摘要
延长组长6油层组是鄂尔多斯盆地主力产油层,平面上储层储集性能差异较大。通过盆地中部大量长6砂岩岩矿资料,结合盆地周缘露头剖面资料系统分析,认为鄂尔多斯盆地中部长6沉积期存在西部、北东、西北、北部、东南方向及多物源控制的沉积区,且受不同方向物源控制的长6砂岩轻、重矿物组合,填隙物类型和组合及成岩矿物等均不相同,其中混源区受多物源的共同影响,但轻、重矿物组合及孔隙发育程度主要受主物源控制;砂岩成熟度、粒径、碎屑组分、填隙物类型与组合和成岩作用是控制长6砂岩储层孔隙发育的主要因素,且不同物源控制区长6储集砂岩的孔隙保存条件不同,物性相差较大。研究结果说明确定不同方向物源控制区、混源沉积区长6储集砂岩孔隙特征及孔隙发育控制因素是掌握孔隙性砂体分布规律的前提。
Chang-6 reservoir is the leading pay formation of the Yanchang Formation in the center of Ordos basin,but reservoir quality of genetic sandbodies shows a big difference in horizontal.By studying the light and heavy mineral combination characteristics of chang-6 reservoir sandstone and typical outcrops,it is believed that there exist five main source directions of the west,northeast,northwest,north and southeast in the depositional period of chang-6 oil-bed of Yangchang Formation in the center of Ordos basin.The characteristics of the light and heavy mineral combination,interstitial matrix and diagenetic mineral of chang-6 reservoir sandstone controlled by different source directions were different.In addition,there exist some mixed sources areas which were converged by the west,northeast,northwest,north and southeast sources.The characteristics of light and heavy mineral combination,interstitial matrix,diagenetic mineral and porosity of its reservoir were affected by the main source.The controlling factors of the sandstone reservoir porosity development of Chang 6 include the sandstone maturity,grain size,detritus composition,interstitial matrix and diagenesis.The reservoir porosity is closely related to the various provenances.As a result,porosity distribution is predictable.
出处
《沉积学报》
CAS
CSCD
北大核心
2011年第1期80-87,共8页
Acta Sedimentologica Sinica
关键词
鄂尔多斯盆地
物源
延长组长6
孔隙
Ordos basin； provenances； Chang-6 oil-bed of Yangchang Formation； porosity
