Dallas Geophysical Society Calendar Events RSS Feed

Joint DGGS Luncheon - Locating High-productivity Areas of Tight Gas-Sand Reservoirs using LF Seismic Surveys at Jonah and Pindale Fields on 14-Feb-12 11:30 AM

Tue, 14 Feb 2012 17:30:00 GMT

Joint DGGS Luncheon - Locating High-productivity Areas of Tight Gas-Sand Reservoirs using LF Seismic Surveys at Jonah and Pindale Fields
Start Date: 14-Feb-12 11:30 AM
End Time: 14-Feb-12 1:00 PM
Location: Brookhaven Country Club, Dallas, TX 75234
Speaker: Brad Birkelo

Event Details:

This is the Spring 2012 JOINT LUNCHEON

for the Dallas Geophysical Society and the Dallas Geological Society

Locating high-productivity areas of tight gas-sand reservoirs
using LF seismic surveys at Jonah and Pindale fields.

by
Birkelo, B., A. Goertz, and K. Cieślik, Spectraseis AG
and E. LaBarre, EnCana Oil & Gas (USA) Inc

Jonah and Pindale fields in southwest Wyoming are prolific tight gas reservoirs. Jonah may have up to 8 TCF of recoverable gas, and estimates at Pinedale exceed 27 TCF. Primary production is from more than 5000 feet of discontinuous, sandstones from Upper Cretaceous Lance and Mesa Verde Formations.

A low-frequency passive seismic survey was acquired over the Jonah and Pinedale gas fields to verify whether changes in the ambient seismic wave field could discriminate the higher productivity areas. The 2D profiles of the survey crossed the field in places that show maximum contrast in well productivity. As part of the ambient wave-field characterization (AWC) processing, the anthropogenic noise generated by the operations and the infrastructure of the field was captured and analyzed.

Results of this analysis show that the AWC seismic attributes correlate well to reservoir properties like estimated ultimate recovery (EUR) and hydrocarbon pore thickness (HPT or SgPhiH) while the anthropogenic noise was not responsible for the measured AWC seismic signal anomaly. This opens the door to the use of AWC seismic surveys to extend existing tight gas-sand fields and to locating the high-productivity areas in tight gas-sand exploration plays.

Brookhaven Country Club

3333 Golfing Green Drive

Dallas, TX 75234

DGeophS Luncheon - Dr. Jack Schuenemeyer - Gas Hydrate Resource Estimation on 22-Mar-12 11:30 AM

Thu, 22 Mar 2012 16:30:00 GMT

DGeophS Luncheon - Dr. Jack Schuenemeyer - Gas Hydrate Resource Estimation
Start Date: 22-Mar-12 11:30 AM
End Time: 22-Mar-12 1:00 PM
Location: Ellison Miles Geotechnology Institute Brookhaven College, Farmers Branch, Texas 75244
Speaker: Dr. Jack Schuenemeyer

Event Details:

Modeling Gas Hydrate Resources in the US Federal Offshore Regions

John H. (Jack) Schuenemeyer

Southwest Statistical Consulting, LLC

Cortez, Colorado

Gas hydrate, which is essentially methane in ice, is a potentially important worldwide energy resource that could one day supplement domestic and world-wide natural gas resources. There is evidence of significant in-place gas hydrateresources in offshore deepwater areas of the world.

Earlier assessments of gas hydrate resources in the United States followed the protocol used for the assessment of conventional oil and natural gas resource where sizes and frequencies of occurrences were specified by expert judgment. More recently, research and data availability have lead the U.S Bureau of Ocean Energy Management (BOEM) to develop a mass-balance cell-based model using stochastic simulation to obtain estimates of available gas hydrate resources.

The principal components of the mass balance model are a subsea floor container, the fraction of container volume that may be filled with hydrate, and available charge. The distribution of resources is estimated via stochastic simulation.

Preliminary in-place results have been published for the Gulf of Mexico where the assessment model structure consists of over 200,000 cells that measure 2.32 km². Models are currently being developed for the Atlantic, Pacific and Alaska Federal Offshore regions.

Dr. John H (Jack) Schuenemeyer, President of Southwest Statistical Consulting, located in southwest Colorado, USA, has over 35 years’ experience as a statistical consultant, teacher, and researcher specializing in energy and earth science applications.

Dr. Schuenemeyer is Professor Emeritus of Statistics, Geography, and Geology at the University of Delaware. He holds a PhD in Statistics from the University of Georgia and degrees in Applied Mathematics from the University of Colorado.

He is an elected fellow of the American Statistical Association . He is a recipient of the International Association of Mathematical Geoscientists (IAMG) Griffith’s Award for outstanding teaching. He is IAMG’s 2011-2012 Distinguished Lecturer.

He is currently a member of the American Association of Petroleum Geologists, Committee on Resource Evaluation, and is a member of the American Statistical Association Committee on Energy Statistics.

He has published over 100 research papers and is the coauthor of a recently published book, Statistics for Earth and Environmental Scientists.

Ellison Miles Geotechnology Institute Brookhaven College

3939 Valley View Lane

Farmers Branch, Texas 75244

13th Annual Crawfish Boil -- Oil & Gas Industry Event on 12-Apr-12 5:30 PM

Thu, 12 Apr 2012 22:30:00 GMT

13th Annual Crawfish Boil -- Oil & Gas Industry Event
Start Date: 12-Apr-12 5:30 PM
End Time: 12-Apr-12 11:00 PM
Location: Winfrey Point White Rock Lake, Dallas, TX
Event Details:

Crawfish, Catfish, Beverages, Conversation,
Music, and more Crawfish

Come out and visit with the Dallas Oil Community at Winfrey Point on White Rock Lake.

Sponsored by the Dallas Chapters of SIPES, the Dallas Geological and Geophysical Societies, the Dallas Association of Professional Landmen, SPE - Dallas and the Texas Energy Council

Pre-register online at http://www.dgs.org/en/cev/142
Payment by Credit Card is required for Advanced Registration.

If you are not a Dallas Geological Society member, you will need to create a login id to the DGS website to pre-register and pay.

To pay by mail, send a check made out to:
   Crawfish
   c/o Dallas Geological Society,
   4925 Greenville Ave., Suite 600,
   Dallas, TX 75206

Winfrey Point White Rock Lake

950 East Lawther

Dallas, TX

DISC | Elements of Seismic Dispersion: A somewhat practical guide to frequency-dependent phenomena on 17-Apr-12 8:30 AM

Tue, 17 Apr 2012 13:30:00 GMT

DISC | Elements of Seismic Dispersion: A somewhat practical guide to frequency-dependent phenomena
Start Date: 17-Apr-12 8:30 AM
End Time: 17-Apr-12 5:00 PM
Location: Ellison Miles Geotechnology Institute Brookhaven College, Farmers Branch, Texas 75244
Speaker: Christopher L. Liner

Event Details:

The Dallas Geophysical Society

is hosting the

2012 SEG

Distinguished Instructor Short Course (DISC)

Elements of Seismic Dispersion: A somewhat practical guide to frequency-dependent phenomena

Christopher L. Liner, University of Houston

Overview

The classical meaning of the word dispersion is frequency-dependent velocity. Here we take a more general definition that includes not just wave speed but also interference, attenuation, anisotropy, reflection characteristics, and other aspects of seismic waves that show frequency dependence. At first impression, the topic seems self-evident: Of course everything is frequency dependent. Much of classical seismology and wave theory is nondispersive: the theory of P- and S-waves, Rayleigh waves in a half-space, geometric spreading, reflection and transmission coefficients, head waves, and so forth. Yet when we look at real data, strong dispersion abounds. This course is a survey of selected frequency-dependent phenomena that routinely are encountered in reflection-seismic data.

1) Time and frequency

The Fourier transform (FT) is a standard frequency-analysis tool, but it yields little information about combined time-frequency content. We will review the FT and its extension to short-time FT and continuous wavelet transform as representative examples of a broad class of timefrequency decomposition methods.

2) Vibroseis harmonics

The vibroseis source injects a long, slowly varying signal into the earth. We commonly find that new frequencies, or harmonics, that are not present in the sweep are present in the earth response. This interesting phenomenon is discussed in relation to a more familiar process, that of human hearing. Those harmonics are illustrative of a general property of nonlinear waves and interaction.

3) Near surface

Velocity dispersion generally is considered not to be an issue in seismic data processing. This is nearly true for seismic body waves (P-, S-, and mode-converted) that propagate in the deep subsurface. In the near surface, however, velocities often show strong dispersion, and the description is considerably inaccurate. This is especially the case in marine shooting over shallow water where, even in the 10- to 100-Hz band, velocities are observed well above and below the speed of sound in water. This paradox arises because shallow water over an elastic earth forms a waveguide whose characteristics we will examine.

4) Anisotropy

In this section, we consider seismic-velocity anisotropy and how it depends on frequency. We will restrict our comments here to velocity variation with respect to the vertical axis (VTI) in a horizontally layered earth. Of the sedimentary rock types, only shale is seen to be significantly anisotropic at the core, or intrinsic, scale. The question is how to calculate apparent anisotropic parameters of a layered medium as seen by very long waves. Backus (1962) solved this problem, and his method can be applied to standard full-wave sonic data. So where does dispersion come into all this? It is buried in the thorny question of the Backus averaging length.

5) Attenuation

The distinction between intrinsic and apparent frequency-dependent seismic properties is nowhere greater than in attenuation. Constant Q and viscous theories of intrinsic attenuation are developed and compared with experimental intrinsic scattering-attenuation data. Intrinsic attenuation is found to be compatible only with the viscous theory, while constant Q yields a better explanation of scattering attenuation caused by layering.

6) Interference

The preceding sections have explored frequency-dependent phenomena related to acquisition and wave propagation, effects that would be seen and dealt with on prestack data. Data processing will remove or correct for those effects and will be unseen by the interpreter. However, dispersion effects (in our broad meaning) remain in the realm of final imaged data. First and foremost is the fundamental, unavoidable phenomenon of interference. We will discuss selected topics in this broad field, including the thin bed, bandwidth effect on reflectivity, single-frequency isolation, and reflection from a vertical transition zone.

7) Biot reflection

Many of the dispersion effects discussed previously contain information about the subsurface, but none as direct and important as the problem of reflectivity

dispersion resulting from a poroelastic contact in the earth. We will review the nature of body waves in porous media and the characteristics of Biot reflection

from an isolated interface and will end with an introduction to Biot reflections in layered porous media.

Learning goals

• gain a broad understanding of dispersive phenomena and related investigation tools

• understand the fundamental difference between intrinsic and apparent dispersion phenomena

• improve knowledge of the reflection process beyond the classic model

• provide an appreciation of historical development and a deep guide to the literature for self-study

Who should attend

The course is framed along the lines of acquisition, processing, and interpretation to contain material of interest to the entire spectrum of seismic geophysicists. The mathematical level of the course is generally on the advanced undergraduate level, but deeper aspects often are included for advanced readers. Familiarity with the Fourier transform and related topics will be beneficial. In all cases, theoretical developments are illustrated by examples or case histories.

Ellison Miles Geotechnology Institute Brookhaven College

3939 Valley View Lane

Farmers Branch, Texas 75244

DGeophS Luncheon on 26-Apr-12 11:30 AM

Thu, 26 Apr 2012 16:30:00 GMT

DGeophS Luncheon
Start Date: 26-Apr-12 11:30 AM
End Time: 26-Apr-12 1:00 PM
Location: Ellison Miles Geotechnology Institute Brookhaven College, Farmers Branch, Texas 75244
Speaker: Sam Gray

Event Details:

2012 Spring Distinguished Lecturer

A Brief History of Depth...and Time
Seismic Imaging

Presented by Samuel Gray

CGG Veritas, Calgary, Canada

From the 1920s to the present, seismic imaging (“migration”) has helped the oil and gas industry locate hydrocarbon traps inside the Earth. Migration has evolved and improved over the years, and it is now used routinely for structural imaging, seismic velocity estimation, and amplitude analysis, among other applications. It is applied to narrow- and wide-azimuth towed-streamer marine data, to marine data with multicomponent sensors placed on the sea floor, to land data from desert and mountainous areas, to data acquired in transition zones, to sparsely and densely acquired data, and even to blended data. Migration is applied in many different kinds of settings, and it comes in many different shapes and sizes.

Was migration in the 1920s anything like migration today? Perhaps surprisingly, the answer is yes. Even the most advanced current methods are based on principles that drove early innovators to exploit the nature of recorded seismic wavefields in mapping subsurface reflectors – sound waves bouncing off reflectors and sending localized packets of wiggle energy back toward recording devices. Of course, the details changed as, first, specialized machines replaced pencil and paper and, later, the digital revolution replaced analog devices and allowed the modeling of wavefields inside the computer. Some methods fell by the wayside and others emerged as computers became more powerful and allowed us to migrate more and more wiggles on more and more traces.

Is migration finished, or even mature? Mature, yes, but by no means finished. We now often apply a complete two-way wave equation when migrating seismic data, but the wave equation we use is almost always an acoustic one applied to waves propagating in an elastic Earth. This itself is a big approximation, and it affects our ability to estimate velocity and analyze amplitudes. Sometimes migration does not use a complete acoustic equation – the equation might not admit two-way propagation, or it might use an approximate ray-based solution. In fact, depending on the seismic acquisition, migrated images using an “incomplete” wave equation are often preferable to more theoretically correct images. So there is still a lot of work to do, both in improving the fidelity of our high-end methods and in refining our lower-end methods to accommodate less-than-ideal acquisition.

Ellison Miles Geotechnology Institute Brookhaven College

3939 Valley View Lane

Farmers Branch, Texas 75244

Annual Awards DGeophS Luncheon on 10-May-12 11:30 AM

Thu, 10 May 2012 16:30:00 GMT

Annual Awards DGeophS Luncheon
Start Date: 10-May-12 11:30 AM
End Time: 10-May-12 1:00 PM
Location: Ellison Miles Geotechnology Institute Brookhaven College, Farmers Branch, Texas 75244
Speaker: Bob Hardage (click here for biography)

Event Details:

Bob A. Hardage
SEG President for 2011 - 2012

(The topic for our luncheon has not yet been determined.)

Ellison Miles Geotechnology Institute Brookhaven College

3939 Valley View Lane

Farmers Branch, Texas 75244

2012 SWS AAPG, Ft. Worth on 19-May-12 8:30 AM

Sat, 19 May 2012 13:30:00 GMT

2012 SWS AAPG, Ft. Worth
Start Date: 19-May-12 8:30 AM
End Time: 22-May-12 5:30 AM
Event Details:

For details, see http://www.swsaapg2012fortworth.org/

A call for Papers and Posters is on the attachment below.