Geology & Geophysics Editors' Vox

Where and How Can We Find New Sources of Oil and Gas?

The editors of a new book on oil and gas exploration describe developments in methods for identifying oil and gas fields, and for making accurate predictions about their extractive potential.

By and

Oil and gas remain an integral part of today’s world and new reserves are being found, as are methods for extracting them. The editors of a new book, published by the American Geophysical Union in March 2017, answer some questions about developments in the field of oil and gas exploration.

Why is this topic timely and important?

According to BP’s Statistical Review of World Energy, world primary energy consumption grew at an average annual rate of 1.5 percent between 2010 and 2015. and reached 13,147 million tons of oil equivalent in 2015 [BP, 2016]. But world oil consumption is continuing to increase while new oil discoveries decrease. Although there has been increasing adoption of renewable energy sources, gas and oil are still essential to fuel and produce a wide range of human activities and products. Thus, new technologies are necessary to find and access new reserves.

What methods are used to locate new oil and gas deposits?

To locate potential deposits, explorers use a range of techniques to scan the subsurface.Seismic prospecting” is the most widely used geophysical technique in hydrocarbon exploration. It sends artificially created elastic oscillations (seismic waves) though the rock strata which can create a “map” of the structure of deposits. “Well logging” is another commonly used method that consists of making a detailed record of rock and fluid properties to find hydrocarbon zones in the geological formations crossed by a borehole.

“Gravity surveying” measures spatial variations in the Earth’s gravitational field which originated from differences in the density of sub-surface rocks. Oil- or gas-bearing rocks have lower density than similar water-containing rocks thus the task of geoscientists is to find locations with abnormally low gravity. Meanwhile, “magnetic prospecting” measures the Earth’s magnetic field in the different magnetic conductivity of rocks. Airborne magnetic surveying enables the identification of anticlines which are natural geological traps for migrating hydrocarbons at large depths.

Another method is “geochemical prospecting” which is used to look for hydrocarbon deposits. This is based on analyses of the chemical composition of underground water and the content of dissolved gases and organic matters within it. Concentration of these components in water increases as it approaches the deposit.

How can new technologies more accurately estimate the size of new oil and gas deposits?

One new technique is the use of three-component measurements of geoacoustic signals from hydrocarbon deposits which makes it possible to solve a wide spectrum of problems through the control of oil and gas borehole exploration. Another is the combining of mobile technology of frequency resonance and remote sensing data which can be used for the “direct” prospecting and exploration of ore mineral and fossil fuels. Meanwhile, the study of magnetic features of the rock increases the provides the possibility of deep structural forecast. There is also the electromagnetic method with a controlled source that helps to reveal disintegration zones (considered as indicators of massif stability) and to understand the reason for the low productivity of oil recovery from boreholes.

What are some of the practical problems with exploring and mining new oil and gas deposits?

Anomalies in oil and gas deposits caused by various structural geological factors are a persistent issue. While different exploration techniques can enable the identification of such anomalies, the integration of all the available data on anomalies in a particular location can lead to more efficient exploration. Additional methods such as subsurface geologic mapping, drilling, and seismic prospecting are needed to further define whether anomalies are real or false and to accurately establish a realistic geological model.

Oil and Gas Exploration: Methods and Application, 2017, 304 pp., ISBN: 978-1-119-22742-7, list price $129.95 (hardcover)

 —Said Gaci, Sonatrach—Algerian Petroleum Institute, Algeria; email: [email protected]; and Olga Hachay, Institute of Geophysics, Ural Branch of Russian Academy of Sciences, Russian Federation

  • drseismo

    Although I am late to the party, I am compelled to comment. The negative comments from others on this article are the most misinformed, biased and flat wrong knee-jerk reactions I have every read on this website. They must be from the liberal, group-think bots out there.

    Noticeably missing in the AGU book were the insightful words of pioneering petroleum geologist Wallace Pratt in 1952: “Where oil is first found, in the final analysis, is in the minds of men.” Seismic prospecting, gravity and geochemical surveys, well logging, direct detection methods, magnetics, etc., are simply tools. We should pray that hydrocarbon exploration will continue to be successful for decades because oil is still waiting to be found in the minds of today’s geoscientists, or else the grasshoppers out there will freeze fiddling in the dark. The misinformed b*** s*** of 8 out of the 11 commenters is irrelevant.

  • Mark

    I quit AGU precisely because of this kind of stunt. Sadly, even though AGU did not need the additional funds, the Board voted to retain ExxonMobil funding: AGU is no longer a purely scientific professional society.

  • Roger Clifton

    Apart from being a bare-faced lie, it is a knowing crime against the commons to say that “an increase in gas reduces emissions”. For that matter, omitting nuclear from the list of possible replacements is neglect in the same category.

  • Seth Claudepierre

    Man is this an ExxonMobil plant piece or what??

  • GeoffDavies

    The claim repeated by some commenters that we need more fossil fuels underestimates the rapid progress in clean energy, including storage. In spite of political obstruction everywhere, clean energies have consistently outpaced forecasts. Pumped hydro storage, battery storage and the rapidly approaching hydrogen economy will overtake fossil fuels and render such exploration redundant.

    Unfortunately Earth is not waiting. For all we know we may already have crossed critical tipping points, and anyway the damage is rapidly mounting. It is hard to see how the Great Barrier Reef can survive, given several decades’ more warming even if we stop burning fossil fuels tomorrow.

  • Walter Kessinger

    I am assuming that those commenting on this article are fellow AGU members, and I believe that AGU needs to be on the forefront of offering realistic solutions to addressing the challenges the anthropological climate change poses for the next hundred years and more. I am disappointed that so many of the vocal posters here have such a shallow understanding of this topic.

    Energy use will continue to increase with economic growth in the next several decades, and much of that energy use will continue to come from fossil fuels. Particularly with the ongoing growth in fossil fuel energy use in developing economies, it is imperative that we do everything possible to limit the contribution of the worst pollution sources, coal in particular. In that light, electric power generation utilizing natural gas rather than coal is a net win for the environment. “Compared with gas, coal is nearly twice as emissions-intensive on average.” (source: International Energy Agency, https://www.iea.org/media/news/2015/news/151104_webarticle_CO2_FINAL.pdf)

    Even in developed economies, we can rapidly achieve reductions in our carbon footprint by replacing coal generation of electricity with natural gas electrical power generation. This strategy will provide the largest reduction in carbon generation in the immediate and near-term future.

  • Ed Lindgren

    A transition from the existing, fossil-fuel heavy, energy mix to renewable resources will take decades to complete (see Vaclav Smil’s work for an excellent discussion of this reality). Oil and natural gas will continue to supply the bulk of the global energy requirements until the latter half of the 21st century. Wind and solar are a long way from being able to carry the load.

    Continued research into advanced geophysical and geochemical techniques applied to petroleum exploration is to be welcomed.

  • Tracy Kugler

    I am disappointed that the AGU published a book on this topic. As other commenters have noted, this is not an area we should be investing scientific and intellectual resources in. We should be seeking innovations – technological, cultural, political, and economic – to sever our dependence on fossil fuels, not to encourage that dependence. Fossil fuels cannot be part of a viable future for people or the planet.

  • Alex

    Given that existing fossil fuel reserves contain more carbon than can be burned without exceeding the carbon budget that would give a reasonable chance of keeping global warming below 2C above pre-industrial levels, why should ethical geophysical scientists and the AGU in general be working to support increased extraction of oil and gas that will almost certainly make us exceed our 2C carbon budget? Scientists should be working to reduce anthropogenic disruptions to the carbon cycle, not exacerbate them.

  • thedad

    Since we are not yet able to operate without fossil fuels and the reserves are finite, its good that some are looking at the future and that even if we dont pull it out of the ground at least we will know where it is if needed.

  • M​a​r​k S​h​o​r​e

    There is also the increasingly important ethical question of whether we should devote any more intellectual capital and research capacity to this field. I would not now advise any bright young geoscientist to look to oil and gas for a career

  • Glenn Jaecks

    Leave it in the ground. Extracting more, and committing to more fossil fuel use is making the world’s problems worse at an accelerating rate.