Articles

On the extraction of angle dependent wavelets from synthetic shear wave sonic logs

David Cho, Craig Coulombe and Gary F. Margrave

The extraction of angle dependent wavelets requires the use of a shear wave sonic log. However, shear wave measurements are often not acquired in a conventional logging suite and must be estimated to produce a synthetic result. The errors associated with the synthetic shear propagate through to the angle dependent…

McKay Oil Sands 2D Seismic Inversion Case Study

Laurie M. Weston Bellman, Amanda Knowles, and Rozalia Pak

Southern Pacific Resource Corp (STP) acquired 211 km of 2D seismic data in September 2007 and an additional 5.1 km2 of 3D in December 2010. The 2D survey was used as an exploration tool which ultimately led to the McKay Thermal Project. Conventional seismic interpretation has been valuable in defining…

Distributed Acoustic Sensing for Geophysical Measurement, Monitoring and Verification

Barbara Cox

Distributed Acoustic Sensing (DAS) is a rapidly maturing fiber-optic technology with numerous applications in geophysical and in-well monitoring, and is being developed in a partnership between Shell and Optasense. DAS transforms nearly any fiber-optic cable into a distributed array of acoustic sensors. Recording data requires a special “Interrogator Unit”, which…

Seismically Driven Characterization of Unconventional Shale Plays

Ahmed Ouenes

Unconventional shale plays are changing the energy sector in many ways. At the macro-economic level, shale plays are becoming a geopolitical game-changer with profound consequences for communities, energy companies, local and regional economies, and our planet. At the financial level, billions of dollars are invested each year in acquiring and…

Do you know what you think you know?

Matt Hall

Long-time US Secretary of Defense Donald Rumsfeld once famously said that there are known knowns, and there are known unknowns. And of course there are unknown unknowns: “things we do not know we don’t know” (Rumsfeld, 2002). Perhaps there are unknown knowns too, though I’m not sure how you’d know.

Geophysical Constraints in Geostatistical Modelling

David I. Close

This case study, focused on a Cretaceous aged Mannville Group pool under water flood, illustrates the benefits of utilizing a quantitative and deterministic geomodelling workflow for reservoir characterization. Geophysical, geological and petrophysical data are integrated into a deterministic static model for simulation. The results of the simulation, in conjunction with…

Quantitative Interpretation Part II: Case studies

Lee Hunt, Scott Reynolds, Scott Hadley and Jon Downton

Quantitative interpretation is the numeric estimate of the earth property of interest from geophysical data. We believe that quantitative methods are crucial to our ability to add value in the oil and gas industry. We also believe that the cultural shift necessary to fully employ quantitative methods has already begun.…

Quantitative Interpretation Part I: Method

Lee Hunt

Recent advances in drilling and completions technology, economics, and in our business model have been profound, and are overwhelmingly concerned with a quantitative description of material properties, stress, and azimuthal properties of our reservoir and its bounding materials. Surface seismic data can provide estimates of many of these variables, but…

The future of geophysics in Canada’s oil and gas industry

The role of geophysics within the Calgary-based oil and gas industry is currently in a state of transition. Declining conventional reserves and the emergence of resource plays have created a different set of geotechnical challenges, and the discipline of geophysics within this newly emerging business environment is redefining itself. The…

Rock Physics Facilities and Research in the Experimental Geophysics Group at the University of Alberta

Douglas R. Schmitt

The Experimental Geophysics Group (EGG) carries out a wide variety of field and laboratory studies. These studies focus on understanding what controls the physical properties of rocks and how these relate to geophysical surface observations. Here, we hope to give some overview of the laboratory facilities that EGG has developed…

Azimuthal Fourier Coefficients

Jon Downton, Benjamin Roure and Lee Hunt

Azimuthal AVO analysis can be split into two parts: the Amplitude Versus Offset (AVO) analysis and the Amplitude Versus Azimuth (AVAz) analysis. For regularly sampled data in azimuth, the properties of the Fourier transform allow these problems to be treated separately. If we calculate a Fourier transform of the AVAz…

Practical Seismic Petrophysics: The Effective Use of Log Data for Seismic Analysis

Tad Smith

This study demonstrates empirical relationships derived from microseismic, 3D inversion attributes and 4D seismic to production in unconventional shale in the Horn River Basin. Production variations are explained through the use of the above mentioned tools and a careful investigation of stimulated rock volume. These production variations are shown to…

Investigating anisotropy in rocks by using pulse transmission method

Jaime Meléndez Martínez and Douglas R. Schmitt

Recent interest in unconventional reservoirs motivates our work in laboratory measurements of seismic anisotropy. Seismic anisotropy is the variation in speed of a wave as a function of its direction of propagation. Analyzing anisotropy in unconventional reservoirs is important since anisotropy leads, for example, to differential stresses upon loading and…

Integration of Rate-Transient and Microseismic Analysis for Unconventional Gas Reservoirs: Where Reservoir Engineering Meets Geophysics

Christopher R. Clarkson

Unconventional gas reservoirs, including tight gas, coalbed methane and shale gas reservoirs, have become a significant source of natural gas supply in North America, and are becoming actively explored for, and in some cases exploited, globally. Most recently, liquids-rich (wet gas, gas condensate and light oil) plays have become a…

Guns, Vibes and Channels

R. Malcolm Lansley

This talk will discuss the nature of recent changes in the seismic industry and the benefits that have resulted. Improvements have been made in recording technology and equipment and these have enabled newer and greatly improved methods of recording data. The increased power of computing systems has allowed efficient data…

Hydraulic Fracture Height Growth

Shawn C. Maxwell

Hydraulic fracture stimulations or ‘fracs’ are vital for economic production in low permeability tight gas and shale gas reservoirs, and the frac height is a key factor for engineers to optimize the hydraulic fracture treatment. As unconventional reservoir development has spread through North America and specifically to regions unaccustomed to…

Hydraulic fracturing: Coulomb failure stress in fracture networks

Kris Vasudevan and David W. Eaton

In hydrocarbon-producing sedimentary basins, the crust can be modelled as a poroelastic medium. The stress state of a poroelastic medium, which entails both the shear and normal stress of the rock, is influenced by pore-fluid diffusion. Coulomb stress changes due to pore pressure changes in a poroelastic medium may lead…

An Introduction to Practical Modeling of Reservoir Geomechanics for Appraisal and Development

Vikram Sen and A. (Tony) Settari

The inter-linking or coupling of geosciences with engineering in cross-disciplinary studies has become increasingly popular in recent years. In the context of the Canadian oil and gas industry, this particularly applies to two major areas: (i) hydraulic fracturing based stimulation of unconventional (i.e. tight) reservoirs or shales, and (ii) thermal…

SEG Distinguished Lecture: Imaging the Earth’s near surface: The why and how of applied geophysics for the 21st century

Douglas W. Oldenburg

The top few kilometers of the Earth’s surface are of extreme importance to our society. This near-surface region houses mineral and hydrocarbon wealth that are crucial for industrialized development, water needed for life, and it is an environment with which we must interact to build our infrastructure. To exploit these…

Fault-Plane Solutions from Moment Tensor Inversion for Microseismic Events using Single-Well and Multi-Well Data

Jing Du, Ulrich Zimmer, and Norm Warpinski

Although microseismic monitoring of hydraulic fractures has primarily been concerned with the dimensions, complexity, and growth of the fractures or fracture systems, there is an ever-increasing desire to extract more information about hydraulic fracturing and/or natural fractures from microseismic data. Source-mechanism analysis, which is concerned with deducing details of the…