泌阳凹陷毕店地区核三段Ⅵ-Ⅶ油组沉积微相研究

Sedimentary microfacies research of He-3 member Ⅵ-Ⅶ oil group in Bidian area of Biyang depression

利用岩心、钻井、测井及分析测试资料,通过岩石相和测井相分析,结合岩石结构特征及相序等,对泌阳凹陷毕店地区核三段Ⅵ-Ⅶ油组沉积微相进行了研究。泌阳凹陷毕店地区核三段Ⅵ-Ⅶ油组位于多物源交汇区,发育三角洲、扇三角洲、湖泊及水下重力流四种沉积体系,进一步分为三角洲前缘、前三角洲、扇三角洲前缘、前扇三角洲、浅湖和中深湖等六个亚相。为了区分三角洲前缘和扇三角洲前缘微相,将三角洲前缘划分为水下分流河道、河口砂坝、三角洲分支间湾、远砂坝四种微相;扇三角洲前缘划分为水下分流河道、前缘砂、扇三角洲分支间湾及席状砂四种微相。分布在北部和西北部的三角洲前缘水下分流河道和南部扇三角洲水下分流河道的砂体较厚;往深凹陷方向,主要发育三角洲前缘远砂坝、扇三角洲前缘席状砂等微相,砂体厚度减薄。在垂向上以退积沉积为主,Ⅶ油组砂体比Ⅵ油组砂体的分布范围更广。三角洲水下分流河道、远砂坝,扇三角洲水下分流河道、前缘砂、席状砂及水下重力流砂体的物性好,是该区有利的勘探目标。

By using core,drilling,well logging and analysis of testing data,through rock facies and logging facies analysis,combined with the rock structure feature and phase sequence,the sedimentary microfacies research ofⅥ-Ⅶ oil group in He-3 member of Bidian area,Biyang depression has been carried out.Located in multiple provenances intersection area,the area ofⅥ-Ⅶoil group in He-3 member has developed four sedimentary systems,namely delta,fan delta,lacustrine and underwater gravity,further can be divided into six subfacies,namely delta front,front delta,fan delta front,fan delta,shallow lacustine and mid-deep lacustrine.In order to make a distinguish between delta front and microfacies of fan delta front,the delta front is divided into four kinds of microfacies,namely underwater distributary channel,river mouth bars,delta branch bay and distal bar.The fan delta front is divided into four kinds of microfacies,namely underwater distributary channel,frontier sand,tributary bay of fan delta and sand sheet.The sand bodies in the north and northwest of delta front underwater distributary channel and underwater distributary channel sand bodies in the south are thicker.In deep depression,the delta front far bar,fan delta front,and sheet sand have been mainly developed,with thinning sand body thickness.In vertical direction,it is mainly with retrogradation deposits,the sand body distribution range ofⅦ oil group is wider than that ofⅥ oil group.The physical properties of delta distributary channel,distal bar,fan delta underwater distributary channel,frontal sand,sand sheet and underwater gravity flow are good,therefore,acting as favorable exploration target in the area.