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A standardised and simplified semi-submersible design could help operators economically produce marginal offshore fields.
As operators seek new but commercially affordable production solutions, hull and topsides companies are stepping up with new designs.
KBR is touting its GVA 10000 FPU as a small semi-submersible that will be economic at $40 per barrel oil prices.
“It uses proven technology on both the hull and topsides and is very easy to construct and is therefore very, very cost effective,” says Graham Hill, executive vice president for global business development and strategy at KBR.
KBR says the design, which it is officially announcing at the 2017 Offshore Technology Conference in Houston, could go from contract to first oil in 36 months.
The company began kicking around the idea for a smaller, standardised and simplified hull and topsides concept in 2015, when BP was seeking a production solution for a smaller Gulf of Mexico project that has since stalled.
"We’ve taken a generic production capacity which we think will satisfy probably 90% of the opportunities out there."
“We have a very robust design for the large hub oil producing fields, like Thunder Horse and Mad Dog,” Hill says. “But the market is moving, and there aren’t those large oil deposits anymore.”
Now, he says, the industry needs to economically produce much smaller projects when “the oil price is against us".
"Oil companies were approaching hull and topsides designers with one request: 'Tell us how we can meet our objective of being economic at $40 oil. You tell us, because we can’t do it on our own'. So we’re telling them.”
A study of global discoveries showed this was not just a Gulf of Mexico issue, but a worldwide one.
“If we didn’t get serious about reducing costs,” Hill says, operators just will not develop “smaller, albeit attractive, opportunities. The oil would just stay in the ground.”
With that in mind, KBR adopted a motto: “There’s a new market, and we need a new solution.”
KBR’s hull and topsides engineers set out to design an offshore development concept that would be economically feasible at $40 per barrel oil prices.
“We came up with this” Hill says of the GVA 10000. “It’s elegant, simple, repeatable, standardised and compliant” with US government safety regulations along with ABS and US Coast Guard requirements.
Smaller and simpler
Big projects like Thunder Horse and Mad Dog operate as hubs for surrounding satellite fields. These large production units use GVA’s deck box hull, which Hill says is not economic under the current oil price slump, nor would it be economic for smaller fields.
“What we’ve set out to do here is to take existing technology of our GVA hull, standardise the topsides, strip out the nice-to-have features and ensure this facility is economic when you put it in place with all the subsea infrastructure, the moorings, the pipeline going back to an adjacent pipeline or an FSO, that will be economic at $40 a barrel,” Hill says.
“In today’s market with oil at $50 per barrel, that’s a damn good deal.”
Coming up with a topsides design that would meet the needs of smaller fields looking for a production solution meant studying the common characteristics of several potential projects.
In the end, the design team offered up a unit with production capacity of 80,000 barrels per day of oil, 70 million cubic feet per day of gas, and 40,000 bpd of water.
“We’ve taken a generic production capacity that we think will satisfy probably 90% of the opportunities out there,” Hill says.
“Operators are getting used to the idea that we standardise, and when we put the facility on station, one of those design criteria may be a constraint.
"They may have a little bit more gas. But what you’ve done is accelerated the production to first oil with a standardised facility. You’ve got it built in a very quick time,” he adds.
“If your reservoir people say, ‘we’d like a little more gas capacity’, you can do a revamp on that down the track, and pay for it out of strong cash flow.”
Back to basics
The key selling point, Hill says, is the field comes on stream faster, with money coming in, setting up a situation where the operator has real-time production data as it evaluates whether the request for more capacity is justified.
The GVA 10000 truss deck is 67 metres by 46 metres, with some 750 square metres reserved for flex space to accommodate extra equipment later, perhaps when water injection and enhanced oil recovery become important.
While there are two decks, the overall topsides can be built in a fabrication yard as a single, integrated piece and lifted as one deck, Hill says.
The open truss design of the deck means large equipment delivered late in the fabrication process can be lifted onto the deck without bottlenecking construction. The design accommodates 60 people on board.
“We have a vision to operate this from the beach,” Hill says, adding that the technology for this exists.
“The resistance is coming from the operator who hasn’t done it in the Gulf of Mexico and hasn’t done it for a floating facility before.”
The goal to operate from the beach could be realised as early as the second generation of the GVA 10000, he says, which means the accommodation on board would drop significantly.
“We’ve stripped out the nice-to-haves and we’ve got down to the absolute basics,” Hill says.
“We’ve taken all the gold-plating and all the silver-plating and half the bronze-plating out of the design and we’ve come up with an industry standard design that is safe, operable, maintainable and flexible to show them they can live with this design.
"It’s not perfect, it’s not tailored, it’s not ideal, but they can live with it.”
The nominal weight of the topsides is 10,000 metric tons. It can accommodate 10 risers. It has a standard design life of 20 years and can be redeployed in other fields. It is designed for water depths of 500 to 3000 metres (1640 to 9843 feet).
“The hull is the same technology we’ve used in many places around the world. We simplified the hull to take the cost out of it” without compromising the safety of the design, Hill says.
To date, KBR has pre-developed the design to the point that about 40% of the front-end engineering and design is complete. “We’re waiting for a customer to work with us and take it to the next step,” he says.
KBR has also pre-qualified four fabricators and validated the pricing and design. The fabricators have provided feedback on the constructability of the design.
“We think this is going to be an industry standard. We think people are just going to order a GVA 10000. And they’ll just live with the constraint, and then down the track, when they have hit a constraint and are making money and profitable, will put a little more money into the topsides to take away that constraint.
"They can do that with the luxury of having cash behind them,” Hill says.