Curved Interface Flow Control Choke for Drilling Fluid Leakage
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Solution Overview
Problem
In wellbore drilling operations, unsealed mud motors experience excessive drilling fluid leakage due to radial bearing wear, leading to inadequate fluid pressure for secondary applications and potential erosion from high-speed fluid jets, which existing flow control chokes with flat interfaces cannot effectively manage under bending or shearing forces.
Innovation Solution
A flow control choke with curved interfaces between a rotatable and stationary section, featuring a biasing mechanism and a ledge portion made from corrosion-resistant materials, allows for controlled fluid flow and movement to reduce wear and prevent erosion, while an anti-rotation mechanism prevents rotation relative to the driveshaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flow control choke with flat interfaces is used to control drilling fluid flow, then the flow can be restricted, but the flat interfaces experience excessive wear and strain under bending or shearing forces
Solution Approach 1:
The patent applies curvature by replacing flat interfaces with curved spherical surfaces at the interface between the stationary and rotatable sections. This curved interface allows the sections to move freely relative to each other under bending or shearing forces, distributing stress and reducing wear, thereby extending the service life of the choke while maintaining flow control reliability.
2Reliability
If drilling fluid flow through the annulus is increased to lubricate the bearing section, then lubrication is improved, but erosion from high-speed fluid jets increases
Solution Approach 1:
The curved interface design modifies the flow path of drilling fluid, allowing it to follow a more gradual trajectory rather than creating high-speed jets. This reduces the erosive impact on surrounding components while maintaining adequate flow for bearing lubrication, thus resolving the contradiction between lubrication effectiveness and erosion prevention.
Data Source
AI summary
A drilling system can be used to drill a borehole. The drilling system may include a first housing defining a main fluid flow path and a second housing defining a bypass flow path toward an annulus of a wellbore. A flow control choke may be positioned between the first housing and the second housing. The flow control choke may include a rotatable section and a stationary section that is stationary relative to the rotatable section. The stationary section may have a curved interface with the rotatable section for restricting a flow of a drilling fluid through the bypass flow path.