准噶尔盆地金龙油田佳木河组火山岩储层孔隙类型及特征

Pore types and characteristics of volcanic reservoirs of the Jiamuhe Formation in Jinlong oilfield, Junggar Basin

王小军 赵飞 张琴 王东学 夏近杰 吴行舟 李晨溪 梅啸寒 吕德红

Wang Xiaojun Zhao Fei Zhang Qin Wang Dongxue Xia Jinjie Wu Xingzhou Li Chenxi MeiXiaohan Lyu Dehong

准噶尔盆地金龙油田佳木河组发育良好的火山岩储层，明确火山岩储层特征及有利储集相带分布是进行火山岩储层勘探和开发的关键。本文通过岩心、薄片观察和高压压汞分析，结合物性资料，分析火山岩储层岩石学及物性特征，并预测了有利储层的分布。结果表明，佳木河组火山岩类储层包括火山熔岩类、火山碎屑熔岩类、火山碎屑岩类和沉火山碎屑岩类4种。火山岩储层物性总体上具有中-低孔和低-特低渗的特征。储集空间类型根据形态分为孔隙和裂缝两大类，根据成因都包括原生和次生两类，其中收缩孔、缝为主要的储集空间类型。不同的火山岩性和岩相表现出不同的压汞曲线类型，包括双峰正偏态细孔喉型、单峰正偏态细-微孔喉型和单峰负偏态微孔-极细微孔喉型3类，总体以微细-细孔喉为主，分选差-中等。岩性上火山角砾岩、玄武岩和安山岩是工区内最好的储层，岩相上火山爆发相和喷溢相上部储层物性最好，平面上最好储集相带位于研究区中部呈北西-南东的条带状分布。

Volcanic rocks in the Jiamuhe Formation are favorable reservoirs in Jinlong oilfield.It is a key step for exploration and development of volcanic reservoirs to analyze the characteristics of volcanic reservoir and define the distribution of favorable reservoir facies belts.Based on core,thin section,high pressure mercury injection and reservoir property data,this paper defined the characteristics of lithology and property of the volcanic rocks,and predicted the distribution of favorable volcanic reservoirs.The results show that the volcanic reservoirs consist of volcanic lavas,volcaniclastic lavas,volcaniclastic rocks and depositional volcaniclastic rocks.The volcanic reservoirs in Jinlong Oilfield are characterized by medium to low porosity and low to extra low permeability.The reservoir spaces are divided into pore vs. fracture classes according to their shapes in the rock,and primary vs. secondary categories on the basis of genesis,of which the contraction pores and fractures are the main reservoir spaces of the volcanic reservoirs in Jiamuhe Formation.Volcanic rocks with different lithologies and petrofacies have different types of mercury-injection curves.There are 3 curve types featuring respectively in fine pore throat with bimodal positive skew distribution,fine-micro pore throat with unimodal positive skew distribution,and micro pore throat with unimodal negative skew distribution.Overall, the micro-fine pore throats are predominant and the sorting is poor to moderate.Lithologically,the volcanic breccias,basalt and andesite are the most favorable reservoirs in the study area,while as to petrofacies,the best reservoirs occur in the explosive facies and the upper part of the effusive eruption facies.The best favorable reservoir facies belt is located at the middle part of the study area and is in NW-SE-trending banded distribution.

10.11743/ogg20170115