Advances in seismic researches on natural gas hydrate in ocean
海域天然气水合物的地震研究进展

The seismic research on marine gas hydrate has made great development.The main subject is how to identify BSR correctly and predict the Gas Hydrate sediment physical parameters(For example: thickness,porosity,concentration,etc.) On the basis of physical property analysis of marine rocks,seismic method is used to identify true and false BSR and predict physical property of hydrate-bearing sediments for recognition of gas hydrate in sea areas.Recently,great progress has been made in seismic researches on marine gas hydrate,which is showed in the following aspects:(1) for theoretical analysis of physical property,simple model has changed into complex model capable of simulating actual situations to the largest extent;(2) for seismic explorations,seismic methods have gone from conventional single- and multi-channel to multi-frequency,high-resolution 2D and 3D and multiple components;(3) for seismic data processing,conventional method has given way to "three highs" and pre-stack time offset processing with emphasis on BSR characteristics;and(4) for identification of gas hydrate and prediction of its physical property parameters,researches on velocity and amplitude have been replaced by AVO,multi-attribute discrimination,multi-elastic parameter and multi-property parameter inversions.Thanks to these new techniques and methods,investigations in gas hydrate in sea areas have been greatly striding forward,and reliability of geophysical recognition of gas hydrate has been significantly heightened.