神狐海域气烟囱构造分布及其对天然气水合物成藏的影响

THE DISTRIBUTION OF GAS CHIMNEY STRUCTURES IN SHENHU AREA AND THEIR INFLUENCE ON GAS HYDRATE ACCUMULATION

对神狐海域多道地震数据进行分析发现了很多天然气水合物及游离气的地震响应特征,包括BSR(似海底反射)、BSR下伏强反射以及烟囱体构造等。该区域气烟囱构造的分布与BSR的分布比较一致,气烟囱构造是深部热解气垂直运移的主要通道,深部烃源岩产生的热解气通过气烟囱等垂直裂隙向上运移至水合物稳定带,产生大量聚集,有利于水合物形成。因此,搞清楚研究区的气烟囱构造分布对于该区域天然气水合物成藏及分布研究具有重要意义。传统识别气烟囱的方法只能通过地震剖面上的弱反射柱状构造或相关属性分析,研究利用基于MLP算法的神经网络结合多属性特征,综合高效的分析了该区域气烟囱构造带的分布,并根据该区域地质构造分布与BSR分布特点分析了该区域气烟囱对天然气水合物成藏的影响。

Many seismic indicators of gas hydrate and free gas,such as BSR（Bottom Simulating Reflector）,bright reflection under BSR and chimney structures,have been found in the Shenhu area by seismic survey.The distribution of BSR is consistent with chimney structures.Chimney is believed the main migration path of the pyrolysis gas from deep sediments.The pyrolysis gas originated in the deep hydrocarbon source rock is transported to HSZ（Hydrate Stability Zone）,which offers favorable conditions for massive gas accumulation,through chimneys.Therefore,it is significant to learn the distribution of chimney structures for understanding the distribution and accumulation pattern of the gas hydrate in the Shenhu area.The traditional method recognizes chimney structures only by use of seismic data based on weak reflection,columnar shape and related attributes.This paper comprehensively and efficiently analyzed the distribution of chimney structures with the method of neural network based on the MLP（Multi-Layer Perception）algorithm.The influence of chimney structure on gas hydrate accumulation is interpreted by integration of BSR distribution and regional tectonics.