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Wresting Hydrocarbons – The Tight and Right Play on the Coating Corrosion Front

Corrosion_Vernal
 
There is little dispute that wresting hydrocarbons from the earth is one of the toughest industries in the world. Climatic, locational, geological forces play in tandem with regulatory, health and safety, market and financial risk factors.
 
With the vast surge in fracking, particularly in North America, the hydrocarbon play has done a complete about face, going from a declining industry to one that seems to be now the very underpinning of the USA’s recovery and financial prospects for the next two decades at least.
 
“Ten years ago, few people could have predicted the staggering, positive effects fracking has had and continues to have on the US economy,” observed Castagra Products CEO, Peter Roosen.
 
“Because we were on the ground, in the oil patch, applying our coating to oil tanks, we witnessed the explosive growth of the fracking business. We saw how small towns were being transformed with truck lots brimming with the latest models and everyone driving them.
 
“There were lots of smiling faces in the truck stops and cafes as frack dollars proliferated outwards into these small economies.”
 
Roosen said that behind all of this has been major technological challenges. While the techniques of tight oil and gas drilling have been down pat for decades now, it has been the chemistry side that has thrown up the major challenges for companies such as Castagra which provide coating protection.
 
“The liquids used to fracture rock and facilitate the extraction of tight oil and gas are literally chemical cocktails. The companies producing them, because of their perceived need to keep the contents secret – perfectly legal I might add – has resulted in some big surprises and major anti-corrosion challenges, especially with sulfuric and formic acids.
 
“The flowback water and formation water can not only contain a proportion of the original chemical cocktails, but also massive amounts of salts, toxic metals and even radioactivity. This all has to be carefully collected and dealt with so that is poses no threat to the environment, including groundwater supplies,” said Roosen.
 
Pioneering work by Saltworks, of Vancouver, is already turning wastewater from Alberta’s Oil Sands into potable water.
 
“Whilst it’s good to know that wastewater can be cleansed to the point where it is fit for human consumption or returning to the environment safely, the anti-corrosion challenge remains huge and unforgiving on two fronts: the sheer variations in the chemistry with new surprises, and the climatic considerations.”
 
Roosen said that even today that once you go above 30% concentrations for HCL and H2S04 there are few coatings that last more than a few months, and many that will fail within days or even hours in frac tanks.
 
The biggest challenge by far are frac liquids with high concentrations of formic acid which can have a rapid and devastating corrosive effect on bare steel.
 
Castagra’s main coating is a plasticised gypsum comprising two main ingredients, castor oil and a common and cheap mineral gypsum. It was first developed as a solid product nearly 25 years ago for use in the housing industry as baseboard moldings and shingles.
 
With its naturally high fire rating due to the fact it gives off water vapor when heated, it was also used to coat manufactured wood strand beams. Its long use as a ferry fleet ship deck coating in British Columbia, demonstrated its total resistance to sodium chloride from sea spray.
 
A 20-year saltwater submersion test with Ecodur flakes has shown no measurable degradation at all.
 
“For frac tanks we developed a two-coat solution because we wanted not only the benefits of different chemical resistance from two layers, but also the benefits of the retained elasticity cushion effect that Ecodur provides as the base layer.
 
Fracking can be mechanically brutal on mobile tanks with impacts and torqueing. Expansion and contraction from wide fluctuations in temperatures which play havoc with conventional epoxy coatings, causing rapid micro-cracking,” said Roosen.
 
Climatic conditions have always meant a severe limitation on coating application in cold climates where once the thermometer dips below freezing, most regular epoxies are severely challenged. Ecodur, however, can be applied down as far as minus 20 degree Centigrade/minus 4 Fahrenheit as long the surface being coated is 4 C or 7 F above the Dew Point.
 
Roosen said Castagra’s Ecodur has been particularly effective in the harsh winter climate regularly experienced in the Bakken in North Dakota.
 
Case Study 1
 
North Dakota experiences some of the severest winter weather conditions in the US so any decision to go ahead and coat at an EOG oil and gas installation in the Bakken needed to take into account how most conventional coatings simply cannot be applied in extremely low temperatures.
 
In this case there was not just a coating to consider, but also a large expanse of geo-synthetic material to be laid for a containment area around a battery of tanks.
 
Problem
The primary one was the work needed to be carried out during winter when extremely low temperatures would be encountered as was the case with the thermometer falling to zero Fahrenheit. The sealing of the geo-synthetic material for a perfect, robust seal was the second major consideration and the third was the need to avoid solvents and volatile organic compounds (VOCs).
 
Of course, with the low temperatures there was also the human factor to consider: all manual work is tough at below freezing temperatures with the risk of frostbite to exposed skin so simplicity and quickness of application was vital.
 
Solution
Castagra’s Ecodur provided the key solutions because it not only provided a robust VOC-free, non-toxic and solvent-free solution, it also acted as an adhesive for the geo-synthetic materials which were applied by Northern Industrial Coatings. The Ecodur 201S was easily sprayed on once it had been brought up to the correct working temperature comfortably above the Dew Point. It also demonstrated its ability to quickly create permanent bonds with the geo-synthetic materials even when used with steel berms, thus eliminating the more laborious conventional sealing methods.
 
With no wafting of VOCs to the general area it meant the entire installation’s personnel were free to go about their duties as per normal. Similarly, with no solvents either used in the content, application or clean-up, the use of Ecodur greatly simplified and reduced the cost of the entire operation. In order to provide a non-slip surface, clean, dry sand was added to the Ecodur.
 
Application results
A total of four drums of Ecodur were used in the project. Because of the extremely low temperatures to 0 degrees F, the majority of conventional epoxy coatings would have been handicapped, with many simply unusable. The resulting sand-roughened surface of Ecodur showed excellent integrity and bonding, especially around the important steel berms which provide the containment area’s holding strength should a mishap ever occur.
 
With the fast cure time, the entire containment area was declared fit for use immediately after the mandatory 24-hour inspection. Ecodur, because of its environmentally benign composition of gypsum and vegetable oil, retains a degree of flexibility far exceeding the more brittle conventional epoxy coatings and does not ‘micro-crack’ and so is ideal for harsh environment containment industrial uses. It is also highly acid resistant which also makes it very versatile for application in the fracking industry.
 
Case Study 2
 
A major oil and gas company, operating in Vernal, Utah, had a series of 400 bbl oil storage tanks of varying ages needing new protective coatings as cheap and robust as possible. They had originally been coated in conventional epoxies which, having very limited flexibility, had inevitably resulted in micro-cracking, particularly in such a climate-extreme state as Utah.
 
Problem
While the bottom line was very important, the company was mindful of the cost effectiveness of doing the job the old fashioned way, by hand, thus making the job open to workers with only modest skill levels.
 
With Ecodur 201M being VOC and solvent free, it meant radically lowered worker risk under normal, compulsory protection protocols of wearing disposable suits, full face/eye protection, and gloves. Consideration too was given to how well coatings would fill pitting, cracks and small holes that were in evidence.
 
Solution
Ecodur 201M can be applied in a very wide temperature range. With its set-up time to touch dry of around 30 minutes, and ability to 100% bond to remedial coats over a virtually indefinite period of time, it’s ideal for the ‘bucket-and-slosh’ technique that requires minimum training.
 
Ecodur has a 20-plus year field use pedigree on steel exposed to the harshest of challenges, including seawater sprayed ship decks in cold climes. Applied on properly prepared surfaces, it will easily outlast conventional coatings because it retains its flexibility indefinitely and shows virtually no degradation from UV. It is ideal for covering pits, cracks and small holes, again due to its retained flexibility.
 
Application results
Despite the less sophisticated application technique which usually results in far thicker coatings than is absolutely required, the job was completed quickly, satisfactorily, and cheaply.
 
“I don’t expect the fracking industry to let up ever on the chemical challenges that it will present to the coatings industry. Wresting tightly held hydrocarbons from Mother Earth is always going to be a severe challenge, however, there is a widespread and very substantial effort to protect the environment as much as possible by preventing leaks and safely handling wastewater.
 
“My challenge is to see that our non-toxic, VOC-free, solvent-free Ecodur plays a major role in the anti-corrosion niche in fracking and the oil industry in general and stays on the cutting edge of chemical change,” concluded Roosen.