Forged Steels for Oil and Gas Exploration

The United States has always been one of the world leaders in the oil and gas business, but with the serious advent of fracking a couple of decades ago, it became the world’s number one producer of crude oil and gas. Fracking, or hydraulic fracturing, is a technique for recovering gas and oil from shale rock. Put simply, it involves drilling into the earth and directing a high-pressure mixture of water, sand and chemicals at a rock layer, to release the natural gas inside. A few years ago it was estimated that of a million or so oil and natural gas wells in the United States, around 70% were drilled and fracked. 

The business here is drilling for oil and gas. Another huge business goes along with it, that of making and shaping and treating the steel and other metals that go to fabricate the drill collars, gears, valve bodies, and fracture pumps. There’s an awful lot of liquid involved in a fracking operation, with millions of gallons of water the major constituent of the liquid feed, topped up by fracking chemicals, and what are called proppants, a sand constituent that is there to keep open the fracking cracks formed from initial drilling. The oil and gas industry are one of the largest consumers of specialty pipe and tube products. These products are used in various applications, such as drilling, production, and oil and gas transportation.

The steel components used in the overall fracking infrastructure must be strong and resistant to the numerous thuds and shocks they’ll undergo during the drilling, extraction, and storage operations. And to the abrasion from all the sand floating around. So which grades of steel are recommended for use in the oil and gas industry?

It seems that grades 4130, 4140 and 4340 are up there to take the honors. These are low alloy steels that may be heat treated to required mechanical properties. They may be easily machined, particularly if heat treated to the spheroidized annealed condition. They are easily welded but should be treated with care.

We will note from the carbon contents that type 4140, for a given heat treatment procedure, will produce a harder, stronger material than will type 4130. Type 4340, a nickel-bearing steel, will produce the strongest material of the three. It will also hold its strength to around 600 degrees F. Further it is tough and will hold its toughness to sub-zero temperatures. The hardenability of type 4340 – the ability to be hardened to depth – is far greater than that of both 4140 and 4130.

Forged components are indispensable in the oil and gas industry thanks to their ability to withstand high pressure, temperature, and corrosive environments. Key applications include forged flanges that provide secure and leak-proof connections in pipelines, valves, and pressure vessels. These forged components, in the grades listed above, will require heat treatment to specified strength and toughness levels. This requires detailed knowledge, garnered over years of experience, of the specific treatments required to obtain these properties. The treatments may be annealing, for optimum machinability, or hardening and tempering to give the strength and toughness levels required. In the event that the forged parts exhibit non-uniform deformation throughout a part – because of a complicated shape – a normalizing treatment will be called for prior to undertaking hardening and tempering. It should be noted that the people responsible for heat treatment are a very important part of this operation. As are those responsible for the forging, where temperatures and reductions come largely from past experience.

The three grades noted above, 4130, 4140 and 4340, will combine to form the necessary infrastructure for a fracking well. The cost of 4340 material will be somewhat higher than that of the other two grades. The oil and gas industry are one of the largest consumers of specialty pipe and tube products. These products are used in various applications, such as drilling, production, and transportation of oil and gas. Pipelines for transportation would typically be made from 4130 grade, less expensive than 4340, but suitable for the application. 

These three steels, forged, heat treated, machined and welded, will each do their part in bringing oil and gas to industry and homes.

To see our Forging Capability Chart for complete inventory availability, size, and weight capability, Click Here