Introduction To April Focus: Engineering Geophysics

In this issue of the RECORDER, our focus topic is Engineering Geophysics. The methods of geophysical prospecting can be utilized in a variety of engineering applications, providing valuable information to improve the safety and reduce the costs of projects. These applications cover a wide range of environmental, mining, civil, geotechnical, and petroleum engineering endeavours.

Our first focus article, by McClymont et al., provides a nice introduction to the field of engineering geophysics and discusses some real projects which use geophysical prospecting methods in geotechnical and environmental applications. These projects cover topics such as methods for geotechnical analysis of construction sites, geophysical surveys for trenchless pipeline water crossing, and geophysical prospecting methods for detection of buried infrastructures.

Induced seismicity is an emerging topic which combines geophysical methods and engineering applications in a novel way. The second article of this issue, by Eaton et al., provides a glossary of terms and definitions that have been adopted in fluid-injection induced seismicity. This article aims to promote the use of standard definitions to reduce the confusion that might otherwise arise. They also introduce a modified scheme for a magnitude-based classification of seismic activities to unify the definitions used in micro-seismic and in global seismology.

In the third article, Boroumand and Maghsoudi provide an overview of current challenges in induced seismicity related to hydraulic fracturing. Their article provides a useful background of various man-made activities that can lead to induced seismic events. This article provides some statistics about the frequency and magnitude of induced seismic events caused by hydraulic fracturing in some of the major basins. Their article summarizes the latest efforts by the energy industry to address the environmental and operational concerns related to induced seismicity.

The last article, by Virues et al., shows how geophysicists and engineers utilize micro-seismic (MS) field data to constrain reservoir models. These geophysical data are used in risk analysis techniques to quantify the impact of uncertainties on reservoir simulation outputs. This article shows how integration of geophysics and engineering could lead to constraints on analytical models for numerical simulation, estimation of production forecasts, and reserves categorization. They also provide some design considerations for multi-well pads and for surveillance data acquisition, such as production logs and chemical and radioactive tracers.