扶余油层沉积特征及对油气分布的控制作用——以松辽盆地大庆长垣以东地区为例

Sedimentary Feature and Oil and Gas Distribution Rule of Fuyu Reservoir——As Areas in East of Daqing Placanticline in Song-Liao Basin

在大量录井和密井网测井数据基础上结合岩芯和重矿物资料,对物源体系、储层沉积特征及单砂体级沉积微相进行了研究。结果表明长垣以东地区扶余层主要受北部拜泉—青冈物源和西南保康物源控制,两物源在徐家围子附近交汇后向东流出,发育典型的河控浅水三角洲沉积体系。以三角洲平原和内前缘亚相为主,微相类型主要为顺直型分流河道,呈北东向和南北向展布;平面上砂体在北部和西南部最厚,向凹陷中心逐渐减薄;垂向上中部(FⅠ6-FⅡ1小层)砂体最发育,是主要的储集层位。沉积微相与构造叠合显示出沉积微相明显控制了油气的分布,分流河道砂与构造合理配置形成的构造-岩性圈闭,为下一步油气勘探的最有利部位。

Combinating of core and heavy mineral data and based on a large number of well logging and density well logging,researches on the material source system,reservoir sediment characteristics and microfacies of single-sandbody class are conducted.The results show that Fuyu oil layer on the east of Daqing placanticline is mainly affected by the northern Baiquan-Qinggang and the southwest Baokang source,which meet around Xujiaweizi then flow to the east,Fuyu reservoir develops typical sedimental system of shallow water delta that controlled by rivers,the main subfacies are the delta plain and the inner front,and along straight distributary channels are main microfacies type,spreading northeast and south-north;the sand is thickest in the north and southwest in the plane,and gradually thinning to the depression center.In the vertical,the sand in central of Fuyu reservoir（FⅠ6-FⅡ1 small layer） best developed,is the main reservoir horizon.Structure superimposed sedimentary microfacies shows the sedimentary facies clearly control the distribution of reservoirs,the structures-lithologic traps formed by reasonable matching of distributary channels and structure are the next most favorable site of oil and gas exploration.