东营凹陷咸化湖相纹层状烃源岩初次生排烃流体特征  

Fluid features during the initial stage of hydrocarbon generation and expulsion in salt-water lacustrine laminated source rocks of Dongying Depression

作　　者：王淼[1,2] 宋国奇 王学军[4] 陈勇 张韩静[1,2] 刘庆[4] 张学军 李冠华 张辉 WANG Miao;SONG Guoqi;WANG Xuejun;CHEN Yong;ZHANG Hanjing;LIU Qing;ZHANG Xuejun;LI Guanhua;ZHANG Hui(Key Laboratory of Deep Oil and Gas in China University of Petroleum(East China),Qingdao 266580,China;School of Geosciences in China University of Petroleum(East China),Qingdao 266580,China;Shengli Oilfield Company,SINOPEC,Dongying 257000,China;Exploration and Development Research Institute of Shengli Oilfield Company,SINOPEC,Dongying 257015,China)

机构地区：[1]中国石油大学(华东)深层油气重点实验室,山东青岛266580 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [3]中国石油化工股份有限公司胜利油田分公司,山东东营257000 [4]中国石油化工股份有限公司胜利油田分公司勘探开发研究院,山东东营257015

出　　处：《中国石油大学学报（自然科学版）》2020年第2期31-41,共11页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金项目(41172111,41703060,U1762108);国家重大科技专项(2016ZX05006-001);中央高校基本科研业务费专项(16CX05005A,17CX06042)。

摘　　要：以东营凹陷古近系咸化湖相成熟页岩内顺层纤维状脉体(Beef)为研究对象,基于脉体岩相学、流体包裹体等方面分析,结合显微荧光光谱和激光拉曼光谱等技术手段,在证明Beef为初次生排烃产物的基础上,确定东营凹陷早期烃类流体特征。结果表明:成脉矿物均为铁方解石,整体上为一期成岩产物,脉体生长过程中伴随的烃类流体成熟度总体较低且含有大量沥青质,烃类流体整体上具有较高的芳烃(质量分数平均为38.8%)、非烃(质量分数平均为6.8%)含量及较高的API度(平均为32.9);基于图解特征参数计算得出平均等效R o为0.59%;Beef是东营凹陷成熟页岩内有机质初次生烃导致流体异常高压产生顺层微裂缝的重要标志,由于咸化湖相烃源岩在低熟阶段具有较高的降解率,因此超压压裂顺层微裂缝排烃是早期数量可观的低熟油气排出烃源岩的一种重要方式,且在水平运移过程中伴随有明显的轻重组分分馏效应。The bedding-parallel fibrous veins(Beef)in salt-water lacustrine mature shales of the Eocene Dongying Depression are studied in this paper.Based on the study of vein petrography and fluid inclusions features,we demonstrate that the Beef was the outcome during the initial stage of hydrocarbon generation and expulsion.We determine the fluid features during this stage by means of the micro-spectrofluorimetry and the laser Raman spectrum.The results show that the Beefs are one-stage fluid products,and the filling crystals are all ferroan-calcites.The hydrocarbon fluids during the Beef formation are characterized by low mature fluids with lots of bitumen.The total contents of the aromatic hydrocarbon(aver.38.8%)and NSO compounds(aver.6.8%)are high,as well as the API degree of the oil(aver.32.9).The average equivalent R o of the bitumen-bearing inclusions calculated based on the Raman spectra is 0.59%.As a consequence,the Beef is a symbol of fluid overpressure caused by hydrocarbon generation and expulsion during the initial stage in mature shales of Dongying Depression.During this stage,the salt-water lacustrine source rocks had high degradation efficiency of organic matters,so the horizontal fractures caused by overpressure can provide important channels for the expulsion of the abundant low mature hydrocarbon fluids in the early stage.The obvious fractionation processes occurred during the horizontal migration of hydrocarbon fluids.

关 键 词：东营凹陷 成熟页岩 顺层纤维状脉体 初次生排烃 低熟油气 

分 类 号：TE122[石油与天然气工程—油气勘探]