Zooming in to Characterize Shale
“Do you know what your shale looks like?” asked Dirk van der Wal, Director Marketing, Natural Resources Business Unit at FEI at the CEE Unconventional & Shale Gas Development Forum in Budapest, Hungary.
“We supply to a number of industries: material science, life sciences and more recently natural resources companies,” he stated of FEI.
Further, Dr. van der Wal said FEI was a US-based public company with a respectable footprint in Europe. “We have the largest development and manufacturing site in Eindhoven, in the Netherlands.”
Regarding shale characterization, he said, “We must take characterizations of the core and cuttings samples very seriously if 4,000 test wells were drilled in Europe. There’s not much to see other than it’s black and extremely fine grained.”
“Whereas optically, on the scale of centimeters, millimeters, sometimes even micrometers, shale tends to be very homogenous – really quite boring,” offered Dr. van der Wal. “It’s at the micron scale, in some cases the sub micron scale, where an immensely exciting world of textures, lithologies, grain sizes, organic matter being porous or not porous is revealed. The big question mark is ‘how do we develop solutions to discover consistency in the observations?’ that we can translate into techniques that can be used in the field to characterize shale plays?”
FEI likely had a few tricks up its sleeve. Van der Wal explained that it was a leading scientific instrumentation company featuring mostly electron and Focused Ion Beam microscopes as well as instrumentation for nano scale applications.
“We’ve developed a technology for SEM referred to as ‘Maps’ that is quite unique in the sense that it covers the length scales all the way from significantly below 1 micrometer all the way up to let’s say a core plug of centimeters.”
He said put that challenge into perspective he would make an analogy with Google Maps. “I’m sure you’ve all used Google Maps,” he remarked. “What’s so special about it is that you can zoom in and zoom in and zoom in, almost without limits and end up seeing your car in your driveway. It’s like an endless ability to zoom in on a satellite image.”
Dr. van der Wal presented a map of the northeast of the US where he said most of the shale plays were. “We’re talking about the scale here of several hundreds of kilometers. And here we’re zooming in on a well pad under construction.
“This is only 3-4 orders of magnitude we’re covering here. We’re zooming in from the scale of hundreds of kilometers to let’s say 100 meters. To go from a core plug down to the scale of 10 nanometers, you have to cover two more length scales. So that is really the microscopy challenge, the characterization challenge that we have to deal with,” he said.
While a lot of shale characterization was taking place in the lab, he said that a big trend was to take advanced analytical equipment from the lab to the field, which was even happening with electron microscopy-based characterization solutions.
He showed a photograph of a device that looked a bit like a refrigerator, which he said had been field tested in Papua New Guinea, working with Halliburton, to characterize a well based on cutting samples collected every 10 feet.
“This resulted in a log of 702 samples. From the cuttings we’ve measured things like grain size, lithology, clay type, any property you can think of that you can derive from optical inspection of cutting samples,” said van der Wal, adding that the unit had also been tested in adverse conditions.
He reported that FEI was also working with Geolog International in Europe.
“The ultimate detail,” he added, “is obviously obtained from core samples in the lab, where you can deploy the highest resolution, most sophisticated analytical tools that you can’t deploy to the field. Derivatives of these technologies to be used at the well site, the data to go into logs and the data in the logs and in particular the comparison of log data with, for example, wireline data goes back to the lab to further understand the significance of the sub micron features that will result in new and improved measurements in the field, improving log data.”