The regional tectonic evolution,core test,thin-section analysis,oil test and logging data are compre-hensively analyzed to identify the key controlling-factors and distribution patterns of Carboniferous weathering crust reservoir in the fault terrace zone of Northwestern Junggar Basin. The weather crust in this area is firstly divided into soil layer,hydrolysis zone,corrosion zone,disintegration zone and parent rock from top to bottom. Favorable reser-voirs mainly develop in the corrosion and disintegration zones.All kinds of lithology can be acted as weathering crust reservoir with coexisting fracture and corroded cave and its physical properties are dependent on parent rock litholo-gy and leaching level. The Carboniferous weathering crusts with a general thickness of 450 m and a thickness of more than 600 m in the fault zone mainly distribute in the high-parts of paleohighs,slope areas and fault areas.The corresponding reservoir scale is mainly controlled by the weather crust reservoir properties.This understanding clears the weathering reworking effect and enriches the rock type and spatial distribution of favorable reservoirs,which could provide certain reference for the hydrocarbon exploration in similar areas.%针对准噶尔盆地西北缘断阶带石炭系风化壳储层主控因素及分布规律不明的问题,综合分析区域构造演化、岩心、薄片、试油和测井等资料,首次提出该地区石炭系风化壳结构自上而下分别为土壤层、水解带、溶蚀带、崩解带和母岩.其中,溶蚀带和崩解带是有利储集层的集中发育带,各类岩性均可形成裂缝和溶蚀孔洞并存的风化壳储层;其物性受母岩岩性和风化淋滤程度控制.石炭系风化壳主要分布于古隆起高部位、斜坡区和断裂发育区,其厚度一般为450 m,断裂发育区的风化壳厚度可大于600 m;风化壳储层物性决定油藏的规模.该认识明确了风化改造对储层的建设性作用,扩大了有利储层的岩类和空间分布,该研究对类似地区的油气勘探具有借鉴意义.
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