Selective Motor Activation in Downhole Drilling Assemblies
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Solution Overview
Problem
Existing downhole drilling technologies face challenges in controlling friction and torque during deep borehole drilling, leading to slowed penetration rates and potential damage, as friction tools require varying drilling fluid flow rates, which can disrupt other drilling components and necessitate time-consuming assembly and disassembly to add or remove tools.
Innovation Solution
A downhole assembly with a Moineau-type motor and a bypass system, including a catch mechanism that allows selective activation of drilling fluid flow through a rotor assembly, enabling control of motor torque without altering surface flow rates, and a rotating valve assembly that generates vibrations for friction reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If friction tools are used to overcome drag and friction in deep boreholes, then the rate of penetration and drilling efficiency are improved, but the operation of other components in the drilling string is disrupted due to variations in drilling fluid flow rate
Solution Approach 1:
The drilling system is divided into independent functional segments: the friction tool section that generates vibrations using localized drilling fluid flow, and the motor section that operates independently with its own fluid intake. This segmentation allows each component to function without interfering with the other, resolving the contradiction between improving penetration rate and maintaining operational stability.
Solution Approach 2:
A bypass channel acts as an intermediary fluid pathway that directs drilling fluid specifically to the friction tool without affecting the motor's fluid supply. This intermediary structure enables selective activation of the friction tool while maintaining stable operation of other drilling components, as the motor continues to receive adequate fluid flow through its dedicated passage.
2Ease of operation
If the friction tool is activated by varying the flow rate of drilling fluid at the surface, then the frequency of vibrations is controlled, but the operation of other components in the drilling string is impacted
Solution Approach 1:
The fluid flow system is segmented into separate channels: one channel supplies the friction tool for vibration generation, while another channel supplies the motor. This segmentation allows independent control of vibration frequency through the friction tool's bypass channel without impacting the motor's operation, as each component has its own dedicated fluid pathway.
Solution Approach 2:
The bypass channel serves as an intermediary structure that selectively directs drilling fluid to the friction tool. By using this intermediary pathway, vibration frequency can be controlled by adjusting flow through the bypass channel while the motor continues to operate stably on its main fluid supply line, preventing disruptions to other components.
3Adaptability or versatility
If the drilling string is reassembled to include the friction tool when needed, then the friction tool can be used at specific depths, but several work hours are consumed in the process
Solution Approach 1:
The friction tool and motor are merged into a single integrated downhole assembly that can be deployed together as one unit. This combination eliminates the need for separate assembly and disassembly operations, allowing the friction tool to be selectively activated or deactivated while remaining in the drilling string, thereby saving significant time compared to physical reassembly operations.
Solution Approach 2:
The system incorporates dynamic activation and deactivation capabilities through the bypass channel mechanism. The friction tool can be selectively engaged or disengaged during drilling operations without requiring physical assembly or disassembly of the drilling string, enabling adaptive response to changing drilling conditions while minimizing time loss.
4Extent of automation
If drilling fluid flow is cut off to cease operation of the friction tool, then vibration generation stops, but the operation of other components in the drilling string is impacted
Solution Approach 1:
The drilling fluid flow system is segmented into independent pathways: the bypass channel supplies the friction tool, while the main channel supplies the motor and other drilling components. This segmentation allows the friction tool to be activated or deactivated by controlling flow through the bypass channel alone, without affecting the stability of drilling fluid flow to other components, thereby maintaining reliable operation throughout the system.
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 control of motor torque and vibration generation within the drilling string without disrupting fluid flow, allowing for seamless integration and disintegration of friction tools during drilling operations, reducing labor and operational downtime.
Implementation Method 1
A downhole assembly with a Moineau-type motor and a bypass system, including a catch mechanism that allows selective activation of drilling fluid flow through a rotor assembly, enabling control of motor torque
Implementation Method 2
a rotating valve assembly that generates vibrations for friction reduction
Data Source
AI summary
A downhole assembly and method are provided for selective activation of a motor in a drilling string. A rotor in a Moineau-principle motor is provided with a fluid passage therethrough and a catch that can receive and retain a blocking implement. A driveshaft is operably connected, for example using universal joints, to the rotor and a first valve component. The driveshaft is effectively supported by a thrust transmission assembly comprising a thrust unit and hanger resting on a spring so that the first valve component is not in contact with a second valve component. When a blocking implement is in place, drilling fluid activates the motor and also increases pressure on the rotor, causing the thrust transmission assembly to move the first valve component down into contact with the second valve component.