博兴洼陷南斜坡沙二—沙四段沉积特征研究及有利区预测

Study on sedimentary characteristics of the second to fourth members of the Shahejie Formation in the southern slope of Boxing Sag and prediction of favorable areas

博兴洼陷南斜坡带油藏类型主要受构造、构造—岩性、地层控制,为多含油气层系、多油藏类型的复式油气区。目前沙河街组地层受剥蚀影响,地层接触关系复杂、沉积特征研究有待进一步细化、多期砂体纵横叠置,勘探程度较低。以沙河街组地层为研究对象,从地层、沉积相、地球物理分析等研究分析出发,开展沉积规律及储层预测研究。研究结果表明,工区内地层厚度由北向南减小,沙一段在南部遭受严重剥蚀;沙河街组物源主要来自南部的鲁西隆起,其中沙三上段水下分流河道发育,砂体沉积厚度大,为主要的有利相带。结合储层预测分析,确定3个有利目标区,其中2个有利区目标层位为沉积及岩性控制的沙三上段,1个有利区为受构造控制的沙二段地层,为下一步勘探目标的部署起到积极的作用。

The reservoir type in the southern slope zone of Boxing Sag is mainly controlled by structure,structure-lithology,and strata.It was a compound oil and gas province with multiple hydrocarbon-bearing strata and multiple reservoir types.At present,the stratum of Shahejie Formation was affected by denudation,stratigraphic contact relationship was complicated,sedimentary characteristics research needed to be further refined,multi-stage sand bodies were stacked vertically and horizontally,and the degree of exploration was low.Taking the Shahejie Formation strata as the research object,starting from the research and analysis of stratigraphy,sedimentary facies,and geophysical analysis,carry out sedimentary laws and reservoir prediction research.The research results showed that the thickness of the strata in the work area decreases from north to south,and the first member of Shahejie Formation suffered severe denudation in the south;the source of the Shahejie Formation mainly came from the Luxi uplift in the south,and the upper Shahejie Formation had developed underwater distributary channels and the thickness of the sand body was large.It was the main favorable phase.Combined with reservoir prediction and analysis,three favorable target areas were identified,among which two favorable areas were the upper Es3 section controlled by sedimentation and lithology,and one was the second section of Shahejie Formation controlled by structure,which was the next step of exploration.The deployment of targets had a positive effect.