徐东地区营城组一段火山岩储层微观非均质性特征

Microcosmic heterogeneity characteristics of volcanic gas reservoir of the first member of Yingcheng Formation in Xudong Area

陈欢庆 胡永乐 冉启全 闫林 王拥军

中国石油勘探开发研究院;

Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China

针对目前火山岩储层非均质性研究薄弱的现状,为了深入认识储层微观结构特征,对火山岩储层有效开发提供参考,利用地质统计分析、岩心观察描述和显微镜下薄片观察等方法,从孔隙非均质性、颗粒非均质性和填隙物非均质等3个方面对徐东地区营城组一段火山岩储层微观非均质性进行分析。结果表明,研究区目的层具有低孔、低渗的特征,孔隙非均质、颗粒非均质和填隙物非均质都很强烈。其中,孔隙非均质受火山岩相和成岩作用共同控制,颗粒非均质受火山喷发特征和火山岩相的共同控制,填隙物非均质主要受成岩作用影响。小层YC1Ⅰ1和YC1Ⅰ2的非均质性要弱于小层YC1Ⅱ1、YC1Ⅱ2和YC1Ⅲ,前者在开发中具有较明显的优势。平面上,储层微观非均质性的分布差异较大,微观非均质性较弱的区域主要集中在研究区的中南部和中北部。

Aimed at the actuality that it was weak in volcanic microcosmic heterogeneity study, in order to deeply understand the microstructure characteristics of reservoir and provide references to effective exploitation of volcanic reservoir, this paper analyzed the microcosmic heterogeneity characteristics of volcanic reservoir of the first member of Yingcheng Formation in Xudong Area from the pore heterogeneity, grain heterogeneity and fillings heterogeneity and by using the methods of geostatistics analysis, core description and slice observation. The results show that the objective reservoir has the characteristics of low porosity and low
permeability, and the grain heterogeneity and fillings heterogeneity are very strong. Pore heterogeneity is controlled by volcanic lithofacies and diagenesis. Grain heterogeneity is controlled by volcanic eruption characteristics and volcanic lithofacies, and the fillings heterogeneity is basically affected by diagenesis. The heterogeneity of thin layer YC1玉1 and YC1玉2 is obviously lower than the thin layer of YC1域1, YC1域2 and YC1芋. The former has obvious advantage in reservoir development. Microcosmic heterogeneity characteristics are different in different areas in plane. The areas with weak microcosmic heterogeneity concentrate on the central south part and central north part in study area.