塔中地区东河塘组储层中高孔渗成因浅析

上泥盆统东河塘组东河砂岩段是塔中地区最重要的油气产层,该套地层为中高孔渗储集层。为此，在地层、沉积特征分析研究和储层物性统计的基础上，对储层特征、中高孔渗储层形成原因进行了综合分析研究。结果认为东河塘组砂岩成分和结构成熟度都很高，孔隙类型以粒间孔隙和粒间溶蚀孔隙为主，在河口湾、前滨-临滨相中的海滩砂坝、滨岸三角洲砂坝中发育中高孔渗储层；刚性颗粒组分含量高和塑性颗粒组分含量低、分选好、古地温低、溶蚀作用是东河砂岩形成中高孔、渗储层的主要原因，这也是该套储层的重要特征。弄清这一点对寻找有利的富集油气带具有积极的意义。

ANALYZING THE HIGH POROSITY AND PERMEABILITY ORIGIN OF DONGHETANG FORMATION RESERVOIR IN TAZHONG AREA

With meso-high porosity and permeability, the Donghe sandstone member of Upper Devonian Donghetang Formation is the most important pay bed. Based on analyzing depositional feature and reservoir physical property, the reservoir characteristics and the origin of forming meso-high porosity and permeability are comprehensively analyzed in this paper. It is recognized that, with high sandstone composition and textural maturity, the pore types of Donghetang Formation mainly are intergranular space and intergrain denudation pore. There are developed reservoirs with middle-high porosity and permeability in the beach sand bar and littoral delta bar of estuary, foreshore-nearshore facies. The high content of rigidity grain component, the low content of plasticity grain component, nice selectivity, low paleogeotemperature and denudation are the main conditions for Donghe sandstone to form meso-high porosity and permeability reservoir, which is of important significance to survey favorable oil-gas enrichment zones in the area