Lower Urho Formation in Region 8 of Karamay Oilfield is an important oil-bearing series, where gravel is dominated.the classification and correlation of its strata are the long existed problems.

• 克拉玛依油田八区下乌尔禾组为一套以砾岩为主的粗碎屑沉积,是该区最重要的含油层系。对其地层的划分与对比,是长期存在的一个问题。