Segmented Choke Valve Gate for Higher Flow and Pressure Control
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Solution Overview
Problem
Existing choke valves in managed pressure drilling systems have limited controllability and flow capacity, leading to increased pressure differences and potential blowouts during drilling operations, as they often have a choke minimum passage area that is only 15-20% of the seat orifice area in fully open positions, restricting fluid flow and debris clearance.
Innovation Solution
The design of a choke valve with an increased gate stroke and a choke minimum passage area that can be up to 100% of the seat orifice area, combined with a worm gear drive and motor system for precise actuation, allowing for greater volumetric flow rates and reduced pressure differences, while maintaining compliance with industry standards for closure time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the choke minimum passage area is increased to improve flow capacity, then the volumetric flow rate increases, but the valve structure complexity increases due to larger gate stroke requirements
Solution Approach 1:
The gate body is divided into multiple metering segments (first metering segment, second metering segment, third metering segment) with different diameters. Each segment can be positioned independently within the seat orifice, allowing precise control of flow area without requiring excessive gate stroke. This segmentation enables the valve to achieve high flow capacity while maintaining a compact structure.
2Area of stationary object
If the gate stroke is increased to achieve greater choke minimum passage area, then the flow capacity improves, but the actuation system complexity increases
Solution Approach 1:
The gate is designed with linear translation capability along the gate shaft, allowing dynamic positioning of multiple metering segments at different heights within the seat orifice. This dynamic adjustment mechanism, combined with the worm gear drive, enables the valve to achieve variable flow areas without requiring an excessively long gate stroke, thus balancing flow capacity with actuation system simplicity.
3Stress or pressure
If the choke minimum passage area is increased to reduce pressure differences, then the pressure control capability improves, but the valve body size increases
Solution Approach 1:
Different metering segments have different diameters (first metering segment has larger diameter, second has intermediate diameter, third has smallest diameter), allowing localized flow control at different positions within the seat orifice. This enables the valve to achieve precise pressure control and reduced pressure differences without requiring a uniformly large valve body, as the flow area is optimized locally at each segment position.
4Reliability
If the valve is designed for rapid closure to meet API 16C standards, then the safety improves, but the flow control precision in open positions decreases
Solution Approach 1:
The valve provides more than one stable positioning state through the multiple metering segments that can be positioned at different heights within the seat orifice. This allows the valve to maintain precise flow control at intermediate positions while still achieving rapid closure when needed, as the segmented design enables quick transition to the fully closed position without sacrificing intermediate positioning capability.
Data Source
AI summary
A choke valve is provided having a body, a seat, and a gate. The body has an internal chamber, an inlet flow passage, and an outlet flow passage. The seat has a seat orifice with an area, the seat positioned at an end of the outlet flow passage contiguous with the internal chamber. The gate has a gate shaft and a gate body affixed to one end of the gate shaft. The gate is linearly translatable within the body between a fully open position and a fully closed position, wherein in the fully closed position the gate body is engaged with the seat orifice. In the fully open position a choke minimum passage area is defined between the gate body and the seat orifice, and the choke minimum passage area is at least 30% of the seat orifice area.