Top-Mounted Mud Pulser Assembly for Low-Force Downhole Telemetry
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Solution Overview
Problem
Existing MWD mud pulser configurations position the main fluid valve downhole, which limits the use of LWD and RSS tools and inefficiently consumes battery power for servo-valve operation, necessitating a more efficient and effective design that allows for real-time downhole drilling data communication to the surface.
Innovation Solution
A top-mounted pulser design positions the main valve uphole of the servo-valve, utilizing a moveable piston valve and a first channel to efficiently control the main valve with minimal force, incorporating a metering orifice to regulate fluid flow and reduce servo-valve robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the main fluid valve is positioned downhole in existing MWD mud pulser configurations, then the valve can be directly controlled by fluid pressure, but this configuration limits the use of LWD and RSS tools and inefficiently consumes battery power for servo-valve operation
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the main valve uphole of the servo-valve instead of downhole. This inversion allows LWD and RSS tools to be positioned downhole near the drill bit while the main valve is located uphole, enabling these tools to function near the drill bit without being displaced. The inverted configuration also reduces battery power consumption because the servo-valve operates with reduced force requirements when controlling the main valve from an uphole position.
2Use of energy by moving object
If a top-mounted pulser design positions the main valve uphole of the servo-valve, then battery power is conserved by minimizing the force required for servo-valve operation, but this requires a different valve control mechanism with moveable piston valve and first channel
Solution Approach 1:
The patent introduces a moveable piston valve as an intermediary component between the servo-valve and the main valve. The piston valve includes a poppet that moves between an open and closed position to control fluid flow. This intermediary mechanism translates the servo-valve's control action into effective main valve operation with reduced force requirements, enabling battery power conservation while maintaining functional simplicity.
Solution Approach 2:
The patent utilizes hydraulic principles through the moveable piston valve mechanism. Fluid pressure differential across the piston creates force that moves the poppet to open or close the main valve. The first channel provides fluid communication between the piston chamber and the region uphole of the main valve, enabling hydraulic control with minimal servo-valve force requirements, thus conserving battery power.
3Force
If a moveable piston valve with poppet is used to control the main valve, then the valve can be efficiently controlled with minimal force, but this requires precise positioning and fluid communication channels
Solution Approach 1:
The moveable piston valve is designed to be actuated by fluid pressure differential that develops naturally during operation. The piston responds automatically to pressure changes in the first channel, moving the poppet to the appropriate position without requiring precise external positioning mechanisms. This self-actuating design reduces manufacturing precision requirements while maintaining efficient force utilization.
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 the use of LWD and RSS tools near the drill bit while conserving battery power by minimizing the force required for servo-valve operation, ensuring accurate and efficient communication of downhole data to the surface.
Implementation Method 1
The moveable piston valve (240) is actuated by a fluid pressure differential to move between a main valve open position and a main valve closed position
Implementation Method 2
incorporating a metering orifice to regulate fluid flow and reduce servo-valve robustness
Data Source
AI summary
A mud pulser for generating pulses in a fluid flow in a wellbore. The mud pulser has a valve housing having an uphole opening for receiving fluid flow, and a piston valve situated in a piston chamber is longitudinally moveable between an open and closed position by closing and opening a pilot port downhole of the uphole opening and in fluid communication with the piston chamber. A first channel extends in the sidewall of the valve housing and fluidly connects the uphole opening and the pilot port. One or more fluid egress ports are in communication with the piston chamber. A metering orifice may be inserted in said one or more fluid egress ports for first channel. Opening and closing the downhole pilot port moves the piston valve and thus opens and closes the uphole opening thereby generating pressure pulses in the fluid flow. A downhole valve is further disclosed.