鄂尔多斯盆地西南缘泾河油田长7-长8古流向及 沉积相分析

对泾河油田三维地震前积反射、钻井取芯砂岩轻重矿物分离测试和砂体剖面结构对比，并结合前人研究结果认为，泾河油田长8-长7砂岩碎屑主要来自于西南部陇西古陆，部分来自于南部秦岭物源，不受北东物源影响。结合物源、岩芯特征和测井相分析结果认为，泾河油田整个长8₁自下而上是河流-三角洲-半深湖的水进沉积过程，发育3条北东向和1条南北向河道。长8₁2为滨浅湖相-三角洲-河流相沉积，发育（水下）分流河道砂岩；长8₁1储层为浅湖-半深湖背景中水进三角洲水下分流河道砂岩。长7₂为浊积砂岩储层，发育9个北东向浊积水道。

Provenance Direction and Sedimentary Facies of Chang7-Chang8 Members in Yanchang Formation of Jinghe Oilfield,Southwest Margin of Ordos Basin

Based on the studies of the progradation reflections on 3-D seismic data, the matrix mineral assemblages and the heavy mineral assemblages in sandstone cores and the shape of the gamma-ray curves of sandstone, we concluded that the provenance of Chang 7-Chang 8 members in Jinghe oilfield mainly came from the magmatic rocks and metamorphic rocks area which are located in the southwest of the Ordos basin, and the provenance of Zhengning area might come from the south. Cores and logging analysis show that the sandstone of Chang 7₂ member is turbidite sandstone reservoir, which developed nine turbidite water channels or lobate turbidite fans in NE direction. The Chang 8₁ member is a water-transgression sedimentary process from fluvial facies to semi-deep lake facies, which developed three water channels in NE direction and one in NS. The Chang 8₁2 member is a shore-shallow lake facial-fluvial facial deposition, which developed underwater distributary channel sandstone; the Chang8₁1 member developed the water-transgression delta distributary channel sandstone under the background of shallow lake to the semi-deep lake facial deposition.