The Method To Suppressing Ghost Wave Based On Wave Field Extrapolation In Variable-depth Streamer

The existence of ghost will cause the low frequency response of the earthquake records and reduce the resolution of seismic section.Sometimes it even produces fake event that causes difficulties of seismic geological interpretation.Therefore,we must try our best to get rid of the ghost in the seismic information processing in order to obtain the high resolution seismic profile.In general,we use the flat cable way to collect data,and then use the dual sensor or predictive deconvolution to reduce ghost,but these ways are very difficult to get high resolution of seismic signal,wide frequency band and the exploration depth at the same time.So in recent years,many people use the method of variable-depth streamer to collect data.This way can make detector at different depth that we can get rich effective frequency band of seismic data.And the notch point location compensates each other depending on the depth of the cable,so we achieve the purpose of broadening the high frequency and low frequency at the same time.But this way of collect data can bring serious notch effect because of the effect of ghost,so we form a complete set to suppress the ghost.This paper studies the ghost wave suppression method based on wave field extrapolation in order to adapt to the seismic data that variable-depth streamer collects.The whole process of seismic wave propagation is divided into two phases by this method.The first stage is the seismic wave that is reflected by the underwater and reaches the datum plane that we set,and the second stage is the seismic records geophone receiving that is these waves on the datum continue to propagate.We can obtain waves on the datum through the detector receives the seismic records by using the ideas of the wave field continuation,so that we suppress ghost.This kind of ghost wave suppression method can adapt to variable depth cable,and it can effectively suppress the ghost on the basis of retain significant wave.At the end of the paper,we verify the effectiveness and stability of theoretical method and program algorithm that this paper study through the model trial and result analysis of a simple and complex models.