Fluid Pressure Pulse Generator for Drilling Telemetry
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Solution Overview
Problem
Current mud pulse (MP) telemetry systems in downhole drilling face issues such as mechanical wear, limited speed of response, incompatibility with air/underbalanced drilling, and degradation in signal quality due to gas presence in drilling fluid, along with challenges in accessing and replacing small parts, which affect the reliability and efficiency of data transmission during drilling operations.
Innovation Solution
A fluid pressure pulse generating apparatus comprising a pulser assembly with a motor, sensor, driveshaft, and processing equipment, which includes a gearbox and mechanical stop sub-assembly, allowing for precise control and calibration of driveshaft rotation and pressure pulse generation, enabling efficient data transmission through varying flow configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If negative pulsing valves are used to create pressure pulses, then data transmission is achieved, but mechanical wear and washing increase due to high differential pressure and valve impact
Solution Approach 1:
The patent inverts the conventional negative pulsing approach by using positive pulsing valves that add pressure to the drilling fluid rather than creating pressure drops. This reversal eliminates the high differential pressure and valve impact issues that cause mechanical wear and washing, while still achieving reliable data transmission through the drill string
Solution Approach 2:
The patent extracts the pulse generating function from the drill string telemetry system and implements it using a dedicated positive pulsing valve assembly. This separate, specialized component performs the pulsing function without being subject to the harmful conditions that affect integrated negative pulsing valves, thereby reducing mechanical wear while maintaining data transmission capability
2Reliability
If rotary valve pulsers are used to generate pressure pulses, then data transmission is achieved, but mechanical wear increases due to continuous rotation and impact
Solution Approach 1:
The patent employs periodic opening and closing of the positive pulsing valve to generate pressure pulses for data transmission. This periodic action replaces continuous rotation mechanisms, achieving the same telemetry function with significantly reduced mechanical wear since the valve only actuates when needed rather than continuously rotating and impacting
Solution Approach 2:
The patent substitutes mechanical rotation-based pulsing with a valve-based pressure control system. Instead of using rotating components that continuously wear through friction and impact, the system uses a valve that controllably adds pressure to the fluid stream, reducing mechanical wear while maintaining pulse generation capability
3Reliability
If skilled technicians are required for setup and maintenance of MP telemetry systems, then proper operation is achieved, but operational complexity and time increase
Solution Approach 1:
The positive pulsing valve assembly is designed to be self-contained and relatively simple in construction, with fewer moving parts that require adjustment or maintenance. The system's robust design allows it to operate reliably without requiring skilled technicians for frequent intervention, reducing operational complexity while maintaining system reliability
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 data transmission reliability and efficiency by reducing mechanical wear, improving signal quality, and allowing operation in challenging drilling conditions, such as air/underbalanced drilling, through precise control of pressure pulses and reduced dependency on skilled technicians for setup and maintenance.
Implementation Method 1
a motor, a sensor for detecting rotation of the motor, a driveshaft rotationally coupled to the motor
Implementation Method 2
a sensor for detecting rotation of the motor
Implementation Method 3
Pressure pulses are generated by changing the flow area and/or flow path of the drilling mud as it passes the MWD tool
Data Source
AI summary
A fluid pressure pulse generating apparatus including a pulser assembly and a fluid pressure pulse generator and methods of using the fluid pressure pulse generating apparatus. The pulser assembly comprises a motor, a sensor for detecting rotation of the motor, a driveshaft rotationally coupled to the motor, and processing and motor control equipment communicative with the motor and the sensor. The fluid pressure pulse generator is coupled with the driveshaft. The sensor provides an indication of the amount of rotation of the motor and this information can be processed by the processing and motor control equipment to determine the position of the driveshaft and to control rotation of the driveshaft based on a predetermined rotational relationship between the driveshaft and the motor.