Articles

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December 1996

Pre-stack Inversion: Evolving the Science ofInversion

Rick Wallace and Roger Young

Over the past 2 decades seismic inversion, ostensibly the process of deriving rock properties from seismic measurements, has evolved significantly. The early methods of recursive inversion converted seismic traces to well log traces providing a measurement of the "pseudo acoustic impedance". The acoustic impedance could also be expressed as "pseudo-acoustic…

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December 1996

One Interpreter’s Most Excellent Adventure

Jan Dewar

Synthetic seismograms are a common tool in geophysical interpretation. They make use of the simple idea of correlating known subsurface information from a well with seismic data recorded on the surface. But sometimes a synthetic seismogram does not match a seismic section very well, and what should be a straight…

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December 1996

Geostatistical Reservoir Characterization of A Canadian Reef Or The Use and Abuse of Geostatistics

Keith Hirsche, Larry Mewhort, Jan Porter-Hjrsche and Rick Davis

Geostatistical methods are becoming widely accepted in reservoir characterization. The appeal of these techniques is the ability to integrate diverse types of information, including seismic data, into a consistent subsurface model. An added benefit of geostatistics over deterministic reservoir description is the ability to assess uncertainty in the modelling process.…

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November 1996

3D Seismic Monitoring for Enhancing Thermal Recovery

John Eastwood, Don Anderson and Tom Boone

A technique is illustrated which uses a single 3D seismic monitor survey along with multiple seismic attributes in conjunction with an offset baseline survey to discriminate heated reservoir from unheated reservoir. 3D seismic monitoring has definitively mapped steam heated regions of the reservoir at two separate geographic locations encompassing more…

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November 1996

In the Foothills, Prestack Depth Migration IS Interpretive Processing

Samuel H. Gray and Gary Maclean

In the Foothills of the Canadian Rocky Mountains, explorationists face a wide spectrum of challenges, ranging from economic ("Is my prospect large enough to justify a multi-million dollar well?" "Can hydrocarbons be transported from the well to the market inexpensively?") to technical ("Can I map my structure using seismic data?"…

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October 1996

Surface Seismic Data Acquisition: Current Technology, Trends and Issues

Dr. Fred J. Barr

We currently find ourselves armed with a dazzling array of technologies with which to acquire seismic data. These technologies, as well as their attendant trends and issues, have developed in response to both market and technical forces, powerful forces at work for several decades. The market forces demand lower costs…

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October 1996

Cascaded Dipole Filters: Extending the Limits of Seismic Resolution

Penny B. Colton and Atul Nautiyal

In the challenging world of mapping thin stratigraphic targets, a geophysicist may choose to try a tactic for increasing resolution, particularly if it is simple, quick and has a known effect. The dipole filters described below, with either even or odd iterations (zero or 90 degree phase shift), can be…

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September 1996

Mining Exploration: A New Frontier for the Canadian Seismic Industry

David W. Eaton, Bernd Milkereit, Matthew Salisbury, Erick Adam and Jianjun Wu

Like the oil and gas industry, the mining industry is a cornerstone of the Canadian economy, with production of non-fuel minerals in the order of $12 billion annually. With a few notable exceptions (e.g., the spectacular Voisey Bay nickel-cobalt discovery in Labrador), the Canadian mining industry is looking progressively deeper…

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September 1996

Surprises in Glauconitic Incised Valley Channel Exploration Using 3D Seismic: Risks and Opportunities

Marilyn J. Mawdsley, Alma L. Eamer and Brian A. Zaitlin

Exploration risks commonly associated with the seismic definition of Lower Cretaceous incised valley channel sandstone (IVCS) reservoirs are: I) the distinction of shale versus sandstone and 2) ambiguities caused by seismic interference from both the underlying Paleozoic unconformity and younger Mannville coals. A post-drill review of two wells drilled during…

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June 1996

The Integration of Logs, Borehole and Surface Seismic

Dick Ireson

The calibration or AVO Walkaway technique, where the downhole geophone array is placed just above the reservoir, is gaining acceptance as a tool for evaluating the full elastic response of the reservoir local to well locations. It may also be used to evaluate the velocity anisotropy of the layers in…

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June 1996

The Blackfoot Seismic Experiments: Broad-Band, 3C-3D, and) 3-D VSP Surveys

Robert Stewart, Robert Ferguson, Susan Miller, Eric Gallant and Gary Margrave

A number of paths could lead to fundamental advances in seismic exploration. These include: broadening of the recorded frequency band, use of the full 3-D elastic properties of the Earth, and 3-D borehole images. We would like to extend the recorded seismic frequency band (both up and down) to increase…

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June 1996

Geoscientist Registration in Ontario

As of March 10, 1996, the Association of Geoscientists of Ontario was formed, following from the Committee for Professional Registration of Geoscientists in Ontario. The aim of this organization is to promote establishment of a system for geoscientist registration in Ontario and to provide a formal channel for communication with…

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June 1996

The Evolution of Shallow Marine Data Acquisition in Canada

Peter Kitson

Prior to 1984, shallow marine exploration in Canada was almost non-existent. Most recording systems were not readily adaptable for working on water. There were no marine cables. Airguns had been in Canada for some time, but were used primarily for infill coverage and testing. Some equipment had been brought in…

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May 1996

Convention Program & Table of Contents

1996 Convention Committee

Overview of 1996 CSEG Convention Program and Schedule.

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April 1996

Applied Seismic Inversion for Estimating Earth Models in Depth

Oz Yilmaz

Processing and inversion, both are intended to estimate earth models from seismic data. Nevertheless, they differ in one fundamental respect - the output domain. Processing yields an earth model in time, whereas inversion yields an earth model in depth.

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April 1996

Professional Registration – The Process Explained

Neil Rutherford

The process of obtaining professional registration in your chosen field can be a daunting task. Many CSEG and CSPG members have given up in their attempts through frustration and lack of understanding of the process. Those more fortunate to have "made the grade" undoubtedly think the trials they endured to…

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April 1996

Professional Registration of Geoscientists in Canada

Gordon D. Williams

Professionals, including engineers, architects and doctors, are registered to practice in Canada under provincial or territorial legislation. Four jurisdictions in Canada currently also register almost 5000 geoscientists, either as Professional Geoscientists (P.Geo.), Professional Geologists (P.Geol.) or Professional Geophysicists (P.Geoph.) under combined engineering and geoscience acts of their Legislatures.

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March 1996

Exploration Applications of High Resolution Magnetic Surveys

Zeev Berger, Ron Sheldrake, Foon Der

High resolution aeromagnetic surveys are excellent tools for mapping geological structures in a wide range of tectonic settings and geographical areas. The improved mapping capabilities of these surveys are achieved by advanced data acquisition techniques which include lower altitudes, tighter line spacing, and broad-band frequency retention followed by advanced data…

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February 1996

The 3-C Struggle: Good News From the Trenches

Dr. Peter Cary

The title of this luncheon presentation seems to imply that some sort of "trench warfare" is going on with three-component seismic data. Those who have had hands-on experience with 3-C data may know just how close to the truth this term sometimes is, but it is not meant to turn…

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February 1996

Good Computer Contouring/Modelling Can Help the Geophysical Interpreter – Part Two

Richard Banks and J. Brian Henry

Most formations were nearly horizontal when deposited and the formations were sub-parallel to each other. Even though geologic forces have deformed the original structures, many suites of surfaces exhibit similar features. This is the familiar geologic principle of conformity that can be applied when contouring several surfaces simultaneously.

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