FOR IMMEDIATE RELEASE
Chris Kahlich
Public Relations
ARC Specialties, Inc.
713-631-7575 X112
chrisk@arcspecialties.com
PIPE DREAM NO LONGER
One sniff of a burnt match and your nose will recoil as your face contorts to a sour grimace. Now imagine that same face at the instant a Petroleum Engineer receives results that a hopeful oil reserve is filled with sour crude oil, a sulfurous mixture that corrodes anything that extracts it. As the well is capped and recorded, that engineer remains optimistic that one day the petroleum industry will develop the technology to safely extract and process sour crude. Now finally after years of mapping sour crude reserves, the reality of producing sour crude has come to grasp with new revolutionary steps in pipe cladding technology. Questions arise. Do we need to produce sour oil now? Can we do so safely and expeditiously? The answer to both of these questions is, "Yes".
Forces that Drive Sour Crude Production
The trend of shifting focus to sour crude has grown in the Petroleum industry over the past decade, and the determination to develop technology to mitigate the corrosive effects of crude oil has held steady. There is an accumulation of many factors that contribute to the need to develop technology to battle corrosion, but the main forces that drive this redirection are demand, environmental concerns, energy independence, and aging infrastructure.
The world's demand for oil is simply outstripping current production. Virtually all of the sweet crude oil reserves with no corrosion issues are already tapped, and many of the famous giants that yielded thousands of barrels per day are now trickling past the stage of peak production. Yet world's consumption continues to increase each year as oil production decreases. Demand requires new production, and estimates show that 3 out of every 4 oil reserves recorded throughout the years contain corrosive sour crude.
Many of the sour crude oil reserves are in the Gulf of Mexico at very deep locations, where volatile conditions such as high pressures increase the oil's corrosivity and make corrosion technology crucial to production. Due to environmental concerns of gulf coast states whose economies rely on the health of their coastal waters, corrosion technology also provides safety and protection from environmental catastrophes resulting from corroded pipelines. The same environmental precautions are also seen in Alaska's delicate Arctic National Wildlife Refuge, another known reserve of sour crude.
Instability in the world's oil-rich regions has historically driven oil prices to record numbers and put strain on the U.S. economy. The lion's share of U.S. oil consumption is imported through OPEC. A consensus has formed in the U.S. over the years to become more energy independent by utilizing national resources. In addition to economic advantages, the national security of the U.S. would improve from a U.S. energy supply that did not depend on regions of heavy anti-U.S. sentiment.
The final significant force that is driving the need for corrosion technology is the ever-growing accounts of aging infrastructure in the oil fields. Most of the oil rigs in service average over 20 years in age and show concern of structural compromise due to corrosion. Pipelines that transport oil are often older, and even more corroded, with leaks creating devastating and costly consequences. Corrosion technology ensures that the infrastructure that supports the U.S. energy supply stays intact.
Understanding Corrosion
Oil corrosivity depends on the levels of Hydrogen Sulphide (H2S), Carbon Dioxide (CO2), and chlorides from saltwater in the oil. Sour crude contains substantial amounts of these corrosive elements, and is defined when partial pressure of hydrogen is about 0.05 psi. As pressure and temperature increases with deepwater wells, the corrosivity increases.
Corrosion occurs on a molecular level when hydrogen ions infiltrate the grain boundaries of steel and then recombine into molecular hydrogen (H2), which weakens the tensile strength in the bond between the steel grains. Embrittlement occurs, where cracks begin to form and cause material failure even when the steel is subjected to tensile stresses well below the steel's normal yield strength.
Pitting corrosion and crevice corrosion are the most detrimental forms of corrosion seen in stainless steel pipelines. Pitting occurs particularly when chlorides are present, such as sour crude containing seawater, where small pits begin to grow along the inner surface of the pipe wall and eventually perforate the pipeline. Crevice corrosion is a type of pitting that occurs in any slot or groove where the corrosive element can lodge itself inside, such as the overlapping boundary between two lengths of steel pipe.
Combating Corrosion
To mitigate the woes of corrosion, engineers clad corrosion resistant alloys, or CRAs, to surfaces that come in contact with sour crude. Cladding is the metallurgical process of welding two metals together to combine their properties. In the battle against corrosion, CRAs are vital because they have chemical properties that block hydrogen ions and other corrosion accelerants.
Clad pipe, also known as overlay pipe, is manufactured by overlaying a layer of CRAs to the inner surface of steel pipe. The end result is a pipeline that possesses the structural strength of steel and the chemical properties of CRAs along the inner wall to prevent corrosion.
The theory behind clad pipe is nothing incredibly new, but engineers worldwide are still trying to find solutions that bring the theory of clad pipe into a real product that can be fabricated quickly and flawlessly in a cost-effective manner. There have been many different approaches to fabricating clad pipe, but most have ended with frustrating results. That is until now. KLADARC from Houston, TX has unveiled a cladding system that expeditiously cranks out clad pipe up to 40 feet in length that meets all the safety-critical requirements necessary to mitigate corrosion and makes sour crude production a real option.
KLADARC is a 50/50 joint-venture of KLAD Manufacturing Company, Ltd. and ARC Specialties, Inc. KLAD is renowned for metallurgical advances through metallurgist owner Dr. Bhaven Chakravarti, while ARC Specialties' owner Dan Allford is a leading expert in automated manufacturing systems that has executed cladding technology to fine-tuned precision.
How the Solution Works
KLADARC revolutionary improvement to traditional cladding systems by delivering an CRA overlay of superior chemistry, unmatched quality, and an unseen fabrication speed. KLADARC utilizes an arc welding process known as Hot Wire Gas Tungsten Arc Welding (GTAW), or Tungsten Inert Gas Welding (TIG). Hot Wire GTAW allows for welding within a tight area, which is ideal for small bores like steel pipe. The most common CRA used is Alloy 625, a Nickel-Chromium alloy with excellent strength, fabricability, and corrosion resistance.
CRA wire is fed into a torch which welds the CRA circumferentially along the inner wall of the pipe. The circumferential weld is created by moving the torch into the pipe, while motorized pipe rollers steadily turn the pipe. Circumferential welds ensure that the overlay of CRA is seamless, and also allows the pipe to undergo long-radius bending after the overlay process. Long-radius bending is crucial for pipes used in refineries, where pipes often need to turn direction within the refinery process.
The cladding system was developed by ARC Specialties, and incorporates dual GTAW torches that simultaneously overlay CRAs onto pipe. The use of two torches allows for unprecedented fabrication speeds, which is a crucial element to making overlay pipe fabrication a viable reality. One of clad pipe manufacturing's pit falls is maintaining GTAW torch rigidity as the torch progresses further into the pipe. KLADARC solved this problem by attaching the dual torches onto a sturdy steel lance that moves into the pipe by use of a travel carriage on a glide rail. Through this innovation the dual torches can overlay pipe up to 40 feet in length.
To increase the speed of fabrication further, KLADARC developed a method to increase the deposition rate while not diluting the overlay. Known as the TripulseTM system, the patent-pending technology is a specially designed waveform in the electro-current pulse that maximizes the deposition rate, and provides a consistent quality weld. Other advantages of the TripulseTM system include a superior bead to bead tie-in with the weld beads, and a weld bead with a flatter, smoother, and more uniform profile.
Additional Design Advances
Another technique integrated into KLADARC's cladding system is oscillation welding. The capability to oscillate the arc provides a weld puddle with longer residence time to bond and eliminates common problems of overlay welding such as leaving holes that penetrate through the overlay layer and thereby exposing the outer steel pipe to corrosive sour crude.
The system also incorporates dual video cameras, one for each torch, which allow for real-time monitoring. The video cameras are designed to withstand to extreme heat with proximity to the welding process, and allow the operator to make any necessary on-the-fly corrections.
Video logging and data logging are also available for the system if required for reliability assessments and archives. Each parameter in the welding process can be logged, including average feedback of the Arc Voltage Control, welding amps, wire speed, torch speed ,and pipe rotation speed.
Achieving Safety-Critical Quality
Guaranteeing Safety-Critical quality is paramount in corrosion technology. Pipeline failure could result in disastrous oil well kicks, production halts, or damage to the environment. KLADARC's cladding system guarantees the deposit chemistry of the overlay to meet the maximum 5% Fe requirement that is standard in an excellent overlay pipe. The thickness of a two layer Alloy 625 overlay is 3.5 mm to guarantee the standard requirement of 3.0 mm thickness.
Safety-Critical quality is then verified by a number of precise tests. First the overlay pipe undergoes a Liquid Penetrant Test, or LPT test, where a dye coating is applied to the inner wall of the pipe to illuminate any discrepancies in the overlay. Depending on the project requirements, an Ultrasonic Test is available to inspect the bonding between the overlay layer and steel pipe. Then starting with the filler metal, each joint in the pipe is tested using Positive Material Identification, or PMI. A Copper Sulfate Test is used lastly to inspect the weld overlay surface to check for "holidays" in the overlay as well as any possible iron contamination.
Clad the Future
The true final test of the overlay pipe fabricated by KLADARC is whether or not the Petroleum Industry deems the cladding system as a viable solution to corrosive sour crude. As KLADARC moves forward with implementing more systems into streamline production, orders are beginning to come in at thousands of meters at a time from leaders in oil and gas production such as Shell, and BP.
A laser based inspection system is set to be implemented soon, and the company is continually striving to find new innovations that will allow for clad overlay in smaller diameter pipes. The bar has been set as KLADARC's revolution in the overlay process will allow for previously recorded sour crude reserves to be reopened for production.
About the Products in the Venture
KLADARC provides superior weld overlay using a patent-pending, dual torch welding system. The overlay in the clad pipe produced meets Quality Assurance standards of 3mm minimum thickness with low dilution in the deposit (less than 5% Fe). Automatic ARC Voltage Control allows for fine-tuned manipulation of the dual torches' positions in real-time. CCTV remote weld monitoring views the weld deposit to aid in immediate torch adjustments, and creates a video record of the overlay process. Welding system software logs data of the weld parameters with full traceability per client and project specifications. For more information contact KLADARC at 713-795-4440 or email sales@kladarc.com.
About KLAD Manufacturing Company, Ltd.
KLAD Manufacturing Company, Ltd. is global provider of weld overlay and clad pipe solutions that mitigate profit losses that result from plant corrosion problems. Solutions manufactured by KLAD include overlay and clad pipe, fittings, bends, fabricated pipe spools, and pressure vessels. KLAD's cladding technology is recognized for its ability to improve production and refining of oil and gas by eliminating the Based in Houston, Texas, KLAD is relied upon by a broad range of companies in the energy industry operating throughout the world. For more information contact KLAD at 713-433-5151 or visit their website at www.clad.com.
About ARC Specialties, Inc.
ARC Specialties, Inc. specializes in complex and unique custom automated and robotic equipment to provide solutions for multiple industries in 22 countries worldwide. Headquartered in Houston, TX since 1983, ARC Specialties has been the supplier of choice for engineering services, systems integration, service, parts, and training. For more information contact ARC Specialties at 713-631-7575 or visit their website at www.arcspecialties.com.
###
ARC Specialties is a registered trademark of ARC Specialties, Inc. All other trademarks are owned by their respective companies.