Characteristics of Sedimentary Facies and Lithofacies Distribution of Deep Shale of Wufeng Formation-Longmaxi Formation

doi:10.3969/j.issn.1006-6535.2024.03.005

Abstract

Abstract: The deep shale gas of Wufeng Formation-Longmaxi Formation in the western Chongqing is an essential area for the next exploration and development of shale gas in China. However, the shale petrographic components in this block are complex and spatially variable, and the fine description of the distribution characteristics of sedimentary facies and lithofacies is lacking, which affect the identification and preference of shale gas “sweet spot” sections. To this end, the sedimentary facies and lithofacies of the deep shale of Wufeng Formation-Longmaxi Formation in western Chongqing were studied in detail through core thin section, scanning electron microscopy, Xray diffraction, FMI imaging, nuclear magnetic resonance, organic carbon analysis and other research tools. The results show that the whole study area is in the deposition of offshore shelf phase, which can be divided into three subfacies: shallow water shelf, semi-deep water shelf, and deep water shelf that have different controlling effects on the shale gas; 10 main lithofacies are developed, and the lithofacies are more stably deposited from the northwestern to the southeastern part of the area, and Longyi₁¹ layer develops three main lithofacies: siliciclastic shale, mud-rich siliciclastic shale, and mud-siliciclastic shale. According to the distribution characteristics of the sedimentary facies and lithofacies, it is predicted that the resource potential of this section in Well Z203 Area is huge, and it is a favorable exploration area in the next step. The results of this study deepen the understanding of the vertical distribution of shale reservoirs in the study area and provide data support for the subsequent efficient development of shale gas.

Key words: deep shale gas, sedimentary facies characteristic, lithofacies distribution, Wufeng Formation-Longmaxi Formation, western Chongqing Area

CLC Number:

TE122.2

Li Wei, Lei Zhian, Chen Weiming, Meng Senmiao, Chen Li, Pu Bin, Sun Chaoya, Zheng Jie. Characteristics of Sedimentary Facies and Lithofacies Distribution of Deep Shale of Wufeng Formation-Longmaxi Formation[J]. Special Oil & Gas Reservoirs, 2024, 31(3): 37-44.

References

[1] 马新华, 谢军.川南地区页岩气勘探开发进展及发展前景[J].石油勘探与开发, 2018, 45(1):161-169.
MA Xinhua, XIE Jun.The progress and prospects of shale gas exploration and exploitation in southern Sichuan Basin, NW China[J].Petroleum Exploration and Development, 2018, 45(1):161-169.
[2] 刘天娇,张妍煜,赵迪斐.四川盆地焦石坝地区五峰组—龙马溪组页岩层序地层划分及含气性预测——以JY-2井为例[J].非常规油气,2022,9(2):34-41.
LIU Tianjiao,ZHANG Yanyu,ZHAO Difei.Sequence stratigraphic division and gas bearing prediction of the Wufeng-Longmaxi Formation shale strata in the Jiaoshiba Area,Sichuan Basin:taking Well JY-2 as an example[J].Unconventional Oil & Gas,2022,9(2):34-41.
[3] 杨祥玉,谭静强,户瑞宁.湘西北地区志留纪早期龙马溪组页岩储层孔隙结构特征[J].非常规油气,2022,9(5):25-35,58.
YANG Xiangyu,TAN Jingqiang,HU Ruining.Characterization of pore structure of shale reservoir of early Silurian Longmaxi Formation in northwest Hunan[J].Unconventional Oil & Gas,2022,9(5):25-35,58.
[4] 付永红, 蒋裕强, 董大忠, 等.渝西区块页岩气储集层微观孔-缝配置类型及其地质意义[J]. 石油勘探与开发, 2021,48(5):916-927.
FU Yonghong, JIANG Yuqiang, DONG Dazhong,et al.Microscopic pore-fracture configuration and gas-filled mechanism of shale reservoirs in the western Chongqing Area,Sichuan Basin,China[J].Petroleum Exploration and Development, 2021,48(5):916-927.
[5] 马新华, 谢军, 雍锐, 等.四川盆地南部龙马溪组页岩气储集层地质特征及高产控制因素[J]. 石油勘探与开发, 2020, 47(5): 841-855.
MA Xinhua, XIE Jun, YONG Rui,et al.Geological characteristics and high production control factors of shale gas reservoirs in Silurian Longmaxi Formation, southern Sichuan Basin, SW China[J].Petroleum Exploration and Development, 2020, 47(5): 841-855.
[6] 张烨毓.川东南武隆—黔江地区龙马溪组页岩储层特征研究[D].成都:成都理工大学, 2015.
ZHANG Yeyu.Research on pore characteristics of shale gas in the Longmaxi Formation, Wulong-Qianjiang district of southeast Sichuan[D].Chengdu:Chengdu University of Technology, 2015.
[7] 沈骋,范宇,曾波, 等.渝西区块页岩气储层改造优化对策与适应性分析[J].油气地质与采收率, 2022, 29(2): 131-139.
SHEN Cheng, FAN Yu, ZENG Bo,et al.Optimization strategies and adaptability analysis of shale gas reservoir stimulation in western Chongqing Block[J].Petroleum Geology and Recovery Efficiency, 2022, 29(2): 131-139.
[8] 张成林, 张鉴, 李武广, 等.渝西大足区块五峰组—龙马溪组深层页岩储层特征与勘探前景[J].天然气地球科学, 2019, 30(12): 1794-1804.
ZHANG Chenglin, ZHANG Jian, LI Wuguang,et al.Deep shale reservoir characteristics and exploration potential of Wufeng-Longmaxi Formations in Dazu Area,western Chongqing[J].Natural Gas Geoscience, 2019, 30(12): 1794-1804.
[9] 尹兴平, 蒋裕强, 付永红, 等.渝西地区五峰组—龙马溪组龙一₁亚段页岩岩相及储层特征[J]. 岩性油气藏, 2021, 33(4): 41-51.
YIN Xingping, JIANG Yuqiang, FU Yonghong,et al.Shale lithofacies and reservoir characteristics of Wufeng Formation-lower Long₁ submember of Longmaxi Formation in western Chongqing[J].Lithologic Reservoirs, 2021, 33(4): 41-51.
[10] 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.
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.
[11] SLAB D, YU Y C, BD A,et al.Tectonic evolution of the Sichuan Basin, southwest China[J].Earth-Science Reviews, 2021, 213(2): 103470.
[12] 陈钢花, 王中文, 李德云, 等.利用多元统计方法自动识别沉积微相[J].石油物探, 1997, 36(1): 71-76.
CHEN Ganghua, WANG Zhongwen, LI Deyun, et al.Auomatic discriminant sedimentary microfacies by means of multivarite statistics analysis[J].Geophysical Prospecting for Petroleum, 1997, 36(1): 71-76.
[13] 张喜淳,胡晨林,田继军,等.川南ZX向斜五峰组—龙马溪组页岩孔隙特征及差异性[J].断块油气田,2022,29(4):469-474.
ZHANG Xichun,HU Chenlin,TIAN Jijun,et al.Characteristics and differences of shale pores in Wufeng-Longmaxi Formation of ZX Syncline, southern Sichuan Basin[J].Fault-Block Oil & Gas Field,2022,29(4):469-474.
[14] 段文刚,吝文,田继军,等.川南罗布向斜五峰组—龙马溪组页岩孔隙分形特征与主控因素[J]. 新疆石油地质,2022,43(2):153-159.
DUAN Wengang,LIN Wen,TIAN Jijun,et al.Fractal characteristics and main controlling factors of Wufeng-Longmaxi Formation shale in Luobu Syncline,southern Sichuan Basin[J].Xinjiang Petroleum Geology,2022,43(2):153-159.
[15] 朱逸青, 王兴志, 冯明友, 等.川东地区下古生界五峰组—龙马溪组页岩岩相划分及其与储层关系[J].岩性油气藏, 2016, 28(5): 59-66.
ZHU Yiqing, WANG Xingzhi, FENG Mingyou,et al.Lithofacies classification and its relationship with reservoir of the Lower Paleozoic Wufeng-Longmaxi Formation in the eastern Sichuan Basin[J]. Lithologic Reservoirs, 2016, 28(5): 59-66.
[16] 柳波, 石佳欣, 付晓飞, 等.陆相泥页岩层系岩相特征与页岩油富集条件——以松辽盆地古龙凹陷白垩系青山口组一段富有机质泥页岩为例[J].石油勘探与开发, 2018, 45(5): 828-838.
LIU Bo, SHI Jiaxin, FU Xiaofei,et al.Petrological characteristics and shale oil enrichment of lacustrine fine-grained sedimentary system: a case study of organic-rich shale in first member of Cretaceous Qingshankou Formation in Gulong Sag, Songliao Basin, NE China[J].Petroleum Exploration and Development, 2018, 45(5): 828-838.
[17] 王濡岳,胡宗全,龙胜祥,等.四川盆地上奥陶统五峰组下志留统龙马溪组页岩储层特征与演化机制[J].石油与天然气地质, 2022,43(2):353-364.
WANG Ruyue, HU Zongquan, LONG Shengxiang,et al.Reservoir characteristics and evolution mechanisms of the Upper Ordovician Wufeng-Lower Silurian Longmaxi shale,Sichuan Basin[J].Oil & Gas Geology, 2022,43(2):353-364.
[18] 胡浩,赵文韬,张爱华,等.龙马溪组高硅质页岩段定量评价及靶体调整——以川南地区Z201区块为例[J].油气地质与采收率,2022,29(4):25-34.
HU Hao,ZHAO Wentao,ZHANG Aihua,et al.Quantitative evaluation and target adjustment of high-silica shale sections in Longmaxi Formation:a case from Block Z201 in southern Sichuan Basin[J].Petroleum Geology and Recovery Efficiency,2022,29(4):25-34.