松南长岭地区坳陷层油气富集规律

Hydrocarbon enrichment rules of depression period layer in Changling region of southern Songliao Basin

以构造、层序和沉积研究为基础,从'层序控砂'和'微相控储'的角度预测有利储层分布;结合油气成藏条件分析,探讨松南长岭地区坳陷层油气富集规律。研究结果表明:层序旋回控制油气富集部位,重点含油层位靠近成熟烃源岩;沉积相控制有利储层发育区带,主要含油区呈环带状分布于三角洲前缘与滨浅湖的交互区域,水下分流河道和河口坝微相中的油气显示较多,且含油气性较好,为有利储集相带;基底断裂带和有利油气聚集区紧密相联,含油气带主要受继承性发育的基底断裂控制与影响;油气富集与地层展布形态、圈闭类型密切相关,中部平缓区为低幅度构造圈闭发育带,东部构造反转区为反转上倾尖灭的岩性和构造-岩性复合型圈闭发育带,而西部斜坡区于西掉断层上升盘,可形成低幅度构造和构造-岩性油气藏。

Based on the research of structure, sequence and sediment, favorable reservoir was predicted from the point of ＂sequence controls sand＂ and ＂sedimentary microfacies control reservoir＂. Combined with analysis of hydrocarbon accumulation condition, rules of depression layer hydrocarbon enrichment in Changling region of southern Songliao Basin were discussed. The results show that sequence cycle controls the place where hydrocarbon accumulates and valuable oil-bearing stratum are near the mature source rocks. Sedimentary facies control the place where favorable reservoir develops. The main oil-bearing areas distribute zonationally in delta front and shore lake crossover region. Underwater distributary channel and mouth bar are beneficial reservoir facies because there are more and better oil and gas. Basal fault zone is closely linked with favorable hydrocarbon accumulation areas. Oil-bearing areas are mainly controlled and influenced by the inherited basement fault. Hydrocarbon accumulation is closely related to strata distribution patterns and trap types. There are low-amplitude structural traps developed in the central flat area. Lithologic traps that are updip pinchout and structural lithologic traps are in the eastern inversion area. And there are low-amplitude structural traps and structural lithologic traps on the upthrow side of west faults in western slopes.