Discussion on genesis and geological significance of "low resistivity and low gas content" of Longmaxi Formation shale in southeastern Sichuan

WEI Fubin; LIU Zhujiang; CHEN Feiran; YAN Wei; WANG Qiang

doi:10.11781/sysydz2023061089

Volume 45 Issue 6

Nov. 2023

Turn off MathJax

Article Contents

Article Navigation > PETROLEUM GEOLOGY & EXPERIMENT > 2023 > 45(6): 1089-1096

WEI Fubin, LIU Zhujiang, CHEN Feiran, YAN Wei, WANG Qiang. Discussion on genesis and geological significance of 'low resistivity and low gas content' of Longmaxi Formation shale in southeastern Sichuan[J]. PETROLEUM GEOLOGY & EXPERIMENT, 2023, 45(6): 1089-1096. doi: 10.11781/sysydz2023061089

Citation:

WEI Fubin, LIU Zhujiang, CHEN Feiran, YAN Wei, WANG Qiang. Discussion on genesis and geological significance of "low resistivity and low gas content" of Longmaxi Formation shale in southeastern Sichuan[J]. PETROLEUM GEOLOGY & EXPERIMENT, 2023, 45(6): 1089-1096. doi: 10.11781/sysydz2023061089

Citation:

PDF( 1794 KB)

Discussion on genesis and geological significance of "low resistivity and low gas content" of Longmaxi Formation shale in southeastern Sichuan

doi: 10.11781/sysydz2023061089

SINOPEC Exploration Company, Chengdu, Sichuan 610041, China

Received Date: 2023-08-31
Rev Recd Date: 2023-11-07
Publish Date: 2023-11-28

Abstract

Abstract

In order to clarify the genesis of "low resistivity and low gas content" in the shale of Wufeng-Longmaxi formations and effectively guide the next step of shale gas exploration in Sichuan Basin, a detailed study on the problem based on a large number of drilling surveys, dissections, and analysis of laboratory test results in the entire area was carried out herein. Low-resistivity wells of Longmaxi Formation shale in this area can be divided into two types based on their electrical and geological characteristics, which are less than 1 Ω·m and 1-10 Ω·m. Shale gas wells with resistivity less than 1 Ω·m are basically gas-free and mostly dry wells with relatively concentrated distribution areas, mainly located in southwestern Sichuan and western Changning. The resistivity curve of the shale exhibits a "thin neck" characteristic, with a Raman reflectance generally above 3.70% and a high amplitude graphite peak. In addition, the variation range of resistance values in rock electrical experiments under different states is small, and they all exhibit extremely low to low resistance characteristics, indicating that the conductivity of the rock skeleton caused by graphitization is the main factor affecting this type of shale. The drilling distribution area of shale with resistivity in the range of 1-10 Ω·m is relatively wider, mainly with slight gas content, distributed both inside and outside the basin. The characteristics exhibited by its electrical properties, laser Raman, and rock electrical experiments are significantly different from those of shale less than 1 Ω·m. The resistance curve of this type of shale exhibits a "gradual" characteristic, with a measured Raman reflectance of around 3.50% by laser Raman spectroscopy. The laser Raman spectrum also does not show obvious graphite peak characteristics. This type of shale undergoes a wide range of changes in rock electrical experiments under two states: dry water and saturated water, with a change in shale resistivity of 7 to 20 times before and after drying, and exhibits medium to high electrical resistance characteristics, revealing a significant impact of shale water content on shale resistivity. Based on actual drilling data, it is believed that the deterioration of shale gas preservation conditions and the increase in water content are the main reasons for this type of low-resistivity well.
- low resistivity,
- graohitization,
- high water content,
- preservation condition,
- shale gas,
- Longmaxi Formation,
- southeastern

All authors disclose no relevant conflict of interests.
The study was designed by WEI Fubin, WANG Qiang, CHEN Feiran and YAN Wei. The manuscript was drafted and revised by WEI Fubin and LIU Zhujiang. All the authours have read the last version of paper and consented for submission.

FullText(HTML)

References(20)

References

[1]	郭旭升, 腾格尔, 魏祥峰, 等. 四川盆地深层海相页岩气赋存机理与勘探潜力[J]. 石油学报, 2022, 43(4): 453-468. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB202204001.htm GUO Xusheng, TENGER B, WEI Xiangfeng, et al. Occurrence mechanism and exploration potential of deep marine shale gas in Sichuan Basin[J]. Acta Petrolei Sinica, 2022, 43(4): 453-468. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB202204001.htm
[2]	魏富彬, 刘珠江, 陈斐然, 等. 川东南五峰组—龙马溪组深层、超深层页岩储层特征及其页岩气勘探意义[J]. 石油实验地质, 2023, 45(4): 751-760. doi: 10.11781/sysydz202304751 WEI Fubin, LIU Zhujiang, CHEN Feiran, et al. Characteristics of the deep and ultra-deep shale reservoirs of the Wufeng-Longmaxi formations in the southeastern Sichuan Basin and the significance of shale gas exploration[J]. Petroleum Geology & Experiment, 2023, 45(4): 751-760. doi: 10.11781/sysydz202304751
[3]	赵文韬, 荆铁亚, 熊鑫, 等. 海相页岩有机质石墨化特征研究: 以渝东南地区牛蹄塘组为例[J]. 地质科技情报, 2018, 37(2): 183-191. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKQ201802025.htm ZHAO Wentao, JING Tieya, XIONG Xin, et al. Graphitization characteristics of organic matters in marine-facies shales[J]. Geological Science and Technology Information, 2018, 37(2): 183-191. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKQ201802025.htm
[4]	王玉满, 魏国齐, 沈均均, 等. 四川盆地及其周缘海相页岩有机质炭化区分布规律与主控因素浅析[J]. 天然气地球科学, 2022, 33(6): 843-859. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX202206001.htm WANG Yuman, WEI Guoqi, SHEN Junjun, et al. Analysis on carbonization distribution and main controlling factors of organic matter in marine shale in Sichuan Basin and its periphery[J]. Natural Gas Geoscience, 2022, 33(6): 843-859. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX202206001.htm
[5]	张琴, 赵群, 罗超, 等. 有机质石墨化及其对页岩气储层的影响: 以四川盆地南部海相页岩为例[J]. 天然气工业, 2022, 42(10): 25-36. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG202210003.htm ZHANG Qin, ZHAO Qun, LUO Chao, et al. Effect of graphitization of organic matter on shale gas reservoirs: take the marine shales in the southern Sichuan Basin as examples[J]. Natural Gas Industry, 2022, 42(10): 25-36. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG202210003.htm
[6]	王玉满, 李新景, 王皓, 等. 中上扬子地区下志留统龙马溪组有机质碳化区预测[J]. 天然气地球科学, 2020, 31(2): 151-162. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX202002001.htm WANG Yuman, LI Xinjing, WANG Hao, et al. Prediction of organic matter carbonization zones for Lower Silurian Longmaxi Formation in Middle-Upper Yangtze region[J]. Natural Gas Geoscience, 2020, 31(2): 151-162. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX202002001.htm
[7]	黄莉莎, 闫建平, 胡兴中, 等. 川南五峰组—龙马溪组低阻页岩特征分析及启示[J/OL]. 西南石油大学学报(自然科学版), 1-15. [2023-11-05]. http://kns.cnki.net/kcms/detail/51.1718.te.20230927.1013.002.html. HUANG Lisha, YAN Jianping, HU Xingzhong, et al. Characte-ristics analysis and its enlightenment of shale of low resistivity in Wufeng–Longmaxi formation in southern Sichuan Basin[J/OL]. Journal of Southwest Petroleum University (Science & Technology Edition), 1-15. [2023-11-05]. http://kns.cnki.net/kcms/detail/51.1718.te.20230927.1013.002.html.
[8]	蒋珊, 王玉满, 王书彦, 等. 四川盆地川中古隆起及周缘下寒武统筇竹寺组页岩有机质石墨化区预测[J]. 天然气工业, 2018, 38(10): 19-27. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201810004.htm JIANG Shan, WANG Yuman, WANG Shuyan, et al. Distribution prediction of graphitized organic matter areas in the Lower Cambrian Qiongzhusi shale in the central Sichuan paleo-uplift and its surrounding areas in the Sichuan Basin[J]. Natural Gas Industry, 2018, 38(10): 19-27. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG201810004.htm
[9]	王玉满, 李新景, 陈波, 等. 海相页岩有机质炭化的热成熟度下限及勘探风险[J]. 石油勘探与开发, 2018, 45(3): 385-395. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201803004.htm WANG Yuman, LI Xinjing, CHEN Bo, et al. Lower limit of thermal maturity for the carbonization of organic matter in marine shale and its exploration risk[J]. Petroleum Exploration and Development, 2018, 45(3): 385-395. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201803004.htm
[10]	薛子鑫, 姜振学, 郝绵柱, 等. 川南深层页岩有机质石墨化对储层孔隙的控制作用[J]. 中南大学学报(自然科学版), 2022, 53(9): 3532-3544. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD202209019.htm XUE Zixin, JIANG Zhenxue, HAO Mianzhu, et al. Controlling effect of organic matter graphitization on reservoir pore structure in deep shale reservoirs, southern Sichuan[J]. Journal of Central South University (Science and Technology), 2022, 53(9): 3532-3544. https://www.cnki.com.cn/Article/CJFDTOTAL-ZNGD202209019.htm
[11]	侯宇光, 张坤朋, 何生, 等. 南方下古生界海相页岩极低电阻率成因及其地质意义[J]. 地质科技通报, 2021, 40(1): 80-89. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKQ202101008.htm HOU Yuguang, ZHANG Kunpeng, HE Sheng, et al. Origin and geological significance of ultra-low resistivity in Lower Paleozoic marine shale, South China[J]. Bulletin of Geological Science and Technology, 2021, 40(1): 80-89. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKQ202101008.htm
[12]	高和群, 丁安徐, 蔡潇, 等. 中上扬子海相页岩电阻率异常成因分析[J]. 断块油气田, 2016, 23(5): 578-582. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT201605007.htm GAO Hequn, DING Anxu, CAI Xiao, et al. Genetic analysis of abnor-mal resistivity of Middle-Upper Yangtze marine shales[J]. Fault-Block Oil & Gas Field, 2016, 23(5): 578-582. https://www.cnki.com.cn/Article/CJFDTOTAL-DKYT201605007.htm
[13]	邹辰, 吴永辉, 章超, 等. 渝西地区龙马溪组页岩低阻主控因素及有利区预测[J]. 东北石油大学学报, 2023, 47(2): 81-90. https://www.cnki.com.cn/Article/CJFDTOTAL-DQSY202302007.htm ZOU Chen, WU Yonghui, ZHANG Chao, et al. Main controlling factors of the low resistivity Longmaxi Formation shale and prediction of favorable area in Yuxi area[J]. Journal of Northeast Petroleum University, 2023, 47(2): 81-90. https://www.cnki.com.cn/Article/CJFDTOTAL-DQSY202302007.htm
[14]	邹辰, 李德华, 杨庆, 等. 滇黔北地区龙马溪组有机质石墨化特征及成因[J]. 天然气工业, 2021, 41(S1): 67-72. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG2021S1010.htm ZOU Chen, LI Dehua, YANG Qing, et al. Characteristics and genesis of organic matter graphitization in Longmaxi Formation, northern Yunnan and Guizhou[J]. Natural Gas Industry, 2021, 41(S1): 67-72. https://www.cnki.com.cn/Article/CJFDTOTAL-TRQG2021S1010.htm
[15]	周天琪. 低温热流体及基底深大断裂对富有机质页岩电性差异的影响[C]//第十七届全国古地理学及沉积学学术会议摘要集——专题21陆相页岩油富集机理与勘探进展. 青岛: [s. n. ], 2023: 9. ZHOU Tianqi. The influence of low temperature thermal fluid and deep fault on the electrical properties of organic rich shale[C]//Summary of the 17th National Academic Conference on Paleogeography and Sedimentology-Topic 21: Mechanism of continental shale oil enrichment and exploration progress. Qingdao: [s. n. ], 2023: 9.
[16]	崔瑞康, 孙建孟, 刘行军, 等. 低阻页岩电阻率主控因素研究[J]. 物探与化探, 2022, 46(1): 150-159. https://www.cnki.com.cn/Article/CJFDTOTAL-WTYH202201016.htm CUI Ruikang, SUN Jianmeng, LIU Xingjun, et al. Major controlling factors of low-resistance shale gas reservoirs[J]. Geophysical and Geochemical Exploration, 2022, 46(1): 150-159. https://www.cnki.com.cn/Article/CJFDTOTAL-WTYH202201016.htm
[17]	王滢, 何嘉, 寇一龙, 等. 长宁地区龙马溪组页岩储层低电阻率成因[J]. 油气地质与采收率, 2022, 29(3): 53-61. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCS202203007.htm WANG Ying, HE Jia, KOU Yilong, et al. Causes of low resistivity of Longmaxi Formation shale reservoirs in Changning area[J]. Petroleum Geology and Recovery Efficiency, 2022, 29(3): 53-61. https://www.cnki.com.cn/Article/CJFDTOTAL-YQCS202203007.htm
[18]	王宏坤, 吕修祥, 王玉满, 等. 鄂西下志留统龙马溪组页岩储集特征[J]. 天然气地球科学, 2018, 29(3): 415-423. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201803012.htm WANG Hongkun, LV Xiuxiang, WANG Yuman, et al. The reservoir characteristics of Lower Silurian Longmaxi Formation in western Hubei[J]. Natural Gas Geoscience, 2018, 29(3): 415-423. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201803012.htm
[19]	刘德汉, 肖贤明, 田辉, 等. 固体有机质拉曼光谱参数计算样品热演化程度的方法与地质应用[J]. 科学通报, 2013, 58(13): 1228-1241. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB201313010.htm LIU Dehan, XIAO Xianming, TIAN Hui, et al. Sample maturation calculated using Raman spectroscopic parameters for solid organics: methodology and geological applications[J]. Chinese Science Bulletin, 2013, 58(11): 1285-1298. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB201313010.htm
[20]	肖贤明, 周秦, 程鹏, 等. 高—过成熟海相页岩中矿物—有机质复合体(MOA)的显微激光拉曼光谱特征作为成熟度指标的意义[J]. 中国科学(地球科学), 2020, 50(9): 1228-1241. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK202009006.htm XIAO Xianming, ZHOU Qin, CHENG Peng, et al. Thermal maturation as revealed by micro-Raman spectroscopy of mineral-organic aggregation (MOA) in marine shales with high and over maturities[J]. Science China (Earth Sciences), 2020, 63(10): 1540-1552. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK202009006.htm

Relative Articles

Supplements(0)

Cited By

Proportional views

Proportional views

通讯作者: 陈斌, bchen63@163.com

1.
沈阳化工大学材料科学与工程学院沈阳 110142

Figures(10) / Tables(2)

Citation

XML

PDF-CN

Article Metrics

Article views (506) PDF downloads(83)

Discussion on genesis and geological significance of "low resistivity and low gas content" of Longmaxi Formation shale in southeastern Sichuan

doi: 10.11781/sysydz2023061089

Abstract

References

Proportional views

Catalog

通讯作者: 陈斌, bchen63@163.com

Article Metrics

Proportional views

Related

Discussion on genesis and geological significance of "low resistivity and low gas content" of Longmaxi Formation shale in southeastern Sichuan

doi: 10.11781/sysydz2023061089

Abstract

References

Proportional views

Catalog

通讯作者: 陈斌, bchen63@163.com

Article Metrics

Proportional views

Related

Export File

Citation

Format

Content