Articles

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December 1995

Effective Geophysical Writing and Presentation

Robert R. Stewart, R. James Brown and Don C. Lawton

James Michener (1992) wrote, "The writer who sits at his or her desk with an empty piece of paper staring back is like the explorer who stands at the edge of a new continent, uncertain of how to proceed" – an exciting but perhaps difficult position. The goal of this…

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December 1995

The Doodlebugs

Sharon Stevens

A doodlebugger? What is a doodlebug and where did that name come from? A definitive answer was what I was searching for. But a variety of responses is what I found...

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November 1995

Depth Imaging of Seismic Data from Structurally Complex Areas

Larry Lines, Wen-ling Wu, Han-Xing Lu, Andrew Burton, and Jinming Zhu

Recent geophysical research has made widespread use of depth migration and velocity analysis in our efforts to improve seismic images in structurally complex areas. Such structural exploration problems include the imaging of salt intrusions and faulted structures from offshore Newfoundland, and the delineation of thrust faulted structures from the Alberta…

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November 1995

From Horses to Helicopters: Bill Sydorko's 45-year Career in Seismic Field Work Mirrors an Industry's Coming-of-age

Samantha-jane Mugridge

Bill Sydorko has progressed from working on geophysical crews of four or five men in 1950 to supervising crews of up to 30 men during the 1980s and 90s. Where 16 or 24 traces per seismic record were once standard, now he routinely deals with a minimum of 144 per…

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October 1995

3-D Prestack Time Migration of Canadian Plains Data: When and Why It is Needed

Mike Perz and Peter Cary

Today's generation of superscalar workstations and high performance supercomputers allows full prestack time migration of 3-D data volumes within a time frame that is manageable from the explorationist's viewpoint. Most geophysicists are aware that performing prestack time migration on structured data sets offers certain advantages, particularly from the viewpoint of…

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October 1995

Applied AVO Analysis: Use and Abuse of Amplitude Variation with Offset

John P. Castagna

The great promise of amplitude-versus-offset (AVO) analysis lies in the dependence of the offset-dependent-reflectivity of reflected compressional waves on the elastic properties of the subsurface. As different lithologies may exhibit distinct Poisson's ratios, and gas bearing strata usually exhibit anomalously low Poisson's ratios, AVO has been recognized as a potential…

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September 1995

Why Perform 3-D Prestack Time migration on the Prairies?

Mike Perz

Hardware platforms have now achieved a level of sophistication which permits the use of full 3-D prestack time migration as a production-style processing tool. While most geophysicists are aware that performing 3-D prestack time migration on structured data sets offers certain advantages, particularly from the viewpoint of velocity analysis, many…

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September 1995

Interpretation of Aeromagnetic Data

Erwin Ebner, John Peirce and Nathalie Marchand

The previous three articles of this series on Potential Field (PF) Geophysics dealt with recent technical improvements in magnetics and gravity instrumentation as well as with critical components concerning data acquisition and PF project management. This article focuses on processing and interpretation of aeromagnetic data. Key aspects of each of…

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September 1995

The CSEG Internet Services

Howard G. Hepburn

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June 1995

Project Planning and Management for Magnetic Gravity Surveys

Erwin Ebner

The first two articles of this series on potential field (PF) geophysics dealt with recent technological improvements in gravity and magnetics survey systems. This article addresses issues from a project management perspective where questions such as Why are we doing this? What are we going to get out of it?…

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June 1995

Using Geostatistics to Aid in Reservoir Characterization

Sheldon B. Gorell

Proper characterization of reservoir heterogeneities is a well recognized requirement to predict reservoir performance accurately. Given the large investment requirements, long development schedules, and the often uncertain economic outlook, sound decision making requires reasonable estimates of how much, and when, oil will be produced. It is no longer sufficient to…

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May 1995

Field Comparison Between 16 and 24 Bit Data Acquisition Systems

John H.J. Paquette and Tony Sartorelli

A test survey was recently conducted to compare the relative performance of three types of seismographs. The equipment used was a DFS/v (Texas Instruments), an I/O System Two (Input/Output, Inc.), and a Bison 24000 (Bison Instruments, Inc.).

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April 1995

The New Wave

Dr. Thomas L. Davis

Increased efficiency of finding and developing hydrocarbon resources while reducing the environmental impact through geophysical technology is critical to the future of the petroleum industry. This technology must remotely determine rock-fluid property characteristics, their geometry, and changes over time. In reviewing advancements in exploration seismology, three component 3-D seismology stands…

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April 1995

3-D, 3-C Seismic Characterization of the Nisku Carbonate Reservoir, Joffre Field, South-Central Alberta

John Arestad, Bruce Mattocks, Thomas Davis and Robert Benson

The Reservoir Characterization Project (RCP) at the Colorado School of Mines has pioneered research into 3-D, 3-C (multicomponent) reflection seismology for nearly a decade utilizing both P-wave and S-wave sources. Multicomponent seismic surveys provide significantly more information about petroleum reservoirs than compressional wave surveys.

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April 1995

Using Amber to Probe the Past: from DNA to Dinosaurs

Ever since Pliny the Elder concluded that amber originated from the resin of extinct trees, humans have been fascinated with the presence of life forms in this magical material. What we do know about the formation of amber will be discussed, along with the characteristics of the enclosed fossils.

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March 1995

Satellite Navigation: Present Capabilities and Future Trends

Elizabeth Cannon

he use of satellites for positioning and navigation has become an important tool for scientists and engineers concerned with locating and monitoring various features and phenomenon. The Global Positioning System (GPS) is a twenty-four satellite system which provides global, all-weather, twenty-four hour a day navigation capability. The elements of the…

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March 1995

Recent Advances in Gravity Acquisition and Instrumentation – Part II

Very high quality gravity surveys have been carried out for nearly half a century now. I have personally seen small gravity survey results from the late 1940's which rival present day quality. The main reason for this lies in the care with which these surveys were acquired. It took considerable…

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February 1995

A New Prospective on Pre-stack Migration Using Equivalent Offset and Common Scatter Point (CSP) Gathers

Dr. M. Elizabeth Cannon

A new process allows prestack migration to be simplified into the three steps of trace gathering, normal moveout, and stacking. This new method has many advantages that range from reduced processing times to more accurate velocity analysis.

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February 1995

An Overview of Digital Optical Disks

Graham Irving

With the explosion of CD Audio and CD-ROM discs today, most people are aware of optical disks and very likely use some form of optical disk technology, whether it be a home CD Audio player or a 2 Terabyte optical disk jukebox. Optical disks are currently making a significant impact…

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February 1995

Data Archival, Storage, and Distribution for the 1990’s and Beyond

Garth Paterson

This article is being written in response to a growing need for data managers and explorationists to gain information regarding the storage of digital seismic field and stack data on optical disk. There are two distinct areas involved in this storage, one is the long-term archive of the data, the…