松辽盆地古龙页岩油富集规律及有利区分布OA北大核心CSTPCD

In recent years,exploration and development practices have confirmed enormous potential of shale oil re-sources developed in Cretaceous strata of Songliao Basin.However,unclear enrichment law of shale oil and uncer-tain distribution of favorable areas hinder the rapid progress of exploration and development of Gulong shale oil.Based on coring and comprehensive experimental analysis of several wells in entire Gulong area,a systematic analy-sis is conducted on oil-bearing properties,reservoir properties and producing conditions of shale oil to clarify shale oil enrichment and distribution laws.Classification criteria for favorable areas is established to systematically evalu-ate favorable areas of Qijia-Gulong Sag in Songliao Basin.The results show that sedimentary background controls vertical regularity of shale mineral components and lithologies of thin interlayers.Main controlling factors for enrich-ment producibility are determined including source rocks abundance and thermal evolution degree controlling"oil",evolution of organic matter generating hydrocarbon and evolution of diagenesis controlling"reservoir",and NMR movable porosity and brittle mineral content controlling"producing".Gulong shale oil in vertically lower Q1-Q4 oil layers are dominated by pure shale,with the best oil-bearing properties but maximum clay mineral content and poor engineering quality,and Class Ⅰ favorable areas are mainly distributed in northern and part of southern Qijia-Gu-long Sag,Class Ⅱ areas mainly cover Qijia-Gulong Sag,with largest distribution area.Middle Q5-Q7 oil layers devel-op shale interlayered with thin dolomite,with moderate oil-bearing properties and engineering quality and minimum NMR movable porosity,and Class Ⅰ favorable areas partially develop in northern Qijia-Gulong Sag,with the small-est area,The scope of Class Ⅱ area is similar with Ro>1.2％range,with area smaller than Q1-Q4 oil layers.Q8-Q9 oil layers develop shale interlayered with thin siltstone,with good oil-bearing properties,relatively low clay mineral content,best engineering quality and maximum NMR movable porosity,providing the best production conditions,and Class Ⅰ favorable areas have the largest area distributing throughout the range of Ro>1.2％.The scope of Class Ⅱ area is similar with Q8-Q9 oil layers.The research provides theoretical guidance for further exploration and de-velopment of Gulong shale oil.