'XMAS TREE' handling for offshore operations

A J D Neuhaus hydraulically operated crane with 80 tonne lift capacity has been delivered for operation on the semisub rig Spitsbergen, designed and built by Aker Solutions for operation on the Norwegian continental shelf.
 
This advanced rig will be used to find new oil and gas resources in the North Sea, and the JDN crane will be used for the transportation of 'xmas tree' assemblies which provide essential flow control, pressure relief, monitoring, feedback and other important functions associated with the wellhead.
 
Some of the specialised features of the crane include a radio control system, together with a rack and pinion drive providing safe power transmission for both crane and hoist travel movements when operating offshore or as vessel mounted units. Simultaneous control of several hoists is also provided together with signal horn, key switch and much more. A stainless steel switch cabinet with receiver is provided to operate as an electro-hydraulic interface, together with all necessary hydraulic pipework.

The crane provided is a double girder overhead travelling design. Single girder cranes can also be supplied, as well as slewing jib cranes and underslung cranes with special low headroom trolley designs. Synchronised hoist and parallel hoist lifting operations can be accommodated, as well as customised crane adaptations for special purpose requirements.

The explosion proofness of the crane and hoist mechanisms ensure suitability for operation in hazardous areas. Non-lube low maintenance, 100% duty rating and the use of offshore rated paint finishes also endorse these high performance products for offshore operations. For further information, e-mail: info@jdneuhaus.co.uk  or view website: www.jdneuhaus.co.uk   Refer to next page

Video inspection and internal weld scanning from a single source

Hugh Davies, Head of Sales at OMS Ltd, discusses how video inspection and internal weld scanning tools are being used to check weld quality on pipes and other deepsea subsea oil and gas structures.

When carrying out inspection, the inside of pipelines and other subsea structures such as valve manifolds, video inspection can provide close-up views of features that are otherwise very difficult to access. Video inspection enablesallows inspectors to assess a wide varietyrange of features relating to welds, internal corrosion, internal structure, coatings and so on.

Whether onshore or offshore, inspectors need the best possible lighting and video technology, as well as a variety of methodsways of deploying the video tools inside different types of structures. Optical Metrology Services (OMS) Ltd has a wide range of state-of-the art advanced video inspection equipment. This includes the latest pan- and- tilt camera technology, auto-focus zoom lenses, tractor systems and motorised cable reels.

For specialist weld inspection applications, OMS designs and manufactures unique digital imaging solutions, which can be deployed inside hot pipes during production welding. OMS also offers tool operators and qualified weld inspectors, who to provide a full turn-key solution. Bespoke designed and manufactured systems can be delivered to solve the most challenging client inspection requirements.

For 'reeling trials', OMS offers video inspection services that can be combined with laser scanning of pipes to provide a combination of imaging and dimensional mapping of pipes or features in 3-D.

OMS inspection reports provide comprehensive independent inspection records, which can include still images, video records, interpretation and analysis.

OMS clients can access the best technology and skilled, experienced operators to deliver the best possible video inspection in challenging pipeline engineering applications. Whether the application is in QC, standards compliance, or in special projects, OMS delivers the best solution.

Internal weld scanning
In oil and gas pipes, the quality of the root pass of a weld is critical to the structural integrity of the girth weld. Oil and gas companies therefore have stringent inspection requirements for checking welds. However, few if any tools currently exist on the market that can perform this kind of work. Welding of clad pipe is especially challenging and requires accurate measurement of the weld area in order to ensure zero defects and to avoid the delay and cost of a weld cut out later in the welding process.

Using its groundbreaking internal weld inspection system, in combination with video-based inspection systems, OMS offers customers comprehensive inspection services for checking the internal size and shape of girth welds on pipes that are destined for use in deepsea subsea oil and gas applications.

The Internal Weld Scanning Tool is a unique system that internally scans welds inside pipes, both visually and dimensionally, enabling the quality of the root weld to be assessed quickly and confidently. The tool is available on a service contract or rental basis, with a trained OMS inspector.

The service is available both onshore and offshore at different stages of the pipe welding process. The internal weld scanning tool can be used on corrosion-resistant alloy-lined pipe to identify sour (aggressive) ingress points, in both clad butt-weld and clad weld inlay applications. The tool can also be used to improve weld procedure development efficiency and to check the root weld and geometry before next passes are deposited. The technology provides similar uses in fatigue-sensitive applications (SCRs) where the pipe is subject to higher dynamic stresses.

Using OMS' internal weld scanning service, a wide range of weld features can be detected, including root penetration, root concavity, cracks, lack of penetration, discolouration, oxidisation, surface porosity and burn-through.

The Internal Weld Scanning Tool can be mounted to a purge dam, with an integrated camera for positioning and inspection. Pipe can be inspected whilst it is being spooled onto a pipe laying vessel or during stalk fabrication/tie-in. Here, the tool is retrieved using a winch and wire system, with weld positioning controlled by a camera and precision motorised system.

The service includes integrated analysis software, which enables the documentation and interpretation of internal weld features, as well as the measurement of cross-sectional data. Scanning a typical 10-, 12- or 14-inch diameter pipe takes around 45 seconds in total. Once the automated scanning of the root weld is complete, the software enables the user to identify the features of the weld and measure them. Cross-sections around the weld, for example, can be chosen and the main features of the weld then measured.

The software is also a traceability tool. Inspectors can choose cross-sections around the pipe at regular angles and log any defects as they are found. The software automatically records all measurements, as well as typed comments from the inspector. This information, including sample images and cross-sectional profile data, can then be archived. Logged data can be directly imported to Microsoft Excel as part of a weld inspection record.

For further information, view website: www.omsmeasure.com or e-mail: denise.smiles@omsmeasure.com  Refer to page 72 

Laser, video and ultrasonic inspection of
pipe root welds is an oil and gas industry first

UK-based specialist pipe measurement technology company Optical Metrology Services (OMS) Ltd has successfully completed an on-site internal weld inspection survey for a major oil company. This is the first time that a combination of laser, video and ultrasonic inspection methods have been used in a production environment to inspect the profile of root welds on pipes. The survey was carried out by OMS' US-based operation.

In late 2009, OMS was approached by a main contractor on an oilfield project and asked to provide a team of on-site inspectors to carry out a full inspection survey of a number of subsea modular valve manifold systems.

Using its laser-based dimensional measurement tools and video-based inspection systems, OMS was responsible for assessing the internal root welds for any defects. The inspection requirements covered the full range of weld features including crown height, undercut, porosity and burn-through. OMS' on-site inspectors were also required to perform inspections at welding temperatures (i.e. up to 250 deg C). In order to do this, OMS adapted its own weld inspection technology to enable it to operate at these elevated temperatures.

Dr Richard Gooch, Director of Technology at OMS commented: "On this project, the pipes on the modular valve manifold system were almost entirely lined with a special corrosion resistant material. Our team of three inspectors therefore had to make sure they didn't overheat these coatings whilst carrying out inspections. On average, it was taking the customer around four days to complete a root weld pass. If there were flaws in a weld, this would have to be repaired or cut out. Our inspectors carried out their inspections immediately after the hot pass."

"The laser and video-based inspection of root welds took approximately 10 minutes to complete. In this time, we gave our initial verdict to the customer's QA engineer on whether we thought there was a problem with the root weld. If we were uncertain, the laser inspection procedure was repeated but this time at finer detail [every 0.5mm] than before and double-checked using video-based inspection technology. The depth of the weld feature could then be examined more closely and a final verdict reached," he added.

Whilst ultrasonic or radiography technology is commonly used to inspect pipe root welds, this technology is not so effective when the weld defects are very small. OMS provided a team of three inspectors at site, one of these being a fully certified weld inspector.

"The modular valve manifolds are mounted on 30-foot skids and are critical junctions within oil or gas pipelines. Our inspection tools were able to pass around 90-degree bends and 33-degree bends in the pipework, as well as inside the valves themselves. In order to do this, OMS designed a special laser-based measurement system that incorporated a slide rail, stepper motor and optical laser sensor. This allowed us to push the tool in very small, half millimetre steps through the pipes to inspect the profile of the welds," explains Gooch.

OMS' solution included blowing cold, compressed air over the inspection tool in order to combat the welding temperatures. A video camera was then used in combination with a shaft encoder to further inspect weld defect areas.

"This is the first time that these types of manifold system have been inspected using a combination of laser, video and ultrasonic measurement techniques. The end customer asked for this and OMS was able to provide it. Many customers think that laser and video-based measurement techniques are too complex and so are only used in laboratory work and not in production environments, but OMS has proved the doubters wrong," enthuses Gooch.

Optical Metrology Services in profile

Optical Metrology Services Limited (OMS) is a market leader in the provision of pipe measuring products and services. The company specialises in measuring equipment and consulting services for use within the pipe manufacturing and pipeline construction sectors, both onshore and offshore. A key focus for OMS is in the dimensional measurement of oil and gas pipes or other structures such as military gun barrels, processing industry tubes or manufactured cylindrical objects, where dimensions are critical.

OMS prides itself on finding out what clients require and delivering it. OMS was recently recognised by being awarded The Queen's Award for Enterprise in the Innovation Category, the company's second award in 2007 (the first award being the Pipeline Industries Guild Award for Land Based Technology).

The OMS Pipe Checker™ range of tools provides dimensional checks on all aspects of manufactured pipe. These tools are used throughout the world for onshore and offshore projects and in pipe mills.

For further information, view website: www.omsmeasure.com or e-mail: denise.smiles@omsmeasure.com  Refer to page 72