DRILLING TECHNOLOGY: Traditional blowout preventer beginning to change

The traditional blowout preventer (BOP) stack has not experienced much change or innovation through the years. The few changes made have been in elastomers and sealing mechanism technologies.

Unique innovations, however, are starting to emerge in BOP technologies. Shaffer has introduced boltless BOP doors, automated ram changing systems, a weldless-cavity enhanced ram locking system, and a floating ram block design, to name a few.

Boltless BOP doors yield benefits such as reduced weight, reduced height, elimination of hands-on manual labor (a key health and safety issue), elimination of cross threaded bolts, and ram change time reduced from four hours to 40 minutes (15 minutes with an automatic ram changer).

The ram locking mechanism within the piston assembly is enhanced with the Shaffer UltraLocktrademark II system. This locking system is not dependent on closing pressure to maintain a positive lock. The system automatically locks in the closed position each time the piston assembly closes.

The system requires no adjustments for varying pipe size. Only one hydraulic function is required when operating the cylinders' open/close function. Maximum hang-off weight is 600,000 lb at full working pressure.

Ram changeout

One of the newest innovations in routine BOP operations is the use of a mechanical ram changing arm. The automated ram changer (A.R.C.trademark) effectively removes personnel from the ram changing operation. The absence of bolts on the Schaffer ram doors creates an immediate time-savings. Traditional ram door bolts can require up to 15 minutes for removal, 30 minutes to clean and prepare threads, and 35 minutes to re-install the bolts. Total change time required can be 30% of a traditional BOP ram design.

Transporting BOP stacks can require multiple equipment loads to the dock for delivery to the offshore platform. The stack arrives at the rig or platform unassembled requiring complete nipple-up. This is efficient and requires valuable rig time to complete. All ram wear components are removable, implying infield repairs are possible now.

The next step for this technology will be taking it to the subsea environment. The ability to change rams without having to pull the BOP stack will result in time-savings. For operations in deep and ultradeep waters, this will contribute directly to the bottom line.

Rotating BOPs

Rotating BOPs are not new to the industry. They have been used for years in different capacities and applications around the world. Most of the work with rotating BOPs has been done on land, with limited use in the offshore environment. Common industry thinking is that rotating BOPs are only useful for under balanced drilling (UBD) applications.

The BOP senses well bore pressure and adjusts annular rubber pressure to a preset differential over kick pressure. One operator currently uses the Schaffer rotating BOP to rotate in the prevention of stuck pipe.

Related Articles

Husky targets mid-year start-up for South White Rose offshore Newfoundland

Dec 17, 2014

Husky Oil expects first oil in mid-2015 from the South White Rose satellite extension offshore Newfoundland & Labrador.

Vaalco reassesses offshore Gabon plans following H2S inflow

Dec 17, 2014

Vaalco Energy says the jackup Transocean Constellation II has completed the first development well drilled from the newly installed Etame platform offshore Gabon.

NPD authorizes three wells offshore Norway

Dec 16, 2014

Maersk Oil has permission from the Norwegian Petroleum Directorate (NPD) for exploration drilling in license PL 510 in the Norwegian Sea.

ONGC makes oil and gas discoveries offshore India

Dec 15, 2014

ONGC has made new offshore oil and gas discoveries – one in the deepwater KG basin off the east coast of India, and the second in the Mumbai offshore basin off the west coast.

Eni completes production test on well offshore Congo

Dec 15, 2014

Eni has completed the production test on the Minsala Marine 1 NFW, located in the Marine XII block offshore Congo.

Trending News

Oceanteam sells vessel stake to J. Ray McDermott Norway

Dec 19, 2014

Oceanteam Shipping ASA has completed the transfer of its 50% ownership stake in its jointly owned pipelay vessel CSV North Ocean 102 to J. Ray McDermott Norway.

Ennsub unveils new deepwater deployment systems

Dec 19, 2014

Ennsub has completed the design and manufacture of two workclass ROV deployment systems, which have been designed and manufactured for ROVOP and are due to be installed into a newbuild, Tier 1 pipelay vessel early in 2015.

‘Largest’ new gantry crane launches Nordic Trym vessel

Dec 19, 2014

The new shipyard facility of Honghua Offshore Oil & Gas Equipment Co. in Jiangsu, China, has launched its first ship, an IMT982 platform supply vessel named Nordic Trym. The vessel was launched in a unique way, using the yard’s new gantry crane. 

Offshore photo of the day

Schlumberger to support Mariner well operations

Dec 19, 2014

Statoil has contracted Schlumberger Oilfield UK to provide integrated drilling and well services on the Mariner field in the UK northern North Sea.

  Offshore
Digital Magazine
Look Inside
Cover
Current Issue

Oil & Gas Jobs

Search More Job Listings >>