Grip Enhanced Tractor Locking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional downhole tractors face challenges in advancing through open-hole wells due to variability in well wall surface characteristics and diameter, leading to issues with frictional footing and mechanical failure from excessive expansion forces.
Innovation Solution
The implementation of a grip locking mechanism that sequentially actuates to establish a secure radial grip before the power stroke, using radially expanding bow springs and a hydraulic grip lock mechanism to maintain continuous advancement without slipping, even in softer well sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If excess expansion forces are applied through the tractor's anchor arms to maintain frictional footing at softer well wall sections, then the frictional footing is improved, but the anchor arms may be over-stressed leading to mechanical failure
Solution Approach 1:
The grip lock mechanism is actuated in advance of the power stroke to establish a secure radial grip on the well wall before the anchor arms are subjected to full expansion forces and axial loads. This preliminary gripping action ensures that the frictional footing is established before excessive forces are applied, preventing both slippage and mechanical failure of the anchor arms
Solution Approach 2:
The system incorporates sensors that detect well wall characteristics and provide feedback to the control system, which then adjusts the expansion forces applied through the anchor arms. This feedback mechanism ensures that forces are optimized for the specific well conditions, maintaining adequate frictional footing without over-stressing the anchor arms
2Reliability
If excess expansion forces are applied to maintain frictional footing, then the grip on softer wall sections is improved, but the tractor may damage itself via attempts to unnecessarily over expand its anchor arms
Solution Approach 1:
The grip lock mechanism establishes a secure radial grip before the full expansion forces are applied, preventing the need for excessive expansion forces that could cause mechanical damage. The preliminary gripping action ensures that the anchor arms are properly positioned and secured before bearing full load
Solution Approach 2:
The system dynamically adjusts the expansion forces based on detected well wall characteristics. By changing the force parameters according to actual well conditions, the system avoids applying unnecessarily excessive forces that would cause mechanical damage while still maintaining adequate grip stability
3Productivity
If the tractor proceeds downhole in a continuous manner to maintain inertia, then the productivity is improved, but the axial load continuously pulls on the anchor arms making it difficult to maintain frictional footing
Solution Approach 1:
The grip lock mechanism is actuated in advance of each power stroke to re-establish the radial grip before the axial load increases during continuous advancement. This ensures that frictional footing is maintained throughout continuous operation, enabling sustained productivity without slippage
Solution Approach 2:
The grip lock mechanism operates periodically in synchronization with the power stroke cycle, establishing a new radial grip before each axial pull. This periodic action maintains frictional footing throughout continuous advancement, allowing the tractor to proceed downhole continuously while preventing slippage
4Ease of operation
If conventional tractoring is used in softer well wall sections, then the simplicity of operation is maintained, but the tractor slipping and ceasing of operations occurs
Solution Approach 1:
The grip lock mechanism automatically actuates in advance of each power stroke to establish a secure radial grip, ensuring reliable frictional footing in softer well wall sections. This preliminary action prevents slippage and maintains continuous advancement without requiring complex manual intervention
Solution Approach 2:
The grip lock mechanism is automatically controlled by the control system based on detected well conditions, eliminating the need for manual adjustment or complex operator intervention. The system self-regulates to maintain adequate grip in varying well conditions, preserving ease of operation while improving 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
This approach ensures continuous downhole advancement by maintaining a secure grip and preventing slipping, allowing tractors to reach greater depths than previously possible while minimizing mechanical stress and damage.
Implementation Method 1
a hydraulic grip lock mechanism to maintain continuous advancement without slipping
Implementation Method 2
radially expanding bow springs and a hydraulic grip lock mechanism
Implementation Method 3
maintaining a secure grip and preventing slipping
Data Source
AI summary
A tractor configured for grip locking during advancement to avoid slippage, particularly in open-hole wells. The tractor is equipped with a grip lock mechanism for independently locking an anchor grip in a radially outward direction. This locking occurs sequentially in advance of the power stroke of a reciprocating drive piston associated with the anchor. Thus, radial outward expansion and gripping are ensured at the time pulling of a load in an axial downhole direction is pursued. Such grip locking may be employed throughout tractoring or intermittently, depending upon well characteristics such as formation hardness and well diameter.