Kings of the Gulf

April 23, 2014

Two of the major deepwater developments that have started production so far in the Gulf of Mexico belong to Shell and BP. Sarah Parker Musarra examines the technology behind two mammoth projects: Mars B and Na Kika.

In Greek and Polynesian mythology, Mars, Olympus, and Na Kika are synonymous with gods and kings: Mars, the Greek god of war; Olympus the great mountain ever-looming in Greek mythology; Na Kika, the Polynesian octopusgod. Mars B Olympus and Na Kika Phase 3 achieved first oil weeks apart in February 2014, and Shell and BP hope the developments reach the same elite status as their respective namesakes.

While Mars B and Na Kika share some surface similarities – both are in the Mississippi Canyon blocks, both are notable in size and in water depth – the main commonality between the two developments is their uniqueness.

Mars B

Discovered in 1989 and brought into production in 1996, Shell’s Mars field is a massive resource in the Gulf of Mexico. The field has produced more than 770MMboe to date, exceeding Shell’s own estimations at the time of discovery. The Mars field is located in 3100ft of water, and is home to the 24-well, 3250ft tall Mars A tension-leg platform (TLP).

As the field aged, Shell surveyed Mars.

“We stepped back and looked back at the opportunities remaining at the Mars field purely as a deepwater giant,” Shell Business Opportunity Manager Derek Newberry, who lead the team accountable for the Mars B Olympus project execution, explained. “It has a hydrocarbon column that spans from 10,000ft below sea level to 22,000ft below sea level.

“It is a significant resource base,” he said.

Shell hit back-to-back discoveries with West Boreas and South Deimos in 2009 and 2010, respectively. At that point, Mars’ future landscape started shifting.

“Once we made those discoveries, we assessed the range of potential hydrocarbon volumes that could be recovered from those fields,” Newberry said. “Once we had the range and potential volumes, we worked out what kinds of development concepts we could place on West Boreas/South Deimos to recover that resource base.”

Newberry said that recognizing the strength of the existing TLP and the close proximity of the West Boreas and South Deimos discoveries led Shell to make a landmark decision for the deepwater development, saying that it was “the first time in the deepwater Gulf of Mexico that the decision has been taken to add such significant infrastructure to an existing field.”

Located in MC807, Olympus, the field’s second TLP, discovered new life on Mars. Shell says Olympus extends the life of the field to at least 2050. Its first well produced first oil on 4 Feb 2014, Shell estimated production will reach 1 billion boe, with potential to deliver production rates at around 100boe/d. The company’s largest floating deepwater Gulf of Mexico platform, it also has a self-contained drill rig.

Reservoirs are located at depths of 10,000 - 22,000ft, which is around 2-4mi below the seafloor.

Newberry said that the infrastructure of the Mars B venture can be broken into three major segments: Olympus, which is located about 1mi. southwest of the existing Mars TLP; West Boreas/South Deimos subsea development; and the development’s export solutions.

The 6-well West Boreas/South Deimos is tied back to Olympus through a single seabed manifold located 3mi. west of the TLP. Two production flowlines along the seabed tie the manifold back to Olympus through production risers. Umbilicals power the wells, and provide the various fluids and chemicals the subsea wells may require throughout their lifetime.

Although Shell considered other options, the decision to employ a tieback fast became the best solution.

“We looked at the concepts and identified that there was tremendous energy (potential) by developing West Boreas/ South Deimos as a subsea tieback to the Olympus TLP,” he said, and explained that the short “competitive” cycle time from discovery into production was “through the tieback.”

FMC Technologies (FMCTI) supplied the subsea system and the controls. For the project, FMCTI used “the first 15,000psi, 300°F vertical tree, ever,” which was a “high-pressure/ high-temperature (HPHT) milestone” for the company and the industry, a spokesperson from FMCTI said. The West Boreas/South Deimos trees were FMCTI’s proprietary Enhanced Vertical Deepwater Tree, which was developed in partnership with Shell. The spokesperson also said that it was “the first HPHT version of this successful deepwater tree.”

The oil and gas export system runs north to the existing West Delta complex. Shell added an additional shallow water platform, West Delta 143C.

“The Mars B development truly is a global endeavor when you’re looking at adding infrastructure of this magnitude,” Newberry said. “We had activities that spanned the globe from Asia, to the US, to Europe. During the period of September 2010 to first oil in February 2014, over 20,000 people will have worked on Mars B within the US alone, covering 30-something states.”

Shell is the operator of Mars B with a 71.5% stake. BP holds the remaining 28.5%

Na Kika Phase 3

As Mars B Olympus maximizes the potential of an existing field, Na Kika’s novel design allows production from multiple independent fields through the host facility, Na Kika semisubmersible platform, which is located in a whopping 6300ft of water. The development’s Octopus-like design is the inspiration behind its name, with the host semisubmersible platform acting as the body, and the flowlines to the eight fields serving as the tentacles.

According to the supermajor, the Na Kika platform has a design life of 20 years. It was BP’s first semisubmersible platform, and was the only semisubmersible in the Gulf of Mexico at the time of installation. It also houses the largest oil storage facility in the Gulf of Mexico.

The original development, which started production on 26 November 2003, consisted of five fields. Like Mars B, Na Kika Phase 3 augmented existing infrastructure through the addition of new equipment to boost production and subsea infrastructure to tieback to the platform. Two additional wells were also drilled and completed. Na Kika Phase 3 achieved first oil 19 February 2014. Another well is expected to come online Q2 2014, BP said.

“The well locations were identified through studies involving the drilling, completion and subsurface teams, evaluating well trajectories to access the reservoir targets, considering subsurface geological structure and well design and execution risks,” Brett Clanton, spokesperson for BP, said.

The giant, 31,475-ton Na Kika platform currently services eight fields through subsea wells and deepwater tiebacks – some of which are predominantly oil, and some of which are predominantly gas – and is capable of producing from additional fields.

The wells are in water depths ranging from 5800ft to 7750ft, making it the deepest subsea cluster in the world. Na Kika field has recoverable reserves of 300MMboe, with a peak production rate of around 110,000b/d oil and 500 million Tcf gas.

“The targeted reservoirs for this project were able to be accessed via wells drilled from locations in close proximity to the existing infrastructure, where subsea tie-in points for future access existed. The location and available facility capacity was key to concept selection for this project,” Clanton said.

According to Shell International E&P Inc.’s W.H. Luyties and Shell E&P Americas’ T.P. Freckleton’s paper presented shortly after Na Kika’s first oil at Offshore Technology Conference 2004 entitled, “Na Kika - Novel Development in Record Water Depths,” “none of the fields on [their] own could be developed economically with the technology available [at the time of production].”

The unprecedented water depth affected most aspects of the development. Luyties and Freckleton listed “designing a robust subsea and surface production system that addressed all the complexities of multiple, small fields tied-back to a host,” along with “drilling and completing the wells, including horizontal wells and multi-zone completions” in “record” water depths as some of Na Kika’s greatest challenges.

Gas is exported through the Okeanos pipeline system, which in turn is a part of the Mardi Gras transportation system. The pipeline is roughly 75mi.-long. Oil is exported through a 74mi., 18in pipeline, which was the “deepest pipeline ever installed in the flooded condition,” according to Shell E&P International – EP Project’s Frans Kopp, Bruce D. Light, Thomas A. Preli, Vidish S. Rao and Kent H. Stingl paper “Design and Installation of the Na Kika Export Pipelines, Flowlines and Risers” presented at OTC 2004. The oil export pipeline is one of several “significant ‘[world]-firsts’” that were achieved in the design and installation of the export pipeline and subsea flowline systems.

FMCTI supplied the 12 enhanced vertical 10,000psi subsea trees, subsea distribution system, flowline connector equipment, and jumpers. FMCTI claimed its own first for the Gulf of Mexico: The Na Kika development is the largest platform to use the standard 4in.- by-2in. vertical tree completion system. Na Kika is a joint partnership between BP, as operator, and Shell, which have equitable holdings. Shell transferred its operatorship to BP upon the start of production in 2003.

As companies jockey for position in one of the most promising exploration areas, Shell and BP’s unique Gulf of Mexico partnership has resulted in two projects that, at least in name and size, reign the Gulf.

Development facts at-a-glance

Na Kika host facility

Mars field facts

Mars B Olympus TLP facts

Building Olympus: a chronology of events

April 1989

Mars oil and gas field discovered over Mississippi Canyon Blocks 762, 763, 806, 807, 850, 851. Production began in 1996.

September 2010

Shell made its final investment decision and sanctioned Mars B.

September 2010

FMCTI won the subsea, topside systems contracts for West Boreas.

July 2011

The US government approved the West Boreas/South Deimos exploration plan and drill permit application.

November 2012

Olympus hull leaves Samsung Heavy Industries’ South Korean yard to embark on a 18,272mi trip to Ingleside, Texas.

January 2013

Olympus hull reached Ingleside after an 18,272mi.

June 2013

Tenaris announced it would provide Olympus’ riser connections.

July 2013

Traversing 425mi in 10 days, four Crowley Maritime high-bollard-pull, ocean-class tugboats worked in tandem to deliver Olympus to the Mars B field.

February 2014

Shell starts production from the Mars B development, extending the life of the Mars field to at least 2050. Combined future production from Olympus and the original Mars platform is expected to deliver an estimated 1billion boe.