Boomtime in the Oil Patch
Ramping up with advanced machine tools
By Jim Lorincz
You don't have to be an expert in international affairs or even the global energy industry to know that there are powerful forces at work pressuring every facet of the efforts now underway to find, develop, and produce energy resources. Every day, news headlines trumpet the global dependence of the industrialized world on imported oil from some of the most troubled and troublesome parts of the world.
The North American oil and gas industry, as a result, is experiencing a cyclic Renaissance in capital investment to refurbish existing rigs both offshore and onshore, and expand production with the addition of new capacity. New leases are being opened for drilling; existing pipelines and production equipment are being replaced and upgraded.
Shops that produce valves and pumps, couplings, tubing and pipe, and virtually every kind of precision-machined workpiece rely on the most sophisticated CNC turning centers, multitasking machining centers, and the software necessary for production machining.
Machine tools must deliver the performance and quality expected and be available. They are valued for their ability to provide:
- Heavy metal removal rates;
- Done-in-one machining;
- Minimum setups and part handling;
- The ability to process difficult-to-machine materials, even so-called exotics, with precision.
Investment in the latest technology has enabled True Turn Machine L.L.C. (Bossier City, LA) to capitalize on increased oilfield production activity and meet the delivery dates, so critical to its customers. To keep his company ahead of his competition, Lee Boquet, True Turn's president, invested in advanced multitasking technology to produce quality parts faster and still keep control over material prices.
The competitive situation in the oil and gas industry is such that prices for raw materials like forgings and steel have surged and lead times have gotten longer. At the same time, commodity components have been lost to overseas competition from countries like China that often can sell parts complete for the cost of raw material.
True Turn adopted a strategy of concentrating on larger components with tighter tolerances that are supplied to manufacturers of oil-wellhead pressure-control equipment. The company machines castings, forgings, and solid bar stock into the high-pressure housings needed for gas rigs. The company has one proprietary product, the Coil Tubing Hanger that feeds smaller-diam tubing into casings of existing wells to enhance pressure and flow from underperforming wells.
By adding five advanced machining systems from Mazak Corp. (Florence, KY) and nine new people, increasing total employment to 41, True Turn was able to quadruple its throughput. Early last year, True Turn installed an Integrex e-650H multitasking machine to process a heavy, complex component that previously required eight setups and a lot of handling and workholding. Using the e-650H, True Turn was able to reduce production time from 24 to 2 hr, and the number of setups from eight to two.
The five-axis e-650H machine has a 60-hp (44.7-kW) turning capability with a complementary 50-hp (37.3-kW) milling spindle, as well as a full C-axis CNC control, a 240° swivel B axis, and a 120-pocket tool-storage magazine. Boquet credits multitasking technology with increasing his competitive advantage by speeding delivery.
A Mazak FH-6800 HMC with a two-pallet changer, which True Turn took delivery of late last year, is in production, enabling the company to move workload from its VMCs and allowing greater spindle uptime because an operator can load and unload parts while the machine is running. An even larger Integrex e-1060V multitasking machine is on order for next year.
Service and support are cited by Boquet as key considerations in choosing a machine-tool partner. Boquet points to Mazak's factory support based in Houston, its centralized parts facility in Florence, KY, and regional distributor Dixie Mill and Supply, which "played a large role in my machine purchases."
Though it might not seem that way to the uninitiated observer, it's hard to imagine more sophisticated combinations of workpieces and materials than those required in the diverse environments of oil and gas production.
"Oil industry products rival aerospace materials for the sophistication of the machining technologies involved," explains Tim Thiessen, senior sales manager, Okuma America Corp. (Charlotte, NC). "Materials include stringy steels to stainless, aluminum, brass, and exotics like Inconel and Hastelloy. It all depends on what environment they are required to work in, whether cutting through rock, sand, or operating in some corrosive acidic environment.
"Products include everything from simple pipe and casing to castings, complex shafts, and drill heads. Many of these downhole tools have very high-tech electronics for GPS positioning used in directional drilling, thermal sensors, and even explosive charges for fracturing the earth," says Thiessen.
"What our customers want are extremely large spindle bores, long beds, wide turrets, and different combinations of single and double-turret machines," says Thiessen. Okuma's four-axis (two-turret) turning centers are able to reduce cycle time by having two turrets in the cut simultaneously. Okuma Oil Patch machines also feature a threading suite of options in its software for machining threads.
The Okuma LOC 650 (Lathe Oil Country model) is available in single or double-turret style machines in three different bore sizes, 7.87, 14.76, and 22.04" (200, 375, 560-mm). The software threading suite includes such options as Thread Start Point Offset, which is used to pick up thread leads; VSST (Variable Spindle Speed Threading, which allows changing rpm during threading while in the cut; and HSSC (Harmonic Spindle Speed Control), which provides for rpm to vary constantly within a range and prevent harmonics or chatter.
"All things being equal in terms of specification, what sets the Okuma apart is the expertise in blending electronics and mechanics for given applications. We call this mechatronics," Thiessen points out.
The runup in the oil-field market has already lasted longer than most observers might typically have expected. As a result, suppliers of such necessary related products as bearings, air chucks, and large castings have been challenged to ramp up their production to meet demand and head off bottlenecks.
"Customers are coming from a time when they haven't been able to make any appreciable capital investment," explains Kenneth J. Campshure, senior sales manager, Giddings & Lewis Machine Tools (G&L; Fond du Lac, WI). "They had factories full of old equipment that had to be refurbished and replaced, and capacity that had to be expanded. Their emphasis is clearly on reducing setups and minimizing part-handling time," he says.
To streamline workpiece handling and minimize its impact on machining, G&L supplies horizontal boring machines with built-in rotary tables and/or pallet shuttles, and vertical turning centers with full C-axis and live tooling capability. Workpieces include valve bodies and parts like bonnets and flanges. Typical difficult-to-machine materials that must be machined include metals like Inconelclad and alloy steels, which must resist tough operating environments such as corrosive gases, sea water, sand, sulfur, and acidic environments.
For the oil and gas industry, where workpieces have elaborate geometry in pockets and seal areas of valves, G&L has partnered to develop a series of tools that can be characterized as NC-controlled facing heads and/or NC-adjustable boring tools. They have been widely used in the US, and are just now gaining acceptance in Europe.
The programmable boring bars utilize the capability of co-linear axes on G&L horizontal boring machines, W and Z axes, to both actuate the tool and position the part. They are available in a range of sizes to machine bores from 1.2 to 22.8" (30–580 mm).
"The nature of the energy industry means that techniques that are successful in one area of the world are more likely to be embraced on the global level, because of the multinational companies involved," says Campshure. "G&L is positioned to support our machines globally, and we can make recommendations based on our experience with the costing, quality requirements, and cycle times possible with advanced machining techniques," Campshure says.
"What oil field shops are looking for is heavy metal removal rate," says Bruce Cates, regional sales manager, Absolute Machine Tools Inc. (Lorain, OH). "Our Johnford CNC lathes and You Ji VTCs have earned their place in the oil industry based on their reliance on box-way construction, gearboxes, and heavy metal removal for machining valves, couplings, and pipe," he says.
"We have a pretty good foot in the door in spite of the fact that we aren't a household name," says Cates. "A number of multinational companies have discovered our products, which deliver rigidity and reliability. Customers are looking for torque and metal removal because at the end of the day, metal removal means money."
There doesn't seem to be an end in sight for the up cycle in the oil patch. Cates explains: "Two years ago we started to see the ramp up in the oil fields in Texas, Oklahoma, and even in Louisiana. At the time, many observers were saying it was a two-year cycle. Then as time went on they upped that to five years, and now some are even saying it could be a seven to ten-year cycle."
Upgrading with the latest advanced technology available from Mori Seiki USA Inc. (Rolling Meadows, IL) has enabled Dixie Iron Works (Alice, TX) to maintain its machining efficiency with higher metal removal rates while minimizing downtime and the effects of potential operator error. Dixie specializes in the production of high-pressure plug valves and mobile well-service pumps for oilfield applications.
Dixie depends on its Mori Seiki machines because of their rugged construction, which allows them to take a beating without ruining the machine's performance or accuracy and makes them more forgiving of operator error. Gerard Danos, Dixie Iron president and owner explains: "All of our operators perform their own setups. We work with an extensive screening and training program to ensure the quality of our workforce. Since most have no previous experience in machining, it's not atypical for a new employee to miss a decimal point or make some other type of mistake from time to time," Danos explains.
Dixie works nearly exclusively with high-carbon alloy steel, usually 4140 or 4340 grades. To boost productivity, Dixie typically runs machines with the spindle load as close to 100% as possible. Most recently, Dixie acquired a Mori Seiki NH8000 DCG HMC. The NH8000 has reduced machining time for a block of 4340 modified steel from 4.5 hr to 40 min.
For machining pump components, Dixie had acquired a Mori Seiki NL2500 turning center with live tooling, which has made it possible to machine and drill the part complete in one setup compared with the previous three setups, eliminating two-thirds of the setup time for these jobs.
Recent new product introductions and product line expansions, many of which were shown at IMTS 2006, have specifically targeted the oil field and energy industries.
Mazak has introduced two Cybertech Turn models for machining large shaft and pipe workpieces for the oilfield and energy industries. The Cybertech Turn 5500 MT is designed for multitasking machining of large shaft and pipe workpieces. The Cybertech Turn 4500 is designed for machining long shafts and large-diam pipes.
G&L's HBM features five-axis and multitasking capability made possible by an optional C-axis vertical rotary table mounted on the built-in B-axis hydrostatic rotary table or a B over C-axis configuration. The VTC Series product line consists of six models with table sizes ranging from 1250 to 3500-mm versions.
You Ji VTCs from Absolute Machine Tools include the VTL-1200 ATC heavy-duty model and the YV-2000 ATC, both with 12-station tool change with turning diam from 63 to 100" (1600–2540 mm). Both models feature boxway design for X and Z axes. The Z axis is a square ram 9 x 9" (228 x 228 mm).
This article was first published in the February 2007 edition of Manufacturing Engineering magazine.