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With the oil and gas industry’s steadfast focus on the safety, reliability and cost effectiveness of new technology, in terms of the size of equipment, it seems that the phrase “quality over quantity” is a commonly embraced mantra. From the seismic industry’s roots in complex networks of miles-long wires and cables, to its metamorphosis into fiber optics and cableless systems, the geophysical world is finding new ways to downsize its hardware and ramp up the power—and capabilities—of its software.
The advancements in modern seismic-acquisition technologies are a far cry from the techniques of the 1970s, where 2D multi-channel acquisition systems had hundreds of wires and conductor cables. As the number of geophones and channels expanded, so did the complexity and durability of cables. The introduction of fiber optics opened up a whole new world of data recording and transmission, and eventually led to the development of cableless systems, setting the idea of “less is more” in motion. The growing number of channels, the shear size of surveys, and expansion of exploration into rugged, remote and challenging environments, however, has made finding a cable-free solution to seismic acquisition less of a luxury and more of a requisite.
Just as, over the course of several decades, the cellular telephone evolved and overtook the traditional hardwire rotary phone, simple forms of cableless systems have been evolving over several decades, with the first comprehensive system introduced by ION Geophysical’s INOVA (at the time known as Input/Output). The technology contained six channels, and data, recorded on a disk drive, was collected manually by a data collection unit. Both OpSeis Eagle and Fairfield BOX also offered limit-channel system, which also had a very limited range of bandwith. While these systems have become vastly more complex and to offer, clearer, continuous acquisition with internal memory, cableless systems remain a small part of the acquisition market.
Just recently, cableless seismic acquisition systems have advanced into a new phase: real-time data collection for high-volume channel surveys. While real-time, full-record wireless systems were initially pioneered in the mid-1990s by VibTech Inc., the technology required a lot of infrastructure to accommodate the cell-communicated units throughout the survey site. Sercel purchased the first-generation real-time wireless system 10 years later, renamed it UNITE, and continued to develop the technology’s hardware. ION, at the time, also developed its patented system, FireFly, which communicated via a VHF radio to a central recorder.
One of the biggest focal points in advancing these cableless systems has been to eliminate the technology’s greatest challenge: remote power generation. Unlike traditional cable-based systems, which utilize wired connectivity to power recorders and field units, cableless systems must be able to operate autonomously for extended periods of time. While the last year has seen a significant step-change in cableless real-time systems, unique engineering prowess has led to some of the technology’s biggest breakthroughs in power generation, including the application of lithium-ion-powered battery sources.
In 2012, International Seismic Corp. (iSeis) and SRD Innovations unveiled a new patented system, hyMesh-Sigma, which is able to collect 2D and 3D real-time seismic survey data through a series of nodes, relays and aggregators housed in wireless units. The system’s recorder, which is powered by 12-volt batteries, modifies the recording program live for data on 10,000-plus channel surveys and offer immediate access to quality control information. Optional solar panel chargers are available, adding additional power to the field units.
Wireless Seismic Inc.’s RT System 2, an upgrade of the company’s RT 1000 system launched in 2010, also scales to 10,000-plus channels and offers advanced data visibility and security, as well as efficient radio systems that address the restrictions of quality control, collection and processing. The fully scalable recording system uses the latest available semiconductors and patented self-test circuitry to deliver data in a common-source format. Because the units’ radios communicate across one group interval, moderate battery power is sufficient to multiple channels.
Sercel recently released its newly updated UNITE system, which is available in two different telemetry modes: real time and autonomous, as well as two different versions: analog and digital. In combination with Sercel’s Micro Electro Mechanical System (MEMS) sensor technology, UNITE is able to harvest data during production via a broad bandwith, creating a clearer, more in-depth imaging. An extended-power internal battery provides two weeks of independent operation.
ION’s FireFly system has also seen a number of upgrades in its latest release, DR31. The technology offers high-efficiency field station battery power, stakeless surveying and first-break signal-to-noise ratio, and trace decay attributes.
In part owing to the large investments made in cable-based data-acquisition systems, it appears that it will be a while before cableless, real-time technology becomes the linchpin of seismic. Advances in remote power sourcing and safer, more cost-effective cableless infrastructures, however, are driving cableless systems to gain momentum in the marketplace and eliciting serious consideration from geophysical operators.
Who knows? The day when cabled seismic equipment is displayed side by side with antique rotary phones at your local museum of science may be closer than you think. 
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