Rotary Steerable Tool Dump Valve for Variable Pad Retraction
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Solution Overview
Problem
Existing directional drilling systems have limited resolution in tool face control, which restricts their dogleg capability and precision in forming directional wells, as the extendable pads or pistons can only extend or retract at a fixed rate.
Innovation Solution
Incorporating one or more dump valves within a rotary steerable tool to control the pads or pistons, allowing for variable extension and retraction rates, thereby enhancing the control over force vectors applied to the borehole wall and improving directional control of the drill bit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pads or pistons are used to extend from the drilling tool to push the drill bit, then directional control is achieved, but the extension and retraction rate is fixed, resulting in low resolution tool face control
Solution Approach 1:
The pad retraction system transitions from a fixed-rate mechanism to a dynamically controllable system using a dump valve. The valve allows operators to adjust the retraction rate by controlling fluid flow, enabling the pad to retract quickly when needed while maintaining slow, precise control during positioning. This dynamic adjustment resolves the contradiction between achieving high-resolution control and maintaining system simplicity.
Solution Approach 2:
The invention changes the flow rate parameter of hydraulic fluid during pad retraction by introducing a dump valve. The valve can be adjusted to different openings, changing the fluid flow rate and thus the pad retraction speed. This parameter change allows the same hardware to achieve both slow positioning and fast retraction, improving tool face control resolution without proportionally increasing device complexity.
2Manufacturing precision
If pads extend and retract at a fixed rate, then the system is simple to operate, but the dogleg capability and precision in forming directional wells is restricted
Solution Approach 1:
A dump valve is introduced as an intermediary component between the hydraulic system and the pad retraction mechanism. This valve mediates the fluid flow, allowing operators to control the retraction rate independently from the extension mechanism. The intermediary device enables precise directional well formation by providing variable retraction speeds while maintaining relatively simple operation through a single control interface.
3Speed
If the pad retraction rate is increased for faster directional changes, then the dogleg capability improves, but the control resolution may be compromised
Solution Approach 1:
The dump valve creates a dynamic control system where the pad retraction speed can be adjusted in real-time. During positioning phases, the valve maintains slow retraction for high precision control. During dogleg operations requiring sharp turns, the valve opens wider to increase retraction speed. This dynamic adaptability allows the system to achieve both high speed and high precision at different operational moments, resolving the contradiction between speed and control resolution.
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
This solution enables more precise and efficient directional control, allowing for sharper turns and improved reservoir exposure by allowing pads to move from the extended to retracted position more quickly, enhancing the dogleg capability and operational speed of the drilling system.
Implementation Method 1
a dump valve in fluid communication with the piston to control fluid flow between the piston and an exterior of the tool body
Data Source
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AI summary
A rotary steerable tool for directional drilling includes a tool body including an outer surface and a flowbore therethrough, a pad movably coupled to the tool body and alternately movable between an extended position and a retracted position, and a piston engageable with the pad to move the pad. The tool further includes a pressurized fluid supply flow path to provide fluid pressure to the piston for the piston to controllably move the pad to the extended position, and a dump valve in fluid communication with the pressurized fluid supply flow path to selectively vent fluid pressure to allow the pad to move from the extended position toward the retracted position.