Articles
Rock Physics for the Rest of Us – An Informal Discussion
Jan Dewar
Rock Physics describes a reservoir rock by physical properties such as porosity, rigidity, compressibility; properties that will affect how seismic waves physically travel through the rocks. The Rock Physicist seeks to establish relations between these material properties and the observed seismic response, and to develop a predictive theory so that…
International Geophysicists in Canada
Gordon Cope
With the rapid expansion of the Canadian oilpatch into international waters over the last decade, many native-born geophysicists have had the opportunity to travel and work around the world. Just as importantly, geophysicists from all points of the globe have had the chance to come to Calgary and practice their…
Aliasing for the Layperson
Larry Lines, Katherine Brittle, Ian Watson, and Peter Cary
Examples of aliasing can be observed in western movies by watching the motion of stagecoach wheels. As the stagecoach starts to move, we observe its wheels rotating in the expected forward direction. As the stagecoach speeds up, we see that the wheels appear to rotate in the opposite direction to…
3D Model Evaluation by Data Simulation
Norm Cooper and Michael Cooper
... A Master License Agreement
G. Fairs, J. Boyd, P. Einarsson, L. Hunt, B. Korchinski, L. Ramescu, C. Walls, B.L. Parlee
For decades the licensing of seismic data was based mostly upon a handshake and an understanding of common industry practice. Over time common industry practice as it relates to the use of licensed seismic data has become quite diverse, even to the point where it could be said that there…
Wembley Halfway B Pool – A Test Case for 3D Visualization Technology
Ronald C. Hinds and Hugh Lavallee
The Wembley Halfway B Pool is situated 20 km northwest of Grande Prairie, Alberta and was discovered in 1978. This Middle Triassic pool contains an oil leg with 23 x 106m3 inplace (145 MM barrels-in-place) and an associated gas cap with 5.7 x 109m3 in-place (204 bcf-in-place). The Halfway B…
Beam Steering and Controlled Illumination
George Adler
Beam steering and controlled illumination are closely related in geophysical processing. The idea of beam steering has been used in physics for a long time. For example, in radar technology it is possible to steer the radar wave without moving the antenna itself, by applying proper phase shifts between radiating…
Seismic Deconvolution: Assumptions, Concerns and Convictions
Peter Cary
Early in our careers as geophysicists, most of us took at least one course on seismic signal analysis where we were taught that standard Wiener deconvolution converts the minimum-phase source wavelet in our seismic data to a wavelet with a phase spectrum that is zero and an amplitude spectrum that…
AVO Processing: Myths and Reality
Guillaume Cambois
AVO processing is meant to make the input data compatible with Shuey’s equation. This task is extremely difficult due to the overly simplistic formulation of the problem compared with the complexity of the real physical experiment. Fortunately, the advent of elastic impedance has made it possible to relax some of…
Imaging Through Gas Clouds: A Case History in the Gulf of Mexico?
S. Knapp, N. Payne and T. Johns
Results from the worlds largest 3D four component OBC seismic survey will be presented. Located in the West Cameron area, offshore Gulf of Mexico, the survey operation totaled over 1000 square kilometers and covered more than 46 OCS blocks. The area contains numerous gas invaded zones and shallow gas anomalies…
How Did M&A’s Impact R&D in Geophysics
Gordon Cope
Long before the slowdown of the Asian economy in early 1998 triggered the collapse of crude oil, petroleum companies around the world had been altering the way that they dealt with research and development. In this third in a series of articles, The RECORDER examines the impact of the latest…
International Negotiations
David Mitrovica
... Refraction Tomography: A Practical Overview of Emerging Technologies
Konstantin Osypov
Near-surface velocity anomalies produce severe distortions in seismic images. If one knew the detailed structure of these anomalies, the best way to tackle this problem would be to perform wave-equation datuming or depth migration from the surface. However, 3-D prestack depth imaging and datuming are computational challenges and highly sensitive…
Non-Hyperbolic Moveout, Polar Anisotropy and Anelasticity
Arnim B. Haase
Experience with anisotropic velocity analysis shows that, occasionally, non-hyperbolic moveout in plains data cannot be satisfactorily corrected with the Grechka/Tsvankin approximation as presented at the 1997 SEG convention (Grechka and Tsvankin, 1997). For this approximation, a Taylor-series expansion is truncated beyond the fourth power in offset. In a subsequently published…
Revisiting the Radial Trace Transform
David C. Henley
In geophysics, as with many other disciplines, it can sometimes be fruitful to review an idea originally conceived many years ago for one particular application, to see whether it can also be used for other purposes. The radial trace transform is an example of such an idea. Originally introduced by…
M&A’s and the Service Industry
Gordon Cope
In early 1998, the collapse of the Asian economy left the world awash in surplus oil. Within months, the price of crude dipped to record lows of $11 per barrel. Petroleum companies scrambled to cut costs, and exploration and production expenditures were the first to be curtailed. In Canada alone,…
Expatriate Recruitment and Effectiveness
David Mitrovica
A dominant theme during the last decade has been, and continues to be, the issue of globalisation. Globalisation encapsulates a description of a rapid, and pervasive, diffusion around the world of production, consumption, investment and trade flows in goods, services, capital and technology.
... Seismic Inversion – The Best Tool for Reservoir Characterization
John Pendrel
The principle objective of seismic inversion is to transform seismic reflection data into a quantitative rock property, descriptive of the reservoir. In its most simple form, acoustic impedance logs are computed at each CMP. In other words, if we had drilled and logged wells at the CMP’s, what would the…
Stochastic Seismic Inversion Applied to Reservoir Characterization
Gary Robinson
Seismic inversion has been used for several decades in the petroleum industry, both for exploration and production purposes. During this time, seismic inversion methods have progressed from the initial recursive inversion method to the present plethora of methods and software packages available to transform band-limited seismic traces to impedance traces.…
A Robust Joint Inversion Algorithm for Rock Property Estimation
Xin-Quan Ma
In the last decade or so, there has been increased interest in prestack inversion. This is because prestack inversion can extract not only compressive information but also estimates of shear information about a rock. The shear wave information is obtained from the variation of reflection coefficients with source-receiver spacing in…
