西湖凹陷天台斜坡带火山机构三维雕刻及成因机制解析

西湖凹陷天台斜坡区火成岩发育尤为丰富，其发育与分布对盆内储层改造、构造演化都有着重要影响。依据区内地震特征和构造环境，划分出中心式、裂隙式2种喷发类型；采用振幅－方差体地震属性分级－拾取－融合技术，系统刻画区内火成岩的三维时空展布以及火山喷发时期，发现区内火成岩具有始新世至中新世多期间歇性发育特征，且火山机构富集于天台斜坡西南部；在区内建立了中心式和裂隙式2种喷发模式，认为这些模式的建立对于正确预测火成岩的分布具有重要意义；最后对火成岩的成因机制进行了解析与探讨，发现区内火山活动与板块构造运动相互影响、火山的时空展布与断裂也具有一定的配置关系，认为裂隙式喷发可能会形成优势的油气运移通道，中心式喷发则有利于形成良好的储集空间。基于此，我们将更容易找到区内有效的火成岩储层，对油气勘探具有重要的指示作用。 

3-D engraving of volcanic mechanism in the Tiantai slope of Xihu Depression and its formation mechanism

The development and distribution of igneous rocks in the Tiantai slope of Xihu Depression have an important influence on reservoir reconstruction and tectonic evolution.According to the seismic characteristics and tectonic environment in the area, two types of eruptions are divided into center type and fissure type.Based on drilling data and 3-D seismic data, the seismic amplitude and variance cube thresholding dispaly, systematically depicting 3-D spatial and temporal distribution of Tiantai of volcanics and eruption phases, revealing the igneous rocks of Mesozoic to the Miocene period in Tiantai have intermittent development more features, and enrichment of volcanism in the Tiantai slope in the southwest.Two types of eruptive modes, the central type and the fissure type, are established in the area.The establishment of these modes is of great significance for correctly predicting the distribution of igneous rocks.Finally, the genesis of igneous rock mechanism is analyzed and discussed. It is found volcanic activities and tectonic movement influence each other, volcanic distribution of space and time and the fracture also has certain configuration relations.It is believed that fissure eruption may form oil and gas migration channel, is characterized by terrigenous central type eruption is helpful to form good reservoir space.Based on this study, it will be easier to find effective volcanic reservoirs in Tiantai area, which plays an important role in indicating petroleum exploration.