春光区块白垩系稠油地球化学特征及成因分析  

Geochemical Properties and Genesis of Cretaceous Heavy-Oil in the Chunguang Block

作　　者：石正勇[1] 金芸芸[1] 李杭兵[1] 张辉[1] Shi Zhengyong;Jin Yunyun;Li Hangbing;Zhang Hui(Sinopec Henan Oilfield Company,Nanyang,Henan 473132,China)

机构地区：[1]中国石化河南油田分公司,河南南阳473132

出　　处：《特种油气藏》2020年第2期37-44,共8页Special Oil & Gas Reservoirs

基　　金：中国石化省级科研项目“春光区块油气成藏特征及有利目标评价”(P12020)。

摘　　要：针对春光区块白垩系稠油地球化学特征、分布规律与成因机制认识不清的问题,应用色谱-质谱等有机地球化学分析方法,对稠油物化特征、空间分布及稠油成因进行分析。研究表明:区块南部以春55-1井为代表的普通Ⅰ类稠油为1~2级轻微生物降解稠油,为成熟原油,有机质来源以低等水生生物为主,陆生高等植物为辅,为湖相还原沉积环境;区块中部以春18井为代表的普通Ⅱ类稠油为4~5级中等生物降解稠油,生物指标化合物特征与Ⅰ类相似,但降解程度更高;区块北部以春10-5井为代表的特稠油降解严重,参数失真,三环帖烷及饱和烃单体烃碳同位素特征显示生源以低等水生生物为主,芳烃化合物成熟度参数均表明特稠油为成熟原油。25-降藿烷的检出、稠油空间分布、地温参数和包裹体特征均表明春光区块稠油属于生物降解成因的中浅层稠油油藏。结合勘探实际综合分析认为,下一步应加大春光区块西南部和中南部稀油、普通Ⅰ类稠油勘探力度。研究成果对春光区块勘探方向的确定具有指导意义。In order to further understanding the geochemical properties,distribution pattern and genesis mechanism of the Cretaceous heavy-oil in the Chunguang Block,chromatography and mass spectrum geochemical tests were used to analyze the physicochemical properties,spatial distribution and genesis. Research indicates that the common Category-I heavy-oil represented by the Well Chun 55-1 in the southern part is considered as a mature crude oil with grade 1-2 slight microbial degradation. The organic matter source is dominated by low-water aquatic organisms and supplemented by terrestrial higher plants in a lacustrine reducing sedimentary environment.The common Category-II heavy-oil represented by the Well Chun 18 in the central part is a medium biodegradation heavy-oil with a grade of 4-5 and a higher degradation level,and the corresponding biomarker properties are similar to those of Category-I. The severe degradation of the ultra-heavy oil represented by the Well Chun 10-5 in the northern part leads to parameter distortion. According to the monomer hydrocarbon carbon isotope properties of tricyclothene and saturated hydrocarbon,the organic matter source is dominated by low-water aquatic organisms,and the aromatic compound maturity properties indicates a mature crude oil. The detection of 25-norbornane,spatial distribution,geothermal and inclusion properties reveal that the Chunguang Block is classified as a medium-shallow heavy-oil reservoir with biodegradation genesis. Based on the comprehensive analysis of hydrocarbon exploration,the further exploration in the Chunguang Block should focus on the thin oil and Category-I heavy-oil resources in the southwest and central parts. This research could provide certain guidance for the further hydrocarbon exploration in the Chunguang Block.

关 键 词：白垩系 色质分析 稠油成因 稠变级别 春光区块 

分 类 号：TE122.1[石油与天然气工程—油气勘探]