Wrap-around Stop Collar for Tubulars
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stop collars for oilfield tubulars face challenges in providing adequate holding forces, especially when marking the tubular is not feasible due to damage concerns or hardness issues, and adhesives lack sufficient durability or bonding strength.
Innovation Solution
A stop collar design featuring a flexible member wrapped circumferentially around the tubular with a tension force applied to create a radially-inward gripping force, combined with a shield for protection in downhole environments, and an optional adhesive layer for enhanced holding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If marking structures (teeth or set screws) are used to engage the tubular, then the stop collar can grip the tubular, but marking the tubular damages the tubular or is incompatible with the application, and hard tubulars prevent adequate biting for sufficient holding forces
Solution Approach 1:
A flexible gripping member is introduced as an intermediary between the stop collar and the tubular. This flexible member wraps around the tubular and can be tensioned to provide gripping force without directly marking or damaging the tubular surface. The flexible member acts as a mediator that transfers the gripping force while protecting the tubular from direct contact with harsh marking structures.
Solution Approach 2:
The invention employs a flexible member (such as a rubber band, elastic band, or flexible strap) that wraps around the tubular in a helical or circumferential pattern. This flexible element can conform to the tubular surface and provide continuous contact without concentrated stress points that would cause marking or damage. The flexibility allows it to adapt to the tubular geometry while maintaining sufficient friction for holding forces.
2Force
If adhesives are used to fix the stop collar position, then the stop collar can be attached to the tubular, but the adhesives lack sufficient durability or bonding strength to provide adequate holding force
Solution Approach 1:
The invention combines multiple attachment mechanisms into a composite system: the flexible gripping member provides mechanical friction-based holding, while adhesives are applied at specific locations (such as at the ends or at intervals along the flexible member) to prevent slippage. This composite approach leverages both the continuous contact friction of the flexible member and the strong bonding of adhesives to achieve reliable, durable attachment with sufficient holding force.
Solution Approach 2:
Rather than relying on a single continuous adhesive bond, the adhesive application is segmented into discrete locations along the flexible member's path on the tubular. This segmentation allows the adhesive to cure properly at each location and creates multiple bonding points, distributing the stress and improving overall reliability while maintaining the flexibility of the gripping member.
3Object-affected harmful factors
If a flexible member wrapped around the tubular is used to provide gripping force, then the tubular is not damaged, but the flexible member needs protection in harsh downhole environments
Solution Approach 1:
A protective shield or sleeve is placed over the flexible gripping member, creating a nested structure where the flexible member is protected inside the shield. The shield can be made of corrosion-resistant material suitable for downhole environments, while the flexible member remains inside to provide the gripping function. This nested arrangement protects the flexible member from harsh environmental factors while maintaining its functionality.
Solution Approach 2:
The system uses a composite structure combining the flexible gripping member with a protective outer layer or coating that is resistant to corrosion, temperature, and other downhole conditions. The flexible member may be coated with a protective material or encased in a protective sleeve that allows it to flex while protecting it from environmental degradation, ensuring long-term reliability in harsh environments.
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
The solution provides a reliable and durable holding mechanism that maintains grip in harsh environments without damaging the tubular, addressing the limitations of traditional marking and adhesive methods.
Implementation Method 1
A tension force on the flexible member causes the flexible member to apply a radially-inward gripping force on the tubular
Implementation Method 2
a radially-inward gripping force on the tubular
Implementation Method 3
a layer of adhesive interposed between at least a portion of the flexible member and the tubular
Data Source
AI summary
A stop collar for a tubular and method for installing a stop collar on a tubular. The stop collar includes a flexible member extending circumferentially around the tubular more than once. A tension force on the flexible member causes the flexible member to apply a radially-inward gripping force on the tubular. The stop collar may also include a shield disposed around at least a portion of the flexible member, to protect the flexible member in a downhole environment. The stop collar may also or instead include an adhesive disposed radially between the flexible member and the tubular.