Rotating Control Barrier Structure for Debris-Excluding Sealing
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Solution Overview
Problem
Existing rotating control devices face issues with debris and abrasive well fluids damaging rotary seals, leading to contamination of bearing lubricant and eventual failure of bearings.
Innovation Solution
A barrier is integrated into the rotating control device comprising interdigitated upper and lower portions with inclined surfaces and slots to create a tortuous path, expelling debris and particulates away from the rotary seals, thereby preventing contact and potential damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rotary seal is used to seal the annulus in a rotating control device, then the seal allows rotation of the tubular while maintaining sealing, but debris and abrasive well fluids can still contact and damage the seal
Solution Approach 1:
A barrier is introduced as an intermediary component between the well fluids/debris and the rotary seal. The barrier includes a barrier seal that prevents direct contact between abrasive well fluids and the rotary seal, thereby protecting the seal from damage while allowing the rotation function to continue.
Solution Approach 2:
The sealing system is segmented into multiple components: the barrier seal, the rotary seal, and the barrier member. This segmentation allows each component to perform its specific function - the barrier seal protects against debris while the rotary seal maintains the sealing function, with the barrier member providing structural support.
2Object-affected harmful factors
If the barrier includes multiple annular walls with inclined surfaces, then debris is effectively expelled from the tortuous path, but the device complexity increases
Solution Approach 1:
The barrier walls are designed with inclined surfaces that create a tortuous path for debris. The curved and angled surfaces guide debris outward and prevent it from following a straight path through the barrier, effectively expelling harmful particles while maintaining a compact structure.
Solution Approach 2:
The barrier structure features nested annular walls where inner walls are positioned within the space defined by outer walls. This nesting arrangement creates multiple concentric tortuous paths that debris must navigate, maximizing debris expulsion effectiveness while minimizing the overall radial footprint of the barrier.
Data Source
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AI summary
A rotating control device (40) can include a bearing housing (52), an inner mandrel (50) rotatably supported in the bearing housing, and a barrier (60) having upper (62) and lower portions (64), the upper portion being secured against rotation relative to the inner mandrel, the lower portion being secured against rotation relative to the bearing housing, the lower portion including annular recesses (72), the recesses being progressively deeper in a radially outward direction. Another barrier can include upper and lower portions, the lower portion including multiple annular walls (66), an upper surface of each wall (70) being inclined downward in a radially outward direction. Another barrier can include upper and lower portions, the upper and lower portions having annular walls, the upper portion walls being interdigitated with the lower portion walls, and the upper and lower portion walls being circumferentially discontinuous, whereby gaps are formed between circumferential ends of the upper and lower portion walls.