Advanced geophysical instrumentation for Airborne Geophysics

By Pico Envirotec

Pico Envirotec Inc. (PEI) is an industry-recognized leader in the research, development, manufacture and integration of airborne geophysical systems and is uniquely positioned to accomplish meaningful improvements in this survey technology.

Oil and gas are precious resources and becoming scarcer every day, and much as we may want to, we cannot do without them, as they are seamlessly integrated in to the fabric of daily life. Demand for these resources increases daily, but supply is limited because these resources have become scarce and the focus now is more and more towards finding oil, gas and minerals in places where once it was thought too difficult to explore.

Exploration is the first step in the whole value chain to bring natural resources to market. New exploration technologies are being regularly developed and exploration methods are constantly evolving, both seismic and non-seismic. Airborne geophysics is a non-seismic survey technology aptly positioned to serve exploration needs. The technology benefits of airborne geophysics are enhanced by its cost effectiveness, and the rapid areal coverage it permits, particularly in areas of rugged terrain and/or heavy jungle cover, where access difficulties and topography make the cost of seismics extremely high.

Airborne Geophysical Surveys
As far back as 1920, gravity and magnetic surveys were the first geophysical methods applied to hydrocarbon exploration. The use of seismic sounding techniques began in the 1930s. Over the years and particularly because of the advent of digital technology and data processing, seismic tools have became more and more powerful, resulting in the three-dimensional presentations of today which dominate petroleum exploration budgets. Historically the non-seismic methods were used mainly in broad reconnaissance surveys to help identify prospective basins and areas within those basins where seismic studies costing many times more might be justified. This notwithstanding, gravity and magnetic techniques and applications have also been enhanced greatly through use of modern technology including more accurate data recording devices, far superior systems for positioning using GPS, and much more robust processing routines with greatly increased resolving power.

A major objective of an airborne geophysical survey is to gain a greater understanding of regional geology in order to economically limit very expensive 3D seismic surveys to the most prospective areas of an oil concession. It may be said that, statistically, 80% of the anomalies located by an airborne geophysical survey over an oil & gas concession will occur in 20% of the concession. It is that 20% “zone” that is being sought, and this is where the 3D seismic survey should be focused. Airborne geophysical surveys will never replace the need for seismic information, but without a doubt, they do greatly aid in cost effectively placing seismic surveys – a critical issue in any broad-scale exploration plan.

Airborne geophysical surveying for hydrocarbon and minerals exploration may be conducted using either fixed-wing airplanes or helicopters, on shore or offshore. The choice of aircraft depends largely on project size, location, budget and application. A fixed-wing airplane has a number of advantages over a helicopter, in addition to its lower operating costs. First, it has a payload and cabin space larger than a helicopter and thus can carry more instrumentation. Second, its operating range is generally three or four times greater than that of a helicopter. Surveys can be flown farther from population centres, thereby reducing some of the logistical problems of a helicopter-borne survey.

The challenge is to continue improving survey resolution to the point that exploration benefits compel wider use of airborne geophysical surveys.

About Pico Envirotec Inc.
Pico Envirotec Inc. is a Canadian company that was established in 1992. Since 1998 it has been engaged primarily in manufacturing advanced instrumentation for use in airborne and ground geophysical surveys for mining, oil and gas and environmental applications. Its core expertise is the development and manufacture of instrumentation that remotely measures magnetic, gravity and gammaray radiation data, using real-time data acquisition and precise satellite (GPS) navigation and positioning. Because of PEI’s close co-operation with other geophysical companies, it provides complete, integrated, turnkey airborne or ground geophysical systems for acquiring geophysical data for mining, oil and gas or environmental applications. This is made possible by its development of “intelligent” instruments, using advanced PC104 technology, which facilitates easy and safe integration of just about any sensor or measuring device into a system. The AGIS (Airborne Geophysical Information System for airborne geophysical exploration) and IRIS (Integrated Radiation Information System for environmental monitoring), are PEI’s most successful systems based on this “intelligent” philosophy.

During the sixteen years PEI has been in business, it has installed more than 100 airborne systems on a wide variety of aircraft and helicopters, for clients that include mining companies, exploration services companies, and government agencies. Airborne systems designed, built, integrated and installed by PEI are flying in many countries around the world, including Canada, USA, UK, Austria, Australia, Brazil, China, Czech Republic, Germany, South Africa, India, Brazil, France, Sweden, Finland, Italy, Egypt, Mexico, Libya, Russia, and Norway. These airborne survey systems include sensors for making measurements of magnetics and magnetic gradients, gammaray spectrometry, time-domain electromagnetics and gravity.

Without a doubt, airborne geophysics is a superlative, and relatively inexpensive, tool for use in oil, gas and minerals exploration. Pico Envirotec is a world leader in the provision of the airborne systems used for such exploration. We leave you with some words by F.R. Haeberle (Reservoir Properties in Petroleum Exploration):

”We have for years looked for traps with seismics, and it has not done everything it was supposed to. We've got a lot of fields that didn't produce much oil, and we've got a lot of areas that didn't produce any oil. So if we look at some of the other things involved in an area besides the seismic, we might have a lot better chance of getting what we're looking for, which is oil that we can make money on.”