渤海湾盆地歧口凹陷沙一下亚段地质特征与页岩油勘探潜力

利用系统取心、地震、测井、录井和系统取样分析资料，对歧口凹陷西南缘沙一下亚段页岩层系沉积环境、岩性及组合特征、生烃条件、储集空间、岩石脆性等方面展开综合研究.研究认为:（1）沙一下亚段为歧口凹陷古近系最大湖泛沉积，西南缘宽缓的湖湾背景有利于细粒沉积稳定分布，具备页岩油发育的沉积背景；（2）优质烃源岩纵向上连续分布（60~80 m），平面上稳定分布（1 518 km2），埋藏适中（1 900~3 000 m），主体处于第1期大量生烃阶段，具备页岩油发育的有利生烃条件；（3）矿物成份多样，以碳酸盐岩和细粒混合沉积岩为主，薄互层白云岩、油页岩、泥岩纵向上交互发育，平面连续分布，具备页岩油发育的岩性及组合条件；（4）岩性组合及生烃条件等参数综合评价，纵向上识别出4个垂向甜点段（C1~C4），甜点段之间发育3个高GR、低RT泥岩隔板层；（5）优选有机质丰度、成熟度和甜点段厚度3个甜点评价参数，平面上识别出4个Ⅰ类甜点分布区共380 km2，为下一步勘探的重点. 

Geological Characteristics and Shale Oil Exploration Potential of Lower First Member of Shahejie Formation in Qikou Sag,Bohai Bay Basin

Using system coring, seismic data, logging, and various analysis data, comprehensive research focus on the sedimentary environment, lithology, hydrocarbon generation conditions, reservoir space and reservoir brittleness of the lower first member of Shahejie formation in Qikou sag, Bohai Bay Basin.The study concluded that:(1) The maximum lake flooding period of the Paleogene in the lower first member of Shahejie formation of Southwestern margin Qikou sag has wide gentle slope background which is conducive to the stable distribution of fine-grained sediments and conducive to shale oil development; (2) High-quality hydrocarbons are continuously distributed in the longitudinal direction (60~80 m) and with wide distribution area(1 518 km2), formation depth in 1 900~3 000 m which is the first phase of the massive hydrocarbon generation phase and have hydrocarbon-generating conditions for shale oil development; (3) Diverse mineral composition and mainly with carbonate rocks and mixed fine-grained sedimentary rocks, thin interbedded dolomite, oil shale, mudstone alternately develop in the longitudinal direction, plane continuous distribution; (4) C1, C2, C3 and C4 dessert are identified in the longitudinal direction which contains three high-GR and low-RT mudstone separator layers; (5) Organic matter abundance, maturity and dessert section thickness can be used for dessert evaluatio and four Class I dessert distribution areas(380 km2) were identified on the plane which is the main exploration target of next step.