Offshore drilling & technology briefs
25-well deepwater batch-casing program uses customized tools, advanced tubular running technology
By Aaron Dauphine, Weatherford
A 25-well batch-casing program in the deepwater Gulf of Mexico (GOM) has exceeded targets around safety and efficiency over a six-month development campaign that logged zero nonproductive time (NPT) and HSE incidents related to tubular-running services (TRS) while reducing running costs by 25%.
The results are the product of a collaborative effort begun early in the planning process and by using new technology. Specialized equipment optimized procedures, and mechanized tubular-running operations were developed.
The multiwell GOM program to batch-set large-diameter casing benefited from TRS services in two key ways: the engineering of custom tools to enhance the integrity of the structural casing, and the safety and efficiency achieved with an advanced tubular-handling and makeup system, including a contingency iron roughneck.
To support the program, Weatherford was asked to create and implement a non-marking (zero-indentation) system to run 38-in. casing and provide contingency equipment to the rig’s primary iron roughneck. The challenge involved bending stresses on the casing when using a surface BOP stack. Specifications required the jet pipe to be absent of indentations, peeling or other means of penetration.
Development of the non-marking running system was achieved with close coordination between the operator and the service company’s engineering groups. The resulting design involved an elevator built to API 8C specifications and an integral baseplate constructed to API 7K specifications. The design project spanned 90 days, from defining project deliverables to design to manufacturing to implementation on the rig.
Contingency use of Weatherford’s TorkWrench modular iron roughneck system was required due to maintenance demands on the primary iron roughneck. Faster trip times and more than 120 days of NPT-free service were achieved with the contingency application.
In the 25-well, six-month batch-casing program, Weatherford ran 153,840 ft (46,890 m) and more than 39 million lbs (17 million kg) in casing diameters ranging from 22-in. to 38-in. OD.
During the campaign, the mechanized TRS equipment achieved zero NPT or HSE incidents. This reduced TRS-related costs by 25% relative to planned expenditures. Trip time was reduced by 20% based on prior experience, and downtime related to maintenance of the rig’s primary iron roughneck was eliminated.
Pacific Drilling integrates ‘disruptive’ DGD technology into 7th-generation drillship
By Joanne Liou, associate editor
A disruptive technology is one that “gets its start away from the mainstream of a market and, then, as its functionality improves over time, invades the main market,” as defined by Harvard Business School Professor Clayton Christensen. The technology revolutionizes industry structure and competition, while making established technologies or strategies obsolete. “Dual-gradient drilling (DGD) is certainly disruptive, changing the way we design wells, opening many new avenues,” Frédéric Jacquemin, Director DGD Program, Pacific Drilling, said at the 2014 IADC DGD Workshop in Madrid on 7 April. Mr Jacquemin, who currently serves as Chairman of the IADC DGD Subcommittee, described Pacific Drilling’s approach to rig integration for its purpose-built, dual-gradient drillship.
Click here to learn more about the DGD technology.
Video: IADC UBO/MPD Committee drafting operating guidelines
One of the most significant initiatives being undertaken by the IADC Underbalanced Operations and Managed Pressure Drilling (UBO/MPD) Committee is to develop operating guidelines for MPD. Guidelines for MPD with a surface BOP stack are under review, and the committee will next address mud cap drilling with a subsea BOP stack, Martin Culen, 2014 Chair of the committee, said. In this exclusive video, Mr Culen, Regional Managing Director & Training Director at Blade Energy Partners, provides an update of committee activities.
The next committee meeting is scheduled for September in Bergen, Norway.
Click here to watch the exclusive video interview with Martin Culen.
Click here to learn more about the IADC UBO/MPD Committee.
New jackup concept could extend Arctic drilling season by one month
By Joanne Liou, associate editor
Companies planning Arctic drilling operations are constantly searching for newer and safer drilling options fit for the ultra-harsh environment. Formidable ice conditions can cause operations to shut down early, leaving wells untested and adding costs. “Considering weather and ice conditions, especially for the Russian Arctic sector, to design a year-round drilling jackup seems like very challenging task,” Maria Urycheva of the University of Stavanger said, “but the jackup drilling rig still remains one of the most adaptive options.”
Ms Urycheva presented a jackup concept at the 2014 Arctic Technology Conference in February in Houston that could prolong the drilling season in the Arctic by one month.
The jackup is a more economical drilling option compared with drillships, she asserted. It could extend the drilling season by up to five weeks and would allow an additional four weeks to prepare the jackup to safely leave the location. Currently, for more conventional jackups, the Arctic drilling season lasts up to three months. The new design would provide an extension for tests and allow the operator to complete a well in one drilling season.
The ship-shaped hull of the concept rig features an ice-breaking bow and winterized topside. “The reinforced design of the hull will allow the jackup to navigate through ice in the beginning of ice season,” Ms Urycheva said. To save deck space, “it is recommended to have outrigger arms to save space.”
The jackup’s legs have a tubular shape, making them more resistant to ice impact. To reduce the drift ice loads on the jackup legs in operational mode, the legs are outfitted with protective cones. “These cones should be strengthened to withstand ice pressure, and during transportation, these cones are also stored inside the outriggers.”
Drilling through one of the jackup legs is suggested to protect the drillstring from possible ice impact. The leg should have a telescopic design to allow the derrick to skid over it before drilling. “Drilling through one of the legs is widely used for jackups in the Arctic, for example in the Cook Inlet, but the issue is that jackups operate at different water depths,” Ms Urycheva explained. “That means the height of leg impacts the depth and will vary from well to well.”
“The height of the leg above the deck should be adjustable,” she noted. “This adjustable leg already exists for jackups, and normally the design comprises two or more sections, which are sliding one above another with a fixing mechanism. Such design will allow adjustments to the leg height.”
Working against the clock and the unpredictable environment in the Arctic, “the industry is looking for an effective and safe solution,” Ms Urycheva said. “This concept could bring some ideas or inspiration for further jackup implementation in the Arctic.”
Chevron’s DGD training program serves array of learners across generations
By Joanne Liou, associate editor
Since 2008, more than 400 people – from operators, drilling contractors, service companies and regulators – have completed Chevron’s dual-gradient drilling (DGD) training. Chevron is drilling some of the deepest, most complex wells in the Gulf of Mexico deepwater using DGD, and the operator approaches training as a risk-mitigating activity, Chevron’s Dale Straub, Senior Drilling Advisor, said at the 2014 SPE/IADC Managed Pressure Drilling and Underbalanced Operations Conference in Madrid on 8 April. “We look at every technology we use from a context of risk reduction. When we move operations to deepwater, the risks are inherently higher.”
Click here to read more about Chevron’s DGD training program.
Video: Chevron’s deepwater assets highlight value of DGD
The “un-drillable” is becoming drillable by using dual-gradient drilling (DGD) to remove the impact of water depth. Dale Straub, Senior Drilling Advisor at Chevron, discussed the impact of DGD on the number of casing strings and completion opportunities at the 2014 IADC Dual Gradient Drilling Workshop on 7 April in Madrid. In this exclusive video, Mr Straub provides an update on Chevron’s DGD program in the US Gulf of Mexico.
Click here to watch the exclusive video interview with Chevron’s Dale Straub.