渤海湾盆地秦南凹陷油气成藏主控因素分析  

Analysis of main controlling factors of hydrocarbon accumulation in Qinnan Depression,Bohai Bay

作　　者：张莹 刘志峰 郭刚 朱文奇 陈少平 王涛 ZHANG Ying;LIU Zhifeng;GUO Gang;ZHU Wenqi;CHEN Shaoping;WANG Tao(CNOOC Research Institute Co.,Ltd.,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028

出　　处：《海洋地质与第四纪地质》2023年第6期157-168,共12页Marine Geology & Quaternary Geology

基　　金：国家科技重大专项“中国近海富烃凹陷优选与有利勘探方向预测”(2016ZX05024-002)。

摘　　要：秦南凹陷经历了46年勘探,只发现了秦皇岛29-2油气田,尤其是近9年勘探无一油气田发现,勘探工作陷入困境。为了弄清秦南凹陷油气成藏主控因素,指明油气勘探方向,利用三维地震、钻井及化验资料,梳理基础石油地质条件,通过已钻井成败分析和类比研究,明确各储盖组合的成藏主控因素,并预测有利勘探方向。研究表明:①秦南凹陷沙三段、沙一段烃源岩发育,TOC为1.5%~4%,类型为Ⅰ—Ⅱ1型,资源潜力大,发育潜山、沙河街组-东营组、馆陶组-明下段三套储盖组合。②潜山下组合成藏主控因素为储层非均质性;沙河街-东营组中组合成藏主控因素为圈闭有效性;馆陶-明化镇组上组合成藏主控因素为油源断层的运移能力。③东洼与东南洼间低隆起、东洼西斜坡、东洼和东南洼大断层下降盘,分别是下、中、上组合今后的有利勘探区带。本研究成果为今后秦南凹陷油气勘探提供了依据,也为类似地区油气勘探工作提供可借鉴的思路。The Qinnan Depression has experienced 46 years of exploration and only the Qinhuangdao 29-2 oil and gas field was discovered.In the past 9 years,no oil and gas fields have been found,and the exploration work runs into difficulties.To clarify the main controlling factors of hydrocarbon accumulation for clear direction of oil and gas exploration,we used 3D seismic,and drilling and laboratory data to sort out the basic petroleum geological conditions.By analyzing the success or failure of drilling and by case analogizing,the main controlling factors of each reservoir and reservoir-caprock assemblage were determined,and the favorable exploration direction was predicted.Results show that the source rocks of the third and first members of the Paleogene Shahejie Formation(Fm)(Es3 and Es1,respectively)of Qinnan Depression are developed with TOC of 1.5%~4%in the types ofⅠ-Ⅱ1,which have great resource potential.Three reservoir-caprock assemblages(1.burial hill;2.Shahejie Fm to Oligocene Dongying Fm;and 3.Miocene Guantao Fm to the lower member of Miocene-Pliocene Minghuazhen Fm)are developed.The main controlling factor on reservoir formation for the first assemblage is reservoir heterogeneity,for the second assemblage is trap effectiveness,and for the third assemblage is the migration capacity of oil-source faults.We suggested that the favorable exploration zones for future direction should be:the low uplift between the eastern and southeastern depressions in the lower place,the western slope of the eastern depression in the middle place,and the downslope of big fault in the eastern and southeastern depressions in the upper place.

关 键 词：储盖组合 主控因素 成藏模式 有利勘探区带 秦南凹陷 

分 类 号：P618.130.2[天文地球—矿床学] P744.4[天文地球—地质学]