Study On Weak Signal Enhancement Of High-density Seismic Data

High-density seismic acquisition method has several advantages,such as high fidelity,wide frequency band and no aliasing.The process includes conducting point-receiver acquisition with digital geophones in the field,and then carrying out combining and stacking indoor.Through small bin size,small spatial interval,resampling and high fold number,high-density seismic acquisition has high resolution and high fidelity,thus it has gradually become a focus in the eyes of many oil fields recently.Because signals and noise are both fully sampled,the fidelity and resolution is improved,however,the SNR is reduced.Thus we cannot detect the weak signals submerged in noise.Therefore,it's important to suppress noise and enhance weak signal in high-density seismic.Through noise suppression to seismic data,we can recover weak signals from noise.In this paper,we do noise suppression to high-density seismic data based on 3D curvelet transform.First,the basic theory and advantage of 3D curvelet transform is introduced,we discuss its feasibility in seismic noise suppression based on its superiority to express seismic signal.Then we proposed a seismic data denoising method based on 3D curvelet transform,the test processing results of modeling and actual data show the feasibility and availability of this method.Through energy compensation to seismic data,we can extract and recover the information of deep events.In this paper,we do energy enhance to high-density seismic data based on generalized S transform.First,the basic theory,derivation process,characters and advantage of generalized S transform is introduced,and then we expand this theory to energy compensation.Second,we proposed the theory and implementation procedure of this method,verify that this method could recover weak signals effectively.With the development of oil exploration,geophysicists realize the importance of amplitude preservation in seismic data processing.In this paper,we investigate the research status at home and abroad of amplitude preservation evaluation method in seismic data processing.Based on the summary and analysis of previous study results,we stated an amplitude preservation evaluation criterion.After long times' testing,we proposed a concept of amplitude preservation coefficient,and gave some criterions of amplitude preservation evaluation in different situations.