Articles
Practical Interpretation of Multi-Component Seismic Data
Murray Roth
Nine months ago, you finalized design for a new multicomponent seismic survey on your company’s key land asset. Seismic modeling of expected P and mode-converted PS seismic response for your reservoir zone convinced you of the potential value for this survey. While minor fluid and lithology changes translate into minor…
Converted-wave seismology for coal exploration
Natasha Hendrick
Despite the success of multi-component seismology and associated converted-wave (PS-wave) imaging methods in the petroleum industry, there has been relatively little effort devoted to shallow, high-resolution converted-wave imaging in the coal sector. By analogy to petroleum-scale applications, converted-wave seismic imaging in the coal environment offers interesting possibilities for independent validation…
Global implications of Arctic climate processes and feedbacks – GLIMPSE
Martin Stendel
The Arctic exhibits substantial natural variability and climate change simulations suggest that it is a region of the world where climate change as a result of increased greenhouse gas concentrations is likely to be largest. The impacts of this warming, including the melting of sea and inland ice and changes…
Anomalous stacking velocities–critique, analysis, explanations and new insights
Emil Blias
A depth velocity model determination is one of the most important problems in seismic processing and interpretation. A velocity model, beyond its initial purpose to obtain a seismic stack, is used for depth conversion and migration, AVO analysis and inversion, pore pressure prediction and so on. Before a well is…
Low temperatures in the Arctic stratosphere have led to severe ozone loss during the spring of 2005
SCOUT project office
25 April 2005. The chemical balance in the stratosphere has changed significantly due to the presence of PSC clouds, altering the breakdown products from man-made CFCs (chlorofluorocarbons) so that rapid chemical ozone destruction can occur in the presence of sunlight. The cold conditions affected the distribution of nitrogen oxides, allowing…
Reducing reservoir risk using 3D-seismic based stratigraphic and geomorphologic analyses
Henry Posamentier
3D seismic data can play a vital role in hydrocarbon exploration and development especially with regard to mitigating risk associated with presence of reservoir facies. Such data can afford direct imaging of depositional elements, which can then be analyzed by applying seismic stratigraphic and seismic geomorphologic principles to yield predictions…
Velocity determination for pore pressure prediction
Satinder Chopra and Alan Huffman
Knowledge of formation pore pressure is not only essential for safe and cost-effective drilling of wells, but is also critical for assessing exploration risk factors including the migration of formation fluids and seal integrity. Usually, pre-drill estimates of pore pressure are derived from surface seismic data by first estimating seismic…
Stereotomography: Past, present and future
Gilles Lambaré
Stereotomography was proposed seven years ago for estimating velocity macro-models from seismic reflection data. Initially the goal was to keep the advantages of standard travel time tomography but remedying for difficult interpretative travel time picking. Stereotomography relies on the concept of locally coherent events characterized by their local slopes in…
Practical applications of P-wave AVO for unconventional gas Resource Plays
Bill Goodway, John Varsek and Christian Abaco
This article is the second of two parts following part 1 in the March 2006 RECORDER. Part 1 described the potential of conventional isotropic AVO to identify optimum geo-mechanical properties for the successful exploitation of tight gas shale Resource Plays through effective hydraulic fracture stimulation. Based on comparisons to the…
Frontier Next Door: Geology and Hydrocarbon Assessment of Sedimentary Basins Offshore Western Canada
Henry Lyatsky
A new, rich petroleum province is waiting to be explored. The sedimentary basins offshore western Canada are currently off limits to hydrocarbon exploration due to a continuing government moratorium. Yet, political developments at the provincial and federal levels give grounds for optimism that this moratorium may be lifted in the…
Junior Geophysicists Forum
Before we update you with news regarding our next event we figured we should update you with our name change. The Young Geophysicists Forum (YGF) has undergone a bit of a name change, and we figured now was the best time to do it. To be more in-line with terminology…
Winds of Change in Recording Seismic Data
Peter Maxwell and Jason Criss
In 500 BC, the Greek philosopher Heraclitus wrote, “Nothing endures but Change”. When referring to man, the natural change of things is usually the result of endless attempts to make something better. When we visualize how seismic data recording will look in 10 years the only thing we know for…
Recent and future developments in marine acquisition technology: An unbiased opinion
Nick Moldoveanu
In June 2001, Gijs Vermeer was invited by the CSEG RECORDER to look at the future developments in seismic acquisition. It was a rather difficult task, considering the seismic industry collapse in 1999 and the severe cuts in seismic industry research and engineering following a cumulative minus $2 billion free…
Recent advances in marine seismic acquisition and processing technology
Thorbjørn Rekdal and Andrew Long
We review the developments in marine seismic technology over the past five years, and then use recent innovations to predict the next five years. Overall, most oil companies are beginning to embrace better acquisition planning as being a necessary foundation to overcome long-standing challenges to better seismic data. In particular,…
Reflections on the Deconvolution of Land Seismic Data
Peter Cary
Convolution is the process by which a wavelet combines with a series of reflection events to produce the seismogram that is recorded in a seismic survey. The familiar model is that a seismogram, s(t), is the wavelet, w(t), convolved with the reflectivity, r(t), and noise, n(t): s(t) = w(t) *…
Wavelet estimation by non-linear optimization of all-pass operators
Somanath Misra and Mauricio Sacchi
A mixed phase wavelet can be parameterized as a convolution of a minimum phase wavelet and an all-pass wavelet. The minimum phase wavelet can be estimated from the data by the Wiener-Levinson algorithm. The technique of cumulant matching is used to estimate the phase of the all-pass wavelet. Higher order…
Developments in seismic anisotropy: Treating realistic subsurface models in imaging and fracture detection
Ilya Tsvankin and Vladimir Grechka
The scope of recent advances in the field of seismic anisotropy is too wide to be thoroughly analyzed in a short overview article. Here, our goal is to emphasize several key recent developments and trends and give a limited number of essential references.
... Towards wave-equation imaging and velocity estimation
Samuel Gray, Daniel Trad, Biondo Biondi, Larry Lines
Prestack depth migration (PSDM) has gained widespread acceptance as a tool of choice for seismic imaging in geologically complex areas. Its ability to honor lateral velocity variations gives geophysicists greater confidence in the precise location of their drilling targets on their image than they can possibly have using prestack time…
Regularized migration/inversion: New Generation of Seismic Imaging Algorithms
Mauricio Sacchi, Juefu Wang, and Henning Kuehl
... Significant developments in multicomponent seismic exploration in the last five years and future directions: Recent developments in converted PS-wave analysis processing of shear S-wave splitting and prestack migration
James Gaiser and Tony Probert
There have been tremendous advancements in 3D multicomponent seismic acquisition, processing, analysis and interpretation over the past five years. Improvements have been made in PS-wave (converted-wave) signal processing, including velocity analyses and anisotropy, interpretation and event registration of PP and PS data, and prestack imaging. Both PS-waves and P-waves (compressional…
