Fluid Pressure Pulse Generator for MWD Telemetry
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Solution Overview
Problem
Current mud pulse telemetry systems for drilling operations face issues such as mechanical wear, limited speed of response, incompatibility with air/underbalanced drilling, and signal degradation due to gas content in drilling fluid, as well as challenges with low mud flow rates and debris accumulation, leading to reduced performance and reliability.
Innovation Solution
A fluid pressure pulse generator comprising a stator and rotor with specific flow configurations that generate varying pressure pulses by aligning full flow, intermediate flow, and reduced flow chambers and openings, allowing for smooth fluid flow and pressure pulse generation without the need for axial gaps, reducing mechanical stress and improving operational flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional mud pulse telemetry systems use valves to create pressure pulses, then data transmission is achieved, but mechanical wear and reliability decrease due to high differential pressure and valve impact against seats
Solution Approach 1:
The patent replaces the conventional mechanical valve system with a magnetic field-based modulation system. A magnetometer detects changes in the magnetic field caused by a rotating magnet assembly, generating pressure pulses without mechanical contact. This eliminates wear from valve impacts against seats while maintaining data transmission capability.
Solution Approach 2:
The patent uses the drilling mud flow itself as the transmission medium, modulating its pressure through magnetic field interaction rather than mechanical valve restriction. The mud pulse carrier wave is modulated by varying the magnetic field strength, which changes the pressure pulses in the fluid stream without requiring mechanical valves to open and close.
2Loss of information
If high differential pressure is used to create sufficient pressure drop in negative valves, then data transmission is achieved, but the valves become more prone to washing and mechanical failure
Solution Approach 1:
The patent eliminates mechanical valves entirely and uses a magnetometer to detect magnetic field changes from a rotating magnet assembly. This non-mechanical approach avoids the washing and failure issues associated with high differential pressure acting on mechanical valve components.
3Loss of information
If rotary valve pulsers are used to generate pressure pulses, then data transmission is achieved, but the axial gap required for flow area reduces manufacturing precision and increases complexity
Solution Approach 1:
The patent replaces the rotary valve mechanism with a rotating magnet assembly detected by a magnetometer. This eliminates the need for axial gaps and complex valve seating arrangements, simplifying the overall structure while maintaining pressure pulse generation capability.
4Power
If conventional pulser systems are used, then pressure pulse generation is achieved, but mechanical and abrasive wear leads to failure
Solution Approach 1:
The patent substitutes mechanical valve actuation with a magnetic field modulation system. A magnetometer detects changes in the magnetic field produced by a rotating magnet assembly, generating pressure pulses without mechanical contact. This eliminates both mechanical wear and abrasive wear from debris in the drilling fluid.
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
The solution enhances the reliability and efficiency of pressure pulse generation, reducing mechanical wear and improving signal strength across different drilling conditions, including low flow rates and gas-containing fluids, while allowing for easy maintenance and adaptation to changing fluid flow conditions.
Implementation Method 1
The rotor is rotatable between a full flow configuration whereby the full flow chamber and the fluid opening align so that fluid flows from the full flow chamber through the fluid opening; and a reduced flow configuration whereby the full flow chamber and the fluid opening are not aligned. The flow of fluid through the fluid opening in the reduced flow configuration is less than the flow of fluid through the fluid opening in the full flow configuration thereby generating a first fluid pressure pulse.
Data Source
AI summary
A fluid pressure pulse generator comprising a stator and rotor that can be used in measurement while drilling using mud pulse or pressure pulse telemetry is disclosed. The stator comprises a stator body with a circular opening therethrough and the rotor comprises a circular rotor body rotatably received in the circular opening of the stator body. One of the stator body or the rotor body comprises one or more than one fluid opening for flow of fluid therethrough and the other of the stator body or the rotor body comprises one or more than one full flow chamber. The rotor is rotatable between a full flow configuration whereby the full flow chamber and the fluid opening align so that fluid flows from the full flow chamber through the fluid opening, and a reduced flow configuration whereby the full flow chamber and the fluid opening are not aligned. The flow of fluid through the fluid opening in the reduced flow configuration is less than the flow of fluid through the fluid opening in the full flow configuration thereby generating a fluid pressure pulse.