Oil & Gas News
Tuesday, 17 February 2009
Bristle Blasting Process: A New Corrosion Removal Method
Robert J. Stango and Piyush Khullar
Introduction and Background
The development of innovative surface cleaning and surface preparation methods for refurbishing corroded surfaces is essential for safeguarding metallic components that are critical to our infrastructure. To this end, maintenance engineers are constantly searching for cost efficient and effective methods for removing corrosive layers and providing a fresh, receptive surface for newly applied paints and coatings.
Although many different tools and equipment have evolved for surface cleaning and restoration, the grit blasting process has emerged as the most common and widely used method for maintaining an aging, corrosion-prone infrastructure. Success of the grit blasting process can be attributed to its' inherent ability to simultaneously perform the following tasks, which are deemed necessary prior to the reapplication of protective coatings:
However, grit blasting operations are inherently complex, and involve the use of equipment that is large, cumbersome and potentially at odds with both the user and the environment. That is, workers must be encapsulated in a specially enclosed suit that will ensure the flow of clean, breathable air that is free of spent media debris. The use of such equipment is confining and strenuous, and places considerable limitations on the ability of workers to function without taking frequent periods of rest. At the same time, spent media must often be recovered in order to satisfy stringent requirements that are enforced by various environmental protection agencies. Altogether, grit blasting is a costly and prohibitive process, and optional approaches for preparing surfaces are needed that can circumvent these problems, without compromising the quality of cleaned surfaces.
In this article, a newly developed surface preparation process termed bristle blasting is presented that can also satisfy all of the above tasks in a single step. Like grit blasting, the bristle blasting process is an impact/crater-formation based technique that repeatedly strikes the target surface with sufficient kinetic energy to remove contamination and expose a fresh, consistently textured surface. The process utilizes a dynamically tuned rotary wire bristle tool whose tips are both hardened and sharpened. Upon impacting the corroded surface, bristle tips immediately retract, thereby causing a repetition of craters that mimic indentations which are commonly associated with grit blast media. Performance of the bristle blasting tool is examined within the context of cleaning severely corroded API 5L piping, which is commonly used in the petroleum industry. The results obtained for surface cleanliness and texture are shown to be on an equal par when compared to traditional grit blasting processes. Unlike grit blasting, however, this new process uses a light-weight power-driven hand tool that only requires the use of nominal safety equipment such as safety glasses, dust mask, and work gloves.
Description and Use of the Bristle Blasting System
The equipment that is used for bristle blasting is shown in Figure 1, and consists of a hand-held power tool system having a main body, control handle, protective shroud, accelerator bar, dust vacuum, and rotating spindle, which operates at approximately 2,500 rpm. Although the pneumatic version of the bristle blasting system is shown in Figure 1,
Figure 1. Overall view of bristle blasting tool system.
an alternate version of the tool is also available that operates on a standard electric power outlet. At the core of the system is the wire bristle blasting tool, which is attached to the power tool spindle. As shown in Figure 2, the tool is comprised of steel wires whose tips are hardened (Rc = 65) in order to ensure efficient corrosion removal and longevity of service life. The bristles protrude through and are securely held by a polymeric/fiber-reinforced belt that is supported by a flexible plastic ring. Together, the plastic ring
Figure 2. Detailed view of bristle blasting tool components and assembly.
and wire-belt assembly are secured by a die-cast hub which, in turn, is fastened to the power tool spindle. Standard use of the tool is depicted in Figure 3(a), whereby a heavily oxidized layer is being removed from the steel surface. Typically, the rotating tool is placed in direct
Figure 3. Removal of corrosive layer via bristle blasting process (3(a)), and final corrosion-free surface obtained at conclusion of application (3(b)).
contact with the corroded surface, and light forces are applied by the user while moving the tool horizontally (i.e., from left-to-right) along the surface as shown. Continued use of the tool in this manner generates a series of cleaned horizontal rows, which leads to the final, corrosion-free surface shown in Figure 3(b).
Mechanical Principles of Operation
Recent experimental studies on the impact mechanics of rotary bristles have shown that, for a properly designed bristle geometry and synchronous rotational speed, collision of the bristle tip with a target surface is followed by an immediate rebound/retraction of the tip from the impact site (1, 2). That is, the collision results in a single/primary impact crater, similar to the micro-indentation that is characteristic of grit blast processes (3). The duration of this contact event occurs over an extremely short time interval, and a digital high-speed camera is needed to record and optimize the process. The collision sequence is illustrated in Figure 4, whereby 11 (eleven) successive frames have been superimposed in order to capture the complete contact event of a single bristle. One may observe that the incoming bristle approaches the surface (bristle is moving from left-to-right) in frames 1, 2, and 3, and undergoes impact with the metallic surface in frame 4. Subsequently, frame 5 indicates that the bristle tip has rebounded from the surface, and
Figure 4. Successive frames of a single bristle taken from high-speed digital camera depicting the approach (frames 1, 2, and 3), contact/collision (frame 4), subsequent retraction (frame 5), and return to equilibrium position (frames 6-11) of bristle.
has actually retracted toward the rearward direction (i.e., behind the initial impact site). Frames 6 - 11 show successive stages of the bristle motion as further recovery occurs, and the bristle eventually returns to an equilibrium position. The actual impact crater that is formed during contact with a ductile surface (API 5L piping) is shown in Figure 5, and indicates a micro-excavation termed "shoveling", which is similar to those generated by grit blast media (3).
Figure 5. Scanning Electron Microscope (SEM) micrograph of impact crater generated during bristle tip collision with ductile surface (API 5L) material system.
Corrosion Removal Performance and Texture
The corrosion removal performance and surface texture that can be achieved via bristle blasting operations is now examined within the context of removing severe corrosion from API 5L piping, which is commonly used for on-shore and off-shore applications in the petroleum industry. The initial surface of a severely corroded pipe that will be cleaned via the bristle blasting process is shown in Figure 6, whereby a uniform corrosive layer appears on both the internal and external surfaces. Examination
Figure 6. Corroded surface of API 5L pipe prior to cleaning via bristle blasting process.
of this corroded pipe suggests that the standard grade condition SSPC Condition D (100% rust with pits) accurately assesses the degree of surface corrosion.
In Figure 7 (top) the interior surface of a cleaned segment of the pipe is shown after bristle blasting, along with the initial corroded segment place directly below in Figure 7 (bottom) for comparison. Careful examination of Figure 7 (top) indicates that the cleaned
Figure 7. Photograph of cleaned API 5L specimen (top). Condition of initially corroded surface shown for comparative purposes (bottom).
surface has a uniform appearance and is free of corrosion. Detailed characteristics of the bristle blasted surface are shown in SEM micrographs appearing in Figure 8(a) and 8(b). A coarsely textured surface that is free of corrosion and corrosive pits is clearly seen in Figure 8(a) (magnification 20x), and evidence of uniformly dispersed craters formed by
Figure 8. SEM micrographs of the bristle blast treated surface shown in Figure 7 (top). Surface details shown in Figure (8a) at 20x; additional magnification of region indicated by the arrow is shown in Figure (8b) at 100x.
bristle tips is readily apparent. Higher magnification of the surface is shown in Figure 8(b) (100x) whereby individually formed craters can be seen that indicate repetitious impact of the bristle tips with the ductile material. Moreover, the craters closely resemble the morphology of the impact crater shown in Figure 5. Direct measurement of the texture appearing in Figure 7 (top) via standard press-film replica tape indicates that a uniform roughness of Rz - 80 (microns) is obtained.
As one may expect, continued use of the bristle blasting tool can lead to the eventual wear of bristle tips and, therefore, the eventual reduction of both corrosion-removal and texture-generating performance. In order to assess this aspect of tool performance, significant testing has been performed.
Based upon the surfaces prepared via bristle blasting (see Figure 3(b) and Figure 7 (top)), a direct comparison can be made with visual cleanliness standards that are published by the Steel Structures Painting Council (SSPC), and widely used by the trained workers in the surface preparation community. In each case, the surfaces far exceed the cleanliness that is associated with published norms for various hand and power tools (4). However, the appearance/cleanliness of these surfaces is quite comparable to SSPC "white metal" standards (that is, SP 5 and SP 10) that are typically associated with grit blasting processes (5).
1. Wojnar, N., 2006, Design and Application of Rotary Bristle Brush for Peening Applications, M.S. Thesis, Marquette University, Milwaukee, WI 53233.
2. Stango, R. J., and Khullar, P., 2008, Introduction to the Bristle Blasting Process for Simultaneous Corrosion Removal/Anchor Profile, ACA Journal of Corrosion and Materials 33 (5), 26-31.
3. Budinski, K. G., and Chin, H, 1983, Surface Alteration in Abrasive Blasting, Wear of Materials, 311-318.
4. SSPC-VIS 3, Visual Standard for Power- and Hand-Cleaned Steel, Steel Structures Painting Council, Pittsburgh, PA 15213-3724.
5. SSPC-VIS 1, Guide and Reference Photographs for Steel Surfaces Prepared by Dry Abrasive Blast Cleaning, Steel Structures Painting Council, Pittsburgh, PA 15213-3724.17:13 0 Comments
Russian and Caspian Oil and Gas News
Russia expects gas output at 700 bn cm in 2009
Russia's gas output is expected to reach 700 bn cm next year, up 3.2 % from an expected 678 bn cm this year, the Russian energy ministry said in a draft document. Last year Russia produced a total of 654 bn cm. According to the ministry's draft General Scheme for Gas Industry Development to 2030, in 2010 Russian gas output is forecast to reach 717 bn cm. The figure is a little higher than the recent outlook by the economic development ministry, which targeted output of 715 bn cm in 2010.
Over the next two years, some 85% of total output will continue to come from the traditional gas provinces in West Siberia. Production from East Siberia and the Russian Far East is expected to account for 16.7 bn cm in 2009 and 22.7 bn cm in 2010, up from 11.8 bn cm in 2007.
Russia is expected to add 783 bn cm of gas reserves in 2008, 686 bn cm in 2009 and 841 bn cm in 2010, the energy ministry's document said. Last year 684 bn cm of new reserves were added.
Turkmen cut 2008 gas output target
Turkmenistan, will cut gas output to 50 billion cubic meters this year from last year's 72.3 Bcm, Oil and Gas Minister Annaguly Deryaev announced.
The government had previously said Turkmenistan would produce 81.5 Bcm this year, but the country halted supplies to neighboring Iran in the first quarter amid a pricing row which led to a cut in output. Turkmenistan and Iran are due to sign a new supply agreement this month.
Turkmenistan sells most of its gas to Russia's Gazprom, but seeks to develop new fields and diversify exports. Deryaev also said Turkmen oil output would be 10 million tones this year, the same as last year.
DOCKWISE concludes USD 84m VYBORG / Shtokman Contract
Following the letter of intent announced in June 2008, Dockwise Ltd. announces that through its subsidiary Dockwise Shipping B.V., it has been contracted by Vyborg Shipyard to transport two topside structures from Korea to the Barents Sea and to install the units on semi-submersible hulls, using the float-over technique. Dockwise will receive USD 84m over the three-year contract, with the revenue contributing immediately to fourth quarter 2008 cash flows.
Vyborg Shipyard was commissioned by Gazflot (the operating arm of Gazprom) to construct two platforms designed for operation in the arctic conditions of the giant new Shtokman field, 600km offshore Murmansk. The first topside structure is scheduled to be loaded end April 2010 for installation between July and August 2010; the second at end October 2010 for installation around February 2011. The structures will be transported from Geoje Island, Korea, to the assembly locations in the Murmansk harbour area. Each topside is estimated to weigh around 22,000 tons.
Gazprom makes Yamal LNG partner list
Russia's Gazprom is considering US giants ExxonMobil and ConocoPhillips for its liquefied natural gas project in Russia's Arctic Yamal region, its deputy chairman said today.
"The list (of possible participants) is currently being made, but we do not exclude majors such as ExxonMobil and Conoco from joining the project," quoted Alexander Medvedev.
He also said Gazprom could work in gas projects in Alaska with Conoco in exchange for the US major gaining access to the Yuzhno Tambeisky deposits in Arctic Yamal. - "But nothing concrete has been decided yet."
Gazprom Neft weighs up MMG swap
The Khanty-Mansi Autonomous Region Government and Salym Petroleum Development N.V. (SPD) signed the Cooperation Agreement for 2009-2013 in Khanty-Mansiysk. The Governor of Yugra Alexander Filipenko and SPD CEO Harry Brekelmans signed the Agreement. This document will replace the current three-year agreement that expires by this year end.
New agreement covers extension of mutually beneficial cooperation aimed to further development of the autonomous region's industrial and scientific potential, application of the world high technologies in hydrocarbons exploration, oil production and processing, associated petroleum gas use and advanced environmental technologies.
Russia to build new pipeline
Russian gas giant Gazprom announced that it would build a pipeline directly to Georgia's rebel region of South Ossetia because of problems with natural gas supplies to the enclave after the recent war with Georgia. Gazprom said the new pipeline was needed because the current pipeline goes through the territory of Georgia proper.
Kupriyanov said the pipeline had been damaged and added that supplies were complicated by the fact that Gazprom had no direct transit agreement with Georgia for gas supplies through its territory to South Ossetia, said a Reuters note.
Rosneft to spend billions on Arctic fleet
Russian state-owned oil major Rosneft says it by year 2030 will need to construct 193 oil exploration and production units as well as vessels in order to meet the objectives of its shelf development programme.
The oil company, the biggest in Russia, intends to acquire 31 offshore licenses, among them on the northern shelf. For the development of the fields, the company will need 22 stationary platforms and ten mobile drilling rigs.
"Nord Stream on track for 2011 startup"
The Baltic Sea gas pipeline project, Nord Stream, is on track to deliver first gas in the fourth quarter of 2011 as it previously promised,
"We're absolutely on track to deliver the project on time and we are in budget," financial director Paul Corcoran said to Reuters.
His comments came as a relief to those supporting the 7.4 billion euros ($9.34 billion) project, which Russian President Vladimir Putin said recently that it could be scrapped if Europe continues to delay the project. The EU has identified the plan to pump 55 billion cubic meters of Russian gas annually to Europe via Germany - involving Russia's Gazprom, Germany's E.ON and BASF and Dutch Gasunie - as a key project to ensure secure gas supplies for Europe. But EU lawmakers have called for a new investigation into the Nord Stream's environmental impact.
Vantage Drilling Company Selects AMOS from SpeTec
Vantage Drilling, a company organized under the laws of the Cayman Islands, has chosen both the AMOS Business Suite for Maintenance and Purchasing and the AMOS2 Enterprise Suite for Quality Management throughout its fleet.
Vantage is dedicated to building and operating offshore rigs including technologically advanced dynamically-positioned Drillships and ultra-premium Baker Marine Pacific Class Jack-ups. Its first rig "The Emerald Driller" is scheduled for completion before Christmas 2008 at the PPL Shipyard in Singapore and is subject to a two-year drilling contract.
Brodospas also chooses AMOS
SpecTec (branch office in Croatia), has signed an Agreement for the delivery of AMOS Business Suite to Brodospas p.l.c., Split based shipping company. Software license includes Maintenance and Purchase as well as Quality and Safety modules.
New initiatives for developing Kazakhstan's oil and gas resources announced at KIOGE
The KIOGE Exhibition & Conference, Kazakhstan's leading oil and gas event, took place on 7-10 October in Almaty, Kazakhstan.
ITE's Oil & Gas Director, Graeme Coombes, explains the significance of the event in Kazakhstan, "Over 16 years, KIOGE has developed a reputation for being a source of the most up-to-date information about the oil and gas industry. Major new initiatives are regularly announced at the event and this year was no exception". This year, the two-day conference attracted a record number of delegates - 1,285.
A number of new initiatives and projects were announced during the KIOGE Conference. Kazakhstan's Minister of Energy and Mineral Resources, Mr. Sauat Mynbayev, revealed that a Memorandum of Understanding has been signed between KazMunayGas National Company (Kazakhstan), ConocoPhillips (US) and Mubadala Development (UAE), agreeing the terms for exploring and developing the N Block on the Caspian shelf. In addition, he announced that Kazakhstan is planning operations to develop the Satpayev and Darkhan shelf blocks.
Finally, Mr. Kiinov announced that a major issue for the industry has been resolved - from 1 January 2009, the price for gas exported through Russia will be determined according to the price in Europe minus GazProm's tariff and margin.
BP to restart last Azeri platform
A BP-led group will resume production in late December at the last Azeri offshore platform that remains shut after a gas leak in September, Azeri state energy company Socar said.
BP in September suspended oil production at two platforms, Western and Central Azeri, of the giant Caspian Sea deposit, Azeri-Chirag-Gyuneshli (ACG), due to a gas leak. It resumed work at Western Azeri in October.
"We will resume oil production at Central Azeri in the end of December," Socar chief Rovnag Abdullayev told reporters. ACG is the main source of oil for the BP-operated Baku-Ceyhan pipeline, which runs from the fields in the Azeri sector of the Caspian Sea to the Turkish Mediterranean coast.
Russia-China talks to pick up
Russia will resume talks with China over $25 billion in loans as part of a broader deal with Beijing over crude supplies within days, Russian Energy Minister Sergei Shmatko recently announced. The loans are of a crucial importance for Russian oil firms, which need cash to refinance their heavy debts and fund growth at a time of plunging oil prices. China is discussing lending Russian state oil major Rosneft and pipeline monopoly Transneft up to $25 billion in loans while Beijing would secure deliveries of Russian crude for 20 years.
Chinese Premier Wen Jiabao visited Moscow in October when the two countries agreed to jointly build a new overland supply route for Siberian oil to carry 300,000 barrels per day between the countries' trunk pipelines from 2009.
Gazprom not interested in Repsol
Russian energy giant Gazprom said it is not interested in buying 20% of Spanish energy company Repsol.
"Gazprom had and has no plans to buy 20% of Repsol," Sergei Kupriyanov, the Moscow-based company's spokesman recently stated. Gazprom supplies about a quarter of Europe's gas and has said it wants to expand into marketing and distribution, as well as liquefied natural gas.
Miller in under-investment warning
The world will face a shortage of oil supplies sooner than expected because companies already under-invest in production said Alexei Miller, chief executive of Russian gas monopoly.
"Oil companies are beginning to under-invest in production due to the financial crisis. I think it means that a supply shortage will come much earlier," he said. Gazprom controls Russia's fifth-largest oil producer, Gazprom Neft.
Daily Production Reaches 140,000 bopd at Salym oilfields
The total daily production from the Salym oil fields in Western Siberia, developed by Salym Petroleum Development N.V. (SPD), has reached 140,000 bopd (over 19,200 tone per day). SPD CEO Harry Brekelmans, commenting on the announcement, said: "Since October 2007, when SPD reached a 100,000 bopd milestone, we have continued increasing production volume in a systematic way by putting on stream new wells and optimizing production processes. Over this period, our daily production went up 1.4 times, which took us to the current benchmark of 140,000 bopd. We have produced over 37 million barrels (over 5 million tones) of oil year-to-date, which is more than 20% increase on our total oil production last year. SPD is steadily moving forward to its goal of becoming one of the best operating companies in Siberia."
Lukoil consider reducing 2009 spend
Russia's second biggest oil producer Lukoil could halve its 2009 capital spending programme to $4 billion if the global oil price falls below $45, chief executive Vagit Alekperov announced recently. Alekperov said that if Lukoil had to reduce the programme, the cut will mostly be applied to its refining projects and the company was not going to delay the launch of new deposits in west Siberia and the Caspian Sea.
"We have worked out three scenarios with oil price of $80, $65 and $45 per barrel," Reuters quoted Alekperov as telling reporters. "At $80 per barrel we will have investment programme of $8 billion, at the next scenario the programme will be less by $2 billion and at $45 the figure will be $4 billion."
TMK lines up ONGC pipe deal
TMK, Russia's largest producer of steel pipes for the energy sector, has said it had signed a deal to supply pipes to India's Oil and Natural Gas Corporation (ONGC).
Under the deal, TMK will supply ONGC with around 20,000 tones of seamless casing pipe over the next two years, Reuters quoted the company as saying in a statement. The pipes will be produced at the company's Volzhsky mill. TMK did not disclose the value of the deal. Yesterday, the company also said it had won a tender to supply pipes to Turkmenistan's national gas company.
Formation of CLYDEUNION – A Global Pumping Leader
Clyde Blowers, the East Kilbride--based group owned by Scottish entrepreneur Jim McColl, had reached agreement to purchase Textron's Fluid & Power Division. As a result of this transaction the former Textron company Union Pump, headquartered in Battle Creek, Michigan, will integrate with Clyde Pumps, the company formed by Jim McColl following the highly-publicised purchase in May 2007 from Weir Group of iconic company Weir Pumps based in Glasgow, Scotland.
These two leading pump companies have been re-branded as CLYDEUNION and its combined workforce of over 1400 will provide a comprehensive range of engineered centrifugal and reciprocating pumps as well as aftermarket parts and service from their global manufacturing facilities and joint venture companies in India and China.15:19 0 Comments
Monday, 16 February 2009
NORD STREAM PROJECT: SIIRTEC NIGI AWARDED THE GAS TREATING PLANT
Milan, February 15, 2009. Siirtec Nigi S.p.A. is pleased to announce that it has been awarded a contract by OAO Gazprom to implement the biggest silica gel plant in the world to be located at the Portovaya Compression Station near the Russian town of Vyborg. Contract value is in the region of 400 million Euros. The contract is part of the ambitious Nord Stream Project which includes the 1,220 km gas pipeline that will carry natural gas from Russia to the European Union via the Baltic Sea. The award follows highly competitive international tender over several months.
The plant will dehydrate and control the hydrocarbon dew point of 170 million cubic meter per day (6 billion cubic feet per day) of natural gas to reach the stringent specifications required by the submarine pipeline. The plant, operating at 75 bar (1088 psi), will use high performance silica gel manufactured by BASF.
Siirtec Nigi's scope of work includes the supply of technology, engineering and procurement of equipment and materials to be delivered in two phases (October 2010 and October 2011). In addition, the company will be responsible for erection supervision and start-up activities. This fast track contract consolidates Siirtec Nigi's experience in the implementation of silica gel gas dehydration plants.16:20 0 Comments