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Designs on the future

Written by  Karen Boman Tuesday, 01 August 2017 00:00

Diamond Offshore is championing a new Floating Factory concept meant to meet future deepwater challenges, but drumming up support during the downturn may be tough. Karen Boman reports.

Photo from iStock.

Offshore drilling contractors have sought to meet future deepwater drilling demands by enhancing current capacity, but the idea of redesigning deepwater rigs altogether has not been a major focus of discussion. Diamond Offshore’s Floating Factory rig concept could change that conversation.

Diamond says it designed the concept with input from operators and service companies to address the entire well lifecycle requirements expected from 2020-2030 and beyond. It says the Floating Factory aims to improve deepwater drilling by creating efficiencies, enhancing safety, reducing overall well costs, and allowing for the future optimization of 12,192m+ long well designs in greater than 3962m water depth.

The concept, using lean methodologies, combines improved safety with automation and robotics to reduce bottlenecks and minimize controllable flat time for the entire well lifecycle, with a reduction in well duration and cost by 15-30%, says James Hebert, director of operations and technical support at Diamond, in a SPE/IADC 2017 paper, The Floating Factory Concept: Engineering Efficiencies Up Front to Reduce Deepwater Well Delivery Cost.

Deepwater drilling efficiency will need to be improved to meet the challenges of exploration in plays such as the Gulf of Mexico Lower Tertiary/Wilcox trend. These challenges include complex sub-salt imaging capability, reservoir depth, high-pressure, high-temperature (HPHT) reservoirs, distribution of sand, flow capability, and cost-effective drilling and completion, Ken Richardson, EVP Offshore for classification society ABS, told OE.

Current floating rigs “drill” only about 20% of the time, with the balance characterized as “flat time.” Flat time can include tripping, drill-line slip and cut, and the sequential rigging up and rigging down of equipment. This leaves considerable room for improvement through enhanced and new rig designs and equipment, said James C. West, senior managing director and partner with investment banking firm Evercore ISI, in a 22 June report.

While the timing for the Floating Factory may not be right for some in the industry. Diamond still believes in the concept.

“From our perspective, we’re still looking at the Floating Factory concept,” said Diamond President and CEO Marc Edwards, in a Q1 2017 earnings call in May. “We’ve got the final designs in place. We’ve spoken to a number of yards. We’ve got a full-scale prototype that has been constructed and has been tested. And, that’s the way we see the market changing moving forward.

“Because the pressure from our clients is to materially take down deepwater cost through efficiency gains, and something like the Floating Factory is what is going to be required to deliver on that opportunity.”

Design and features

Floating Factory concept. Photo from Diamond Offshore.

The Floating Factory rig is a variation of Diamond’s patented Huisman 12000 rig design. Huisman conducted the basic vessel design, and is designing all the mission critical equipment except for the subsea gear. No other contractors are involved in the basic design phase.

“The objective here is that vessel and equipment are designed simultaneously to optimize the whole drilling unit,” Anne de Groot, project director with Huisman, told OE. It took about a year and a half to design the rig, which is based on a previous design for Noble Drilling’s Globetrotter rig and on Diamond Offshore’s operational experiences, de Groot says.

There’s not yet a contract in place to build one of the rigs, but Huisman is conducting engineering for Diamond in preparation for construction, with the goal of readying the Floating Factory rig for work in 2020, de Groot says. In May this year, ABS announced it had approved the basic Floating Factory drillship concept.

A typical sixth generation floater has 2900sq m of free deck space, a 15-20m elevated drill floor, and measures 230m by 42m. In comparison, the new design offers 4600sq m of free deck space, a drill floor on the same level as the deck, and measures 216m by 38m.

The Floating Factory rig features an all-robotic drill floor, with tools that use condition-based monitoring and offline tool maintenance apps, West said in Evercore’s report. The rig has a casing running tool integrated into the well center, with automated changes to the casing clamp, and uses a fully automated pipe handling system. The center of gravity on the rig also is reduced, and the weight is pushed outward. This reduces vessel roll, which is crucial for dealing with bad weather.

A dual multipurpose tower capable of handling 55m stands of pipe has replaced the standard derrick and substructure, reducing connection times, as the design is believed to be able to trip at speeds of 1524m/hr. The hoisting system is also designed for 1500-ton static hook load compared to an average of approximately 1250-ton for sixth generation drillships, West said.

The design eliminates the potential for dropped objects by using welded connections and an open character philosophy, or more open space for procedure prep. A dual mud pit system allows for mud and completions fluid to be treated simultaneously. The Floating Factory also will have three rooms with three medium-sized engines in each versus older generation designs that have three rooms with two large engines a piece. This should allow optimal engine loading, reduced fuel consumption and lower engine wear and emissions output, West said. The rig can be fitted with a 15,000psi or 20,000psi blowout preventer, de Groot says.

Building a better mousetrap

Instead of looking at new designs, the focus of rig construction in the past has been on building bigger rigs, Leslie Cook, principal analyst, upstream supply chain with Wood Mackenzie, told OE. To boost capacity for sixth- and seventh generation rigs, drilling contractors added greater top drive and mud pumps capacity, and dual, larger blowout preventers with more shear rams. More storage capability was added to allow more equipment to be stored onboard.

Strong demand for rigs in 2000-2014 contributed to a lack of new innovation in rig design, West said. Then when the downturn hit it was all about survival. “We’re finally at a period where rig companies are turning towards the future and the innovation that is necessary to compete,” he added.

Shipyards also drove the design of drilling units instead of the drilling contractors who had to work with them. This has led to a situation that is not accepted in other, more competitive sectors of the offshore industry, de Groot says.

Getting a new floating rig design off the ground in the next three to five years will be challenging, Cook says, due to the lack of appetite for newbuild rigs, and the difficulty rig contractors will face in convincing shareholders that more newbuild rigs is a good strategy. According to Wood Mackenzie, the marketed utilization for the global floating rig fleet is 60%, while total utilization for floating rigs is around 40%.

The downturn – which has forced drilling rig contractors and many others into a period of harsh self-reflection – will provide a fantastic opportunity for new technologies over the long-run, Matt Adams, senior analyst, Douglas-Westwood, told OE. However, Adams doesn’t expect the Floating Factory to be added to the existing fleet any time soon. Instead, drilling contractors will mainly focus on improving efficiency and desirability of their existing fleets before looking to new designs.

“From a capex perspective, it would likely make more sense for contractors to retrofit/upgrade their existing idled units, rather than come up with new rig designs and start a new ordering cycle,” Adams says. By doing that, they can both help operators, by bringing down well costs and improving project economics, and help themselves by increasing the likelihood of picking up contracts.

 

Focus on efficiency

Drilling contractors have been looking to upgrade their current fleets to reduce non-productive time when rigs are on contract, and increase their likelihood of being picked up for new contracts. Over the past year, drilling contractors have primarily focused on reducing operational, maintenance and repair costs, which account for 25% of daily cash costs, so they can continue to work through the low day rate, low oil price environment.

To reduce costs, contractors are leveraging Big Data and analytic tools, Cook says. The oil and gas industry has lagged in adopting these kinds of Silicon Valley technologies, but is now looking at putting sensors on equipment and using predictive analysis to accurately predict when equipment needs to be changed, or which parts of the drilling and operations processes need to be improved. Examples of these efforts include Ensco’s new asset management system, Diamond’s pressure control by the hour, Noble Drilling’s digital rig solutions, and Transocean’s performance dashboard.

“In the context of the price environment, it appears that the rig contractors are looking to provide the best value for money for their clients – providing faster drilling, higher spec rigs,” Adams says. “I would infer that their strategy, while rig day rates are low, is to show operators ‘how good it could be,’ getting them to pick-up cheap, high spec rigs so that when/if day rates recover, operators choose to stick with the high spec rigs due to greater efficiencies, rather than going for cheaper but lower spec rigs.”

Of course, Diamond believes the Floating Factory could aid in creating further efficiencies. Edwards said in the Q1 call that while the dual derrick system brings the most advantage, creating a 6-10% efficiency gain, the Floating Factory could potentially do better than that, however. “We’ve done some [deepwater operations plans] with our Floating Factory designs and over and above the dual derrick rigs, we can put a further 20-30% efficiency gain on drilling the wells out there,” Edward said. “So, that itself is quite compelling.”

Drilling days saved with the floating factory in a GoM deepwater well

DMPT efficiency aspect Quantification assumptions Floating factory saving (days)

Spud to BOP run sequence

Increased offline casing and BOP handling 1.4

Unrestricted hi-speed tripping Where surge and swab is not a limiting factor

Hi speed tripping of drill pipe d BHA only

  • 5000ft/hr in open water and riser
  • 4000ft/hr inside casing down to 16in OD

4.2

Restricted tripping Where surge and swab is a limiting factor

180ft stands saves 2 connections per 1000ft

  • Tripping inside 16in and smaller casing
  • Ability to run 16in casing from setback vs from main deck
  • Large bore or specialty tools
8.3

Reduced drilling connections

180ft stands saves 2 connections per 1000ft 0.7
Dual multi-size power slips  Pipe OD range from 3.5in to 9.75in do not require insert changes. Case slips can be installed quickly. 1.7
Drill-line slip & cut Slip & cut is not required 2.1
  Total days saved 18.4 days
  Percentage of total well time saved 16%


Drilling days saved with the floating factory in a GoM deepwater well

Floating factory efficiency aspect Estimate assumption Floating factory saving (days)

Increased deck 
storage area

 


Improved logistics by increasing the amount of materials and equipment which can be stored on board improving off-line rig-up & rig-down capability. Also decreases risk of potential weather related NPT.
 
4-7

Increased POB

Provides space for extra 3rd party personnel to support the off-line rig-up & rig-down activity.

2-4

Dual mud system

Allows off-line handling, storage and treatment of drilling, completion fluids, including spacers & flushes. Provides for safe and off-line cleaning of shaker pits, mud pits and suction piping.

1-7
Direct crane access to a large drill floor area

Improves the ability to be assembled and tested off-line and placed on the drill floor as a larger system as 
compared to handling with drill floor tuggers.

1-2
Off-line rig-up & rig-down of completion equipment

Supports the ability to rig-up & rig-down items such as lift-frames, surface flow trees, and hoses off-line while deploying the subsea trees.

1-2
  Total days saved 9 to 22

Source: Company Reports, Evercore ISI Research

E-BOP

A subsea electric blowout preventer made waves at UTC in Bergen. Elaine Maslin sheds light.

 

Norway’s Electrical Subsea & Drilling (ESD) has been awarded the Subsea Upcoming Company of the Year at the Underwater Technology Conference in Bergen for its work on subsea electric blowout preventer (BOP) controls.

Since the 2010 Macondo disaster in the Gulf of Mexico, ESD, based near Bergen, has been working on its all-electric BOP concept that it says will make drilling safer and much more cost-effective. The core components of the technology are electro-mechanical actuators, integrated with well barrier utilities, and a new control system including condition-based monitoring (CBM).

The subsea industry, particularly in Norway, has been moving towards all-electric controls for subsea production systems for some time, driven by ultra-long tiebacks, to avoid the need for long and expensive hydraulic production control umbilicals and improve subsea control system reliability. In the OG21s strategy document – Norway’s Oil & Gas Technology Strategy for the 21st Century – all-electric subsea wells are listed as one of the prioritized technology needs.

All electric controls for well access systems, however, are relatively new to the industry and subsea drilling.

“After Macondo, regulatory authorities will be phasing in new requirements for the drilling industry, some of which will be difficult to satisfy with current BOP technology,” says former Dril-Quip and Cameron exec John Dale. “A change from electro-hydraulic to all electric BOP control system technology, will provide much better CBM and maintenance data resulting in quick turn-around between operations and exact position monitoring of well barrier elements.”

According to Dale, the benefits include: high actuator force output, monitoring and control of applied force, no discharge of hydraulic fluid to the environment, improved redundancy, facilities for mechanical override and increased reliability through system simplification with the elimination of critical error sources. Reduced weight through removal of hydraulic equipment, real-time monitoring of available back-up power using batteries instead of hydraulic accumulators are other benefits.

“When it comes to ultra-deep high pressure and high temperature drilling, current BOP technology is stretched to the limit,” he says. “The increased BOP stack weight affects drilling rigs, handling equipment and subsea wellhead integrity. Our all-electric BOP will make it possible for existing drilling vessels to operate in much deeper waters, without major modifications.”

The award was made by GCE Subsea, Sparebanken Vest, CONNECT Vest and the Underwater Technology Foundation.

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