Enhanced jackups with dual-pipe handling
Three newbuild jackup drilling rigs are to be delivered in 2013 and 2014 for development projects in the Norwegian market by three major operators. Maersk Drilling is constructing the XL Enhanced rigs in Singapore. Their design is based on input from customers, crews, in-house specialists and eight years of operational experience with the Mærsk Innovator and Mærsk Inspirer.
The XL Enhanced jackups will maximize uptime and drilling efficiency by utilizing dual-pipe handling. While one string is working in the wellbore, a second string (e.g., casing, drillpipe or bottomhole assembly) can be assembled/disassembled and stored in the set-back area, ready for subsequent transfer for use in the wellbore, thus reducing non-productive time.
The drill floor features multi-machine control (a fully remotely operated pipe handling system allowing all standard operations, such as stand building and tripping, to be conducted without personnel on the drill floor) to ensure a high level of consistency across crews and improved efficiency. With a leg length of 678 ft, the rigs are designed for year-round operation in the North Sea, in water depths down to 492 ft. A green rig philosophy minimizes CO2 and NOx emissions. 
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| Eight years of operational experience with the Mærsk Innovator, plus input from customers, crews and in-house specialists were used to design Maersk’s new XL Enhanced jackups. |
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Modular rig handles harsh-weather drilling
When winds approaching 60 mph sweep across the North Dakota plains, most workover rigs in the lucrative Bakken shale must be shut down. However, in such an instance, RT Energy Services’ Versa-Rig 300 kept pulling 1/2-in. casing, since the rig is designed to handle harsh North Dakota winters and is rated to withstand winds of up to 120 mph. The rig has no guy wires, is self-supporting and has run “24/7” for ten months. When many rigs are expected to shut down later this winter, the Versa-Rig 300 is predicted to keep operating.
A key rig component is its heated slip bowl window that is designed to prevent rig hydraulics from freezing. A heated control room, enclosed by retractable wind walls, protects personnel from the elements. It also is more efficient since, unlike conventional rigs where the supervisor and mud pump operator are outside and could be several feet apart, personnel are inside, making communication easier. They sit side-by-side in the control room with an unobstructed view that is enhanced by cameras, which allows every situation to be monitored. Joy sticks control rig operations.
The rig features 300,000 lb of pull and 150,000 lb of push for snubbing. It operates with a six-man crew designed to eliminate logistical and safety considerations for third-party services, such as rig-assisted snubbing, coiled tubing operations, and casing runs with pick-up and lay-down units, as required by a conventional rig. A pipe conveyor system raises and lowers tubing to, and from, the rig floor, and a hydraulic catwalk raises and lowers tubing to racking height.
Another innovation is the customized hydraulic tongs, with top and bottom seals for removal of all liquids from tubing, thus allowing for hands-free operation. This eliminates dangers to personnel from exposure to tubing fluids, and eliminates environmental damage.
The rig's top drive is mounted on a Rogers Technology air-ride system. Teflon guides hold the top drive directly in line with the tubing string, making it virtually impossible to cross or damage threads.
Another unique feature is the rig’s hydraulic derrick position system. Hydraulic cylinders can position it over multiple wells or move the derrick to one side of the well to allow wireline or other services. This four-direction movement provides perfect alignment over a wellhead, and all weight is suspended on the rig, itself. Rig mobility is another advantage—moves from one well to another take about one hour. Pad-to-pad rig down and rig up takes about 12 hr.
The modular rig can run to depths of more than 27,000 ft and be used to complete extended-reach horizontal wells. The rig has drilled as many as 23 composite frac plugs in 12 hr.
The Versa-Rig 300 was specifically designed by Rodgers for use in the Bakken region. The first version was awarded a contract in 2011, with the rig being redesigned to target the needs of pad locations in the Bakken. RT Energy Services is part of Rodgers Technology, headquartered in Chickasha, Okla.
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| RT Energy Services’ Versa-Rig 300 is rated to withstand winds up to 120 mph. |
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Flexible, modular rigs for North American shales
The Sparta drilling system has increased its presence in North American shale plays, as Integrated Drilling Equipment recently fulfilled its twelfth contract for the safe, highly efficient, fast-moving rig. Designed for well programs where drilling time is minimal and fast, efficient rig moves are essential, this flexible, modular design is capable of rigging up the V-door in either the X- or Y-axis position from well-to-well, meeting strict U.S. Department of Transportation load limitations.
All Sparta contracts have been for complete rig packages—designed, built and tested at the company’s Houston facility. The Sparta drilling package includes: AC technology, cable festoon systems, alternative fuel upgrades and advanced drilling controls. Additional options include integrated skidding systems and automation upgrades. The design is IDE’s most popular, quick-moving drilling rig, and several drilling contractors that adopted it subsequently returned for successive multiple-rig orders.
The Sparta combines two structure technologies—a vertically erecting mast and the hydraulic, winch-raised parallelogram substructure. The free-standing mast can be supplied in Range II triples. The rig is available in 1,000- and 1,500-hp versions with the availability to transport the masts as a single load with top drive, traveling block and drill line spooler.
During the past two years, IDE has delivered 12 Sparta-style land rigs, nine Self Elevating Drilling System (SEDS) style land rigs, and additional rig designs and refurbished rigs, totaling 56 rigs delivered since 2007.
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| Designed for fast, efficient rig moves, the Sparta drilling package includes AC technology, cable festoon systems, alternative fuel upgrades and advanced drilling controls. |
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High-efficiency “walking” rig for flexible well layouts
A new generation of high-efficiency walking rigs is available from Patterson-UTI. Various aspects of the APEX walking rig system operation, from on-pad mobility and drilling performance optimization to structural design and winterization, result from improvements that maximize safety, while minimizing non-productive time.
The intuitive electronic drilling system (EDS) allows maximum PDC bit and downhole motor performance by automatically maintaining constant weight on bit, differential pressure or penetration rate. Superior safety features integral to the EDS system include the Wichita DM 236 electric brake, and advanced crown block and floor protection.
The rig’s proprietary walking system moves the rig forward, sideways or in a circle with pipe racked back, providing flexibility for well layout or location constraints. Innovations in the electronic festoon system, flowline manifolds and mud system allow the rig to walk along well layouts in excess of 150 ft without the need to move any primary equipment other than the rig, itself.
The rig features one of NOV’s Ross Hill 1400 SCR drive systems. Like all other rig components, the drive system focuses on simple operation, reliability, superior performance and ease of maintenance. A Wrangler 3500 hydraulic catwalk eliminates the need for manual tubulars handling. Its remote-controlled functionality allows operation from the rig floor, removing personnel from the danger area while picking up and laying down pipe. The catwalk is always rigged up and ready, eliminating the costs and potential delays of calling out laydown crews.
The top drive is an NOV TDS 11, 800-hp AC system, developed for use as a portable unit. Its compact size allows for easy installation and transportation. The continuous and breakout torque ratings allow for efficient drilling and reaming operations, even in larger hole diameters or extended reach applications. An ST-80C Iron Roughneck is specifically designed to optimize floor space and still provide the fast, safe and reliable tubular make-up and break-out functions of the original ST-80.
Mud tanks have a 1,000-bbl working capacity and a separate 50-bbl pre-mix tank. Brandt King Cobra linear motion shale shakers and 24/3 mud cleaners ensure that the recirculation of drill solids will not be a detriment to maintaining mud properties and drill bit performance.
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| Patterson-UTI’s APEX walking rig moves forward, sideways or in a circle with pipe racked back, providing flexibility for well layout or location constraints. |
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