Downhole Tractor Hydraulic Flow Routing for Higher Conveyance Speed
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Solution Overview
Problem
Current downhole tractor technology faces limitations in speed and control during milling operations due to the modular construction of hydraulic drive sections, which reduces conveyance speed and available torque, and lacks effective management of hydraulic fluid distribution, leading to inefficiencies and obstacles in navigating oil well sections.
Innovation Solution
Incorporation of a pressure-setting valve between the hydraulic supply lines to redirect excess fluid from the tractor arm line to the wheel drive line, enhancing the speed of the downhole tractor without altering the load on the pumps, and the use of a hydraulic switch for selective fluid dumping to optimize low-speed operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If multiple hydraulic drive sections are added in parallel to provide more pulling force, then the pulling force increases, but the conveyance speed reduces due to reduced available flow per motor
Solution Approach 1:
The patent implements dynamic control of hydraulic flow distribution through a control section that can adjust the number of active drive sections in real-time. This allows the system to optimize the balance between pulling force and conveyance speed during different operational phases, resolving the contradiction by making the system adaptable rather than static.
Solution Approach 2:
The patent changes the flow distribution parameters by using a control section to regulate hydraulic flow to different drive sections. By adjusting flow parameters dynamically, the system can maintain optimal performance across varying operational requirements, addressing both force and speed requirements.
2Productivity
If the tractor is configured for high-speed conveyance, then the rig time reduces, but the control over milling parameters such as axial force and torque becomes limited
Solution Approach 1:
The patent divides the hydraulic control system into separate control sections - one for conveyance operations and another for milling operations. This segmentation allows independent optimization of each function, enabling high-speed conveyance when needed while maintaining full control capability during milling operations.
Solution Approach 2:
The control section dynamically adjusts hydraulic flow distribution based on operational mode. During conveyance, flow is optimized for speed; during milling, flow is redirected to provide precise control over axial force and torque, allowing the system to excel at both functions at different times.
3Adaptability or versatility
If hydraulic supply lines are configured for both tractor arm actuation and wheel drive, then functional versatility is achieved, but fluid distribution management becomes complex
Solution Approach 1:
The patent designs a universal hydraulic supply line system that can serve multiple functions - actuating tractor arms for engagement and driving wheel motors for propulsion. The control section manages this multi-functionality by dynamically routing hydraulic flow to the appropriate components based on operational requirements.
Solution Approach 2:
The control section acts as an intermediary that simplifies the management of complex fluid distribution. It centralizes the control logic and provides a unified interface for managing flow to multiple components, reducing the operational complexity despite the system's functional versatility.
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
This configuration results in a significant speed increase of up to 25% for the downhole tractor, maintaining pulling force and reducing rig time, while allowing for efficient navigation through oil well sections with improved control over milling parameters.
Implementation Method 1
a pressure-setting valve provided in between the first hydraulic supply line and the second hydraulic supply line. The pressure-setting valve is configured for feeding excess hydraulic fluid in the first hydraulic supply line to the second hydraulic supply line to increase the speed of the downhole tractor
Data Source
AI summary
A downhole tractor has at least one hydraulic drive section, comprising a first hydraulic supply line for actuating at least one hydraulic cylinder for actuating at least one tractor arm and a second hydraulic supply line for driving at least one hydraulic motor for rotating at least one tractor wheel. The downhole tractor further comprises a hydraulic power pack configured for supplying hydraulic fluid to the hydraulic supply lines. The hydraulic power pack comprises a pressure-setting valve provided in between the first hydraulic supply line and the second hydraulic supply line, wherein the pressure-setting valve is configured for feeding excess hydraulic fluid in the first hydraulic supply line to the second hydraulic supply line to increase the speed of the downhole tractor.