澳大利亚吉普斯兰德盆地中,速度分析为勘探的最严峻的问题。勘探经验说明许多外观上的构造是速度降低,但是,其它可靠的构造却被复杂地质构造产生的强速度梯度掩蔽了。文中以目前澳大利亚最大的生产油田王鱼油田为例,说明了这些梯度的大小和对作构造图的影响。由于用正常时差推导的速度和均方根速度之间的变化关系不确定,而且缺乏作图层次的地震速度资料,由正常时差速度推导真速度的迪克斯法在吉普斯兰德盆地中并不实 In the Gippsland Basin, Australia, velocity analysis is the most serious problem of exploration. Exploration experience shows that many façade structures are slowed down, however, other reliable structures are masked by strong velocity gradients created by complex geological formations. In this paper, the current kingfisher oil field in Australia, the largest production oilfield, is taken as an example to illustrate the influence of these gradients on the structure map. Due to the uncertainty of the relationship between velocity and root mean square velocity derived from normal time difference and lack of seismic velocity data at the mapping level, the Dix-law method of deriving true velocity from normal time-lag velocity does not occur in the Gippsland Basin real