This article was published in North American Oil & Gas Pipelines. The full text version can be found here.
By Christina Lomasney
Building a Better Infrastructure
Corrosion-resistant, structural tubulars and casings are important infrastructure assets in the oil and gas industry. While largely passive during well operations, tubulars and casings are subject to some of the most aggressive well conditions, serving to permit operations across extreme formation and production pressure differentials, in high temperatures and in highly corrosive environments containing hydrogen sulfide (H2S), carbon dioxide (CO2) and chlorides.
Although production tubulars and casings are not subject to the same reciprocating operations as pumps, they are nonetheless constantly being worn by frequent placement and removal of downhole pump and monitoring tools, resulting in additional degradation due to the combination of downhole corrosion and wear.
Tough Choice: Cost vs. Performance
Despite operating conditions that are becoming increasingly aggressive, the decision to move from low-carbon steel options to higher-grade tubular alloys is a difficult one due to the high upfront cost of the well infrastructure.
Because the cost of casing and tubular materials can represent a significant percentage of the overall well cost, oil producers are challenged with recovering the higher cost of a more corrosion-resistant tubular or casing material. To combat increased corrosion and cut production costs, oilfield producers today are left with two high-risk choices: pay up front for the higher performing, corrosion-resistant metallurgy, or run the risk of an expensive workover down the road.
Enter a new, third option: a conventional low-carbon steel tubular or casing, clad with a “nanolaminated” alloy. Nanolaminated alloys are a new class of metal that have a layered structure (think plywood) even as they are deployed as a coating. By leveraging phenomena that occur at the interfaces in layered materials, Modumetal has demonstrated dramatic improvements in the performance of metal alloys.
These nanolaminated alloy coatings are much more durable than conventional cladding systems and are highly resistant to corrosion and wear in environments containing H2S, CO2 and chlorides. In autoclave testing, the nanolaminated alloys have shown 10 times the improvement in the resistance of carbon steels to degradation and in some cases, no measurable degradation of the nanolaminated-clad alloy.
A Behind-the-Scenes Look at Nanolamination
Nanolamination has been a technology of interest for many years. Search the term, and hundreds of scholarly articles will tell of the unique properties of these materials in toughness, strength, thermal properties, corrosion and wear — to name a few. Search for a commercial supplier and only one will emerge. The challenge associated with nanolaminated materials has been the cost and scale of production, which has necessarily limited their production to academic research and small-scale components.
Several years ago, Modumetal began quietly scaling up a patented process for manufacturing nanolaminated alloys at a scale that would enable industrial use and at a cost that is competitive with even conventional metals manufacturing. The Modumetal process involves precise, time-based control of the electrolytic reduction of metals in a process that looks very similar to conventional electroplating.
Today, Modumetal is producing clad pumps, valves and tubulars that are currently being fielded with key launch customers.
Nanolaminates in Oil and Gas
By deploying nanolaminated materials as a cladding on conventional alloys, the cost of corrosion and wear protection is significantly decreased. By deploying the corrosion and wear protection through a durable, high toughness, nanolaminated metal alloy cladding, a robust corrosion protection capability can be deployed without the common risks of failure typically associated with conventional surface coatings. Modumetal has the potential to dramatically change the return on assets equation for the oil and gas industry by leveraging the same raw materials used today in conventional metals production in a more efficient, nanolaminated configuration.