碎屑岩中长石蚀变形成次生孔隙的试验研究

次生孔隙发育带是深层寻找有利油气勘探目标区的基础,酸性地层水是含油气盆地内部物质迁移和能量交换的主要介质。利用含乙酸溶液,模拟地层水,对济阳坳陷的长石砂岩进行高温高压条件下溶蚀试验,使用扫描电镜、X-衍射分析设备对实验产物进行对比检测。实验证明：（1）高温高压条件下乙酸对长石矿物有很强的溶蚀作用。（2）斜长石比钾长石更容易遭到溶蚀。结合济阳坳陷深层勘探实际,认为深层长石溶蚀耗水作用导致岩石孔隙度变大,形成次生孔隙,从而改善深层储层物性。同时长石溶蚀耗水作用是油气运移成藏活动一种驱动力。

Feldspar alteration of clastic rock form secondary pore experimental study

The secondary pore development zone is the base of seeking favorable exploration area in deep zone.Acidic formation water is the mainly medium for substance migration and energy exchange in oil and gas basin.Using the liquor which contains acetic acid simulate formation water,making corrosion experimental to feldspar sandstone of Jiyang depression under the high temperature and high pressure condition,and using scanning electron microscope、X-ray diffraction analysis apparatus proceed comparison test to experimental product.Experimental evidence：（1） Acetic acid has strong denudation to feldspar mineral under the high temperature and high pressure condition.（2） Plagioclase is more corrosive than potash feldspar.Unite exploration practice in the deep zone of Jiyang depression,think that,water consumption function of feldspar denudation leading rock porosity bigger in the deep zone,form the secondary pore,thereby improving reservoir quality in deep zone.At the same time,water consumption function is a driving force for oil and gas migration and forming reservoir.