Digitized Outcrop Geomodeling of Ramp Shoals and its Reservoirs： as an Example of Lower Triassic Feixianguan Formation of Eastern Sichuan Basin

作     者：QIAO Zhanfeng SHEN Anjiang ZHENG Jianfeng Xavier JANSON CHANG Shaoying WANG Xiaofang CHEN Yana LIAO Yisha 

作者机构：Petrochina Hangzhou Research Institute of Geology Hangzhou 310023 Zhejiang China CNPC Key Laboratory of Carbonate Reservoir Hangzhou 310023 Zhejiang China Bureau of Economic Geology Jackson School of Geosciences The University of Texas at Austin Austin Tx 78731 USA Chongqing Gas District of SouthWest Oil and Gas Company of CNPC Chongqing 400021 China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2017年第91卷第4期

页      面：1395-1412页

核心收录：

学科分类：0820[工学-石油与天然气工程] 081803[工学-地质工程] 0709[理学-地质学] 0819[工学-矿业工程] 08[工学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0816[工学-测绘科学与技术] 082002[工学-油气田开发工程] 

基　　金：supported by grants from the National Key Oil and Gas Program of China(No.2016ZX05004002) from Special Program of PetroChina(No.2014E-32-02) 

主　　题：Digitized outcrop geomodeling ramp shoal reservoir Feixianguan Formation Sichuan Basin 

摘      要：Numerous hydrocarbon accumulations are found in ramp crest shoals worldwide and therefore this depositional setting has a high potential of being the hydrocarbon reservoir. In this paper, we combined digital outcrop geology and traditional geological mapping to build an outcrop-based geocellular model of the ramp-crest shoal complex of the Lower Triassic Feixianguan Formation in the Eastern Sichuan Basin. The outcrop model serves as an analogue for the subsurface reservoir of the Feixianguan Formation and illustrates the complexity of the lithofacies types, stratigraphic architecture, and reservoir heterogeneities at a scale below conventional subsurface data resolution. The studied ramp -crest shoal complex consists of thirteen types of lithofacies that can be grouped into three facies-groups corresponding to subtidal intraclastic shoal, sub- to inter-tidal oolitic shoal, and tidal flat depositional environments respectively. The stratigraphic architecture of the shoal complex shows mostly a strong progradation of the high energy facies associated with an overall decrease of accommodation space associated with relative sea level still stand. Two reservoir facies associations have been recognized. The first one consists of supratidai dolomudstone and upper intertidal partially dolomitized oolitic packstone with anhydrite or nodules. These facies were deposited above the high energy oolitic grainstones and occurs as thin-bedded and laterally continuous layers, characterized by high porosity and low permeability. The second reservoir facies association is composed of intertidal crystalline dolomite and subtidal intraclastic bindstone that occurs stratigraphically below the oolitic grainstones. These deposits consist of massive laterally discontinuously beds, and are characterized by high porosity and high permeability. Both types of reservoir facies tend to be stacked vertically and migrated laterally with the progradation of the shoal complex. The construction of the outcrop-based 3D geological model provide a description and quantification of the facies distribution within a robust stratigraphic framework and the style and amount of reservoir heterogeneities associated with a ramp-crest shoal complex reservoir such as the one found in Lower Triassic Feixianguan Formation and Cambrian Longwangmiao Formation in Sichuan Basin or other ramp-crest reservoir worldwide.