苏北盆地高邮凹陷古近系阜宁组二段页岩油成藏条件分析  

Shale oil accumulation conditions in the second member of Paleogene Funing Formation,Gaoyou Sag,Subei Basin

作　　者：付茜[1] 刘启东[1] 刘世丽[1] 段宏亮[1] FU Qian;LIU Qidong;LIU Shili;DUAN Hongliang(Research Institute of Exploration and Development,SINOPEC Jiangsu Oilfield,Yangzhou,Jiangsu 220009,China)

机构地区：[1]中国石化江苏油田分公司勘探开发研究院,江苏扬州220009

出　　处：《石油实验地质》2020年第4期625-631,共7页Petroleum Geology & Experiment

基　　金：国家科技重大专项“高邮—金湖凹陷区页岩油资源潜力与地质评价研究”(2017ZX05049001-005);中国石化科技部项目“苏北盆地致密油形成条件与勘探潜力评价”(P18060—4)资助。

摘　　要：碳酸盐岩夹层型页岩油为苏北盆地页岩油勘探的主要类型之一,高邮凹陷深凹—内坡带是阜宁组二段(E1f2)碳酸盐岩夹层型页岩油勘探的有利区。为进一步明确高邮凹陷E1f2页岩油"甜点"层段,运用扫描电镜、高温压汞、氮气吸附、CT扫描、X衍射、三轴力学、多温阶热解等多种研究方法,对比分析了E1f2各页岩段的源岩品质、储层品质、工程条件及可动性。E1f2^页1、E1f2^页2为干热还原咸水的沉积环境,发育优质页岩;有机质丰度较高,平均有机碳含量分别为2.33%和1.63%,干酪根类型以Ⅰ、Ⅱ1为主,生烃条件最为有利;黏土矿物层片间孔较发育,储集空间以宏孔、裂缝为主;E1f2^页1—E1f2^页5脆性矿物含量在59.1%~63.6%,黏土矿物以伊/蒙混层和伊利石为主,E1f2^页2脆性指数最高为64.25%;在埋深大于3500 m的范围内伊蒙混层向伊利石转化明显,页岩脆性及可压裂改造条件更好。高邮凹陷深凹—内坡带E1f2^页1、E1f2^页2页岩层段是下一步苏北盆地页岩油勘探方向之一。"Carbonate sandwich shale oil"is a main exploration target in the Subei Basin.The deep depression-inner slope zone of the Gaoyou Sag is a favorable area for the exploration of"carbonate sandwich shale oil"in the second member of Funing Formation(E1 f2).The source rock and reservoir quality,engineering conditions and movability of each shale section of E1 f2 were analyzed in order to further clarify"sweet spot"sections by using scanning electron microscopy,mercury intrusion at elevated temperature,nitrogen adsorption,CT scanning,X-ray diffraction,triaxial mechanics,multi-temperature pyrolysis and other research methods.The E1 fs2^hale1 and E1 fs2^hale2 in the deep depressioninner slope zone of Gaoyou Sag were deposited in a dry,hot,reducing and brackish water environment,developing favorable shale with high organic matter content.The TOC contents are 2.33%and 1.63%,respectively Kerogens are mainly of typesⅠandⅡ1,with the most favorable conditions for hydrocarbon generation.The interlamellar pores were well developed,and the reservoir space is dominated by macropores and fractures.The brittle mineral content of E1 fs2^hale1 to E1 fs2^hale5 is 59.1%-63.6%,and the clay minerals are dominated by illite/montmorillonite mixed layer and illite.The brittleness index of E1 fs2^hale2 is 64.25%at most.In the range of burial depth greater than 3500 m,the conversion of the illite/montmorillonite mixed layer to illite is obvious,and the shale brittleness and fracturing transformation conditions are better.The E1 fs2^hale1 and E1 fs2^hale2 in the deep depression-inner slope zone of Gaoyou Sag are exploration directions for shale oil in the Subei Basin.

关 键 词：碳酸盐岩夹层 页岩油 成藏条件 阜宁组二段 高邮凹陷 苏北盆地 

分 类 号：TE132.8[石油与天然气工程—油气勘探]