doi:10.16186/j.cnki.1673-9787.2019080035

Received:2019/08/10

Revised:2019/10/16

Published:2021/01/15

Influences of marine sedimentary environment and sedimentary sequence ongas-bearing property of shale reservoir ：Taking Wufeng-Longmaxi formation of Qianqian well-1 as an example

ZHAO Difei1,2,3,4, GUO Yinghai2, ZENG Chunlin3,4, JIAO Weiwei3,4, REN Chengyao5, WANG Yujie2, YU Jinqiao2

1.Artificial Intelligence Research Institute,China University of Mining and Technology,Xuzhou  221000 Jiangsu,China;2.School of Resources and Geosciences,China University of Mining and Technology,Xuzhou  221116 ,Jiangsu,China;3.Key Laboratory of Shale Gas Exploration,Ministry of Natural Resources,Chongqing Institute of Geology and Mineral Resources,Chongqing  401120 ,China;4.National and Local Joint Engineering Research Center of Shale Gas Exploration and Development,Chongqing Institute of Geology and Mineral Resources,Chongqing  401120 ,China;5.Sustainable Minerals Institute,U niversity of Queensland,Brisbane  4072 .Australia

Abstract:To explore the influence of marine sedimentary environment and sedimenrary sequence on gas-bearing property of shale reservoir,Wufeng-Longmaxi formation shale reservoir of the Qianqian well-1 were taken as an example to explore the relationship and influence between sedimentary environment and shale reservoir gasbearing property by methods of rock hand specimen study,fossil study,core thin section observation,logging wavelet analysis,geochemical tests and reservoir characteristic tests.The study showd that three third-order sequences in the Wufeng-Longmaxi formation were developed in the Qianqian well-1 ,a high resolution sequence stratigraphic framework was established.By logging wavelet analysis,combining with petrological,geochemical and fossil characteristics,three third-order sequences,five medium-term cycles A-E and 11 graptolite belts were identified.Cycle A corresponded to the shale reservoir of Wufeng formation.The enrichment of organic matter and minerals was affected by the degree of detention and blockage of sedimentary environment.The abundance of organic matter and brittle minerals was high,which corresponded to WF1-5 of graptolite zone.Cycle B corresponded to the shale reservoir of the bottom Longmaxi formation.The development of sedimentary structure,the enrichment of organic matter and minerals benefited from the rapid deepening of sedimentary conditions.Together with Cycle A,it constituted the high-quality shale reservoir section of Wufeng-Longmaxi formation shale strata in the Qianqian well-1 ,corresponding to the graptolite zone of LM1-3.Cycle C corresponded reservoir of to the lower Longmaxi formation.The depth of water body became shallower,and the disturbance increased.The development of organic matter and nano-pore system was deteriorated,thus,the reservoir quality decreased significantly.Cycle D-E corresponded to the middle-upper part of the Longmaxi formation,the water body became shallower further,the sedimentary structure and mineral composition changed significantly.Under the control of sedimentary environment,the material composition,microstructure and physical properties of the reservoir have significant heterogeneity,which made different intervals had different gas generation capacity,gas storage capacity and “ holding“ gas （ self sealing） capacity,thus affected the gas bearing property of shale reservoir.

Key words:shale gas reservoir;gas-bearing;heterogeneity;marine sedimentary environment;Longmaxi-Wufeng formation;sedimentary sequence;graptolite zone

海相沉积环境与沉积层序对页岩储层_省略__以黔浅1井五峰组_龙马溪组为例_赵迪斐.pdf