风化火山期次界面识别及控藏作用——以西准噶尔地区为例

西准噶尔地区风化火山期次界面分为两类,Ⅰ类界面自然伽马值高、电阻率值低、密度值低;Ⅱ类界面自然伽马值高、电阻率值高、密度值低。界面发育在火山机构的分界线上,地震剖面上具有超覆、强反射的特征。风化火山期次界面为流体的运移通道,流体对界面两侧的岩石产生强烈的风化作用,使界面附近岩石内部产生微裂缝、溶蚀孔洞,最终使风化火山期次界面区域成为油气成藏的优势区域。

Interface identification of weathering volcanic period and reservoir forming control:a case study in the area of western Junggar

The weathering volcanic sub-interfaces in the area of western Junggar can be divided into two types.Type Ⅰ interface in well logging has the characteristics of high GR, low resistance and low volume density,while type Ⅱ interface has the characteristics of high GR, high resistance and high-volume density. By seismic method, the basic feature of the interface is developed on the boundary line of the volcano mechanism, which has the basic characteristics of overlying and strong reflection. The main reservoir formation of the weathering volcanic interface is the migration channel of oil and gas, and the fluid in the interface has a good transformation effect on the upper and lower volcanic rocks of the interface, which will produce micro-cracks and corrosion holes in the rock internal near the interface. Finally, the sub-interface area of weathering volcanic period becomes the dominant area for hydrocarbon accumulation.