Application And Analysis On The Combined Method Of Deconvolution For Improving The Resolution Of Seismic Data

In recent years, with the development of world oil and gas industry and the progress of oil and gas exploration in china, exploration of the main objectives have been changed from the structural reservoir to the lithologic reservoir, seismic conditions have been more complex, the exploration area has been changed from the plain area into the mountains, Desert, and plateau, the geological conditions have changed from the thick layer with good properties to the terrestrial clastic to the thin interlayer, therefore, making every endeavor to improve the resolution and signal to noise ratio of seismic data has been the critical and the focus of seismic exploration. In seismic data processing, the method of prestack deconvolution to ensure the consistency of wavelet of seismic data is an important means to enhance the seismic data resolution.Yu wavelet deconvolution has the characteristics of compression of wavelet, expansion of frequency band and suppressing the high and low frequency noises, while the two-step surface consistent deconvolution (ie, surface consistent deconvolution on shots and surface consistent deconvolution on detectors),can overcome the impact of the shot points, receiving points, offset and the other factors on the seismic data, and this two-step mehod has been widely applied in the Daqing oil field. This paper will adopt a new combination of deconvolution method: Yu wavelet combining the two-step deconvolution , firstly through reshaping ability of Yu's wavelet deconvolution to unify the wavelet shape in the same window, broadening frequency band, and increasing the energy of high-frequency part of the effective wave; and then through the surface consistent deconvolution in the domain of shots, correcting the seismic wavelet, and clearing the influence of inconsistency factors to the Wavelet, improving the seismic data resolution and broadening frequency as much as possible.The geological task of Changdde gas field in daqing is T3 target layer requires a higher resolution to identify thin layers, T4 target layer requires that the characteristic of igneous rocks should be distinguished in the section, which requires low-frequency characteristics of igneous rocks, but also able to distinguish the sedimentary and facies of igneous in different Stages . To this end, the section has been required to be with wide frequency band , that is ,the low frequency part should be remained ,but also the high frequency of effective wave should be protected as much as possible. Therefore, according to the geological tasks of Changde gas field ,this paper will first test of two results : Yu wavelet deconvolution combined the two-step surface consistent deconvolution and two-step anti-surface consistency deconvolution, through comparing the wavelet autocorrelation ,the frequency of target layers and the wave character of two sets of migration section ,and comparing the horizontal slices, coherence slices, and the synthetic records from the forward of well data in the area of the two migration results ,and then to proof the advantage of the method of Yu wavelet deconvolution combined the two-step surface consistent deconvolution, and to provide a reference for the high resolution in processing.