Articles
Thomas Bayes versus the wedge model
Jason M. McCrank, Gary F. Margrave and Don C. Lawton
This paper demonstrates the use of the Bayesian inference to estimate model parameters in a synthetic example. The demonstration data are a set of zero-offset seismograms synthesized from a variation on the wedge model that thins in a general trend but with thickness that varies randomly about that trend. The…
SAGD Well Planning Using Stochastic Seismic Inversion
Franck Delbecq and Rémi Moyen
The complexity of heavy oil geology in SAGD (Steam Assisted Gravity Drainage) projects, especially in the presence of thin shale barriers that are beyond the resolution of traditional deterministic seismic inversion, makes the integration of seismic data with well data challenging. Stochastic inversion represents an improvement over deterministic inversion in…
The Contribution of HRAM Data to Exploration in Canada: An Overview
Zeev Berger, Martin Mushayandebvu and Michelle Boast
High resolution Magnetic (HRAM) data has been flown over most of the active sedimentary basins of the world. These data has been widely used for exploration and exploitation of both frontier and mature basins. The objective of this paper is to show case studies where HRAM data interpretation has made…
It’s the Fluids that Count
Mike Batzle
Locating and identifying pore fluids is usually the ultimate goal of any geophysical activity. This not only involves oil and gas recovery, but also assessing ground water resources and tracking pollution plumes. As we strive to make geophysical methods, particularly seismic results, more quantitative, we must have a thorough understanding…
Depth Conversion and Seismic Lithology Inversion of a McMurray Oil Sands Reservoir
Rainer Tonn
The Lower Cretaceous McMurray Formation in NE Alberta is a prolific oil sands reservoir. In Statoil Canada Ltd. Leismer leases, about 100 km south of Fort McMurray, the bitumen saturated reservoir lies at a depth of approximately 450 m with SAGD (Steam Assisted Gravity Drainage) being the optimal method for…
Seismic Wave Phenomena and Implications for Accuracy of Microseismic Results
B. Fuller, L. Engelbrecht, R. Van Dok, M. Sterling, M. Kniffin, and L. Walter
A primary goal of microseismic surveys is to locate the origination point of seismic events that occur in response to hydraulic fracture stimulation in a reservoir. Accurately locating the origin point of seismic events relies upon a complete understanding of wavefield propagation phenomena that occur in the environment of the…
The more we listen the more we see: Microseismic monitoring of induced seismicity is coming of age
Juan M. Reyes-Montes, Will S. Pettitt and R. Paul Young
The growing demand of energy and resources from society has moved the energy industry to maximize the productivity of reservoirs and search into the exploitation of new resources in increasingly challenging environments. Technologies such as Enhanced Oil Recovery and Engineered Geothermal Systems have become normal practice in the exploitation and…
Microseismic Moment Tensors: the Good, the Bad and the Ugly
David W. Eaton and Farshid Forouhideh
Seismic moment tensors provide a general mathematical representation of point sources that can be used to distinguish between various microseismic source types. We use synthetic tests with borehole receiver arrays to determine the geometrical conditions necessary to estimate reliably the six independent components of a full moment tensor by leastsquares…
How much experience is enough?
Tom Sneddon
Maybe it’s just me, but every day when I arrive at the jobsite I feel like this day’s challenges are different from anything I’ve done before. I think that maybe someone more experienced than me should be called in for advice on whatever topic needs to be tackled. This has…
Refraction Statics: The Art and Science of Near-Surface Interpretation
Chuck Diggins
Every step in refraction statics determination involves intrepretation. On acquisition, many decisions impact the quality of the refraction analysis: array lengths, group and shot intervals, furthest distance, wide vs narrow azimuth, source types, receiver types, etc. Each of these decisions should and probably rarely or never are considered from the…
Central Alberta Aggregate Study
B. Janet Morrissey
An OhmMapper apparent resistivity survey was undertaken at a site in central Alberta to identify and delineate an aggregate deposit. The results show that the apparent resistivity method has defined the lateral and vertical extent of the main aggregate zone as well as several smaller high-resistivity regions on the periphery…
Magnetic and Gravity Methods in Mineral Exploration: the Value of Well-Rounded Geophysical Skills
Henry Lyatsky
The word “geophysics” in oil exploration is often used synonymously with “seismic”, overlooking many other fruitful techniques. In mineral exploration and engineering projects, applicability of seismic imaging is often limited and other geophysical methods take the front seat.
Gravity and magnetic methods, which are discussed in this article, are extremely…
Beyond Isotropy – Part II: Physical Models in LMR Space
Marco Perez
The following is the second part of the article “Beyond Anisotropy – Part 1: A Prestack Perspective” (RECORDER, 35-7). This section provides an in depth analysis of the seismic reflection of anisotropic media, specifically using the Lambda-Mu-Rho (LMR) crossplot. In Part 1, anisotropic reflections were analyzed from the perspective…
A Geoscientist in Antarctica: Following in Shackleton’s footsteps 100 years later…
Susan R. Eaton
I began by assembling the basics for my field trip to Antarctica and South Georgia: surface geology maps, topographic maps, hiking boots, wool socks, a back pack and two digital cameras. My gear list soon ballooned to include a hydrophone, an Iridium satellite phone, a lap top computer, an Arctic-rated…
15 years of passive seismic monitoring at Cold Lake, Alberta
Richard J. Smith
The first test of passive seismic technology at Imperial Oil’s heavy oil operation in Cold Lake, Alberta was conducted in 1995. Since 1998 passive seismic monitoring has been integrated into the commercial operations. There are currently ~100 dedicated monitoring wells with 5, 8, 10 or 12 tri-axial geophones deployed in…
Natural Fractures from the Perspective of Diagenesis
S.E. Laubach, J.E. Olson, P. Eichhubl, S. Fomel, and R.A. Marrett
Information about chemical changes that occur in rocks during burial—diagenesis—can help improve geologic fracture characterization and prediction by accounting for rock mechanical property changes through time and by providing evidence for how fractures grow and become sealed. Diagenesis information can also be a key ingredient in better geophysical interpretation of…
Comparison between faults extracted from seismic and Elastic Dislocation Modelling
Thibaut Cheret, Jonathan Long, and Jonathan Turner
Most fault enhancement techniques rely on enhancing the discontinuities within the seismic signal. However, there is a large variety of phenomena that cause discontinuities in the seismic signal. Furthermore, fault heaves are lower than the Fresnel zone width thus not fully resolvable and as a result, faults are often poorly…
Beyond Isotropy – Part I: A Prestack Perspective
Marco Perez
The seismic response is composed of two parts: the traveltime of a signal from the surface to and from a reflector and the amplitude of the reflection. Of interest here is the amplitude of the reflection, which is primarily a function of material properties at a given geological interface; specifically…
Time Lapse Interpretation of Cold Heavy Oil Production
Ken Hedlin, Arthur Chan and Bob Godfrey
A number of papers have been published that show seismic amplitude anomalies in CHOPS (Cold Heavy Oil Production with Sand) fields correlated with production (e.g. Hedlin & Chan, 2009; Chen et al, 2004 and Mayo, 1996). Modeling and 2D seismic experiments conducted in 2002 by Husky Energy suggested that drainage…
Carbon capture and storage: opportunities and challenges for geophysics
Don Lawton
Carbon capture and storage (CCS) involves capturing CO2 from point-source surface facilities and injecting it into subsurface geological formations, particularly depleted oil and gas reservoirs, unmineable coal seams or deep saline aquifers. In 2008 the government of Alberta committed CDN$2B to accelerate CCS in the province, with the goal of…
