运用铸体薄片鉴定、扫描电镜、阴极发光、物性测试等手段,研究柴达木盆地北缘潜西地区上干柴沟组的储层岩石学、孔隙类型、物性特征及成岩作用特征.储层岩石类型以岩屑长石砂岩和长石岩屑砂岩为主,岩石结构成熟度和成分成熟度均较低；储层类型主要为孔隙型,孔隙类型以粒间溶孔和粒内溶孔为主,孔隙结构为特小孔细喉.储层平均孔隙度为14.45％,平均渗透率为59.66×10-3μm2,属中低孔低渗储层.沉积作用和成岩作用是控制储层发育的基础和关键,辫状河道、水下分流河道和浅湖滩坝砂体是有利的储集相带,压实作用和胶结作用是导致储层原始孔隙损失的主要因素,但碳酸盐胶结作用对储层的发育有双重影响,溶蚀作用是对储层发育贡献最大的建设性成岩作用.%Using impregnated thin section, scanning electron microscopy, cathode luminescence and porosity and permeability test, this paper studies the petrography, pore type, physical properties, as well as diagenesis of sandstone reservoirs of the Neogene Shangganchaigou Formation in the Qianxi area of the northern Qaidam Basin. The reservoir dominantly consists of lithic arkose and feldspathic litharenite with low textural and compositional maturities. Intergranular and intragranular dissolved porosities are main pore types with a pore structure of extremely small pore space and thin throat. The reservoir has middle-low porosity and low permeability. Sedimentation and diagenesis are the main factors controlling the development of reservoirs. Braided channel, distributary, and beach-bar sand bodies are most favorable for the formation of reservoirs. Among other factors, compaction and cementation are responsible for the major porosity loss. Nevertheless, carbonate cementation, to some extent, enhances the reservoir properties by dissolution. Descriptive statistics show that dissolution accounts for 2%~6% of porosity, so it contributes most to the development of reservoirs.
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