准北哈山地区二叠系风城组云质岩储层特征及成因分析

Characteristics and Genetic Analysis for Dolomite Rocks Reservoir of Permian Fengcheng Formation in Hassan Block, the Northern Junggar Basin

摘要: 云质岩作为重要的储集类型，已在准噶尔盆地乌夏地区获得重大突破，哈山地区云质岩勘探亦初见端倪。哈山地区云质岩储层岩石类型复杂，主要为不同程度云化的粉砂岩，泥岩和凝灰岩，常见微层理构造；储集空间为裂缝和溶孔双重介质，整体为低孔、特低渗储层，局部发育溶蚀孔隙型与裂缝-孔隙型两类“甜点”储层；哈山地区二叠系风城组沉积时期为蒸发干燥半封闭半咸化-咸化还原湖相环境，云质岩多为准同生成因，受后期热液和埋藏作用的影响，古斜坡背景或深大断裂发育带利于云质岩发育。

Abstract: Dolomite rock is an important reservoir type and major breakthrough has been made in Wu-Xia Area, Junggar Basin and the exploration of dolomite rocks in Hassan block is also beginning to emerge. The rock types of dolomite reservoirs are complex in Hassan block. There are siltstone, mudstone and tuff of different dolomitic degrees, which have microlayered structure. The reservoir space is two kinds of crack and hole. It is a low porosity and low permeability reservoir and there are two kinds of “dessert” reservoirs, where the dissolution pore and fissure-pore are developed. It is the semi-closed, semi-salinized and salinized reduction lake facies environment in the sedimentary period of the Permian Fengcheng formation in the Hashan area. Most of the dolomite rocks are penecontemporaneous cause, influenced by the hydrothermal and burial effects. The paleoslope background or deep fracture development zone is conducive to the development of dolomite rocks.