Helix Hand Reversal Mitigation in Fiber Optic Cable Deployment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fiber optic sensing cables deployed in oil field operations are prone to failure due to spontaneous helix hand reversals, which cause mechanical stress and breakage, especially when torsional stiffness opposes the coiling direction, leading to weak points in the cable.
Innovation Solution
A cable introduction system that initializes the fiber optic cable with a predetermined handedness as it enters the coiled tubing, using a spool assembly and rotator assembly to rotate the cable about multiple axes, ensuring consistent coiling direction and reducing the likelihood of hand reversals by imparting controlled energy to the cable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fiber optic cable is pumped into coiled tubing during oil field operations, then the cable can be deployed for sensing environmental conditions, but the cable becomes prone to kinking, failure, and breakage due to spontaneous helix hand reversal
Solution Approach 1:
The cable is pre-coiled with a specific helix hand (left-handed or right-handed) before deployment. This preliminary configuration ensures that the cable maintains its intended coiling direction throughout deployment, preventing spontaneous hand reversals that would otherwise cause mechanical stress and failure. The pre-established helical structure acts as a preventive measure against the harmful reversal phenomenon.
Solution Approach 2:
The invention changes the physical parameter of cable coiling configuration by deliberately introducing a controlled helical structure with specific handedness. This parameter change (from random/straight to controlled helical) transforms the cable's mechanical behavior, allowing it to accommodate deployment stresses without undergoing harmful spontaneous hand reversals.
2Strength
If the cable has torsional stiffness that opposes the coiling direction, then the cable maintains structural integrity, but spontaneous helix hand reversal occurs creating weak points and potential failure
Solution Approach 1:
The invention applies preliminary anti-action by pre-coiling the cable in the opposite direction to the spontaneous reversal tendency. If the cable naturally tends to reverse from left-handed to right-handed coiling, it is initially configured with left-handed coiling. This preliminary opposing configuration counteracts the spontaneous reversal impulse, preventing the formation of weak points and maintaining both strength and reliability.
Solution Approach 2:
The invention introduces asymmetry by deliberately configuring the cable with a specific helix hand (either left or right) rather than a symmetric or random configuration. This asymmetric pre-coiling creates a preferred coiling direction that resists spontaneous reversal, allowing the cable to maintain its structural integrity while preventing the harmful effects of hand reversal.
3Ease of operation
If the fiber optic cable is straightened, then it can be deployed, but spontaneous helix hand reversal occurs causing mechanical stress and cable breakage
Solution Approach 1:
Instead of straightening the cable before deployment, the invention applies preliminary action by pre-coiling the cable in a controlled helical configuration. This pre-established structure allows the cable to be deployed while maintaining its helical form, eliminating the straightening step that would otherwise induce spontaneous hand reversal and mechanical stress during subsequent coiling.
Solution Approach 2:
The invention changes the deployment parameter from straightened-to-coiled to pre-coiled-to-deployed. By configuring the cable with a specific helical parameter (handedness and pitch) before deployment, the cable can be fed into the wellbore in its coiled state, maintaining mechanical strength while achieving ease of operation through controlled coiling behavior.
Data Source
AI summary
A cable introduction assembly that can include: a spool assembly including a spool having a first axis, the spool configured to retain a cable wound around the first axis in an undeployed mode; and a spool mount assembly configured to retain the spool and introduce the cable in a deployed mode into a conduit configured for a downhole environment, the conduit having a proximal end and a distal end, the cable in the deployed mode extending from the proximal end towards the distal end, wherein the spool assembly is configured to provide a handedness to the cable in the deployed mode.