|GustoMSC’s Magellan-class drillship is designed for 20,000-psi well control, and both managed-pressure and dual-gradient drilling.
As offshore operations continue their advance into deeper waters and harsher environments, offshore drilling contractors and shipbuilders are meeting the new challenges with innovative rig designs. The new designs are evolving to deal with a variety of operating conditions, and to place a growing emphasis on efficiency, reliability and safety.
GustoMSC has introduced its Magellan-class drillship, named after the 16th century Portuguese explorer Ferdinand Magellan, who was the first to circumnavigate the earth by sea. GustoMSC says the Magellan-class drillship will outperform the current-generation fleet with respect to redundancy, autonomy, safety and load-carrying capacity.
“The design is the result of a specific focus on operators’ requirements,” says Sjoerd Hendriks, design manager of the Magellan project. “After the Macondo incident in 2010, for example, there were many recommendations concerning operational procedures and rig design, with an emphasis on safety.”
The Magellan is the largest drillship that GustoMSC has designed to date. The design backbone of the ship, the company says, “consists of the well-established and field-proven principles of its predecessors.” The Magellan design is equipped for 20,000-psi well control systems, including the associated increases in capacity, such as high hookloads and setback capacities. The Magellan design provides the ability to accommodate higher pressures, highly variable loads, mud volumes and setback capacities, and incorporates advanced drilling techniques, such as managed pressure drilling (MPD) and dual-gradient systems.
JURONG ESPADON III DRILLSHIP
Several contractors have ordered drillships for delivery in 2017 and 2018 that are based on Jurong Shipyard’s Espadon III design, Fig. 1. Specifically designed for enhanced ultra-deepwater drilling operations, the drillship is equipped with advanced facilities, including a large moon pool to cater to a larger riser angle, and bilge boxes designed for superior motion characteristics. The drillship also features larger deck space, with an enclosed riser bay and round mud pits inside the hull for operational efficiency and safety. Equipped with DP-3 (Dynamic Positioning Class 3) capabilities, the drillship will be capable of operating at a 12,000-ft water depth and drilling to depths of 40,000 ft, with accommodation facilities for a crew of 220. The drillships for Transocean will be outfitted initially with one 15,000-psi BOP, with the ability to add a second BOP.
|Fig. 1. Jurong Shipyard’s Espadon III drillship design includes a large moon pool to cater to a larger riser angle, and bilge boxes designed for superior motion characteristics.
F&G DS 3810 DRILLSHIP
The DS 3810 drillship from Friede & Goldman is designed to drill 40,000-ft wells in waters to a 12,500-ft depth, with limited support in remote, harsh environments, Fig. 2. Ninety-day endurance means there will be fewer supply boat runs required. The derrick has a stand-building center for greater efficiency. Large pipe racks are available, within a semi-enclosed deck area, with an overhead gantry crane and subsea access. Ample below-deck workshops have forklift and crane access. Large slop tanks are provided to capture drainage and storm water for zero discharge. Integrated ballast water treatment and IMO Tier III gensets, along with a dedicated waste management system and double-skin tanks, minimize the environmental footprint for operations in sensitive areas.
|Fig. 2. The DS 3810 drillship from Friede & Goldman is designed to drill 40,000-ft wells in waters to 12,500-ft depths, with a 90-day endurance.
HEAVY DUTY JACK-UP
In another innovative step, Maersk Drilling has embarked on an extensive newbuilding program that includes what it describes as four of the world’s largest jackup drilling rigs. Earlier this year, Maersk took delivery of its first ultra harsh-environment jackup, Maersk Intrepid, from the Keppel FELS shipyard in Singapore, Fig. 3. The jackup has a four-year contract with Total E&P Norge AS.
|Fig. 3. The Maersk Intrepid is the first in a series of four newbuild, ultra-harsh-environment jackups to enter Maersk Drilling’s rig fleet in 2014-16.
Maersk Intrepid is the first in a series of four newbuild, ultra-harsh-environment jackups to enter Maersk Drilling’s rig fleet in 2014-2016. The four jackup rigs represent a total investment of $2.6 billion. The first three jackups, including Maersk Intrepid, will be delivered from the Keppel FELS shipyard during 2014-2015, and the fourth will be delivered from the Daewoo Shipbuilding and Marine Engineering (DSME) shipyard in South Korea during 2016.
The Maersk Intrepid will be drilling demanding and complex wells on the Martin Linge field development in the Norwegian North Sea. The contract includes four one-year options. The estimated value for the firm contract is $550 million. The “XL Enhanced” jackups, designed for use in the ultra-harsh environment of the North Sea, represent a total cost of $2.6 billion.
Before designing the new rigs, Maersk Drilling asked customers and crews what it would take to create a genuine next generation rig. The result will be a family of rigs that include more automation and sophisticated technology—innovations that Maersk says will boost uptime and improve safety, thanks to a reduced need for manual work on the platform.
Built from 30,000 MT of steel per rig, the hulls measure approximately 89 x 105 x 12 m, and the legs are more than 200 m long. Because the hulls are so big, they have to be built in two parts, then floated out to sea separately and joined while afloat. The first of the three rigs completed construction in April, with the other two planned for completion in October 2014 and February 2015. Long-term contracts have already been signed for all three rigs. New or improved features include:
- Dual-pipe handling to maximize uptime and drilling efficiency. While one string is working in the wellbore, a second string can be built or disassembled at the other work station. This significantly improves operational efficiency.
- An automated, remotely operated pipe handling system allows all standard operations, such as stand building and tripping, to be conducted without personnel on the drill floor, ensuring a high level of consistency, as well as improved safety and efficiency.
- The XL Enhanced rigs have a rated drilling depth of 12,000 m and are designed for year-round operation in the harsh environment of the North Sea, handling water depths up to 150 m.
- Cantilever reach from stern to well center is 30.5 m, and from centerline to each side, it is more than 11 m, with a combined cantilever load up to 1,400 MT
- 2,500 sq m of deck space
- Fully equipped for HPHT drilling
- Drilling and workover through surface, and prepared for upgrading to subsea BOP
- 18¾-in., 15,000-psi BOP system
- Automated solids control system, with five triple-deck shakers in separate rooms
- Automated, dust-free mud mixing system
- Accommodation for 150 people in one-man cabins, versus the current 120 maximum in two-man cabins.
ENHANCED LETOURNEAU JACK-UP
Ensco has ordered two high-specification jackups, which are enhanced versions of the LeTourneau Super 116E jackup design. These jackups will include design specifications to comply with the regulatory and customer requirements in the Middle East, the primary target market for the new rigs. The rigs are scheduled for delivery in mid-2016 from Lamprell’s shipyard in the United Arab Emirates.
The rigs will feature enhanced crane capacity, liquid mud storage and living quarters with 140 beds. Ensco’s Canti-Leverage Advantage technology allows the operator to drill more wells from one location, when utilizing the enhanced hoisting capacity at the farthest reach of the cantilever. Other key features of the rig design include a dual-drilling fluid system, a 1.5-MM-lb derrick, TDS-8 top drive and a 15k BOP. The rigs will outfitted initially to drill to a maximum TD of 30,000 ft, in water depths as great as to 340 ft (with upgrades to 400 ft).
RIG WITH HYDRAULIC HOIST
Meanwhile, Italian rig designer and manufacturer Drillmec will provide what it says is a new hydraulic technology HH-220 (Hydraulic Hoist) rig for Aker Solutions, that will be installed on a fixed platform in the North Sea. The contract includes engineering, study, development and manufacturing of an HH Drillmec rig, specifically designed for offshore platform drilling.
The design provides a smaller footprint and a significant reduction in operating costs, according to Drillmec. The HH model is designed to increase safety by automatic operations through its hydraulic technology. The rig is being built at the Drillmec manufacturing plant in Piacenza and will be installed on the first platform during the second-half of 2014.
JACK-UP WITH P&A
Keppel FELS has signed an engineering services agreement with Workfox, a subsidiary of the Seafox Group, to embark on an engineering study of a purpose-built accommodation jackup rig, with well intervention and plug-and-abandonment (P&A) features.
The Seafox 8 project is being developed to address a gap in the current P&A market. Subsea fields are reaching the ends of their productive lives in areas, such as the North Sea and the Gulf of Mexico. With increasing environmental concerns and regulations, there are a substantial number of wells in both these regions that will need to be properly sealed up in the next few years.
Seafox 8 will offer P&A and well intervention services, as well as accommodation and crane support services. It has a spacious deck and comprehensive amenities for the comfort of 282 persons onboard. The jackup also can be configured for other offshore support services. The hull and legs of this new-generation rig will be based on Keppel’s new KFELS J Class design, which is customized to operate in water depths of up to 112 m, in the harsh, offshore environmental conditions of the Norwegian North Sea.
The industry estimates that as many as 12,000 wells in the Gulf of Mexico qualify as P&A candidates. In the UK sector of the North Sea, alone, it is estimated that more than 500 structures with about 3,000 wells are slated for permanent abandonment in the near future. In the Norwegian sector of the North Sea, more than 350 platforms and more than 3,700 wells eventually must be abandoned permanently.
Meanwhile, classification society ABS has achieved what it says is an industry first with the completion of the Rowan Companies’ Rowan Renaissance drillship. This newbuild, built in the Hyundai Heavy Industries (HHI) yard in Ulsan, South Korea, is the first in the world to have earned ABS’ Integrated Software Quality Management (ISQM) notation.
“As reliance on computer-controlled systems has increased, verifying software programs—including their integration—has become critical to safe and efficient operations,” says ABS chairman, president and CEO Christopher J. Wiernicki. “ABS developed ISQM, a risk-informed software development and maintenance process, to verify software at the time of installation, and monitor for consistency and reliability when software updates or hardware changes are made.”
Historically, class rules have focused on steel and equipment. ISQM focuses on the software that controls the equipment. The ISQM process has a goal of reducing safety, environmental and productivity risks while increasing efficiency and productivity of the drillship. The ISQM notation provides a clear process of minimizing software-related risk throughout the life of an asset, ABS says. In its first application on the Rowan Renaissance, ABS says that ISQM facilitated reliable integration of products from more than half-a-dozen major suppliers and more than 35 subsystems.
NEWBUILDS VS. UPGRADES
As the offshore industry continues its advance into more challenging operating conditions, rig contractors face acute challenges with their fourth- and fifth-generation units. As offshore driller Seadrill commented in a recent report to shareholders, “The oil companies’ new requirements after Macondo, and the focus on increased water depth areas, have significantly limited the contractibility of older equipment. The owners will face the choice of investing significant amounts into 20- or 30-year-old assets, in order to try to meet the new demands, or simply just lay up the unit. Some contractors may also attempt asset swaps with newbuilds without a contract for older assets on long-term commitments, in an attempt to secure work for their premium units, while saving cost on large capex upgrades.”
Seadrill adds that “The market for high-specification jackup units continues to perform well. Operators have come to appreciate the increased recovery factors that new assets can provide. Coupled with the lack of building activity over the last decades, there is still a shortage of capable rigs in the near term.”