南皮地区石盒子组沉积微相特征与有利储集相研究

Study on sedimentary microfacies characteristics and favorable reservoir facies of Shihezi Formation in Nanpi area

大港南皮地区目的层石盒子组碎屑岩砂体分布广泛、厚度大,但沉积展布及有利储集相分析并不完善。为此,以沉积环境研究为基础,依据测井沉积学理论,利用测井曲线形态特征与岩性剖面的对应关系,对研究区单井沉积微相精细解释与划分。运用均方根振幅属性切片技术,分析了沉积相空间展布规律。研究表明,石盒子组曲流河相沉积体系主要有3种亚相7种微相,砂体由北东向南西展布。其中,河床滞留沉积相与边滩相主要以陆源砾石为主且粒度较粗,孔隙连通性好,在研究区是砂岩和储油物性最发育的层段。泛滥平原泥质含量高,孔隙喉道较窄,沉积颗粒细,储油性差。该区研究能为油气藏的合理高效开发和其他地区沉积研究提供理论依据。

The target layer of the Shihezi Formation in the Nanpi area of Dagang is widely distributed and has a large thickness of clastic rock sand bodies.However,sedimentary distribution and favorable reservoir facies analysis are not perfect.Therefore,based on sedimentary environment research and the theory of well-logging sedimentology,by utilizing the correspondence between the morphological characteristics of logging curves and lithological profiles,fine interpretation and division of sedimentary microfacies in single-well in the study area can be achieved.The root-mean-square amplitude attribute slicing technique was employed to analyze the spatial distribution patterns of sedimentary facies.The research indicates that within the Shihezi Formation,fluvial sedimentary systems primarily consist of three subfacies and seven microfacies,with sand bodies extending from the northeast to the southwest.Among these,the riverbed deposition subfacies and marginal bar subfacies are dominated by terrestrial gravel with coarse grain size and excellent pore connectivity,making them the most prolific layers in terms of sandstone and oil-bearing properties within the study area.In contrast,the floodplain subfacies exhibits high mud content,narrow pore throats,fine sediment grains,and limited oil-bearing properties.This study provides theoretical foundations that can contribute to the rational and efficient development of oil and gas reservoirs in the region and also serve as a basis for sedimentary research in other areas.