川西二叠系火山机构地震特征及机理

Seismic Features and Mechanism of Permian Volcanic Institutions in Western Sichuan

摘要: 近年来钻井揭示川西地区龙潭组之下发育厚层火山岩碎屑岩地层，但火山机构平面特征及成因机理尚不明确。为刻画火山岩岩相分布，预测火山岩储层展布，理清分布规律，通过分析火山岩岩性及岩相，划分火山岩岩相类型，运用波形分类属性、波谷个数属性及古地貌恢复技术，对火山通道相、爆发相、喷溢相、火山–沉积相地震相特征进行识别，将火山机构平面相带划分为火山口、近火山口、近源及远源相带。探讨川西其他地区火山岩发育、地震相特征及发育背景，结果表明川西地区发育大面积火山岩沉积，其中近火山口爆发相内的火山碎屑岩为较好储层，是川西二叠系火山岩勘探的有利目标区。

Abstract: In recent years, drilling revealed that thick volcanic rock clastic rock strata developed under Longtan formation in western Sichuan Basin, but the plane features and genetic mechanism of volcanic mechanism are not clear. In order to characterize the volcanic facies distribution, predict the volcanic reservoir distribution, and clarify the distribution law, the volcanic lithology and petrofacies were analyzed to classify the types of volcanic lithofacies. The characteristics of volcanic channel facies, eruptive facies, flooding facies, volcano-sedimentary facies and seismic facies were identified by using waveform classification attribute, number of trough attribute and ancient landform recovery technology. The volcanic mechanism plane facies belt was divided into volcanic crater, near crater, near source and far source facies belt. Exploring the development of volcanic rocks in other areas of western Sichuan Basin, seismic phase characteristics and development background of volcanic rocks, the results show that a large area of volcanic deposits developed in western Sichuan Basin, the pyroclastic rocks in the eruptive facies near the crater are the better reservoirs, the Permian in western Sichuan Basin is a favorable target for volcanic exploration.