Over the past few years there’s been copious buzz about new gee-whiz gizmos in the geophysical industry -- recording systems advances, new imaging techniques, etc., etc.
Yet it’s the relatively mundane, “behind-the-scenes” gear that’s essential to get a survey to the point where the more razzle-dazzle equipment and technology can be applied.
This aspect of the business harbors its own kind of cachet, which becomes obvious when you consider some of the innovative approaches being used to modify equipment from other industries for application in the seismic world.
“Rather than use the same cut-and-dried equipment that’s been in the industry for the last 20 to 30 years we’ve gone out and tried to look for equipment in the construction, agriculture and timber industries that would better fit our needs on particular jobs.”
Those are the words of Steve Hammond, worldwide manager for mechanical equipment at [PFItemLinkShortcode|id:12626|type:standard|anchorText:Global Geophysical|cssClass:asshRef|title:Global Geophysical|PFItemLinkShortcode]
“Also, the way the oil market goes up and down,” Hammond said, “a lot of companies supplying equipment specific to our industry really struggled in the past decade -- some had to downsize just to stay in business.
“As a result, the lead times for equipment now are way, way out,” he added. “In going to these other industries that are not suffering those setbacks, we find equipment is more readily available.”
Morookas and Fabteks
Hammond noted Global is constantly on the lookout for something that will work better than what they’re currently using. It could be an apparatus that’s more robust, or one that would maneuver better than what’s being used on the terrain at a particular [PFItemLinkShortcode|id:12626|type:standard|anchorText:survey locale|cssClass:asshRef|title:survey locale|PFItemLinkShortcode].
“Some of it is R&D,” Hammond said. “I’ll try to find something I think will work in a specific area for us, and then try to get one machine and build it up and then put it on a crew to try out and work the bugs out of it.”
They’ve produced some winners.
For instance, they took the Morooka -- widely used in the heavy equipment construction industry -- and adapted it to make it ideal for drilling and equipment carrying.
The Morooka is a track machine like a Caterpillar, but it’s rubber-tracked, making it more environmentally friendly than steel tracks.
“It’s basically a rubber track dump truck -- a carrier -- but it gets around to a lot of places we couldn’t get to with the traditional rubber-tired buggy,” Hammond said. “There are a lot of Morookas being used in Canada for drilling, but we’re putting together our own custom package.
“We remove the dump bed and start with the bare frame and build up our equipment on the back end of it,” Hammond noted. “We’re building the drill ourselves and mounting it on the carrier.
“In addition to the drills, we’re using the Morookas as carriers for our new accelerated weight drop machines.”
From the timber industry, Hammond said they acquired the Fabtek buggy, which has more armor and protection than a regular drill buggy, making it more suitable for use in heavily forested areas.
It’s being customized by Global to carry cable, ground equipment and personnel, and also for drilling and for fuel/water transport. In fact, the same drill design is being used for the Fabtek as for the Morooka.
The company currently is equipping Fabtek vehicles to use in the wooded areas in Arkansas. They’re also using them in the heavy sands in Algeria -- far removed from a forest setting -- because of their availability and flexibility as a multi-application, heavy mechanized vehicle.
The Case Quad Track, which is a tractor from the agriculture industry, also is finding a niche in the seismic business.
“Some of us at Global had past experience with these while working with other geophysical companies,” Hammond said. “They worked well in Alaska, and now we’re using them in Algeria.
“Whereas dozers are used strictly for line clearance, the Quads are multi-purpose,” Hammond noted. “They have blades for moving earth and are faster than dozers for line cutting. They can also be used to tow camps, fuel trailers, water tanks and such.”
Aside from the focus on new, improved ways to use iron, industry contractors are embracing the relatively new airborne LiDar (Light Detection and Ranging) remote sensing technology to enhance survey planning, design and layout.
The LiDAR system integrates a laser scanner, a Global Positioning System and an Inertial Measurement Unit. It’s particularly useful as a means to provide an accurate high-resolution representation of the earth’s surface in areas of steep terrain and coniferous canopy -- so long as light can penetrate.
The system measures surface elevation via a laser scanner mounted on a fixed wing aircraft or helicopter. LiDAR survey data are acquired by the oil company rather than the seismic contractor on most occasions.
Global currently is using LiDAR data on a survey in Arkansas, according to Vlad Vanovac, worldwide manager of surveying and navigation at the company.
“In Arkansas it’s crucial because of the vegetation coverage of the area,” Vanovac said. “It allows us to go into the trees and get the vertical position component accurately, and we can go in with GPS to get the horizontal component.
“It’s a cost-effective approach,” Vanovac added.
Using LiDAR-derived elevation (Z) value for seismic points versus acquiring Z via GPS units on the ground -- which can take an inordinate amount of time -- increases the efficiency of survey crews, especially where there’s heavy vegetative canopy, added Mark Wagaman, geophysicist at CGG Veritas.
The accurate measurements of land surface elevations can make all the difference in how a survey proceeds -- and, in turn, how much it costs.
A project using dynamite as a source provides a good example.
“The economic way to use dynamite is to put it on a buggy or truck to move it,” Wagaman said. “If you use a helicopter and a heliportable rig where the ‘copter drops it down and it drills the hole, loads it and the ‘copter picks it up, that’s expensive ‘copter time.
“If you find rough terrain where you need heliportable drilling,” Wagaman said, “and you move the points not very far (using LiDAR) and make it accessible by drill buggy or vibrator, you can save a lot of money.”
LiDAR has become almost routine in some of the rougher areas in Canada, according to Wagaman, who added it’s also often used in the rugged areas of Utah, Wyoming and Colorado.
CGG Veritas used the LiDAR technology successfully in 2004 on its LaBarge 3-D project in the Green River Basin of Wyoming. The operating challenges included elevations ranging from 2,100 to 2,750 meters, carbonate outcrops and a thick tree canopy of pine and aspen stands.
LiDAR data applications for the LaBarge survey included source pre-planning and elevation substitution. In some instances pre-planning enabled movement of source points from areas requiring heliportable drilling, which enhanced project economics -- the price difference to drill a shotpoint with a heliportable rig versus a buggy rig was $470 U.S.
CGG Veritas currently is using LiDAR technology in New York state.
In case you’re pondering what to do if your survey includes excessively dense vegetation, bridges and such that are impenetrable by light, not to worry.
B-PINS (Backpack Portable Inertial Navigation System) likely will meet your needs.
“You start from a known point and carry it on your back as you walk,” Vanovac said, “and it calculates your position as you walk. It’s autonomous and will give horizontal and vertical accuracy sufficient for geophysical operations in areas where LiDAR can’t penetrate.
“The advantage is speed, and it requires fewer people than a conventional survey crew,” Vanovac added. “It allows us to weave between the trees and basically flag the line for the drilling or recording crew to follow, with minimal tree cutting.
“There’s one person with one helper instead of three working on a GPS crew or a half dozen on a conventional crew.”