Sliding Standoff Assembly Friction Reduction
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Solution Overview
Problem
Current sucker rod systems in oil well extraction face high friction and mechanical wear due to interaction with well tubing, leading to energy wastage and limitations in sensor placement and electrical isolation.
Innovation Solution
A standoff assembly comprising an annulus body with a sliding material component and a dissolvable temporary component, along with an energy storage spring, which reduces friction and provides electrical isolation by allowing the sucker rod to translate with minimized contact, enabling efficient energy transfer and sensor placement without additional wiring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a rubber standoff or centralizer is molded to the rod, then friction forces are reduced, but electrical isolation is insufficient requiring additional conductor cable
Solution Approach 1:
The standoff assembly uses a composite structure combining a PTFE (Teflon) liner inside a steel annulus body. The PTFE provides low friction coefficients for rod translation, while the steel outer structure provides mechanical strength and electrical isolation properties. This composite material approach resolves the contradiction by achieving both friction reduction and electrical isolation without additional cables.
Solution Approach 2:
The PTFE liner acts as an intermediary between the steel annulus body and the sucker rod. It provides the low-friction sliding surface while the steel annulus body maintains electrical isolation. The dissolvable component also serves as a temporary intermediary to secure the assembly during installation before being removed to enable rod translation.
2Loss of energy
If friction reduction measures are implemented, then energy wastage is reduced, but mechanical wear and tear on tubing increases without proper isolation
Solution Approach 1:
The standoff assembly with PTFE liner serves as a mediator between the sucker rod and tubing, providing a low-friction interface that reduces energy wastage while protecting the tubing from direct contact and mechanical wear. The friction component with spring-loaded elements further mediates the interaction by controlling contact forces.
Solution Approach 2:
The PTFE material changes the friction parameter at the rod-tubing interface from high friction (metal-to-metal contact) to low friction (PTFE sliding surface). This parameter change reduces both energy wastage and mechanical wear on the tubing by minimizing contact forces and improving sliding characteristics.
3Measurement precision
If sensors and measurement devices are placed down hole, then measurement capability is improved, but additional conductor cable is required increasing complexity
Solution Approach 1:
The sucker rod system is given multiple functions: it serves as both the mechanical drive element and as an electrical conductor for power and data transmission. The standoff assembly enables this dual functionality by providing electrical isolation where needed while allowing the rod to function as a conductor, eliminating the need for separate cables and simplifying the overall system.
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 reduces friction and mechanical wear, extends the lifespan of sucker rod components, and allows for effective electrical isolation and power transmission, enhancing the efficiency of oil extraction while enabling the placement of downhole sensors.
Implementation Method 1
a sliding material component located along the second surface... designed to reduce friction forces predominantly acting along the long axis of a bore hole
Implementation Method 2
a dissolvable component disposed to allow the sliding material component to interact with the sucker rod upon dissolving
Implementation Method 3
an energy storage component... the energy storage component is a spring disposed to actuate a friction component radially towards the inner surface of a tubular
Implementation Method 4
a friction component designed to interact with an inner surface of a tubular and restrict motion of the assembly relative to the tubing
Data Source
AI summary
Embodiments of the present invention disclose a standoff assembly for a sucker rod used for sucker rod pumps. The assembly includes an annulus body, a hole that passes through the annulus body, the hole configured to permit a sucker rod to translate through the hole, a sliding material component located along the surface of the hole, and a temporary component; wherein upon elimination of the temporary component, the sliding material component interacts with the sucker rod to reduce sliding friction as the sucker rod translates through the assembly.