It’s astonishing to see how the capabilities of the latest semisubmersible drilling rigs and drillships have transformed over the years.

Mr. Charlie, the industry’s first mobile submersible drilling unit, was a technological marvel at the time of its creation in 1953. It arrived in the Gulf of Mexico (GoM) in 1954 to start work for Shell Oil near the mouth of the Mississippi River in East Bay. It was able to accommodate a crew of 58, while the rig barge itself was approximately 67 m (220 ft) long and 26 m (85 ft) wide. It drilled hundreds of wells over a career spanning nearly four decades before it was put out to pasture as an exhibit at the Rig Museum in Morgan City, La.

That’s enough reminiscing. Fast forward to the present time, and the scale and expense of the latest generation drilling units as well as their technological advances are on another planet.

The subject of these advances came up during the recent Society of Petroleum Engineer’s Annual Technology Conference and Exhibition (ATCE) in New Orleans, very near to where Mr. Charlie now sits.

Latest generation units

Diamond Offshore is one of the companies at the forefront of the push to add more of the latest generation ultra-deepwater drilling units to the global fleet. Its vice president, Moe Plaisance, highlighted some of the innovations that have changed the face of the offshore rig business during one of the ATCE panel discussion sessions.

“If you look at the old rigs such as Mr. Charlie, it cost US $1 million to build and had a maximum water depth capability of 40 ft [12 m],” Plaisance said.

He then compared Mr. Charlie to today’s fourth- and fifth-generation rigs such as Diamond’s Ocean Apex semisubmersible, which is currently being revamped and upgraded into a deepwater unit using the hull from the older cold-stacked unit, the Ocean Bounty, at Jurong Shipyard in Singapore.

“That rig [Ocean Apex] has cost $370 million to build and has a 6,000-ft [1,829-m] maximum water depth,” Plaisance said.

The unit was originally built in 1976, with its latest incarnation as the Ocean Apex expected to be delivered by 2Q 2014. This was done, Diamond said, at the time of the contract award to Jurong to help reduce the cost as well as the time required to construct the rig.

The Ocean Apex has been designed to surpass the specifications for a fourth-generation newbuild unit and can carry a variable deck load of 7,840 tons. The rig – with a crew capacity of 140 – also will include a 15,000-psi, five-ram BOP and will be able to drill wells to a total depth of 9,144 m (30,000 ft). It also will feature a hookload capacity of a maximum 2 MMlb as well as one of the largest deck areas of any semisubmersible rig in the world, according to Diamond.

Diamond has another rig, the Ocean Onyx, also going through the same process at a yard in the US but at a more advanced stage. That similar-specification rig has already landed a contract for $490,000 per day starting during 1Q 2014.

Build cost of $750 million

Moving up to the top of the food chain, Plaisance discussed the latest sixth-generation unit the company is building, pointing out a harsh-environment semisubmersible that will be used offshore South Australia and will cost around $750 million to build.

One of its latest fleets of drillships also under construction will cost around $650 million to build, he added, with both units having the ability to drill wells in water depths of up to 3,658 m (12,000 ft) – not a bad increase compared to Mr. Charlie’s maximum effort.

Diamond has been one of the busiest rig players in terms of lining up the latest generation newbuilds to tackle the demands of the ultra-deepwater market. In 2011 it ordered three ultra-deep drillships: the Ocean BlackHawk, Ocean BlackHornet, and Ocean BlackRhino. The following year it ordered the two deepwater semisubmersibles mentioned earlier, the Ocean Onyx and Ocean Apex, as well as another ultra-deep drillship, the Ocean BlackLion. And last year it placed yet another order for a further ultra-deep harsh environment semisubmersible rig, the Ocean GreatWhite (due for delivery in 2016).

The Ocean BlackHawk and Ocean BlackHornet will start operations for Anadarko in the US GoM in 2014, while the Ocean BlackRhino (to be received in 2014) and Ocean BlackLion (2015) are both currently available.

Fleet changers

Diamond describes these four identical ultra-deep drill-ships, built by Hyundai Heavy Industries and based on a variant of the Gusto P-10,000 design, as “fleet changers” for the company, featuring the latest state-of-the-art equipment. This includes all of the features that an oil company now demands for its ultra-deep rig requirements – dynamic positioning (DP), dual-activity capability, a maximum hookload capacity of 1,250 tons, and two seven-ram BOPs. All will have the same water-depth capability of up to 3,658 m and a total drilling depth capability of up to 12,192 m (40,000 ft).

Aspects such as the dual BOP capability are a must for the latest generation rigs in today’s maximum utilization drive by the operators. Plaisance said that being able to carry out the required maintenance when pulling a BOP by “immediately taking one out and putting another one straight down produces a tremendous saving for operators.”

He also expressed the need for rig contractors to be in at the design phase of a field development. “Collaboration is key,” he said. “We need to be in on the design phase; we are not just drillers anymore.”

CAT I drillship

When it comes to harsh-environment units, Statoil obviously believes the limit has not yet been reached. It is still looking to push the boundaries, especially with its eyes turning increasingly to the world’s icy northern waters.

It awarded a contract in September 2013, after a six-month design feasibility competition, to fellow Norwegian company Inocean for the conceptual study and an option for a FEED study for the operator’s CAT I drillship.

“Being developed for arctic operations, we are probably speaking of the most advanced and sophisticated unit evolved within drilling operations,” said Inocean’s CEO Jon Erik Borgen. “Having this opportunity to develop the drillship of tomorrow is a big recognition of our design and engineering capabilities.”

The CAT I drillship is being tailored for Statoil’s “Arctic step-up” program through the development of suitable winterization, increased capabilities, and a hull suitable for operations in ice-infested waters. Based on Inocean’s INO-80 drillship design, the further concept design and option for the FEED is planned to go on until year-end 2014.

Statoil wants the drillship to be tailor-made to operate across its arctic acreage. It has ongoing R&D activities under way to qualify drilling and other critical support technologies.

Inocean’s drillship design, dubbed “IN ICE,” is based on the compact INO-80 ultra-deepwater design, which features dynamic positioning and large free deck areas for year-round operations. The design was first unveiled at the Offshore Technology Conference in 2011.

Seventh-generation semisub

Frigstad is another player looking to establish itself at the top end of the rig market in terms of the specifications of its units.

It has two seventh-generation drilling units of its own Frigstad D90 design on order. These units are developed by Frigstad Engineering and tailor-made for exploration and development drilling in ultra-deep waters. The rigs will be capable of operating in water depths of up to 3,658 m and drilling to a total depth of 15,240 m (50,000 ft).

The units also will be outfitted with a DP3 system with eight thrusters, a full dual-activity hydraulic drilling package each with a 1,400-metric-ton (mt) hoist, and seven-ram BOPs.

The first two units are being built under turnkey construction contracts by the Yantai CIMC Raffles shipyard in China, with options for another four units. The first pair are scheduled for delivery at the end of 4Q 2015 and 2Q 2016, respectively, with the total project cost put at approximately $1.3 billion. The construction, marketing, and operation of the rigs will be managed by Frigstad Offshore.

“These rigs represent yet another significant step forward in terms of equipment specifications, operational efficiency, flexibility, and reliability,” said Simen Skaare Eriksen, CEO of Frigstad Offshore. “We will be well positioned to take advantage of a strengthening ultra-deepwater market.”

World’s largest semisub

The company has, of course, already built one unit of the proprietary Frigstad D90 designs – the Frigstad Oslo, which was acquired by Italy’s Saipem in 2007 and renamed Scarabeo 9.

The D90 rigs have specifications including vertical racking capacity for 3,078-m (10,100-ft) drilling risers in 30-m (100-ft) stands and 15,240-m drillpipe in 28-m (93-ft) stands as well as a variable deckload capacity of more than 8,000 mt and two 150-mt platform cranes. Other features include a large moonpool opening of 42 m by 8 m (138 ft by 26 ft) and a fully integrated cuttings storage and handling system.

Frigstad said the rig is simply the world’s largest semi-submersible deepwater exploration and development drilling unit based on combined power and capacities.

It’s all a far cry from the days of Mr. Charlie. Then again, 60 years is a long time in any industry if we take just a quick look over our shoulders at what has happened over the same time period in the aviation, automobile, and computing sectors.

However, there may be a limit to just how far, how large, and how complicated the industry and the contractors within it can make their rigs. As Moe Plaisance said in his closing remarks at ATCE, “We cannot keep building ‘bigger hammers.’ We are going to have to slim these down at some point to get the job done.”