Conductivity, a material's ability to carry an electrical current, is one of the most useful measurements of core samples. The conductivity of a geological formation depends on the direction of measurement, so it's considered "anisotropic."
"Anisotropy is usually the result of many thin layers of oil-bearing sandstone rocks sandwiched between thin shale layers, which form a laminate structure that may be tens to thousands of feet thick and contain a large amount of oil," explains John Kickhofel, a research scientist. In anisotropic layers of the Earth, the conductivity in one direction is different from that of others.
Tools to measure a core sample's electrical anisotropy have been sadly lacking, says Kickhofel. To solve this problem, he and colleagues at the company Schlumberger found inspiration in a type of logging technology currently used by the modern oil industry. They created a device capable of noninvasively measuring electrical conductivity -- a device they describe in the journal Review of Scientific Instruments, which is published by the American Institute of Physics.
"We designed a probe that uses a core from the formations and measures its electrical anisotropy without destroying the core," Kickhofel says. "This device can make continuous measurements on cores that are hundreds or thousands of feet long."
Cores are valuable because they provide firsthand information about the structure and nature of rock layers and need to be preserved for future reference. "It's very important to preserve the cores, and the new device provides a way to do this. We can't overstate the value of such a measurement to the oil industry in an era when most fields are in decline -- yet the world's demand for oil and gas continues to skyrocket," adds Kickhofel.
The article "Inductive conductivity tensor measurement for flowline or material samples" by John L. Kickhofel, Amine Mohamide, Jonatan Jalfin, Joshua Gibson, Philip Thomas, Gerald Minerbo, Hanming Wang, and Dean M. Homan was published online in the journal Review of Scientific Instruments on July 2, 2010. See: http://link.aip.org/link/RSINAK/v81/i7/p075102/s1
Journalists may request a free PDF of this article by contacting email@example.com
NOTE: An image is available for journalists. Please contact firstname.lastname@example.org
Image caption: The directionality of the coil-generated magnetic fields is shown, along with the induced currents (influenced by the directional conductivity) when the transmitter coils for measuring the axial Z-directional conductivity (middle) and for measuring the X- and Y-directional conductivity (right) are energized.ABOUT REVIEW OF SCIENTIFIC INSTRUMENTS
Jason Socrates Bardi | Newswise Science News
In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy