Engineering Research To Enhance The S/N Ratio And Resolution Of Seismic Data Acquired From Middle And Deep Layer In Western Depression Of Liaohe Basin

This paper is mainly aiming at work out a technique series for improving the seismic data signal to noise ratio and resolution of middle and deep layer at Western Sag of Liaohe Basin, Northeast China.The paper is also aim at confirming corresponding research techniques and methodologies for low range formation, tiny fault and thin sandy layer based on the study of the geological features and the high resolution 3D seismic data of the research target zone.The paper started from former data and difficulties of acquisition techniques, further to the analysis of seismic geological conditions, former acquisition methodologies, noises, and acquired raw shots and stacks, also expatiate on the factors which affected the signal to noise ratio and resolution of deep layer and difficulties of acquisition techniques. Furthermore, the paper summarize that enhancement of resolution are highly restrained by absorbing of ground via researches on absorbing of ground, methodologies of source and receiver and other acquisition techniques, and along with research on methodologies of processing.So, suitable acquisition parameters could be selected by calculating with rational ground absorbing attenuation theory, every parameter of weathering layer could be acquired exactly by interpreting up-hole with kinematic and mechanical theories, prime lithology for source could be decided, and along with survey of weathering layer, better source result could be ensured, energy of valid signal could be enhanced, and valid frequency range could be expanded. By using pattern hole the sources energy propagation could be boosted, signal to noise ration of high frequency signal could be enhanced greatly, valid frequency range could be expanded, and consequently the resolution of middle and deep layers. By adopting proper geophone could improve coupling, by utilizing right geophone array could enhance its sensitivity to receive weak high frequency signal of middle and deep layers. Recording with wide frequency band (without low cut), high pre-amplification while filed operation could expand capability of recording system for recording weak signal, and enhance weak signal to a certain range.