Enrichment rules and exploration practices of Paleogene shale oil in Jiyang Depression, Bohai Bay Basin, China  

作　　者：SONG Mingshui LIU Huimin WANG Yong LIU Yali 

机构地区：[1]Sinopec Shengli Oilfield Company,Dongying 257000,China [2]Exploration and Development Institute of Shengli Oilfield Company,Sinopec,Dongying 257015,China

出　　处：《Petroleum Exploration and Development》2020年第2期242-253,共12页石油勘探与开发（英文版）

基　　金：Supported by the National Key Basic Research and Development Program(973 Program);China(2014CB239100);China National Science and Technology Major Project(2017ZX05049)

摘　　要：Based on formation testing data of more than 40 wells with industrial oil flow, systematic observation of 1 010.26 m long cores taken from 4 wells and test data of over 10 000 core samples combining with drilling and pilot fracturing data of multiple wells, the geological characteristics of the upper submember of the Sha 4 Member to the lower submember of the Sha 3 Member of Paleogene(Es4s-Es3x) in the Jiyang Depression were investigated to find out factors controlling the enrichment of shale oil and the accumulation model of shale oil, and a comprehensive evaluation method for shale oil sweet spots was established. It is found through the study that the target shale layer is characterized by strong heterogeneity, weak diagenesis, low thermal evolution and high content of clay and carbonate minerals. Shale lithofacies, microcrack, thin interlayer and abnormal pressure are the main factors affecting enrichment and stable production of shale oil, the organic rich laminar shale has the best storage and oil-bearing capacity, microcrack network system improve the storage capacity and permeability of the shale, the thin interlayer is the main flow channel for stable shale oil production, and the abnormal high pressure layer is rich in free state shale oil and high in oil content. The shale oil layers in the target section were divided into three types: matrix, interlayer and fracture ones. According to the occurrence state and exploration practice of shale oil at home and abroad, it is concluded that the interlayer shale oil is the most profitable type at present. The selection parameters for the different types of shale oil were determined, and accordingly the favorable areas were pointed out by comprehensive evaluation of multiple factors. Vertical wells in the interlayer shale oil reservoir, such as Fan 159, Fan 143 and GX 26, were stimulated by volume fracturing and high conductivity channel fracturing jointly. After fracturing, they had a daily oil production of over 6 t, up to 44 t, and stable productivity. Shale

关 键 词：shale oil enrichment elements enrichment model shale oil sweet spot lithofacies MICROCRACK thin interlayer abnormal pressure Jiyang Depression 

分 类 号：P618.13[天文地球—矿床学]