松辽盆地齐家北地区下白垩统泉头组泉四段沉积微相特征

笔者通过大量的岩心观察、测井及录井资料的研究,结合粒度分析,对齐家北地区泉四段沉积特征进行了系统的分析,共识别出三角洲平原和三角洲前缘两个亚相和水上分流河道、天然堤、分流河道间湾、水下分流河道、水下分流河道间湾、河口坝、远砂坝等7个微相。通过对研究区内泉四段7个含油小层的平面展布特征及沉积演化规律的深入研究,并结合泉四段砂体的含油气性分布特征综合分析研究表明:研究区油气分布明显受控于沉积微相的展布;水下分流河道由于具油源近、储集物性较好而成为最有利的油气聚集相带;河口坝、水上分流河道是油气富集的较有利相带。

Sedimentary microfacies of the fourth member of the Lower Cretaceous Quantou Formation in northern Qijia,Songliao Basin,Heilongjiang

The examination of the sedimentary microfacies of the fourth member of the Lower Cretaceous Quantou Formation in northern Qijia is based on the cores, well logs and granulometric analysis. Seven sedimentary microfacies have been distinguished, including the distributary channel, natural levee, interdistributary bay, subaqueous distributary channel, subaqueous interdistributary bay, channel mouth bar and distal bar microfacies grouping into the delta plain and delta front subfacies. The oil and gas distribution is mostly controlled by the sedimentary microfacies cited above. The subaqueous distributary channel microfacies is selected as the most favourable area for hydrocarbon accumulation due to the proximal provenance and good reservoir quality whereas the channel mouth bar and distributary channel microfacies are considered as the favourable area for hydrocarbon accumulation.