Articles
Image Mispositioning in Foothills Seismic Data Due to a Dipping Transversely Isotropic Overburden: Implications from Physical Seismic Modelling Studies
J. Helen Isaac and Don C. Lawton
Significant errors occur in the position of a target imaged beneath a dipping transversely isotropic (TTI) overburden if the effects of anisotropy are not included during data processing. Using 2-D and 3-D seismic data acquired over scaled physical models, we demonstrate that the imaged position of a target is shifted…
The Prairie Meteorite Search
Alan Hildebrand, Dan Lockwood and Andrew Bird
Meteorites have been accumulating on the Canadian land mass since the end of the last glaciation, approximately 10,000 years ago. The current rate of fall for meteorites >100 g mass (surviving to the ground) is ~27 per year per 106 km2. With a 10,000 year integration time, and presuming that…
Tectonic Evolution of the East Coast of Canada
Keith Louden
The East Coast of Canada is generally divided into three regions: the Nova Scotian margin in the south, the Newfoundland margin in the centre and east, and the Labrador margin in the north. These margins formed during the past 200 million years as the supercontinent of Pangea rifted apart, first…
Tectonic Evolution of the Canadian Beaufort Sea – Mackenzie Delta Region: A Brief Review
Larry S. Lane
The Canadian Beaufort Sea continental margin is probably the best known segment of the Arctic Ocean margin, based on the interpretation of multiple datasets defining the deep crustal architecture, regional structural trends and the temporal-spatial tectonic evolution. Of 53 oil and/or gas discoveries, most are trapped in structures formed during…
On Seismic Waves in Linearly Elastic, Anisotropic and Nonuniform Continua
Michael A. Slawinski
Most sedimentary rocks are anisotropic. Most sedimentary basins are nonuniform. Consequently, exploration seismologists benefit from knowledge of these properties. This knowledge provides us with rock-physics information and also enables us to account for the effects of anisotropy and nonuniformity on seismic imaging. Anisotropy and nonuniformity are conveniently studied in the…
Discovery of Ring Faults Associated with Salt Withdrawal Basins
Steven J. Maione
The Jurassic Louann salt has played a dominant role in influencing the structural and depositional history of the East Texas Basin. Petroleum traps within the basin exhibit structural and stratigraphic elements influenced by salt tectonics, particularly during the Jurassic and Cretaceous periods. Petroleum reservoirs in East Texas Basin include the…
Integrating Coherence Cube Imaging and Seismic Attributes
Satinder Chopra
Coherence Cube imaging essentially generates a cube of coherence coefficients (from the input 3D seismic data volume) that portrays faults and other stratigraphic anomalies clearly on time or horizon slices. These images show up distinctly, depicting buried deltas, river channels, reefs etc. Traditional seismic time slices are often used for…
Coals and their confounding effects
Mike Perz
If someone were to compile a list of “usual suspects” most often blamed for processing artifacts observed on Western Canadian Sedimentary Basin (WCSB) seismic sections, high amplitude coal reflectors would be found somewhere near the top (right alongside other well-known culprits such as ground roll, anisotropy, inadequate spatial sampling and…
Examining Due Diligence & Liabilities — CAGC Symposium
John Bertsch
“Where exactly does the buck stop?” and, “Although the job was done in good faith, was it done in blind ignorance?” These questions were recently posed to those attending the Fifth Annual Canadian Association of Geophysical Contractor’s (CAGC ) Oil & Gas Symposium, held in Calgary on August 21-22, 2001.
... CSEG MLA: Procedure and Questions
On October 25, 2001 the MLA Committee presented the Master License Agreement to interested members of the CSEG. The legal document was presented and interpreted for attendees of the forum. A plethora of examples of the MLA in action were given, and numerous questions from the audience were also addressed.…
Safety and Due Diligence — A Geophysicist’s Perspective
Randy Walker and Ross Brown
What do you, as a staff geophysicist, need to know and do about safety on the geophysical programs you are undertaking? What are your responsibilities or more importantly, where might you be found liable if something goes wrong during the completion of what often is extensive, costly and inherently hazardous…
Integrated Pre-Stack Depth Migration of VSP and Surface Seismic Data
M. Graziella Kirtland Grech, Don C. Lawton and Scott Cheadle
In the conventional approach to VSP and surface seismic imaging, the VSP and surface seismic data sets are processed and migrated independently. The VSP image is then spliced into the surface seismic result. Although good images can be obtained in this way (e.g. Hinds et al., 1993; Zhu and Lines,…
A Standard Data model for the Energy Industry
Ross Huntley and Trudy Curtis
The PPDM Association is an independent, not-for-profit association that represents over 100 energy companies, vendors, and regulatory agencies worldwide. Formed in 1990 and supported by many dedicated volunteers, the Association delivers vendor-independent standards that serve as the Industry foundation for managing information as an essential asset in the global resource…
Ancient Evenings – Seismic Visualization Using Very Old Techniques
Steve Lynch
A few years ago I was fortunate enough to visit the city of Tunis in North Africa. I was there to teach a training course and when the course was over, as has become my habit, I stayed on for a few days to tour the local sites. One of…
Strategic Infill Drilling Targeted Using Crosswell Seismic – ‘Two Case Studies’
Rena Hatch and Jeff Meyer
Reservoir optimization has been identified by many as the last frontier of the oil and gas industry. As fewer giant fields are discovered, improving the low recoverability from existing oil and gas reservoirs will be the focus of increasing capital spending within the industry. 3-D surface seismic information has been…
Reservoir Monitoring and Characterization for Heavy Oil Thermal Recovery
Sam Sun
Extracted post-stack seismic attributes from time-lapse 3-D seismic data have been used extensively to map steam areal conformance by using statistical analysis in the development and monitoring of follow-up processes at Imperial Oil’s Cold Lake production project. A quantitative cross-calibration scheme between time-lapse seismic surveys has been developed using data…
A Lake-Bottom Cable Seismic Survey: Acquisition and Processing
Robert R. Stewart, Han-Xing Lu, Henry Bland and Lawrence E. Mewhort
The CREWES Project and AOSTRA in collaboration with Husky Energy Inc. conducted a detailed study of Husky’s Pikes Peak heavy oil field near Lloydminster, Saskatchewan. The target of interest in this area is the oil-saturated Waseca sand at a depth of about 500 m. The principal objective of the study…
Seismic Anisotropy: Yesterday, Today, Tomorrow
Vladimir Grechka
Directional dependence of elastic properties of crystals, or their seismic anisotropy, was recognized a long time ago. By the end of the nineteenth century the first laboratory measurements of seismic velocities in sedimentary rocks were made and the main theoretical result in elastic wave propagation ( the Christoffel equation (…
Shear-Wave Anisotropy: A New Window into the Crack-Critical Rockmass
Stuart Crampin
In the last ten years, it has become recognised that crack-induced shear-wave splitting, with azimuthal anisotropy, is an inherent characteristic of almost all rocks in the crust (and upper mantle). This indicates that most in situ rock is pervaded by stress-aligned fluid-saturated cracks. The evolution of such stress-aligned fluid-saturated grain-boundary…
Depth Imaging – “If We Could Turn Back Time”
Larry Lines, Shawn Rushton, Don Lawton and Samuel Gray
Seismic migration is an essential processing step in exploration plays involving any structural complexity, since migration is the process of placing seismic reflection energy in its proper subsurface location. The popular song “If I Could Turn Back Time” can describe the process of achieving accurate migration of seismic data through…
