齐家-古龙地区页岩油参数井泉头组-青山口组沉积微相特征

SEDIMENTARY MICROFACIES OF QUANTOU FORMATION-QINGSHANKOU FORMATION OF SHALE OIL PARAMETRIC WELLS IN QIJIA-GULONG AREA

沉积微相发育特征对页岩油赋存及开发潜力具有重要的影响.以松辽盆地北部齐家-古龙地区松页油1井和松页油2井泉头组四段上部—青山口组二三段下部岩心为研究对象,通过大比例尺岩心观察和精细描述,以岩心岩性、层理构造、化石、含有物、电性特征为依据,开展沉积微相研究.研究认为,松页油1井和松页油2井岩心中,主要发育湖泊相沉积,分为浅湖和半深湖—深湖2种沉积亚相,可进一步识别出浅湖滩坝砂、介壳滩、泥质浅湖、半深湖—深湖泥和油页岩5种沉积微相.青一段下部主要发育半深湖—深湖亚相,浅湖亚相主要分布在青一段上部、青二三段下部和泉四段上部层位.泥质浅湖微相、半深湖—深湖泥微相以及油页岩微相均是有利于页岩油形成的沉积微相类型.

The development characteristics of sedimentary microfacies significantly affect the occurrence and exploitation of shale oil.Taking the cores from the upper part of 4th Member of Quantou Formation and lower part of 2nd-3rd members of Qingshankou Formation from SYY1 and SYY2 wells in Qijia-Gulong area of northern Songliao Basin as the research object,the paper studies the sedimentary microfacies through large-scale core observation and fine description based on core lithology,bedding structures,fossils,inclusions and electrical characteristics.It is concluded that lacustrine facies deposits are mainly developed in the cores of SYY1 and SYY2 wells,which can be divided into two sedimentary subfacies of shallow lake and semi-deep-deep lake,with five sedimentary microfacies including beach-bar sands in shallow lake,ostracoda beach,argillaceous shallow lake,semi-deep-deep lake mud and oil shale.The lower part of 1st Member of Qingshankou Formation is dominated by semi-deep-deep lake subfacies;while the upper part of 1st Member and lower part of 2nd-3rd members of Qingshankou Formation and upper part of 4th Member of Quantou Formation,by shallow lake subfacies.The latter three microfacies are all favorable to form shale oil.