陕北地区延长组储层孔隙控制因素分析

Analysis of controlling factors of reservoir pores in the Yanchang Formation of Northern Shaanxi area

储层微观孔隙结构是决定储层储集及渗流特征的关键因素，分析其成因类型及分布规律，对深入研究储层特征差异及预测优质储层具有重要意义。岩石的孔隙率是储层的重要评价指标，面孔率是孔隙率的重要组成部分，其分布特征和含量多少直接影响储层的质量。面孔率和孔隙率的控制因素实际上也是储层质量的控制因素。储层的孔隙类型与其储集性能有极其密切的关系，分析储层孔隙类型及其在成岩过程中的演化规律是寻找和预测有利产建目标区的重要手段。陕北地区延长组砂岩中孔隙以粒间孔、长石溶孔、沸石溶孔和岩屑溶孔为主。其中粒间孔是主要的储集空间．且延长组各层组表现不一，并与压实作用、胶结物含量等相关。

The microscopic pore structure of reservoir is the key factor to determine the reservoir characteristics and percolation characteristics. Analyzing its types of the formation causes and distribution law is very important for deep study of reservoir characteristics differences and prediction of quality reservoirs. The porusity of rock is an important index of reservoir evaluation. Pore- section or pore-profile area ratio （ planar porosity ） is an important component of porosity. Its size and distribution characteristics directly affect the quality of the reservoir. The controlling factors of pore-profile area ratio and porosity are actually the controlling factors of reserw）ir quality. The pore types of reservoirs are closely related to their reservoir properties. The analysis of reservoir pores types and its evolution in diagenesis is an important means to predict and find the favorable target area （s） of constructing production capacity. The pores in the sandstone of Yanchang Formation in northern Shaanxi are dominated by intergranular, feldspar-dissolved, zeolite-dissolved and lithic dissolution pores, among which intergranular pores are the main reservoir spaces. And their presence in each horizon group of the Yanchang Formation is different, being related to the compaction effect, cement content, and so on.