古龙南凹陷葡萄花油层储层层序地层及沉积体系研究

利用高分辨率层序地层学原理建立松辽盆地古龙南凹陷葡萄花油层储层层序地层格架,结合岩心、测井、录井等资料对其进行沉积微相研究。结果表明,该储层可以划分为1个中期基准面旋回的基准面下降旋回,3个短期基准面旋回以及5~8个超短周期基准面旋回。该储层主要发育湖泊-三角洲沉积体系,并进一步细分出水下分流河道、分流河道间、河口坝、前缘席状砂、前三角洲泥、浅湖等沉积微相,水下分流河道及前缘席状砂沉积微相可形成优质储层。其物源主要为北部和西部方向：西部地形较陡,其物源较近,形成辫状河三角洲沉积体系;北部地形平缓,其物源较远,形成曲流河三角洲沉积体系。早期沉积以北部物源为主,晚期以西部物源为主。古龙南凹陷主要有构造、构造-岩性、岩性、断层-岩性及上倾尖灭5种类型油气藏,其中上倾尖灭油气藏分布于古龙南凹陷的西部斜坡区,岩性及断层岩性油气藏主要分布于凹陷的中心部位,构造-岩性油气藏发育于凹陷东部的斜坡区,构造油气藏则发育于凹陷东部的鼻状构造。

Study on sequence stratigraphy and sedimentary system of Putaohua oil reservoir in South Gulong Depression

Using the principle of high resolution sequence stratigraphy,this paper built the stratigraphic framework of Putaohua oil reservoirs in South Gulong Depression of Songliao Basin and studied its sedimentary microfacies combined with the core,well logging and mud logging data.The research shows that Putaohua oil layer can be divided into one base level downward hemicycle of medium term base level cycle,three short term base level cycles and five to eight super-short term base level cycles.A lake-delta sedimentary system can be identified in Putaohua oil layer,which can be subdivided into the underwater distributary channels,mouth bars,frontal sheet sands,frontal delta mud and shallow lakes.High quality reservoirs mainly lay in the underwater distributary channels and frontal sheet sands occurred,whose main source is from the north and the west.The west is generally steep,so the source is near and the braided river delta forms.It is flat in the north,so the source is far,forming meandering river delta sedimentary systems.Earlier deposition is mainly from the north,while later it is mainly from the west.South Gulong Depression consists of structural reservoir,structurallithologic reservoirs,lithologic reservoirs,fault-lithologic reservoirs and updip pinchout reservoirs,in which the updip pinchout reservoirs occur at the west slope of South Gulong Depression,lithologic reservoirs and fault lithologic-reservoirs mainly at the center,structural-lithologic reservoirs at the east slope area,while structural reservoirs at the nose-like structures in the east of depression.