Modular BOP control element retrieval and replacement
Retrievable BOP Controls is an integrated system for retrieving and replacing ROV-retrievable subsea controls components—whether planned or unplanned. The system enables the drilling rig to maintain the primary well control barrier during the repair without a stack pull and the associated risks. Retrievability reduces NPT for BOP controls by up to 80%, which can translate into 10 or more days saved.
Control system components are the most complex elements on the BOP stack. A component malfunction could lead to a stack pull, increasing NPT costs and HSE operational risks. Packaging the control system and ancillary components into modularized ROV-retrievable sections, components can be independently retrieved, repaired, and reinstalled while maintaining the primary well control barrier and mud column.
There are three primary elements to the Retrievable BOP Controls system. The first is the retrievable module which is a package for components of a BOP control system. The functional content of a specific module depends on the specific application.
The module is attached to the BOP stack via a simple and robust receiver using connections that rely on the module’s function. The connections use elements common in the subsea BOP controls industry, such as self-energized packer seals for hydraulic connections up to 5,000 psi. The receiver also provides docking points for the third section, the ROV interchange device (skid).
The ROV skid transports a module to and from the receiver. The skid is designed to be compatible with the various working class ROVs typically used on deepwater drilling rigs. It incorporates adapters to change between ROVs, if needed. Skid controls can utilize spare fiber optics or copper in the ROV umbilical and are independent of the ROV controls system. All elements are designed according to relevant standards.