Case Study

Engineered solution supports PLEM valve actuator deconstruction and installation in Gulf of Mexico.

Industry

Oil and Gas

Year

2023

Region

North America
Overview

In early 2023, Oceaneering was contracted by a major Gulf of Mexico operator to provide a fast-track engineered solution to address a leaking gate valve on one of their pipeline end manifolds (PLEMs).

The valve needed to be deconstructed subsea prior to assessing and remediating the issue and safely restoring production.

Oceaneering designed, built, and tested the custom equipment required to gain access to the valve, remove the actuator, clean the valve body, and help perform a visual inspection of the valve.

The offshore operations were completed in three phases to ensure efficiency and meet the expedited schedule as best as possible.

Our Solution

Oceaneering provided a custom suite of ROV-operable tools to gain access, clean, inspect, and protect the valve body prior to the required repairs being executed. The team leveraged extensive experience in ROV tooling, ROV operations, and expedited intervention operations to ensure the suite provided the maximum level of redundancy.

Execution Plan

Oceaneering’s initial engagement with the customer was to complete a front end engineering and design (FEED) study that developed concepts of the tooling suite.

A successful FEED evolved into delivery of complete manufacturing drawings and subsequent fabrication, assembly, and testing of the equipment. The team worked with the customer to outline requirements for completing key milestone activities and the scope was completed in three phases between July and November 2023.

The tooling build and offshore execution was split into two phases to meet offshore vessel schedules and mitigate risk. Prior to mobilizing the tooling suite offshore, each tool was subjected to vigorous site integration testing (SIT) at Oceaneering’s facility in Houston, Texas. The team built various test jibs to mimic the live, offshore assets, enabling confirmation of the custom-designed tools’ suitability for operations and providing valuable learning for the project’s technicians and engineers.

Cutting Guide on PLEM

The cutting guide was lowered onto the top of the PLEM, enabling the super grinder to make clean cuts while preventing the ROV from damaging the PLEM internals. The ROV used the modified super grinder to make all required structural cuts. The cutting guide also allowed the cut panel from the PLEM to be safely handled and lifted into a recovery basket without damaging any other components.

Tooling Used
  • Super grinder with custom blade guard
  • Super grinder cutting guide
  • Removal fixture

PLEM Repair and ToolingThe critical operation in this phase was the installation of the elevator actuator removal tool designed to centralize above the actuator and required to lock onto the PLEM structure. Guide clamps were installed first to ensure the actuator removal tool landed in the correct location. The guide clamps were added to the scope three weeks prior to project execution and ensured the correct placement of the elevator for Phase 3.

Next, the removal tool was lowered into position and clamped onto the valve actuator interface. After locking, it pulled the valve actuator straight up with a weight of 4,500 lb (plus any additional friction forces) without damaging any other equipment on the PLEM. The final force required to remove the actuator was calculated to be 64,000 lb, which included the use of the contingency jacking tool. This tool was not originally part of the scope and was included in the suite after being suggested by the Oceaneering team.

Tooling Used
  • Hydraulic tubing cut and crimping tool
  • Hydraulic torque tool for flange nut removal
  • Stud removal tool
  • Contingency stud jacking tool
  • Contingency flange spreading tool
  • Actuator removal tool guide clamps
  • Actuator removal and lifting tool
  • Gasket removal tool
  • Contingency gasket wedge removal tool
  • Gasket hub cleaner
  • Valve gate seat fishing tool
  • Valve body debris cap

During ongoing operations, the customer asked Oceaneering to provide additional support. They wanted to use the actuator elevator frame, originally designed to support extraction, to help install the repair solution. The Oceaneering team modified the design to meet these requirements, enabling the installation of a new flange capable of sealing the valve body and restoring flow.

Results

While the project had a tight deadline and not all deliverables were known upfront, our engagement and collaboration with the customer was pivotal to delivering a solution that met their needs and schedule.

The requirements evolved during the project and required agile and creative project management and execution to meet deadlines.Our strong vendor relationships ensured timely and efficient manufacturing.

Strategic decisions, including using technicians in the offshore operations who were involved with the assembly and SIT of the tooling was integral to the project’s success as their firsthand knowledge proved invaluable to the execution of the offshore campaign.

Oceaneering was able to supply and support the complete deconstruction tooling suite from development and fabrication, through assembly, testing, and offshore execution. Each tool worked exceptionally well and without issue to successfully complete the project.

The project was completed without incident and the operator brought the flowline back online on schedule.

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