砂糖状白云岩通常以高孔高渗为特征，因而长期以来是碳酸盐沉积学家和储层地质学家关注的热点。本项申请，拟针对四川盆地西北部中二叠统栖霞组发育的一类较特殊的非均质砂糖状白云岩，其以不同结构-孔渗中-粗晶砂糖状白云岩交织共生为特征，展示出非均质性，通过较系统的岩心薄片、扫描电镜、核磁共振、CT扫描研究，精细刻划白云岩岩石学特征。在此基础上，结合全岩以及原位微区地球化学分析，查明白云岩及其储层形成过程中的流体来源、性质及其与岩石相互作用机理。基于岩石学和地球化学分析结果，在地质格架中重构白云岩及其储层形成演化过程，建立具有普适性的非均质砂糖状白云岩及其储层形成模式。研究结果可望丰富发展砂糖状白云岩这一领域研究热点的基础理论与油气地质意义研究，另一方面也可为区域油气勘探提供科学依据，故而可望具有重要的基础科学与实践应用研究意义。

Sucrosic dolomite have long been a heated topic in the fields of carbonate sedimentology and reservoir geology for their high porosity and permeability. This study aims to investigate a special, heterogeneous sucrosic dolomite in Middle Permian Qixia Formation, northwestern Sichuan Basin, which are interlaced paragenesis of medium-coarse crystal sucrosic dolomite with different structures and physical properties. Based on comprehensive analyses including thin section observation, SEM analysis, NMR measurement, and CT scanning, this study will finely scribe the petrological characteristics of such dolomite. Subsequently, bulk-rock and in-situ geochemical analysis will be combined to clarify the sources and properties of the fluids in the dolomite-forming process as well as the mechanism of their interaction with rocks. Finally, based on the results of petrological and geochemical analysis, efforts will be made to reconstruct the formation and evolution of dolomite and its reservoir in the geological framework, and attempts will be made to establish the universal mode for the formation of heterogeneous sucrosic dolomite. Results of this study are expected to enrich the basic theory and research significance of the sucrosic dolomite in the oil and gas geology field, and they can also provide scientific basis for regional oil and gas exploration. Therefore, this study is of important basic scientific meaning and great practical application significance.