Variable Rotor Bypass Valve for Fluid-Actuated Motor Speed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fluid-actuated motors, such as Moineau pump-type drilling motors, lack the ability to change their internal geometry downhole without diverting fluid flow outside the drill string, leading to inefficient drilling due to suboptimal rotational speed adjustments and reduced fluid circulation for cooling and cutting removal.
Innovation Solution
A variable rotor bypass valve is installed within the motor to alter the rotational speed of the drill bit by separating and recombining fluid flow paths, allowing for speed adjustments without diverting fluid outside the drill string, utilizing a cam mechanism to control fluid flow through the rotor and stator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the internal geometry of the motor is changed to adjust drill bit speed, then the rotational speed can be optimized for different formations, but the motor must be removed from the well which is time consuming and expensive
Solution Approach 1:
The patent applies the dynamics principle by making the motor's internal geometry changeable while in operation. The bypass valve mechanism allows the rotor-stator clearance to be dynamically adjusted between tight and loose configurations, enabling speed optimization for different formations without removing the motor from the wellbore.
Solution Approach 2:
The patent implements parameter changes by modifying the physical state of the motor's internal geometry through the bypass valve. By changing the clearance parameter between rotor and stator via fluid pressure control, the motor adapts its performance characteristics to match different drilling conditions and formation hardness levels.
2Productivity
If fluid flow is bypassed outside the drill string to change motor internal geometry, then speed adjustment is possible, but fluid circulation for cooling and cutting removal is reduced
Solution Approach 1:
The patent extracts the geometry-changing function from the main fluid flow path by introducing a separate bypass valve mechanism. This allows the motor's internal geometry to be modified using a portion of the fluid flow without diverting the entire circulation system, maintaining adequate cooling and cuttings removal capability.
Solution Approach 2:
The bypass valve acts as an intermediary mechanism that mediates between the need for geometry change and the need for fluid circulation. It selectively diverts only the minimum necessary fluid flow to achieve geometric adjustment while allowing the majority of the fluid to continue circulating for cooling and cuttings removal.
3Adaptability or versatility
If the motor operates at fixed internal geometry, then the structure is simple and reliable, but the rotational speed cannot be optimized for different formations
Solution Approach 1:
The patent applies universality by designing the bypass valve mechanism to serve multiple functions: it controls the motor's internal geometry, adjusts rotational speed, and adapts to different formation conditions. This single added component enables the motor to handle various drilling scenarios without requiring multiple specialized motors.
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 efficient adjustment of drill bit speed and maintains fluid circulation for cooling and cutting removal, reducing operational costs and time by allowing speed changes without removing the motor from the well.
Implementation Method 1
The bypass valve separates the fluid flow through the power section into two paths. One path is directed through that part of the power section that causes the drill bit to rotate while the other path is directed around it.
Implementation Method 2
utilizing a cam mechanism to control fluid flow through the rotor and stator
Implementation Method 3
The actual internal geometry of the fluid flow through the power section in conjunction with the fluid flow pressure maintained at the mud pump determines the actual speed of rotation.
Data Source
AI summary
A method and apparatus for changing the speed of a drill bit down hole in a fluid-actuated motor, including a positive displacement motor and a hydraulic motor, is disclosed. The apparatus comprises a bypass valve installed in the motor for controlling flow through and around the power section of the motor. When closed, the bypass valve forces all fluid to flow through the power section of the motor, imparting maximum speed to the drill bit. When opened, a portion of the fluid flow is allowed to flow around the power section of the motor, thereby reducing the speed of the drill bit. The bypass valve may be opened or closed mechanically, electrically, hydraulically, pneumatically, or by any other means, including a removable plug.