoir character, sweet spot

DOI

10.3969/j.issn.1001-1986.2021.06.001

Recommended Citation

LI Xiaoming, LIU Jirong, LIN Wen, et al. (2021) "Characteristics of the shale gas reservoirs and evaluation of sweet spots in Wufeng Formation and Longmaxi Formation in Jingmen exploration area," Coal Geology & Exploration: Vol. 49: Iss. 6, Article 2.
DOI: 10.3969/j.issn.1001-1986.2021.06.001
Available at: https://cge.researchcommons.org/journal/vol49/iss6/2

Reference

[1] ZHANG Junfeng, XU Hao, ZHOU Zhi, et al. Geological characteristics of shale gas reservoir in Yichang area, western Hubei[J]. Acta Petrolei Sinica, 2019, 40(8): 887-899. 张君峰, 许浩, 周志, 等. 鄂西宜昌地区页岩气成藏地质特征[J]. 石油学报, 2019, 40(8): 887-899.

[2] JIN Zhijun, HU Zongquan, GAO Bo, et al. Controlling factors on the enrichment and high productivity of shale gas in the Wufeng-Longmaxi Formations, southeastern Sichuan Basin[J]. Earth Science Frontiers, 2016, 23(1): 1-10. 金之钧, 胡宗全, 高波, 等. 川东南地区五峰组-龙马溪组页岩气富集与高产控制因素[J]. 地学前缘, 2016, 23(1): 1-10.

[3] WANG Pengwan, LI Chang, ZHANG Lei, et al. Characteristic of the shale gas reservoirs and evaluation of sweet spot in Wufeng-Longmaxi Formation: A case from the a well in Zhaotong shale gas demonstration zone[J]. Journal of China Coal Society, 2017, 42(11): 2925-2935. 王鹏万, 李昌, 张磊, 等. 五峰组-龙马溪组储层特征及甜点层段评价: 以昭通页岩气示范区A井为例[J]. 煤炭学报, 2017, 42(11): 2925-2935.

[4] GUO Man, LI Xianqing, ZHANG Mingyang, et al. Reservoir-forming conditions and evaluation of favorable area of shale gas in Niutitang Formation in Northern Guizhou[J]. Coal Geology & Exploration, 2015, 43(2): 37-43. 郭曼, 李贤庆, 张明扬, 等. 黔北地区牛蹄塘组页岩气成藏条件及有利区评价[J]. 煤田地质与勘探, 2015, 43(2): 37-43.

[5] ZHANG Hui, WEI Xiaoyan, YANG Qinglong, et al. The morphology-origin types of mineral pores in the marine shale reservoir[J]. Coal Geology & Exploration, 2018, 46(4): 72-78. 张慧, 魏小燕, 杨庆龙, 等. 海相页岩储层矿物质孔隙的形貌-成因类型[J]. 煤田地质与勘探, 2018, 46(4): 72-78.

[6] LIANG Mai, TAN Xianfeng, CHEN Xianjun, et al. Sequence stratigraphy of Wufeng-Longmaxi Formation in the southeastern Chongqing area and its geological significance[J]. Coal Geology & Exploration, 2018, 46(6): 40-51. 梁迈, 谭先锋, 陈现军, 等. 渝东南地区五峰-龙马溪组层序地层特征及地质意义[J]. 煤田地质与勘探, 2018, 46(6): 40-51.

[7] MA Yanni. Shale reservoir characteristics and gas bearing controlling factors of Longmaxi Formation in Jingmen area[D]. Chengdu: Southwest Petroleum University, 2015. 马燕妮. 荆门地区龙马溪组页岩储层特征及含气性控制因素分析[D]. 成都: 西南石油大学, 2015.

[8] DENG Mingzhe, HE Dengfa. The geological structure in the Dangyang area and its significance to the shale gas exploration in Yichang area, China[J]. Journal of Chengdu University of Technology(Science & Technology Edition), 2018, 45(4): 487-500. 邓铭哲, 何登发. 当阳地区地质结构及其对宜昌地区志留系页岩气勘探的意义[J]. 成都理工大学学报(自然科学版), 2018, 45(4): 487-500.

[9] JI Wenming, SONG Yan, JIANG Zhenxue, et al. Micro-nano pore structure characteristics and its control factors of shale in Longmaxi Formation, southeastern Sichuan Basin[J]. Acta Petrolei Sinica, 2016, 37(2): 182-195. 纪文明, 宋岩, 姜振学, 等. 四川盆地东南部龙马溪组页岩微-纳米孔隙结构特征及控制因素[J]. 石油学报, 2016, 37(2): 182-195.

[10] CHEN Zhipeng, LIANG Xing, ZHANG Jiehui, et al. Genesis analysis of shale reservoir over pressure of Longmaxi Formation in Zhaotong demonstration area, Dianqianbei Depression[J]. Natural Gas Geoscience, 2016, 27(3): 442-448. 陈志鹏, 梁兴, 张介辉, 等. 昭通国家级示范区龙马溪组页岩气储层超压成因浅析[J]. 天然气地球科学, 2016, 27(3): 442-448.

[11] ZOU Caineng, DONG Dazhong, WANG Yuman, et al. Shale gas in China: Characteristics, challenges and prospects(Ⅰ)[J]. Petroleum Exploration and Development, 2015, 42(6): 689-701. 邹才能, 董大忠, 王玉满, 等. 中国页岩气特征、挑战及前景(一)[J]. 石油勘探与开发, 2015, 42(6): 689-701.

[12] LIU An, BAO Hanyong, LI Hai, et al. Analysis of the shale gas geological conditions of the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in Hubei Province and predict the favorable zone[J]. Geology and Mineral Resources of South China, 2016, 32(2): 126-134. 刘安, 包汉勇, 李海, 等. 湖北省上奥陶统五峰组-下志留统龙马溪组页岩气地质条件分析及有利区带预测[J]. 华南地质与矿产, 2016, 32(2): 126-134.

[13] XU Zuxin, GUO Shaobin. Application of NMR and X-CT technology in the pore structure study of shale gas reservoirs[J]. Advances in Earth Science, 2014, 29(5): 624-631. 徐祖新, 郭少斌. 基于NMR和X-CT的页岩储层孔隙结构研究[J]. 地球科学进展, 2014, 29(5): 624-631.

[14] LI Zhiqing, SUN Yang, HU Ruilin, et al. Quantitative analysis for nanopore structure characteristics of shales using NMR and NMR cryoporometry[J]. Journal of Engineering Geology, 2018, 26(3): 758-766. 李志清, 孙洋, 胡瑞林, 等. 基于核磁共振法的页岩纳米孔隙结构特征研究[J]. 工程地质学报, 2018, 26(3): 758-766.

[15] WANG He, SHI Yongmin, XU Dawei, et al. Unconventional reservoir pore structure characterization techniques and progress[J]. Petroleum Geology and Recovery Efficiency, 2019, 26(5): 21-30. 汪贺, 师永民, 徐大卫, 等. 非常规储层孔隙结构表征技术及进展[J]. 油气地质与采收率, 2019, 26(5): 21-30.

[16] WANG Kun, ZHOU Hangyu, LAI Jie, et al. Application of NMR technology in characterization of petrophysics and pore structure[J]. Chinese Journal of Scientific Instrument, 2020, 41(2): 101-114. 王琨, 周航宇, 赖杰, 等. 核磁共振技术在岩石物理与孔隙结构表征中的应用[J]. 仪器仪表学报, 2020, 41(2): 101-114.

[17] LI Zhiyuan, CUI Yunjiang, GUAN Yeqin, et al. Permeability confirmation method of low porosity and permeability reservoirs based on pore distribution and T₂ spectrum[J]. Journal of China University of Petroleum(Edition of Natural Science), 2018, 42(4): 34-40. 李志愿, 崔云江, 关叶钦, 等. 基于孔径分布和T₂谱的低孔渗储层渗透率确定方法[J]. 中国石油大学学报(自然科学版), 2018, 42(4): 34-40.

[18] FU Yonghong, SIMA Liqiang, ZHANG Kaichen, et al. Preliminary study and comparison of shale core gas-porosity test parameters[J]. Special Oil & Gas Reservoirs, 2018, 25(3): 144-148. 付永红, 司马立强, 张楷晨, 等. 页岩岩心气测孔隙度测量参数初探与对比[J]. 特种油气藏, 2018, 25(3): 144-148.

[19] GE Mingna, REN Shoumai, GUO Tianxu, et al. Identification method of marine shale gas "high-quality layer" in the Lower Paleozoic area, southern China and its application[J]. Rock and Mineral Analysis, 2020, 39(3): 350-361. 葛明娜, 任收麦, 郭天旭, 等. 中国南方下古生界海相页岩气"优质层段"识别方法与应用[J]. 岩矿测试, 2020, 39(3): 350-361.

[20] LIU Shugen, JIAO Kun, ZHANG Jinchuan, et al. Research progress on the pore characteristics of deep shale gas reservoirs: An example from the Lower Paleozoic marine shale in the Sichuan Basin[J]. Natural Gas Industry, 2021, 41(1): 29-41. 刘树根, 焦堃, 张金川, 等. 深层页岩气储层孔隙特征研究进展: 以四川盆地下古生界海相页岩层系为例[J]. 天然气工业, 2021, 41(1): 29-41.

[21] LI Yufeng, SUN Wei, LIU Xiwu, et al. Study of the relationship between fractures and highly productive shale gas zones, Longmaxi Formation, Jiaoshiba area in eastern Sichuan[J]. Petroleum Science, 2018, 15(3): 498-509.

[22] ZENG Qingcai, CHEN Sheng, HE Pei, et al. Quantitative prediction of shale gas sweet spots based on seismic data in Lower Silurian Longmaxi Formation, Weiyuan area, Sichuan Basin, SW China[J]. Petroleum Exploration and Development, 2018, 45(3): 422-430.

[23] ZOU Caineng, YANG Zhi, PAN Songqi, et al. Shale gas formation and occurrence in China: An overview of the current status and future potential[J]. Acta Geologica Sinica(English Edition), 2016, 90(4): 1249-1283.

[24] ZHANG Chenchen, WANG Yuman, DONG Dazhong, et al. Evaluation of the Wufeng-Longmaxi shale brittleness and prediction of "sweet spot layers" in the Sichuan Basin[J]. Natural Gas Industry, 2016, 36(9): 51-60. 张晨晨, 王玉满, 董大忠, 等. 四川盆地五峰组-龙马溪组页岩脆性评价与"甜点层"预测[J]. 天然气工业, 2016, 36(9): 51-60.

[25] ZOU Chen, ZHOU Songyuan, MEI Jue, et al. Geological evaluation of Upper Ordovician-Lower Silurian gas-bearing shales and optional potential areas in the north of Dangyang Synclinorium, Hubei[J]. Marine Origin Petroleum Geology, 2016, 21(2): 22-28. 邹辰, 周松源, 梅珏, 等. 湖北当阳复向斜北部页岩气地质评价与有利区优选[J]. 海相油气地质, 2016, 21(2): 22-28.