王府凹陷储集层成岩作用及对储集性能的影响

Diagenesis and its Influence on Property of Reservoirs in Wangfu Depression

详细分析了王府凹陷上侏罗统和下白垩统砂岩储层的成岩作用及其对储层物性的影响 .成岩作用的主要类型包括机械压实作用、胶结作用、交代作用、溶蚀作用、破裂作用等 ,成岩阶段属晚成岩 A期 .其中 ,机械压实作用、化学胶结作用是导致砂岩孔隙度降低、储集性能变差的主要因素 .机械压实作用主要表现为软碎屑的塑性变形、颗粒间由点接触向凹凸接触演变 ;胶结作用表现为石英和长石的次生加大、自生粘土矿物、碳酸盐和硬石膏胶结物的依次形成并充填孔隙 .破裂作用及溶蚀作用在一定程度上提高和改善了砂岩储集性能 .影响成岩作用的主要因素为沉积环境、岩石结构、孔隙水性质 .

The diagenesis of the sandstone reservoirs of the upper Jurassic—lower Cretaceous series in Wangfu depression was analysed systematically. The result shows that the diagenesis includes compaction, cementation, replacement, dissolving, and cracking, etc. The compaction and cementation are the main factors causing the reduction of porosity and making the physical property of reservoirs become poor. The main characteristics of the compaction are the plastic deformation of soft clastics and the development from point contact to concave convex contact between grains. Cementation is showed by the secondary enlargement of quartz and feldspar,the successive formation and pores filling of cementing material of authigenic clay mineral, calcite and anhydrite, etc. Cracking and dissolving could improve the physical property of sandstone reservoir. The main factors influencing the diagenesis of sandstone reservoir are sedimentary environments, nature of pore fluid, and textures of sandstone.