Tuesday, February 1, 2011
Gulf Pipeline Patrol
One area of flying, that may surprise some readers, is the use of helicopters for pipeline patrol.
The Federal Energy Regulatory Commission (FERC) requires all pipeline owners and operators to inspect their lines periodically to help in maintaining pipeline integrity. Most opt to do so by aerial means, the vast majority being done by fixed-wing aircraft. We are talking thousands and thousands of miles here, over farmland, mountains, deserts, even through metropolitan areas. Airplanes are faster in most cases and no doubt, are cheaper to operate, but, as the late Paul Harvey would say, “Here’s the rest of the story.”
A great number of hydrocarbon pipelines originate here in the Gulf to begin their journey north. Some deliver gas, others liquid. The lines could be as far as 150 miles or more off shore (sub-sea) and they too are inspected for leaks, which would be evidenced by bubbles or perhaps an oil sheen. This is a helicopter task and one that has been met with many successes over the years; that is finding and reporting suspected leaks.
You might ask, why would a line under the sea leak? These lines are required to have a minimum of six feet of earth or mud cover when the pipe is put down. To get it, a trench is dug by using what is referred to as a jet barge that uses very high pressure water jets to dig the trench, the pipe is then set in the trench and covered. Over the years, anchors are dropped on it, shrimp fishermen foul nets in it, and movement of the sea can uncover portions of the line. There could also be internal corrosion taking place.
Though I do not have the exact number of hours flown annually in the immediate Gulf area, my personal experience tells me it is at least several thousand and that would only cover the sub-sea, marsh areas and maybe 50 miles in from the beach. There are hundreds of pipelines lying on the floor of the Gulf.
No doubt, it is difficult to fly directly over a line that has no ground markers (sub-sea) and perhaps having a crosswind to contend with. GPS can help by establishing waypoints over known locations that can keep a reasonable track going, plus many pipes are laid that connect platforms (rigs) in a network. It is often possible to see a distant platform from the current deck you are on, and then fly the track between the connecting platforms. Other problems that arise could be determining the originating location of the bubbles or oil sheen. Underwater currents can displace the bubble pattern and surface winds spread the sheen indicator downwind from its source. Once the problems have been discovered and reported, the owner of the line can bring in surface vessels with more sophisticated equipment to fix the exact location of the leak and begin repairs.
The overwater flights certainly will not account for the large number of hours flown by helicopters for pipeline inspection. Quite a few of the major oil and gas companies have come to realize the value that rotorcraft bring to the table and they use the helicopters from the beach all the way into the interior of the country. Visibility from the helicopter is unequaled in an aerial vehicle, except maybe a balloon basket or the Space Station. The highly variable speed allows more time for minute examination of an anomaly. The ability to land at the site has prevented numerous potential accidents by the aircrew’s actions in shutting down and conferring with bulldozer and backhoe operators who were approaching the lines and were not aware of the dangers.
Encroachment is a major concern of pipeline companies, some of which are the above mentioned excavating equipment operators, owners of mobile homes who place them over the lines, all types of construction projects including barns, swimming pools and homes.
There are many other inspection processes done during the flights, such as leak surveys and right-of-way condition reports, but it is not my intent to cover those activities. The purpose here is to inform the reader of one of the many uses of energy industry aircraft here on the Gulf Coast, especially one that is so critical to our nation’s movement to the green side.