TDW Helps Relieve Stress on Riser Offshore Malaysia

Posted by Eric Haun
Thursday, June 26, 2014
Photo courtesy of T.D. Williamson

Comprehensive pipeline services solution allows preventive measures to be carried out safely

T.D. Williamson (TDW) announced that it recently completed a comprehensive pipeline services program for a major offshore operator to assist with efforts to relieve increasing contact stress between a gas export riser and platform jacket offshore East Malaysia.

Due to changes in seabed conditions, the platform jacket had moved, producing stress on the gas export riser attached to the platform jacket. The stress was most acute at the contact point between the bracings - or riser clamps - that anchor the riser to the platform structure. Concerned that the amount of stress developing at the contact point could eventually damage the riser, the operator decided that the best solution was to cut out and remove a section of the jacket bracing. Removal of the brace would not affect the technical integrity of the structure.

To ensure that the bracing could be safely removed from the pipeline, the customer requested TDW to isolate the affected section of the subsea line by inserting and setting a remotely-operated SmartPlug isolation tool in the line approximately 100m from the platform. By doing so, only a short section of the pipeline had to be depressurized and isolated while the bracing was removed. The only alternative would have been to depressurize the entire pipeline, which would have been extremely time consuming and costly. Further complicating the situation was the fact that the line is tied in to another major pipeline that extends to a central riser complex. This line would have had to have been bled down as well, causing major disruption to overall production from the field.

Before the pipeline could be isolated, however, it became apparent that one of the topside motor-operated valves (MOVs) closest to the pig launcher would not open properly, so it would have to be replaced in order that the SmartPlug tool could reach the point of isolation. To rectify this, TDW performed a hot tap and STOPPLE plug isolation on the line at a point located on the riser above the shutdown valve (SDV), thereby providing double-block isolation so that the operator could safely replace the malfunctioning MOV. Once the MOV was replaced, TDW launched the SmartPlug tool to the set location in order to isolate the line connected to the jacket bracing, which required a section removed. The line was isolated for five ¬days, which allowed a diving contractor to safely remove the bracing without disrupting production. The SmartPlug tool was then unset and retrieved back to the launcher.

Unexpected situation demands full range of pipeline services
As a result of the unforeseen requirement to replace the MOV, the challenges faced by the customer grew significantly. TDW worked closely with the customer to make certain that, in spite of the MOV replacement, the bracing would be safely removed within the original timeframe. First, TDW manufactured a special custom fitting for the hot tap and STOPPLE plugging operation at its manufacturing plant in Tulsa, Oklahoma in a very short time. TDW then managed the entire operation, working closely with its teams in Norway, Belgium and Singapore, and collaborating with its network of trusted specialists to provide welding, and nitrogen and water pumping services. TDW performed all this in just four months.

“Our customer was faced with a unique and pressing challenge: to relieve the increasing stress on the riser by removing the subsea bracing, without disrupting production,” said Rolf Gunnar Lie, Business Development Manager – Asia Pacific for TDW. “The fact that a defective MOV prevented us from immediately isolating this line so that the bracing could be removed safely could have been a real setback, delaying this critical work for months. In addition to SmartPlug pressure isolation services, TDW has deep experience in hot tap and STOPPLE plugging services, so we were able to help solve this problem and move forward rapidly,” he added. TDW made it possible for the customer to extract the bracing, which alleviated the growing pressure on the riser, ensuring that it continues to operate safely.

TDW’s relationship with the operator dates back 12 years, supplying pipeline pressure isolation services to facilitate safe maintenance activities on export lines and pipeline tie-ins. This recent operation was executed as part of a framework agreement between the two companies, which was extended in 2012.

Construction works trigger increased demand for isolation services

With operators keen to protect live pipelines and maintain production while construction or repair works take place, TDW reports increased demand for its specialist pipeline isolation services, particularly in Asia Pacific. By isolating a designated section of a pipeline with its SmartPlug technology, customers avoid the trouble and expense of having to completely depressurize the entire line. In addition, the line can remain isolated for extended periods - months, if necessary - while work is carried out, or if work is delayed due to inclement weather or other extenuating circumstances.

tdwilliamson.com

 

  • Photo courtesy of T.D. Williamson

    Photo courtesy of T.D. Williamson

Maritime Reporter August 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

Ship Repair & Conversion

China’s Shipyards Face Tough Times

As the shipping market continues its prolonged downturn five shipyards have filed for bankruptcy this year, reports SCMP.   China's leading private shipyards

Ferguson to Build Two CalMac Ferries

Scottish minister Nicola Sturgeon have named Ferguson shipyard as the preferred bidder for a £97 million contract for the biggest new ferries on the Clyde since

Private Ship Repair Moves Dry Dock Timelines

A delay in private repairs to the hospital ship Africa Mercy has caused a two-and-a-half week adjustment of timelines for Transnet National Ports Authority’s R30

News

China Merchants Profit up 29pct

While China’s ports continue to face growth pressure, the country’s largest port operator is reaping the rewards of years of investments in overseas projects.   China

Swire Upgrades Asia-Pac Coverage

Singapore-based liner trade division of The China Navigation Company (CNC) Swire Shipping has upgraded its multipurpose liner service coverage in the Asia Pacific region.

Baltimore Port Shipments Hit New Record

Helen Delich Bentley Port of Baltimore's public terminals shipped a record 9.74 million tons of general cargo in the 2015 fiscal year ending June 30, it said Monday.

Maritime Safety

Seychelles to Join India-led Maritime Security Alliance

Seychelles  said that Indian ocean region "belongs" to countries sharing maritime boundaries and said it was "actively" considering participating in a security

Hurricane Fred Strengthens in Eastern Atlantic

Hurricane Fred strengthened early Monday in the eastern Atlantic as it approached the Cape Verde Islands, while the remnants of Tropical Storm Erika brought flooding to parts of South Carolina,

Cargo Ship Collides with Fueling Vessel at Sea

A 24-meter fuelling vessel, Erin Wood, was towed to Peterhead Saturday after a collision with a Cyprus registered cargo vessel, Daroja, the U.K. Maritime and Coastguard Agency (MCA) reported.

Offshore Energy

Harkand: Expanding the Fleet, Growing a Global Business

International inspection, repair and maintenance (IRM) company Harkand aims to be a $1 billion company. MR’s Tom Mulligan recently met with John Reed, the company’s CEO,

HHI Orders Regasification Systems from Wärtsilä

South Korean shipyard Hyundai Heavy Industries (HHI) has ordered two seawater/propane based regasification modules from Wärtsilä. The systems are to be installed

Hitachi Gas Supply System Order for MHI

Mitsubishi Heavy Industries, Ltd. (MHI) has received an order from Hitachi Zosen Corporation for a high-pressure gas supply system enabling use of natural gas as fuel in marine engines.

 
 
Maritime Careers / Shipboard Positions Maritime Contracts Maritime Security Offshore Oil Pod Propulsion Salvage Ship Repair Ship Simulators Shipbuilding / Vessel Construction Winch
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 1.0016 sec (1 req/sec)