Low Profile Rotating Control Device Nested in BOP Housing
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Solution Overview
Problem
Smaller drilling rigs with limited substructure height are unable to perform managed pressure and underbalanced drilling due to lack of pressure containment, posing safety and environmental hazards from escaping gases and inability to drill with compressible fluids, and existing rotating control devices (RCDs) are too tall to fit on these rigs.
Innovation Solution
A low profile rotating control device (LP-RCD) system that fits within the limited space of smaller rigs, featuring a compact design with an integral annular BOP seal, allowing for efficient lubrication and seal replacement without physically dangerous work under the rig floor, enabling drilling with compressible fluids and accommodating misaligned tubulars.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional RCDs are used, then pressure containment and sealing are achieved, but the device height exceeds the limited substructure space on smaller rigs
Solution Approach 1:
The RCD is nested within the BOP housing structure, with the RCD housing positioned within the annular BOP housing. The bearing assembly is nested within the RCD housing, and the seal assembly is nested within the bearing assembly. This nested configuration allows multiple functional components to occupy overlapping spatial volumes, reducing the overall height of the combined system while maintaining all necessary pressure containment and sealing functions.
Solution Approach 2:
The patent combines the RCD and BOP into a single integrated assembly where the RCD housing is positioned within the annular BOP housing. The BOP housing serves dual purposes as both a blowout preventor and as the outer housing for the RCD. This merging of functions eliminates the need for separate RCD and BOP housings, thereby reducing the overall device height while maintaining both pressure containment and sealing capabilities.
2Reliability
If RCD with bearings positioned above lower seal is used, then sealing is achieved, but the combined height of RCD and housing exceeds available space
Solution Approach 1:
The patent repositions the bearing assembly laterally adjacent to the lower seal rather than vertically above it. This dimensional change from a vertical stacking arrangement to a lateral arrangement allows the bearing assembly and seal assembly to occupy different radial positions within the same axial space, thereby reducing the combined height of the RCD and housing while maintaining both sealing and bearing functions.
Solution Approach 2:
The seal assembly is positioned within the bearing assembly in a nested configuration, where the seal housing is contained within the bearing housing. This nesting allows the seal and bearing components to share the same spatial envelope, reducing the overall height of the assembly while maintaining both sealing and support functions.
3Adaptability or versatility
If smaller rigs are used, then operational flexibility and cost are improved, but pressure containment capability is lost
Solution Approach 1:
The patent merges the RCD and BOP into a single integrated assembly that can be installed on smaller rigs with limited substructure height. The BOP housing serves dual purposes as both a blowout preventor and as the outer housing for the RCD, providing pressure containment capability on compact rigs that would otherwise lack this functionality.
Solution Approach 2:
The RCD is nested within the BOP housing structure, allowing the pressure containment functions of the BOP to encompass the RCD. This nested configuration enables smaller rigs to achieve both RCD sealing functionality and BOP pressure containment within a compact footprint, maintaining safety capabilities while using smaller, more flexible rig equipment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables safer and more efficient drilling operations on smaller rigs by containing hazardous gases, allowing the use of compressible fluids, and accommodating misaligned tubulars, while reducing the need for physically hazardous maintenance and increasing operational flexibility.
Implementation Method 1
a bearing assembly with an inner member, an outer member, and a plurality of bearings therebetween
Implementation Method 2
a stripper rubber seal that seals the annular space between the inserted tubular and the RCD housing
Implementation Method 3
a hydraulic piston that can be actuated to push the tubular through the RCD during tripping of the tubular
Data Source
AI summary
A system and method is provided for a low profile rotating control device (LP-RCD) and its housing mounted on or integral with an annular blowout preventer seal, casing, or other housing. The LP-RCD and LP-RCD housing can fit within a limited space available on drilling rigs. An embodiment allows a LP-RCD to be removably disposed with a LP-RCD housing by rotating a bearing assembly rotating plate. A sealing element may be removably disposed with the LP-RCD bearing assembly by rotating a seal retainer ring. Alternatively, a sealing element may be removably disposed with the LP-RCD bearing assembly with a seal support member threadedly attached with the LP-RCD bearing assembly. The seal support member may be locked in position with a seal locking ring removably attached with threads with the LP-RCD bearing assembly over the seal support member. Spaced apart accumulators may be disposed radially outward of the bearings in the bearing assembly to provide self lubrication to the bearings.