Blending in: GGS is using more than 28,000 high definition nodes to efficiently record the Permian Basin subsurface.Photos courtesy of Global Geophysical Services
Plays are hot.
Then they’re not.
Often, all it takes to jumpstart them once again is some new technology along with a passel of geoscience smarts – and favorable commodity prices.
The hydrocarbon-rich Permian Basin in West Texas and New Mexico is a sterling example of boom, bust and then boom again.
There’s much ado about horizontal drilling, hydraulic fracturing, and other new techniques triggering the U.S. shale drilling frenzy, improving production in mature fields, and more.
Truth be told, seismic technology often plays a significant role, perhaps deserving a more prominent position in the spotlight.
Certainly, the Permian Basin, with its intense rejuvenation activity, is one of many regions in a position to benefit from advanced seismic technology.
Its basically rugged, inhospitable terrain ranges from flat to sometimes nearly vertical, and it is populated by any number of cable-gnawing creatures, both large and small. It’s not the ideal environment for ordinary seismic data acquisition systems strung together by heavy high-maintenance cables, which are infamous for troubleshooting issues, and other problems.
Here, as in many areas around the world, the data gatherers and their oil company clients are taking steps to transition to the newest land systems technology generally known as nodes.
Whether dubbed cableless, wireless, cable-free or whatever, these systems include FairfieldNodal’s ZLand® system and its transition zone shallow water counterpart Z700, INOVA HAWK® , Sercel UNITE, OYO GSR, among others.
As one would expect from any arena where companies are battling for exploration advantages, the technology competition continues to escalate.
A New Kid in Town
The newest arrival in the autonomous land node systems milieu is Global Geophysical Services’ (GGS) Autoseis® High Definition Recorder (HDR) developed by its wholly owned subsidiary Autoseis Inc.
GGS crew members download nodal data for its Permian operations.
The HDR has been used successfully since early 2011 in varying environments and far flung geographic locales, including the Amazon and the Arctic. Its first commercial program commenced in July 2011. A marine version is scheduled to make a commercial debut soon.
“The simple, totally scalable Autoseis HDR has no interconnecting cables and no complex radio links to or between the nodes,” said Tom Fleure, VP of geophysical technology at GGS. “And it’s the only system on the market today that records double precision, true 32-bit seismic data.
“We have deployed more than 100,000 HDR-1C units, principally in heavily wooded areas, jungles, swamp environments or mountainous areas,” Fleure said. “These are locales where terrain, weather and other elements of nature typically challenge the large equipment and crews ordinarily needed to acquire high-quality seismic data.
“In our first year using Autoseis HDR units, we increased our average production rate by 2.3 times over our cable systems, with projects repeatedly coming in under budget,” Fleure added.
This powerful node looks deceptively simple with a lightweight plastic case measuring approximately 2.5 by 3.5 by 0.5 inches. Pop open the case, and the see-through inner pack with the brains tells you this is far-out technology.
A couple of rubberized links, attached to the outer case, terminate in small tube-like gizmos. These are the connectors for the battery and for the receiver group, ordinarily a geophone string.
Each receiver station is attached to a station stake, where they remain unattended until recording is complete. Each HDR provides an independent GPS measurement of its location during recording, which can be used to verify its actual placement.
Near and far trace offsets are easily manipulated, given that channels can be added or subtracted without changing anything in the field if the receivers are deployed.
Once the data are collected, the nodes are retrieved and taken to a specially equipped field trailer. There, the data are downloaded and the batteries recharged prior to redeployment.
With 12-hour/day recording, battery life is 40 days vs. 20 days for 24-hour/day recording.
In line with other available nodal, or wireless systems, Autoseis provides:
- Flexible acquisition geometries.
- Reduced downtime and maintenance.
- Increased productivity.
- Improved health, safety and environmental (HSE) conditions.
- Enhanced access to challenging locales.
Without the potential for cumbersome cables strung out here, there and everywhere, permitting tends to become a bit less trying (read: less expensive and less time-consuming).
Plus, landowners tend to be a happier lot, for the most part.
Handling Complex Geology
Given that the Permian Basin is such a hot spot and has so much potential for the future, GGS zeroed in on the opportunity to work a multi-client survey using Autoseis. The project’s focus is the Ozona Arch, specifically Reagan, Crockett and Upton counties in the southern reach of the Midland Basin.
Dubbed the University Lands Project, phase 1 of the high resolution RG3D® Reservoir Grade 3-D survey will cover 355 square miles, which harbor a number of different target horizons.
The likely completion date was expected to be late October; kickoff times for phases 2 and 3 will depend on underwriting availability.
The Ozona Arch exhibits a variety of terrain types, with some areas being excessively steep. To avoid having the vibrator source trucks constantly navigating such difficult areas and to eliminate excessive driving time, some fleets are positioned at the high elevations while others are bottom dwellers, so to speak.
The receiver stations for the survey are laid out in lines, although the flexibility of the system allows for any surface geometry configuration. The stations are positioned 55 feet apart.
“We have six fleets in the Permian with two vibrators for each fleet and are using offset separated source fleets and slip sweep vibroseis technology to optimize crew productivity,” said AAPG member Duncan Riley, GGS’ VP-North America. “We have 120 crew members managing 28,000 channels, or nodes.
“In combination, this receiver and source effort results in really phenomenal sampling and imaging of the complex geology,” Riley noted.
“Compared to conventional 3-D surveys, which have a typical trace density of 350- to 450 thousand traces per square mile, the University Lands program boasts a trace density in excess of 4.3 million traces per square mile,” he emphasized.
In step with a general trend in the industry to go nodal, the company is in the process of converting all of its land crews to Autoseis technology. A 3C version to record both P wave and shear wave data is nearly ready to be launched.
As the name Global suggests, president and CEO Richard Degner thinks big.
Degner, an AAPG member, envisions implementing complete, contiguous seismic coverage over the heart of the Permian Basin, i.e. Midland and Delaware basins and Central Basin Platform, versus the “postage stamp” approach of numerous yet discontinuous seismic surveys, which are the norm here and other places.
“I think,” Degner said, undaunted by the prospect of such a challenge, “it could be done in maybe five years or so.”