准噶尔盆地玛北斜坡区扇三角洲砂砾岩储层主控因素

准噶尔盆地西北缘玛北斜坡区三叠系百口泉组发育典型的扇三角洲砂砾岩储层，具有成分成熟度低、结构成熟度中等及低孔、低渗等特征。为查明砂砾岩储层主控因素，探寻有效储集体，利用铸体薄片、扫描电镜、荧光薄片和物性分析等资料，探讨了玛北斜坡区三叠系百口泉组岩性、沉积相、沉积构造和古地貌、成岩作用及油气充注对砂砾岩储层的控制作用。结果表明：岩性是砂砾岩优质储层形成的物质基础；有利沉积相对储层质量起决定性作用；沉积构造和古地貌控制砂砾岩的平面展布；成岩作用和油气充注产生的次生孔隙可有效改善储层物性。研究区有利砂砾岩储集体主要分布于水动力条件稳定且较强的扇三角洲前缘水下分流河道和河口坝，其次为扇三角洲平原分流河道。

Main controlling factors of glutenite reservoir of fan delta in Mabei slope,Junggar Basin

Typical glutenite reservoirs of fan delta are developed in Triassic Baikouquan Formation in Mabei slope,northwestern margin of Junggar Basin, which are characterized by low porosity and low permeability with low compositional maturity and middle textural maturity. In order to disclose the main controlling factors for the development of glutenite reservoirs and predict favorable reservoir distribution, based on the data of thin sections, scanning electron microscope, thin section examination of fluorescence characteristics and physical properties, the controlling effects on glutenite reservoirs were discussed of the following aspects: lithology, sedimentary facies, sedimentary structure and palaeogeomorphology, diagenesis, as well as hydrocarbon- charging. The results show that lithology is the material basis of forming high quality glutenite reservoir; the favorable sedimentary facies is crucial for reservoir quality; sedi?mentary structure and paleogeomorphology decided by strong syngenetic faulting plays a key role in theglutinite body distribution; diagenesis and hydrocarbon-charging are favorable for improving the properties of glutenite reservoir. Fan delta front subaqueous distributary channel glutenite and mouth bar sandstone are favorable reservoirs whose hydrodynamic condition is stable and stronger, and fan delta plain distributary channel glutenite is fair.