The Processing Method And Application Of Single Channel Seismic

There are three procedures used in offshore seismic exploration: data gathering,signal processing and interpretation. The offshore seismic exploration instruments used for data gathering include two parts: source used for generating signal and electric cable composed by hydrophone array used for accepting the signal. The offshore seismic exploration has many patterns based on the different locations and methods of hydrophone array units, each method has advantages and disadvantages. The single channel seismic has many advantages: the ways of survey is easier; the efficiency is higher; orientation accurately and so on, this method has been used more and more widely in offshore seismic exploration in the world.The high signal-to-noise ratio (SNR) and resolution is the aim that people are pursuing for gaining good seismic profile and geologic interpretation. The prerequisite condition of improving the resolution of seismic data is to improve the signal-to-noise ratio. This paper also analyses the definition of resolution, the classification of resolution as well as its influenced factors. Aiming at characteristicing noises of offshore seismic data, several methods of removing coherent noises and random noises are briefly introduced, and the formation theory and classification of marine multiple in detail. With the development of seismic signal processing theory, exploration techniques, information techniques and seismic data processing software, the techniques of improving seismic data SNR and resolution, multiple attenuation have made a big progress.Finally, take the survey of single channel seismic data actual processing in Dalian area as an example, this paper introduces the methods of data gathering in this survey, by analyzing the single channel seismic profiles found out the frequency range of high equality is 200-300ms mainly under the seafloor. The multiple-reflection and interfaces noises are widespread in the original profiles, so the key point and difficulty of this processing is how to strengthen the efficiency signal in the deep, improve the SNR and attenuate multiple-reflection.The processing workflow as follow: Through interactive spectral analysis get the central range of frequency. Using bandpass filter parameter test to remove the noise. Compared many different ways to attenuate multiple-reflection and find out the predictive deconvolution is appropriate for this processing, by parameter testing make sure the best decon operator lengths and operator prediction distances to attenuate multiple-reflection. Using f-k filter and windows gate attenuation at the area the predictive deconvolution is unuseful. True amplitude recovery can balance the energy of shallow and deep layers. Compared the profiles before and after processing can make a conclusion that this processing can achieve the goal of strengthening the efficiency signal, improving the SNR and attenuating multiple-reflection. This is helpful for the next step of interpretation.