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- Volume 17, Issue 4, 1999
First Break - Volume 17, Issue 4, 1999
Volume 17, Issue 4, 1999
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Why seismic attributes may become a key issue for understanding the reservoir
By A. McBarnetRock Solid Images is a company which has brought together some eminent figures from the geoscience community to market the advanced technology needed to make the most of seismic attributes. Andrew McBarnet reports on progress so far. This may not seem like the moment to launch a new venture into the oilfield services sector but Richard Cooper, president of Rock Solid Images, says he is cautiously confident that things will work out. His reason for optimism is based as much as anything on the pioneering technology the company is offering and the geoscience pedigree behind the new enterprise which includes such distinguished names as Amos Nur and Turhan Taner. Rock Solid Images, based in Houston, started life last November through the merger of three small companies - The Discovery Bay Company, Seismic Research Corporation and Petrosoft. All three units faced the same basic dilemma of how to survive, grow and at the same time avoid being gobbled up by a bigger organisation. Cooper says 'small companies in our industry face many difficulties in planning for growth and longevity. The general pattern is for them to persist without having the strength to further develop their initial products, or to be acquired by a much larger organization, which generally fails to properly integrate their technology. Neither option is attractive to customers or employees.'
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Remote sense in oil and gas exploration
Some of the most interesting hydrocarbons-related presentations at the 13th International Conference on Geologic Remote Sensing, held in Vancouver last month were based on data from China. First Break reports. At a conference dominated by mineral exploration concerns, the case for using various remote sensing techniques as a first step in the search for oil and gas was elegantly made by scientists from the Institute of Remote Sensing Applications at the Chinese Academy of Sciences, Beijing, in one case in collaboration with the Dutch-based research agencies. One paper advocated the detection of hydrocarbon seepage of petroleum accumulations as a rapid and cost-effective method for exploration, particularly in conjunction with ëairborne magnetic surveys and elastic wave of reflection shooting.
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Comparison of 2D filters for suppressing noise in common shot gathers
Authors X. Liu and N. R. GoultyFrom the point of view of reflection signal fidelity, the best way of removing strong regular noise from a common shot gather is to estimate the noise and then subtract it from the data. This minimizes the distortion of the signal. The Karhunen±Loe¡ve (K±L) transform is the basis of such a method, and may be used to extract high-amplitude coherent noise from common shot gathers acquired in seismic reflection surveys on land. In this paper we compare the results of filtering synthetic and real data examples in the frequency±wavenumber (f±k) domain, by hyperbolic velocity filtering in the intercept-slowness (tau-p) domain, and by extracting the noise using the K±L transform. The f±k and hyperbolic velocity filters cause serious distortion of the reflection signals, especially when the difference between the apparent velocities of signal and noise is small. In contrast, the K±L transform enables the noise to be extracted with minimal distortion of the reflection signals. It is a common experience in processing land seismic reflection data to be confronted with data containing weak reflection signals submerged by strong, regular noise such as groundroll or air waves. Although the stack-array approach to the choice of acquisition parameters is a powerful technique for suppressing these types of noise in processed sections, applications such as AVO analysis of the prestack data require that the noise be suppressed with minimum distortion of the reflection signals. For such prestack applications, the choice of filtering method to remove the noise is very important. Other types of source-generated noise, commonly observed in land data, are reverberant refraction events parallel to the first breaks. They are even more difficult to suppress than groundroll and airwaves because their apparent velocities are close to the apparent velocities of the reflection events at far offsets. We show synthetic examples to evaluate the performance of the three filtering methods when the apparent velocities of strong, regular noise are similar to, and different from, the apparent velocities of reflection signals. We then show a real data example which illustrates the superiority of the K±L transform method of noise extraction for suppressing the reverberant refracted arrivals.
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Volumes & issues
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Volume 42 (2024)
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Volume 41 (2023)
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Volume 40 (2022)
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Volume 39 (2021)
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Volume 38 (2020)
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Volume 37 (2019)
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Volume 36 (2018)
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Volume 35 (2017)
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Volume 34 (2016)
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Volume 33 (2015)
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Volume 32 (2014)
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Volume 31 (2013)
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Volume 30 (2012)
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Volume 29 (2011)
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Volume 28 (2010)
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Volume 27 (2009)
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Volume 26 (2008)
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Volume 25 (2007)
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Volume 24 (2006)
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Volume 23 (2005)
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Volume 22 (2004)
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Volume 21 (2003)
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Volume 20 (2002)
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Volume 19 (2001)
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Volume 18 (2000)
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Volume 17 (1999)
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Volume 16 (1998)
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Volume 15 (1997)
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Volume 14 (1996)
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Volume 13 (1995)
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Volume 12 (1994)
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Volume 11 (1993)
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Volume 10 (1992)
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Volume 9 (1991)
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Volume 8 (1990)
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Volume 7 (1989)
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Volume 6 (1988)
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Volume 5 (1987)
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Volume 4 (1986)
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Volume 3 (1985)
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Volume 2 (1984)
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Volume 1 (1983)