白音查干凹陷西部洼陷下白垩统碎屑岩储层属干热陆相断陷湖盆近源高速冲积沉积 ,具有成分成熟度和结构成熟度低、重矿物成分复杂等特点。微观孔喉结构研究表明 ,该区储层孔隙类型多 ,孔隙、孔喉半径变化大 ,分选性、连通性差 ,为物性较差的低孔低渗及特低孔低渗型储层。导致这种储集层物性的主要原因是沉积环境及碎屑颗粒物理性质差 ,同时较强的成岩作用对原始孔隙也具有一定的影响 The Lower Cretaceous clastic rock reservoir in western depression of Baiyinchagan Sag is characterized by near-source high-speed alluvial deposition of dry-hot terrigenous faulted lacustrine basin with low maturity of composition and complex structure of heavy minerals. The study of microscopic pore-throat structure shows that there are many pore types, many changes in pore diameter and pore throat radius, poorly sorted and poor connectivity, and are poor low porosity and low porosity and low permeability reservoirs. The main reason for this reservoir physical property is that the sedimentary environment and the physical properties of the clastic particles are poor, while the strong diagenesis also has some influence on the original porosity