为深入研究湖相低熟页岩储层纳米孔隙特征和主控因素,选取黄骅坳陷沧东凹陷孔二段12块样品分别进行X衍射、有机地球化学测试、扫描电镜、低温氮气吸附等测试工作,对孔二段页岩储层进行分析。结果表明:沧东凹陷孔二段页岩总有机碳含量为0.48%~7.23%,有机质热演化程度为0.45%~0.84%,整体上处于低熟阶段;页岩纳米孔隙的晶间孔、溶蚀孔隙、有机质收缩缝发育丰度较高,有机质孔次之;纳米孔隙形态整体上呈较开放的状态,孔隙结构以中孔和宏孔为主;页岩孔体积的变化受机械压实、有机质生烃、黏土矿物转化等因素的综合影响,孔体积与黏土矿物含量和总有机碳含量呈一定的正相关性,有机质的赋存形式是页岩有机质孔发育的关键因素。该成果为湖相低熟页岩储层评价提供了理论依据,对湖相低熟页岩资源评价具有一定的参考价值。
In order to deeply study the characteristics and main controlling factors of nano-pores in lacustrine low-mature shale reservoirs, 12 samples was taken from the Member 2 of Kongdian Formation in Cangdong Sag, Huanghua Depression, and tested for X-ray diffraction, organic geochemical testing, electron microscopy scanning, and low-temperature nitrogen adsorption to analyze the shale reservoirs in Member 2 of Kongdian Formation. The results indicated that the total content of organic carbon of the shale in the Member 2 of Kongdian Formation in Cangdong Sag was 0.48% to 7.23%, and the thermal evolution of organic substances was 0.45% to 0.84%, indicating that the shale was in the low-mature stage as a whole; the nano-pores in the shale were developed with an abundance of intercrystal pores, dissolved pores and shrinkage joints of organic substances, followed by organic substance pores; the nano-pores were relatively open as a whole, and mainly composed of mesopores and macropores in structure; the shale pore volume was changed mainly by the comprehensive effects of mechanical compaction, hydrocarbon generation of organic substances, transformation of clay minerals, and other factors; there was a positive correlation between pore volume and mineral content in clay and total content of organic carbon; the occurrence form of organic substances was the key factor for pore development of organic substances in shale. The results provide a theoretical basis for the evaluation of lacustrine low-maturity shale reservoirs, and serve as references for the evaluation of lacustrine low-maturity shale resources.
[1] SLATT E M,O'NEAL N R.Pore types in the Barnett and Woodford gas shales:contribution to understanding gas storage and migration pathways in fine-grained rocks[J].AAPG Bulletin,2011,95(12):2017-2030.
[2] CHALMERS G R,BUSTIN R M,POWER I M.Characterization of gas shale pore systems by porosimetry,pycnometry,surface area,and field emission scanning electron microscopy/transmission electron microscopy image analyses:examples from the Barnett,Woodford,Haynesville,Marcellus,and Doig units[J].AAPG Bulletin, 2012,96(6):1099-1119.
[3] 孙梦迪,于炳松,李娟,等. 渝东南地区龙马溪组页岩储层特征与主控因素[J].特种油气藏,2014,21(4):63-66.
SUN Mengdi,YU Bingsong,LI Juan,et al.Features and major controlling factors of Longmaxi Shale Reservoir in southeastern Chongqing[J].Special Oil & Gas Reservoirs,2014,21(4):63-66.
[4] 许露露,张焱林,陈程,等. 鄂西地区黄陵背斜周缘五峰组—龙马溪组页岩气储层及含气性特征[J].特种油气藏,2019,26(5):26-32.
XU Lulu,ZHANG Yanlin,CHEN Cheng,et al.Shale gas reservoir and gas-bearing properties of Wufeng-Longmaxi Formations in the periphery of Huangling Anticline of western Hubei Province[J].Special Oil & Gas Reservoirs,2019,26(5):26-32.
[5] 刘小平,刘庆新,刘杰,等.黄骅坳陷沧东凹陷孔二段富有机质泥页岩地球化学特征[J].岩性油气藏,2015,27(6):15-22.
LIU Xiaoping,LIU Qingxin,LIU Jie,et al.Geochemical characteristics of organic-rich shales of the second member of Kongdian Formation in Cangdong Sag,Huanghua Depression[J].Lithologic Reservoirs, 2015,27(6):15-22.
[6] 周立宏,蒲秀刚,肖敦清,等. 渤海湾盆地沧东凹陷孔二段页岩油形成条件及富集主控因素[J].天然气地球科学,2018,29(9):1323-1332.
ZHOU Lihong,PU Xiugang,XIAO Dunqing,et al.Geological conditions for shale oil formation and the main controlling factors for the enrichment of the 2nd member of Kongdian Formation in the Cangdong Sag,Bohai Bay Basin[J].Natural Gas Geoscience,2018,29(9):1323-1332.
[7] JAVADPOUR F,FISHER D,UNSWORTH M.Nanoscale gas flow in shale gas sediments[J].Journal of Canadian Petroleum Technology,2007,46(10):55-61.
[8] 邓远,蒲秀刚,陈世悦,等. 细粒混积岩储层特征与主控因素分析——以渤海湾盆地沧东凹陷孔二段为例[J].中国矿业大学学报,2019,48(6):1301-1316.
DENG Yuan,PU Xiugang,CHEN Shiyue,et al.Characteristics and controlling factors of fine-grained mixed sedimentary rocks reservoir: a case study of the 2nd member of Kongdian formation in Cangdong Depression, Bohai Bay Basin[J].Journal of China University of Mining & Technology,2019,48(6):1301-1316.
[9] 吴林钢,李秀生,郭小波,等.马朗凹陷芦草沟组页岩油储层成岩演化与溶蚀孔隙形成机制[J].中国石油大学学报(自然科学版),2012,36(3):38-43.
WU Lingang,LI Xiusheng,GUO Xiaobo,et al.Diagenetic evolution and formation mechanism of dissolved pore of shale oil reservoirs of Lucaogou Formation in Malang Sag[J].Journal of China University of Petroleum(Edition of Natural Science),2012,36(3):38-43.
[10] SURDAM R C,CROSSEY L J,HAGEN E S,et al.Organic-inorganic interactions and sanstone diagensis[J].AAPG Bulletin,1989,73(1):1-23.
[11] 薛冰,张金川,唐玄,等. 黔西北龙马溪组页岩微观孔隙结构及储气特征[J].石油学报,2015,36(2):138-173.
XUE Bing,ZHANG Jinchuan,TANG Xuan, et al.Characteristics of microscopic pore and gas accumulation on shale in Longmaxi Formation, northwest Guizhou[J].Acta Petrolei Sinica,2015,36(2):138-173.
[12] CURTIS M E,CARDOTT B J,SONDERGELD C H,et al.Devel-opment of organic porosity in the Woodford Shale with increasing thermal maturity[J].International Journal of Coal Geology,2012,103 (1):26-31.
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