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Analysis On Seismic Data Quality Factors In Deep Earth And Research Of Seismic Acquisition Methods

Posted on:2015-03-09Degree:MasterType:Thesis
Country:ChinaCandidate:X LeiFull Text:PDF
GTID:2250330428466921Subject:Geophysics
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In recent years, the deeper and deeper energy reservoirs explored requires geo-physicists to enormously improve the seismic resolution. Conventionally, seismic ex-ploration could identify the reservoirs with one quarter of seismic waves thick. How-ever, this resolution cannot meet the requirement of prospecting in areas with deepand complex structures, especially when the seismic data acquired has low sig-nal-to-noise ratio(S/N), weak reflections, and narrow frequency band. In this paper, Ifacilitated amplitude map, which has higher resolution compared with conventionalinterpreted methods, to data from deep and lithological formations. It can enhance theresolution from one quarter of seismic waves to one sixteenth. For seismic data acqui-sition, the key to use the method of amplitude map is that the S/N of data meets somecondition. The work I have done in my dissertation is as follows, including footprintselimination, noise suppression and frequency alias prevention.1) Analyzed the particular resolution of amplitude map method in Dongpu de-pressed area and its requirement on signal-to-noise ratio;2) Proposed the maximum receiver distance required by no frequency alias ofnoise and reflections in seismic data and the sensitivity of surface wave’sfrequency alias to surface wave elimination by analysis of frequency alias’seffects on seismic imaging;3) Estimated conventional S/N in Dongpu depress area and established the rela-tion between fold and S/N;4) Established the relations between footprints and seismic acquisition spacingand between requirements of amplitude map and maximum footprints.5) Designed a seismic geometry that could acquire data with high resolution toutilize amplitude map method.The finished work is meaningful to other acquisition tasks which need high reso-lution and have deep and complex structures.
Keywords/Search Tags:resolution, amplitude map, footprints, frequency alias, S/N
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