Airfoil Rod Guide Geometry for Composite Sucker Rod Fall
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Solution Overview
Problem
Sucker rods made of composite materials experience inadequate rod fall due to low density, leading to resistance from reservoir fluid.
Innovation Solution
A rod guide configuration with protuberances, such as ribs or lobes, is coupled to the sucker rod pump to mitigate drag and enhance movement, featuring an air foil shape and annular space for improved fluid flow and reduced contact with the reservoir fluid conductor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If composite rods are used in sucker rod pumps, then the environmental friendliness and corrosion resistance are improved, but the rod fall becomes inadequate due to low density
Solution Approach 1:
The patent applies aerodynamic foil-shaped protuberances to the rod surface. These curved, airfoil-like structures are designed to interact with the surrounding fluid, creating lift forces during the rod's reciprocating motion. The curvature and shape of these protuberances are optimized to generate upward lift during the downward stroke, compensating for the low density of composite rods and improving rod fall.
Solution Approach 2:
The patent converts the harmful effect of fluid resistance during upward motion into a beneficial effect. The foil-shaped protuberances are designed so that during the upward stroke, they experience lower drag, and during the downward stroke, they generate lift forces. This asymmetry in drag coefficients (with the downward drag being significantly lower than upward drag) transforms the resistive fluid forces into propulsive forces that enhance rod fall.
2Weight of moving object
If composite rods with low density are used, then the weight is reduced, but the resistance from reservoir fluid increases
Solution Approach 1:
The aerodynamic foil-shaped protuberances utilize curved surfaces optimized for fluid flow. The airfoil cross-section and three-dimensional shaping create favorable pressure distributions that reduce pressure drag and form wake regions. This curvature-based design minimizes the resistive forces from reservoir fluid acting on the lightweight composite rod.
Solution Approach 2:
The patent changes the surface geometry parameters of the rod by adding protuberances with specific dimensional characteristics. The height, width, spacing, and foil shape parameters are optimized to alter the flow regime around the rod, reducing drag coefficients and minimizing fluid resistance effects on the lightweight composite structure.
3Speed
If protuberances are added to the rod configuration, then the drag ratio is improved, but the device complexity increases
Solution Approach 1:
The rod guide configuration is segmented into multiple identical protuberance units distributed along the rod length and circumferentially arranged. Each protuberance is a simple, standardized component with a defined foil shape. This segmentation allows the complex overall function to be achieved through repetition of simple elements, facilitating manufacturing and maintenance while achieving the desired drag ratio improvement.
Solution Approach 2:
The protuberances serve multiple functions simultaneously: they generate lift forces to improve rod fall, reduce drag during upward motion, and maintain structural integrity of the rod assembly. This multi-functionality is achieved through the universal application of the same foil-shaped protuberance design throughout the rod configuration, eliminating the need for separate mechanisms for each function and thereby reducing overall complexity.
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 rod guide configuration reduces drag and enhances the movement of composite sucker rods, minimizing resistance and maintaining efficient fluid production by scraping away debris and encrustations.
Implementation Method 1
each one of the at least one protuberance, independently, defines an air foil shape... a ratio of a first drag co-efficient, of the protuberance, measured in a direction of movement of the protuberance, relative to the reference fluid, in an upwardly direction, to a second drag co-efficient, of the protuberance, measured in a direction of movement of the protuberance, relative to the reference fluid, in a downwardly direction, is at least ten (10)
Data Source
AI summary
A conveyor for a sucker rod pump, for deployment downhole within a passage defined by an inner surface of a reservoir fluid conductor that is emplaced within a wellbore extending into a subterranean formation, for effecting production of reservoir fluids, comprising. The conveyor includes a rod configuration, and a guide configuration. The guide configuration is coupled to the rod configuration, and is defined by at least one protuberance. The protuberance defines an air foil shape.