Wireline Cable Torque Balance via Asymmetric Armor Coverage
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Solution Overview
Problem
Current wireline cables used in deviated wells face issues such as torque imbalances, high friction, and weight-related drag, leading to limited travel speed and potential damage during tractoring operations, with existing designs failing to effectively balance torque and minimize friction.
Innovation Solution
A wireline cable design featuring a cable core with a substantially smooth exterior surface, a reduced outer armor wire coverage to balance torque, and a polymeric jacket to minimize friction, along with a balanced lay angle of armor wire layers to reduce weight and drag, ensuring balanced torque and minimized friction during use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If typical wireline cables with 98% coverage outer armor wire strength member layer are used, then cable protection and strength are improved, but torque imbalances occur causing cable rotation during tension changes
Solution Approach 1:
The patent applies asymmetry by using two layers of armor wires with different coverage percentages (first layer at 98% coverage, second layer at 76% coverage). This asymmetric configuration balances the torque generated by each layer, preventing cable rotation during tension changes while maintaining protective strength.
2Strength
If wireline cables with metallic armor wires on the outside diameter are used, then cable strength is improved, but high friction with the wellbore increases power requirements
Solution Approach 1:
The patent applies local quality by making the outer surface of the cable smooth while maintaining the metallic armor wires for strength. This localized modification reduces friction with the wellbore in the contact area without compromising the overall structural strength of the cable.
3Adaptability or versatility
If the tractor pulls the cable and associated equipment through deviated wells, then well service operations are enabled, but cable weight imparts drag limiting travel speed
Solution Approach 1:
The patent applies anti-weight principles by optimizing the cable structure to reduce overall weight while maintaining strength through the two-layer armor wire configuration. The reduced weight decreases drag on the tractor, enabling faster travel speeds through deviated wells while maintaining service capability.
4Adaptability or versatility
If wireline cables are used in horizontal well sections, then deviated well operations are enabled, but torque imbalances lead to knotting or bird caging during sudden releases of cable tension
Solution Approach 1:
The patent applies asymmetry through the two-layer armor wire structure with different coverage percentages. This configuration creates torque balance that prevents cable rotation and twisting during sudden tension releases, eliminating knotting and bird caging while maintaining operability in deviated wells.
Data Source
AI summary
A wireline cable includes an electrically conductive cable core for transmitting electrical power, an inner armor layer disposed around the cable core, and an outer armor layer disposed around the inner armor layer, wherein a torque on the cable is balanced by providing the outer armor layer with a predetermined amount of coverage less than an entire circumference of the inner armor layer, or by providing the outer armor layer and the inner armor layer with a substantially zero lay angle.