doi:10.16186/j.cnki.1673-9787.2019100001

Received:2019/10/05

Revised:2019/11/15

Published:2021/03/15

Development characteristics and influencing factors of Marine-Transitional shale ofPermian strata in Chaohu area

ZHAO Difei1,2, ZHENG Wentao1, CHEN Haibing3, XU Youwei3, YIN Junkai4, LIU Jing1, HU Xinmeng5

1.Artificial Intelligence Research Institute， China University of Mining and Technology ，Xuzhou  221116 Jiangsu， China;2.Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process， the Ministry of Education， Xuzhou  221008 ， Jiangsu， China;3.Institute of Geology of 10 th Oil Production plant， Changqing Oilfield Company， PetroChina ， Qingyang  745100 ， Gansu， China;4.Shandong Taishan Resources Exploration Co.， Ltd. ， Jinan  250000 ， Shandong， China;5.Institute of Geology and Geophysics， Chinese Academy of Sciences ， Beijing  100000 ， China

Abstract:The Gufeng formation， Longtan formation and Dalong formation in Chaohu area constitute a series of Marine-Transitional shale system controlled by sea-level advance and retreat. By methods of thin slice observation ，X-ray diffraction ， high-pressure mercury injection ， low -temperature nitrogen adsorption ， argon ion polishing-field emission scanning electron microscope， the shale reservoirs development characteristics of the Gufeng， Longtan and Dalong formations in the Chaohu area were studied， with Yaojiashan section as an example. The results showed that the organic matter abundance of shale reservoirs was relatively high， ranging from 1.89% to 11.84% ， and the maturity was in mature stage； The mineral components were mainly composed of brittleness minerals and clay minerals， and the brittleness minerals were mainly quartz and carbonate minerals ； The types and morphological characteristics of reservoir pores were complex， and pore-micropore was the most developed one， and the pore size distribution mode belonged to single peak type ； organic matter and quartz had a positive contribution to the development of reservoir pores， high organic matter abundance was beneficial to the increase of reservoir space and adsorption sites， while the increase of clay mineral and carbonate mineral content was not conducive to the development of pore system. The major influencing factors of shale reservoirs of Gufeng formation， Longtan formation and Dalong formation were different. The factors such as sedimentation rate and water redox condition affected shale reservoir development under the control of relative sea level rising and falling. The sedimentary conditions and higher paleoproductivity of deep-water detention basin in oxygen poor anaerobic environment of Dalong formation and Gufeng formation， the supplement of terrigenous organic matter of Longtan formation and relative fast deposition rate were beneficial to the development of high-quality reservoirs. High quality reservoirs were mainly developed in the continental margin-basin transition environment during the transgressive sedimentary period of Gufeng formation， lagoon-supratidal mud-flat sedimentary environment of Longtan formation， and deep-water detention basin sedimentary environment under the oxygen poor and anaerobic environment of Dalong formation.

Key words:shale reservoir;pore structure;influencing factor;sedimentary environment;Chaohu area;Permian strata

 巢湖地区二叠系海相_过渡相页岩发育特征及影响因素_赵迪斐.pdf