The Major Controlling Factors and Different Oolitic Shoal Reservoir Characteristics of the Triassic Feixianguan Formation,Eastern Longgang Area,NE Sichuan Basin,SW China  

作　　者：GU Yifan JIANG Yuqiang LEI Xiaohua CHEN Zhiyong ZHOU Lu FU Yonghong JIANG Zengzheng 

机构地区：[1]School of Geoscience and Technology,Southwest Petroleum University,Chengdu 610500,China [2]Department of Geology,University of Regina,Regina,Saskatchewan,SK S4S 0A2,Canada [3]Northeastern Sichuan Oil and Gas District,PetroChina Southwest Oil and Gas Field Company,Dazhou,Sichuan 635000,China [4]Chongqing Gas Field,PetroChina Southwest Oil and Gas Field Company,Chongqing 400021,China [5]Sichuan Geotech Science and Technology Ltd.,Chengdu 610041,China

出　　处：《Acta Geologica Sinica(English Edition)》2021年第3期895-908,共14页地质学报（英文版）

基　　金：This research was supported jointly by the National Natural Science Foundation of China(Grant No.41972165);National Science and Technology Major Project(Grant No.2017ZX05008-004-008);National Science and Technology Major Project(Grant No.2016E-0607).

摘　　要：Based on comprehensive analyses of occurrence,petrological observation,pore structure and geochemistry,the different reservoir characteristics and reservoir evolutionary pathways between different oolitic shoal reservoir types of the Feixianguan Formation on the west side of the Kaijiang-Liangping Trough have been studied.There exist three stages of high-energy slope break belts in the Feixianguan period,the corresponding three stages of oolitic shoals gradually migrating in the direction of the trough.Three types of oolitic shoal reservoirs,namely,residual-oolitic dolomite,mold-oolitic dolomite and sparry oolitic limestone,were formed during sedimentary-diagenetic evolution,the pore types being intergranular dissolved pore,mold pore(or intragranular dissolved pore)and residual intergranular pore,respectively.The petrology,physical properties and pore structure of the different types of oolitic shoal reservoirs are quite different.Residual-oolitic dolomite reservoirs have the best quality,while sparry oolitic limestone reservoirs have the poorest.Combined with analyses of trace elements,rare earth elements and carbon-oxygen isotopes,it is suggested that the formation of residual-oolitic dolomite reservoirs is jointly controlled by penesaline seawater seepage-reflux dolomitization and hydrothermal dolomitization.Mold-pore oolitic dolomite reservoirs are controlled by penesaline seawater seepage-reflux dolomitization and meteoric water solution.The burial dissolution of organic acid not only further improves the reservoir qualities of previously formed oolitic dolomite reservoirs,but also preserves residual intergranular pores in the sparry oolitic limestone reservoirs.

关 键 词：oolitic shoal reservoir evolution geochemical characteristics Triassic System Feixianguan Formation Sichuan Basin 

分 类 号：P618.13[天文地球—矿床学]