Usually long-path multiples have traveled more in the slower (shallower) part of the section than primaries with the same arrival time, so that they ordinarily show more normal moveout and can be attenuated by common-midpoint stacking.[1]. While some progress has been made to our understanding and in the development of new ideas and methodologies, a … Ключови думи: primary reflections, multiple reflections, attenuation, deconvolution. Figure 2 shows … To demonstrate this, percentage differences in wavelet amplitudes between stack sections produced with and without processes like f-k demultiple are shown. Surface related multiple elimination uses the recorded data to predict multiples produced by the downward reflection at the sea-surface, without the need for any information on the subsurface. The application of these techniques to data from the Timor Sea is presented as a case study. Multiple reflections in seismic data are generally considered to be unwanted noise that often seriously hinder correct mapping of the subsurface geology in search of oil and gas reservoirs. 2015 ExxonMobil The Ideal Seismic Response Increase in Impedance Decrease in Impedance Able to resolve boundaries of beds a few meters thick 1 meter 43 ExxonMobil Seismic - Units 10’s of Meters Thick 10 m Predominantly Shale Predominantly Shale Predominantly Sand 44. He has worldwide experience in multiple geological challenges and environments. discussed separation of pegleg multiples and primaries in prestack data. Later in the life of a field, seismic data may be revisited to answer questions about fine-scale reservoir architec-ture or fluid contacts, or may be compared with a later monitor survey to infer fluid … Short-period multiples attenuation is a difficult problem for shallow water marine seismic data processing. (1993). The suppression of multiples in seismic data processing can be achieved by several means of which filtering in the parabolic Radon Transform domain is the most common (Hampson, 1986). Multiple diffractions and coherent noise in marine seismic data Neil Hargreaves* and Richard Wombell, Veritas DGC Limited, Crawley, UK Summary Multiple reflections from irregularities on the sea floor, (multiple diffractions), can share a number of characteristics with the primary scattering that is also generated by such irregularities. Multiples from the bottom of a body of water and the air-water interface are common in marine seismic data, and are suppressed by seismic processing. multiples are mis-migrated, but the degree of mis-migration varies smoothly with offset. Registered in England & Wales No. Our strength lies in our experienced team with over 20 years of experience directly in seismic data … Once the shaping filters have been designed, the refined multiple estimate f M *M is then subtracted in step 116 from the seismic data within the data windows D for all the traces in the bin. multilayer perceptron neural networks. One noise that is often recorded in seismic data is multiple noises. In one embodiment, the method comprises the steps of regularizing the gather of seismic data traces, … In recent years, several methods have been developed to attenuate seafloor multiples in seismic data, and a broad literature on this subject is available. The method involves choosing a component of the wavefield and selecting two or more components of the wavefield data necessary to attenuate multiples in the chosen component. The data for a multiple reflection generated between a and b will delineate the imaginary bed (a-b)' having a reflection time equal to that of the deeper actual reflecting bed, plus the difference in the reflection times of the two actual reflecting beds:EquationCompared with the rays reflected from bed b, the seismic rays corresponding to the multiple reflection travel over an additional … These are targeted for a specific class of multiples — those which are either associated with the free surface or water bottom. He joined KOC in 1995 and is currently responsible for seismic data acquisition and processing. Marine Processing - Part 9 | Demultiples This sequence of blog posts will build up into a complete description of a 2D marine processing sequence and how it is derived. as a Data Processing Seismic Engineer in Kuwait, followed by a Testing Geophysicist role in Houston, before his current position. 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