HOUSTON -- Successfully finding and extracting hydrocarbons is becoming more challenging in some parts of the world, and devising new technology will become even more crucial in meeting the growing global energy demand.
Australia is no exception.
“One of the really big challenges in supply is both in finding and delineating what reserves we actually got, then working on how we are going to get them out of the ground,” Volker Hirsinger, managing director of Petrosys Pty. Ltd., said while moderating the technology panel Jan. 30 during the Australian American Chamber of Commerce’s energy conference in Houston. “In our industry we utilize a huge variety of technology, and we keep having to invent more of it because it is getting harder and harder to get more out of the ground.”
From technology created to get better seismic data to new methods to characterize rock from cuttings during the drilling process, experts recently shared some of the latest techniques being used in the industry. Some of these new technologies are not only improving processes but saving companies millions of dollars.
Developed on Australia’s North West Shelf, an infill management technique called Fresnel Zone binning allows streamers to be fanned out to cover a wider area when shooting seismic and eliminates the need to have more distant streamers as close together. The Apache Corp.-created marine acquisition technique aims to reduce infill.
Mike Bahorich, executive vice president and chief technology officer for Apache (NYSE: APA), compared the seismic problem previously experienced to cutting grass and leaving some behind. “We had the same problem with seismic. We call that infill,” Bahorich said. But Fresnel Zone binning includes only lines that are needed to process certain seismic data. “That is important because it ends up saving you a tremendous amount of money.”
The technology is being used in about half of the boats around the world for a savings of about US$250 million annually, Bahorich said.
CGG (NYSE: CGG), which has a license to use the technology on its 3-D vessels, said analysis using Fresnel Zone binning is instrumental in designing high-resolution surveys for shallow targets. Conventional binning parameters usually don’t account for the zone being smaller than the bin dimension, which results in suboptimal illumination, CGG said on its website. The company also said infill is often reduced by a factor of two or more.
Another technology includes high-resolution subsurface imaging. A problem faced in gathering seismic data is reflections from the sea surface, which cause a notch in the frequency spectrum. This means “we don’t have as broad information and figures as we like,” said Simon Bittleston, vice president of research for Schlumberger Ltd. (NYSE: SLB). Another problem encountered is poor sampling in the crossline due to the spacing of streamers – every 100 meters (328 ft.).
With the IsoMetrix marine seismic technology introduced by WesternGeco, a division of Schlumberger, pressure sensors are added in the cable’s particle velocity sensors. This allows upgoing waves to be distinguished from downgoing waves with streamers, eliminating the ghost notch, for a broad-frequency spectrum. “More importantly than that, we’ve got information in three directions about the particle velocities, and we can start to reconstruct in the crossline direction the full wavefield,” Bittleston added.
The technology, suitable for deep reservoir characterization and 4-D reservoir monitoring, enables subsurface structures to be detected vertically, inline, and crossline between the streamers, yielding more detailed seabed-to-reservoir imaging. It also allows “accurate reconstruction of the full 3-D wavefield between the streamers, isometrically sampled at a 6.25-meter by 6.25-meter [20.5-ft. by 20.5-ft.] point-receiver surface grid of data,” according to WesternGeco. “This fine sampling makes the data suitable for use in a wide range of interpretation and modeling applications, including high-resolution near-surface imaging, deep reservoir characterization, and 4-D (time-lapse) reservoir monitoring.”
Other technologies aim to better characterize reservoirs and the total organic carbon in a piece of rock – reflective infrared FT spectroscopy. “It’s done basically by shining a light, an infrared source; you make a reflection of it. You grind up the sample to a certain composition. You can get a bunch of multiple reflections. You then regather them through another reflection and a detector,” Bittleston said. “All of this is quite well known. Interpreting it is a bit harder. It’s quick, robust, and low-cost.”
The technique can be done during the drilling process by taking cuttings, making it ideal for wellsite applications, he said. Each scan takes about 20 seconds, but the perforation takes longer.
Efforts are also being taken on the production side, especially when it comes to reducing the amount of fresh water used during hydraulic fracturing. In the Permian Basin, Apache has a team looking for brine water for fracing. No fresh water is being used in the company’s largest area in West Texas, Bahorich said.
“In the oil and gas industry, for years we started with fresh water, then we added salt to it before we used it,” he said. “Maybe we can start with salty water.”
Bahorich, however, pointed out that different challenges at well sites call for various solutions. While fresh water can be used in some situations for fracing, at other times it can be done with brackish water or with produced water that is then recycled.
In addition, “There are lots of ways you can mix this water. You can add fresh and brackish water, add produced water, maybe even saline water,” he said. “You have different challenges for different situations, so it isn’t a one-size-fits-all.”
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