The Research Of Pre-stack Noise Attenuating Technology Of Seismic Data In The Soil Yuan

Seismic data mixes with large amounts of noise because of affects form external conditions when acquiring them. With its strong energy and extensive distribution, the noise reduces the s/n of data and hinders the pre-processing. In terms of seismic data processing, the goal is high s/n, high resolution and high fidelity. And high s/n can offer seismic data processing better data and high resolution will supply powerful guarantee for meticulous seismic data interpretation. High s/n is basic work to improve resolution. So pre-stack noise attenuation must be done well to get data with high s/n. In The Soil Yuan area, terrain and landform are all complicated. Its surface is covered with thick soil and elevation varies sharply.In the area with loose sedimentary layer, the excitation and reception of seismic wave are affected badly. The thickness and velocity of the low velocity layer vary greatly, which causes wave to be absorbed and attenuated. All the situations lead to the result that seismic data is companied by more noise with more strong energy and wider frequency band that bring lower s/n. Pre-stack noise attenuation seems to be especially important as a powerful means for increasing s/n.All usual types of noise are summarized, brief discussions about formation mechanism of noise as well as corresponding methods and concrete analysis about fundamentals of all kinds of methods and merits and faults during using them are made. In addition, I also sum up characteristics of seismic data in The Soil Yuan area and present research status about pre-stack noise attenuation methods in this area, make reasonable processing flow of attenuating noise according to characteristics of data, choose rational methods and technology to reduce noise based on features of energy and frequency spectrum on the premise of keeping authenticity and extent, and put data into different domains to grasp peculiarities of noise better so that the differences between signals and noise can be maximized and then be separated. For example, frequency-devising method in shot gather are raised to eliminate near-shot strong energy, f-x is used to attenuate ground wave. For unusual low frequency and high frequency noise, I take advantage of random header to eliminate. Meanwhile, I discuss the attenuating order of processing and analyzing the final noise-eliminating efforts. At last, a summary about the whole pre-stack noise attenuation processing is done in the paper. Through all the work, I achieve further perception about seismic data processing and noise attenuating methods and new view about the train of pre-stack noise attenuation.