The Magazine for Underwater Professionals
Aberdeen, UK-headquartered subsea services provider Bibby Offshore reports it has successfully completed a contract worth more than £2 million for BP in the North Sea.
The project utilised Bibby Offshore’s diving support vessel Bibby Topaz to carry out inspection, repair and maintenance operations in the Rhum gas field, approximately 380 kilometres north-east of Aberdeen.
The scope included control system low insulation resistance diagnostics and component replacements, manual valve operations and ROV inspection works at BP’s Bruce platform, which is located 44 kilometres south of Rhum.
The project was also supported by an onshore engineering team to meet urgent client needs, the company said.
Howard Woodcock, chief executive at Bibby Offshore, added: “This is an important contract award for Bibby Offshore, and highlights the ongoing strong relationship between ourselves and BP.
“This most recent phase of work is the latest in a number of projects we have supported BP on and we look forward to continuing to work with BP now and in the future.”
Microsoft co-founder-turned-explorer Paul Allen has discovered the long-lost wreck of the World War Two aircraft carrier USS Lexington at the bottom of the Coral Sea.
The crew of Allen’s personal research vessel Petrel found the missing ship 3000 metres below the surface and about 500 miles (800 kilometres) off the eastern coast of Australia.
First conceived as a battlecruiser, the Lexington was redesigned to be one of America’s first operational aircraft carriers in 1922. She and another US aircraft carrier, the USS Yorktown, fought against three Japanese aircraft carriers from 4-8 May 1942 in the Battle of the Coral Sea, the first ever between carriers.
The badly damaged Lexington, nicknamed “Lady Lex”, was deliberately sunk by another US warship at the conclusion of the battle. More than 200 members of the crew died in the battle but most were rescued by other US vessels before the Lexington sank.
“Lexington was on our priority list because she was one of the capital ships that were lost during World War Two,” said Robert Kraft, director of subsea operations for Allen. “Based on geography, time of year and other factors, I work with Paul Allen to determine what missions to pursue. We’ve been planning to locate the Lexington for about six months and it came together nicely.”
The search team has released pictures and video of the wreckage of the Lexington and some of the remarkably preserved planes which went down with the ship. On one aircraft, an emblem of the cartoon character Felix the Cat can be seen along with four miniature Japanese flags thought to depict “kills”.
Phoenix, USA, reports it has completed an abandonment campaign in the Gulf of Mexico utilising its atmospheric diving system (ADS) Hardsuit and a surface supplied air diving spread mobilised on board a vessel of opportunity.
The project was executed in two phases.
In phase one of the project, Phoenix cut, plugged and abandoned a six-inch pipeline and umbilical exiting a J-tube at a depth of 530 feet (162 metres). Cuts were made using a guillotine saw and shears, followed by the ADS pilots capping the umbilical, plugging the pipeline, and abandoning both segments in place as per the Bureau of Safety and Environmental Enforcement (BSEE) permit. An ADS pilot then drilled a two-inch hole in the platform side of the cut pipeline using a magnetic drill and a messenger wire was deployed for the pilot to connect to the cut pipeline which was laid on the sea floor for subsequent recovery.
Phase two consisted of removing two six-inch (15.2-centimetre) risers and all riser clamps, two three-inch (7.6-centimetre) umbilicals and two umbilical I-tubes and all I-tube clamps to a depth of 430 feet (131 metres). ADS pilots, using a standard hydraulic impact wrench, opened and removed all clamps below 160 feet (49 metres), while surface divers completed the same from 160 feet to the surface. The risers were then lifted out and cut into sections by a platform-based construction crew with embedded Phoenix safety personnel.
In total, 20 ADS missions were completed with 61 hours in the water and divers performed 38 dives with 33 hours of total bottom time. The entire project was performed over 18 days using 3964 man-hours without a lost time incident, Phoenix said.
Norway’s Aker BP has received consent from the Petroleum Safety Authority (PSA) Norway to perform manned underwater operations in the North Sea at the Alvheim, Ula and Valhall fields.
The operations – scheduled to start in Q3 or Q4 of 2018 – will be undertaken by Aker BP’s contractor Subsea 7, utilising the DSV Seven Falcon, DSV Seven Atlantic and LDC Seven Spray.
The Alvheim field has been developed using a floating production, storage and offloading unit. The field includes three discoveries: Boa, East Kameleon and Kneler. These have been developed using individual subsea facilities tied back to the Alvheim FPSO.
The Ula field is in the southern part of the Norwegian sector of the North Sea. The development consists of three conventional steel facilities for production, drilling and accommodation, which are linked by bridges.
Valhall is an oil field in the southern North Sea in 70 metres of water. The field was originally developed with an accommodation facility, a drilling facility and a production facility. In 1996 a wellhead facility (Valhall WP) was installed, with slots for 19 extra wells.