准噶尔盆地乌尔禾地区砂砾岩蚀变模式

准噶尔盆地乌尔禾地区二叠系发育热液成因的蚀变砂砾岩。地震构造解释表明,热液蚀变地层均产出于风南断裂附近,且均分布于断裂上盘,具有明显的断裂控制特征;岩石学特征分析表明,热液蚀变地层伴生碳酸盐矿物、次生石英、沸石类和黄铁矿等多种蚀变矿物。根据岩心刻度测井思想,提出一种基于因子分析技术的热液蚀变作用识别方法,在此基础上,结合其构造特征、与围岩关系及地球物理响应特征等研究成果,提出热液横向顺层迁移和热液纵向穿层迁移2种蚀变模式,并指出在热液流体演化后期,硅化作用占主导地位的蚀变地层由于次生溶蚀孔隙的发育而易形成优质储层,为下一步油气重点勘探方向提供科学依据。

Alteration model of sandy conglomerate of Wu'erhe Area in Junggar Basin

Sand conglomerate in the Permian Formation,Wu'erhe Area,Junggar Basin,is altered.The seismic structure interpretation shows that hydrothermal alteration Formation has the obvious characteristics of the fracture control feature,which is near to the Fengnan Fault and distributed in the upper part of the fault,and petrological analysis shows that the hydrothermal Formation associated with carbonate minerals,seeondary quartz,zeolites,pyrite and variety of alteration minerals.According to the core calibration log,a method of thermal fluid alteration identification based on factor analysis was proposed.On the basis of its structural features,and its relationship with surrounding rocks and the characteristics of geophysical responses,two alteration modes of hydrothermal lateral bedding transfer and hydrothermal longitudinal wear layer were put forward.In the late evolution of hydrothermal fluid,the dominant alteration strata of the silicon Formation is easy to form quality reservoir due to the development of secondary dissolution porosity,which provides scientific basis for petroleum exploration direction.