Articles
Seismic Imaging: Post-Stack
John C. Bancroft
Seismic imaging is a general term that geophysicists now use to describe processes that convert seismic data into a geological “representation” of the subsurface. These “representations” may vary from simple structural images that use migration algorithms, to ones that estimate rock properties with algorithms that are based on inversion theory.…
Seismic Attributes in Your Facies
Arthur E. Barnes
Imagine having a “seismic search engine”. Built into your seismic data viewer, it would rapidly locate features in your seismic data, like search engines help you locate information on the worldwide web. It could work like this. You are looking at a large 3-D seismic survey for the first time.…
Seismic Attributes
M. Turhan Taner
Since their introduction in the early 1970’s, Complex Seismic Trace Attributes have gained considerable popularity, first as a convenient display form, and later, as they were incorporated with other seismically-derived measurements, they became a valid analytical tool for lithology prediction and reservoir characterization. In recent decades, over 600 papers have…
Multicomponent Seismic Exploration in Canada – One Person’s Perspective
Peter Cary
Let me set something straight from the beginning. This is not going to be one of those review articles where the author gushes with excitement about his subject like some sort of cheerleader. I will try to be more rational than that. This is not because I have nothing good…
Monitoring Production Processes by 4-D Multicomponent Seismic Surveys
Thomas L. Davis
Multicomponent, time lapse seismology has great potential for monitoring production processes in reservoirs. The reason is simply the presence of fractures. Shear waves are much more sensitive than P waves to the presence of fractures or microfractures and the fluid content within the fracture network. Fractures introduce seismic anisotropy into…
Developments, Trends and Future Directions in Vertical Seismic Profiling and Crosswell Seismic Profiling
Bob A. Hardage
Fessenden’s patent of 1917 appears to be the first documented seismic application involving buried sources and geophones. One illustration from this patent is shown in Figure 1. In this diagram, item 49 is a borehole acoustic energy source, and items 15 and 18 are borehole acoustic receivers. Dashed lines 46…
VSP: An In-Depth Seismic Understanding
Robert R. Stewart
Vertical seismic profiling has been a useful measurement to obtain rock properties (velocity, impedance, attenuation, anisotropy) in depth as well as to provide a seismic image of the subsurface. The VSP can also give insight into seismic wave propagation and provide processing and interpretive assistance in the analysis of surface…
VSP for the Interpreter/Processor for 2001 and Beyond: Part 1
Ronald C. Hinds and Richard D. Kuzmiski
The use of the Vertical Seismic Profile (VSP) has expanded during the past 20 years into an economical and viable exploration and exploitation tool. Having started as an extension to the Check Shot survey, an interpreted VSP dataset is seen as a high-resolution subsurface image that is the intimate link…
The CSEG Ratifies a Master License Agreement for Seismic Data
G. Fairs, J. Boyd, P. Einarsson, L. Hunt, B. Korchinski, L. Ramescu, C.Walls, B. Lawrence
The use of seismic data in the exploration and development of oil and gas reserves has never been more important or widespread as it is now. The acquisition of seismic data is expensive and time consuming. It is being conducted with an ever increasing attention and care for its physical…
3D Seismic Surveys – Past, Present and Future
Mike Galbraith
Overviews are often useful and this paper is written for the geophysicist who has not been deeply involved with the design and analysis of 3D seismic survey acquisition for the past 15 years or so, and would like to have an idea of what happened, what’s happening now and what…
Seismic Data Acquisition Developments in the Last Decade and in the Next – A Biased View
Gijs Vermeer
Almost simultaneously with the invitation to contribute to this special issue of the Recorder, the January-February 2001 issue of Geophysics happened to arrive. The latter contains a special section: “Geophysics in the new millennium”, put together under the direction of Larry Lines (2001), whose name also featured under the letter…
AVO Analysis
John P. Castagna
The great promise of pre-stack amplitude-versus-offset analysis (AVO) of reflected compressional waves lies in the dependence of the reflectivity with increasing offset on the elastic property contrasts at the reflecting interface. As different lithologies may exhibit distinct Poisson’s ratios, and gas-bearing strata usually exhibit anomalously low Poisson’s ratios, AVO has…
AVO: Yesterday, today, and (a peek at) tomorrow
Mike Graul
Amplitude variations with offset (AVO) have been used for over a quarter of a century in the hunt for gas and oil. The first public disclosure of the technique was made by Bill Ostrander, at the 1982 SEG convention in Dallas. At the time, Bill was reporting on a seasoned…
AVO and Lamé Constants for Rock Parameterization and Fluid Detection
Bill Goodway
For more than 3 decades, industry has known that shear seismic waves (S-waves) contain different rock information than do our standard compressional seismic waves (P-waves). Periodically, efforts to record S-waves, even on the seabed, have attracted industry attention with increasing success. Separate efforts to analyse conventional P-waves for the S-wave…
AVO Feasibility and Reliability Analysis in the Presence of Random Noise
Jon Downton and Larry Lines
AVO inversion provides a cost effective means for predicting elastic parameters and rock properties of the earth. However, the results of AVO inversion are sensitive to noise. For some acquisition, geometries and noise levels predictions from the AVO inversion may not be reliable. By studying the influence of random noise…
AVO and the General Inverse Theory
Guillaume Cambois
The 1980s saw the development of two new technologies: AVO and general inverse theory. In those days, general inverse theory was applied to full waveform inversion, compared to which AVO is a very simple problem. Almost two decades later we observe that the interest for full waveform inversion has waned,…
Prestack Waveform Inversion Using a Genetic Algorithm – The Present and the Future
Subhashis Mallick
Use of prestack data for quantitative analysis of hydrocarbon reservoirs has gained popularity over the past decades. Most of these quantitative studies rely on the seismic reflection amplitude variation with offset or AVO analysis. AVO makes a simple assumption that every reflection event on the prestack seismic data is a…
Natural Gas Hydrate Studies in Canada
R.D. Hyndman and S.R. Dallimore
Scientific field studies of natural gas hydrates have been carried out in Canada for many years by the Geological Survey of Canada and by a number of universities. This article describes the two largest programs: (1) Arctic permafrost-related hydrate studies, including the Mallik research drilling on the Mackenzie Delta and,…
Vibroseis Deconvolution: An Example from Pikes Peak, Saskatchewan
Katherine Brittle and Larry Lines
Vibroseis has enjoyed worldwide popularity in land seismic acquisition ever since its development by Conoco’s researchers (Crawford et al., 1960). Crosscorrelation of the sweep with the recorded data, which emulates the methods developed in chirp radars by Klauder et al. (1960), will ideally produce zero-phase wavelets with a flat spectrum.…
The Application of AVO and Inversion to the Estimation of Rock Properties
David Gray and Eric Andersen
Inversion of Amplitude versus Offset (AVO) results can be used to derive elastic rock properties, which can in turn be used for quick determination of lithology and fluid content of reservoirs. In this paper, this approach is illustrated using case histories from a Western Canadian gas-field development, exploration in the…
