构造-热液白云岩化作用与白云岩储层

热液白云岩储层的岩石特征与密西西比 Pb-Zn 硫化矿床的白云岩容矿层相似,以广泛发育的基质交代型和孔-缝充填的鞍形白云石为标型特征,同时含有少量其他热液矿物如闪锌矿、方铅矿、石英、黄铁矿、重晶石以及萤石等,另外还经常可见被鞍形白云石充填的因剪切应力形成的微裂缝、斑马纹构造和白云岩角砾。由于热液流体对原碳酸盐岩(主要是灰岩)的差异性溶蚀,往往保留了未被充满的孔洞、缝,为油气的充注提供了空间。输导热液流体的断裂系统通常为张性或扭张性断裂系统,白云岩化作用主要发生在断裂系统的上盘,并沿着孔渗性相对较好的原岩侧向推进。借助于高分辨率地震属性分析和成像技术,可以对热液白云岩储层进行表征和预测,从而为油气勘探决策提供依据。

Structure-controlled hydrothermal dolomitization and hydrothermal dolomite reservoirs

Sharing similar lithologic characteristics with dolomite seam hosting MVT Pb-Zn sulfide ores,hydro- thermal dolomite reservoirs contains mainly massive-matrix-replacement dolomites and void-or fracture-filling saddle dolomite dotted with small amount of other hydrothermal ores,such as sphalerite,galena,quartz,pyrite, barite,and fluorite.Saddle dolomite-filling microfractures and zebra textures formed by shear stress and dolomite breccias are also common in these reservoirs.Unfilled vugs,fractures,and pores ...