冀中饶阳凹陷深部碎屑岩储层研究

STUDY OF DEEP CLASTIC ROCK RESERVOIR IN RAOYANG DEPRESSION NORTH CHINA BASIN

本文根据饶阳凹陷大于4000m 深井钻探资料、测井资料及岩心实验室研究,从岩心入手综合分析本区深部碎屑岩储层,其层位属下第三系沙河街组,岩性为长石砂岩及岩屑长石砂岩。孔隙类型以粒间孔及溶孔为主。沉积环境控制着储层分布,由于成岩后生作用的影响,通常深部储层不甚发育,但因有时条件适合,溶蚀作用强烈,次生溶孔发育,可以存在相对较好的储集层。研究埋深与成岩阶段划分,找出成岩后生中期的第一、二迅速转化带,次生孔隙异常发育,是寻找深部储层的指向。伊/蒙混层中的蒙皂石层百分比、石英长石次生加大现象标志着有酸性介质环境,有利于溶蚀作用产生,借以预测碎屑岩次生孔隙发育带,寻找深部储集层。

This paper analyzes systematically deep clastic rock reservoir in Raoyang depression beginning with an analysis of core data,according to the inform- ation of well drilling,well logs and core analysis from reservoirs below 4000m in depth.The formation is Shahejie group and its lithology consi- sts of feldspar sandstone and debris feldspar sandstone mainly.The types of porosity are inter-partical and dissolution pores.Sedimentary environ- ments control the distribution of the reservoir.Because of diagenesis affects, deep reservoir generally does not exist.when condition is suitable,intensive dissolution happens,secondary dissolution pore is formed.Studying depth and diagenetic stage to find first and second rapidly tranform zones that deve- lop secondary pore in the middle and later stage of diagenesis is the appro- ach to find deep clastic rock reservoir.Organic acid content in formation water and percent of S layer in I/S mixed layer and the secondary growth of quartz and feldspar in the reservoir formation indicate organic acid medi- um enviroment,where favourable dissolution happens.Using these results, we can predict secondary pore formation zones and deep clastic rock reserv- oir.