Articles
Propagation of borehole derived properties via a Support Vector Machine (SVM)
Yexin Liu and Mauricio D. Sacchi
Rock mechanical properties are an essential piece of information for applications like borehole instabilities analysis during drilling. It is estimated that borehole instability problems cost the oil industry worldwide about 1.0 billion dollars per year (Erling, et al., 1996). Traditional methods of propagating mechanical properties from a given borehole to…
Successful AVO and Cross-plotting
Satinder Chopra, Vladimir Alexeev, Yong Xu
Cross-plotting has evolved to be a widely used technique in AVO analysis, as it enables the simultaneous and meaningful evaluation of two attributes with ease. Generally, common lithology units and fluid types cluster together in AVO cross plot space, allowing identification of both the background lithology trends and anomalous off-trend…
Coal-Bearing Formations and Coalbed-Methane Potential in the Alberta Plains and Foothills
Andrew Beaton
Alberta contains substantial coal resources in the Plains and Foothills. Coal rank ranges from lignite and subbituminous in the eastern Plains, up to low-volatile bituminous and anthracite in the Foothills/Mountains. Potential coalbed methane targets exist in the Scollard Fm. (Ardley coal zone), Horseshoe Canyon Fm. (Carbon-Thompson, Drumheller coal zones), Belly…
A Summary of Coalbed Methane Potential in British Columbia
Barry Ryan
For the first part of 2003 wholesale natural gas prices have been in the range of 4 to 6 $US per million btu, this compares to prices of about 2.2 $US in 1998. The price increase reflects increased demand and a decrease in reserves within USA and Canada. In fact,…
Microbial Methanogenesis and its Role in Enhancing Coalbed Methane Recovery
Karen Budwill
It has been recognized in recent years that ongoing methane production is occurring in deep coal beds. This observation was deduced from studies of isotopic fractionation of coal gases, changes in coal-gas chemistry and the biodegraded nalkane pattern of some coal-extract samples (Scott, 1999). Research is limited in understanding the…
Michelangelo, Seismic and Seeing What’s There
Jan Dewar, Jon Downton, Glen Larsen
In oil painting restoration, masterpieces dirtied by centuries of grime and smoke are cleaned to reveal the original brilliant image. The recent cleaning and restoration of the frescoes in the Sistine Chapel are a familiar example. Once the unwanted dirt had been removed, the beauty and vibrant colors of the…
Visualization and Volume Interpretation in Geoscience: 3-D Seismic and Beyond
Steven R. May
Volume interpretation technologies are revolutionizing the way geoscientists interpret seismic data and engineers evaluate reservoirs, thereby improving the accuracy of subsurface predictions. The development and application of visualization and volume interpretation technologies within petroleum geoscience has experienced rapid change within the past decade. This history provides an interesting case study…
Multicomponent Seismic Data Acquisition… The Economics Revisited
John Gibson, Howard Watt, and Steve Roche
Over the past several years, significant advances have been made in the acquisition, processing and analysis/interpretation of converted-wave (PS) multicomponent seismic data resulting in renewed enthusiasm for use of this technology. The development of purpose-built multicomponent data acquisition systems based on MEMS (Micro Electro Mechanical System) digital accelerometers has resulted…
Full-Wave Digital Seismic Recording and the Impact of Vector Fidelity on Improved P-wave Data
D.J. Tessman and P. Maxwell
In 2002 Input/Output commercialized its full-wave digital sensor system known as VectorSeis™. Since the initiation of field testing in 1999 more than 65 surveys have been acquired worldwide with these MEMS (micro electro-mechanical systems) based sensors. Of these, 38 have been commercial seismic surveys in Western Canada. Observations by interpretation…
Combined Ocean Bottom Stations and Streamers
S. Ronen, C. Ansorger, R. Leggott, K. Hawkins, K. Mills, P.Nicholls, A. Ratcliffe and L. Scott
We propose to combine sparse multi-component (MC) seismic data with dense single component (1C) data. Such a combination provides the best of both: cost effective imaging and AVO analysis from the streamers, together with cost effective VP/VS ratio and MC AVO from the multi-component ocean bottom stations.
... Filling in the Gaps in Our Understanding of Converted-Wave Fold
Peter Cary and Don Lawton
For a newcomer to converted-wave processing, one of the most confounding things that is encountered early on is the realization that the fold of P-S data can differ so much from the fold of ordinary P-P data.
... Analyzing Multicomponent Seismic Data from the Mackenzie Delta, N.W.T.
Carlos E. Nieto and Robert R. Stewart
A set of seismic test lines was acquired in the spring of 2001 by the CREWES Project and Devon Canada Ltd. (formerly Anderson Exploration Ltd.) in the Mackenzie Delta, N.W.T. The lines, shot with dynamite and vibrator sources, included a 750m spread of 3-C geophones across a transition zone from…
9C, 4D Seismic Processing for the Weyburn CO2 Flood, Saskatchewan, Canada
Robert R. Kendall, Robert Winarsky, Thomas L. Davis and Robert D. Benson
We present a summary of the 9C, 4D processing used for the seismic monitoring of a CO2 flood in the Weyburn Field, Saskatchewan, Canada. The resultant time-lapse amplitude anomalies for both the P- and S-wave volumes are coincident with the locations of the CO2 injection patterns. Furthermore, the anomalies we…
Utilization of Seismic Attributes for Reservoir Mapping: A Case Study from Cambay Basin, India
A.K. Srivastava, V. Singh, B.G. Samanta and G. Sen
Multi-layered Hazad sands of Middle Eocene age deposited in deltaic environment are the main hydrocarbon producers in south Cambay Basin, India. These sands are broadly divided into twelve units (1 to 12) from bottom to top. These individual sand units are further subdivided in to smaller subunits which are selectively…
The Controversial Pore Pressure Conversion Factor: PSI to PPG MWE
Selim S. Shaker
Geoscientists are inclined to use pore pressure (PP) plots expressed in PSI vs. Depth (P-D). This graphic illustration is beneficial for prospect and play-concept compartmentalization and seal integrity appraisals. On the other hand, drillers and engineers prefer to use Mud Weight Equivalents (MWE) in pound per gallon vs. depth (PPG-D)…
Russian Oil and Gas: A Compelling but Troubled Future
Michael J. Economides
An energy story, bigger than Iraq, bigger than Venezuela and Nigeria combined, is unfolding in Russia. The government of President Vladimir Putin has thrown down the gauntlet at oil “oligarchs”, most prominent among which is Mikhail Khodorkovsky, CEO of Yukos, Russia’s largest oil company and the world’s second largest oil…
Pseudo Gamma Ray Volumes Estimated from Offset Seismic
David Timko
Using seismic to explore for clastic reservoirs in the Western Canada Sedimentary Basin is often difficult due to the inability to distinguish between interbedded sand and shale lithologies using acoustic impedance. The problem is made even more difficult when the AVO response to sand-shale interfaces distorts the reflection amplitudes on…
Multi-Attribute Seismic Analysis on AVO derived parameters – a case study
Satinder Chopra and Doug Pruden
Prospecting for reservoir zones in mature trends sometimes requires unconventional exploration tools. AVO has been successfully used as a direct hydrocarbon indicator in some clastic rocks. Lately, AVO inversion for Lame parameters (λρ and μρ) has been shown to enhance identification of reservoir zones (Goodway et al, 1997). However, the…
Seismic anisotropy of shales
Pavlo Y. Cholach and Douglas R. Schmitt
Shales are volumetrically the most abundant sedimentary rocks. Shales are also known to be anisotropic to the propagation of seismic waves. Thick shale layers may significantly affect seismic wave propagation and contribute to the distortion of a seismic image. The elastic behavior of shales is usually associated with the properties…
Summary of the Poisson’s Ratio Debate 1990 – 2003
Peter Gretener
Summary of the Poisson's Ratio Debate 1990 - 2003
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