OTC 2023: HYTORC bolts and washers utilized for deepest subsea hot tap operations in GoM

By Ariana Hurtado, Editor and Director of Special Reports

HOUSTON — Speaking with Offshore during the Offshore Technology Conference (OTC), HYTORC President Eric Junkers detailed one of the company's recent subsea bolting and washer case studies.

"A major oil company needed to secure a solution and install the hot tap over a mile deep (1.75 km)," he said. "In conjunction with C-Innovation and others, HYTORC was able to provide products and support for a successful offshore campaign of two separate installations. The washer allows for an easier installation due to the removal of the reaction arm from the bolting process. With an application at such depth, a solution that minimized the possibility of errors was absolutely critical."

HYTORC, which has decades of experience in subsea bolting, was chosen to supply hydraulic bolting tools that could provide precise torque at such a depth, and the company provided its HYTORC Reaction Washer.

Case study

HYTORC Reaction Washers are utilized for the deepest subsea hot tap operations in the Gulf of Mexico (GoM). HYTORC and C-Innovation, a company that specializes in ROV support and services, worked together to resolve a unique operator challenge.

The platform and flowlines needed injection lines installed at the sea floor.

"A common method of tying into an existing line is to 'hot tap' the line," Junkers said. "By definition, this is a method of tapping into a live line without stopping production or flow. This is inherently dangerous and critical that every component performs as designed without any deviation. The success of the entire operation is relying on the fasteners holding the two hot tap halves together. Additionally, the Dynamic Landing Structure needed to be secured to the vertical riser prior to hot tap operations."

Methods for torquing the fasteners on both the Dynamic Landing Structure and the hot tap operations were overlooked until two weeks prior to deploying offshore.

"HYTORC was able to supply a solution with Reaction Washers that was unparalleled by any other fastener company," Junkers said. "No need for reaction points, easy stabbing for the ROV, no worry about severing a hydraulic line with reaction arms, and no worry about damaging tubing or sensitive umbilicals with a reaction arm. This also allowed for a lighter-weight solution, which was less cumbersome for the ROV."

Full-scale shop operations and qualification took place within two weeks, and the Reaction Washer system was qualified and approved as "fit for service" and meeting the 20-year life expectancy. The Reaction Washers and studs were Xylan coated. The Reaction Washers replaced the existing carbon steel flat washers from the original design.

Both hot taps were deployed and installed in 5,670 fsw. "C-Innovation and the customers were very happy and pleased with how quick and seamless the installs went," Junkers said.

"HYTORC Reaction Washers are an unmatched upgrade for very little cost, saving time and money for owners and operators while providing an easier, safer method of installation for service companies," he added. "HYTORC Reaction Washers are qualified for long-term subsea installation while providing superior quality, performance and proven time-saving benefits."

Development process

The HYTORC Washer was developed to eliminate the risk of injuries due to pinch points but also provides for more accurate and precise performance due to the elimination of sideload. The outside sleeve of the socket driver remains stationary and engages with the washer, which is held in place by the nut.

The HYTORC Washer is manufactured in accordance with the requirements in the ASTM F3394/F3394M Standard Specification for Hardened Steel Backup and Reaction Washers. This standard covers general-purpose mechanical and structural use of washers with bolts, nuts, studs, direct tension indicators and other threaded fasteners.

Capabilities and applications

The HYTORC Washer provides axial tool alignment resulting in improved repeatability, reduced bolt load scatter and increased accuracy, according to Junkers.

It is available with several coatings to meet the needs of a variety of environments including deepsea applications. The washer can be used with any HYTORC Hydraulic, Pneumatic and Electric tools that are compatible with the HYTORC Washer Driver. Available in a wide range of sizes, the HYTORC Washer can be used in most structural bolting, subsea bolting, pressure vessel applications or flange applications in the offshore industry.