Self-Adjusting Sucker Rod Pump Spacing to Prevent Tagging
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Solution Overview
Problem
Conventional methods fail to provide a simple and economical solution for self-adjusting the operational spacing of sucker rod pumps in oil and gas production, leading to issues such as tagging, fluid pound, and gas lock, which cause damage to downhole and surface equipment.
Innovation Solution
A self-adjusting downhole sucker rod pump spacing tool that maintains optimal spacing by using a piston and cylinder arrangement with a narrow lateral space and suitable viscosity fluid, allowing the piston to move only during initial tagging, thus maintaining consistent length during normal pumping operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional fixed spacing methods are used for sucker rod pumps, then initial spacing can be set, but the spacing cannot adapt to changes in rod string stretch and overtravel, causing tagging or excessive spacing
Solution Approach 1:
The patent applies the dynamics principle by making the spacing tool length variable through a piston-cylinder mechanism. The tool transitions from a fixed length structure to a dynamic system where the piston can move within the cylinder, allowing the overall tool length to adjust automatically based on rod string stretch and overtravel conditions during pump operation.
Solution Approach 2:
The patent implements self-service by designing the spacing tool to automatically adjust its own length without external intervention. The piston-cylinder system with fluid pressure automatically responds to changes in rod string mechanics, enabling the tool to self-regulate spacing based on operational conditions rather than requiring manual adjustment.
2Productivity
If the sucker rod pump is spaced too close to the rod string, then compression ratio is maintained, but tagging occurs causing damage to downhole and surface equipment
Solution Approach 1:
The patent applies preliminary anti-action by providing a cushioning mechanism that prevents tagging before it occurs. The fluid-filled cylinder acts as a buffer that absorbs the impact forces, creating a preventive measure against the harmful tagging effect rather than merely mitigating it after damage occurs.
Solution Approach 2:
The patent implements beforehand cushioning by incorporating a fluid-filled cylinder that provides elastic cushioning prior to potential tagging events. The fluid pressure system is pre-configured to absorb shock loads, protecting the rod string and pump equipment from damage before the tagging force can be transmitted to surface equipment.
3Object-affected harmful factors
If the sucker rod pump is spaced too far from the rod string, then tagging is prevented, but compression ratio decreases reducing production efficiency
Solution Approach 1:
The patent uses dynamics to create a spacing system that is neither fixed at one position nor statically adjustable, but dynamically responsive. The piston-cylinder mechanism allows the tool to maintain optimal spacing dynamically, adjusting in real-time to prevent tagging while preserving compression ratio through automatic length changes.
4Reliability
If manual spacing adjustment is performed by relocating the polished rod clamp, then spacing can be corrected, but the well must be shut down causing loss of production time
Solution Approach 1:
The patent implements self-service by enabling the spacing tool to automatically correct its own positioning through the piston-cylinder mechanism. The tool performs its own spacing adjustment function without requiring well shutdown or manual intervention, maintaining reliable spacing accuracy while eliminating production time loss.
Solution Approach 2:
The patent applies continuity of useful action by enabling continuous spacing adjustment during well operation. The piston-cylinder system allows the spacing tool to maintain and adjust optimal spacing continuously throughout pump operation, eliminating interruptions and ensuring uninterrupted production while maintaining spacing accuracy.
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 tool effectively adjusts and maintains optimal sucker rod pump spacing, reducing damage from tagging and fluid pound, and preventing gas lock, ensuring efficient well production by minimizing fluid movement during regular pumping cycles.
Implementation Method 1
fluid simply transfers back and forth as needed within the cylinder, above and below the piston
Implementation Method 2
the piston and piston rod share a central longitudinal axis with the cylinder... the piston has an outside diameter that is slightly less than the inside diameter of the cylinder
Data Source
AI summary
A downhole tool comprises a cylinder, piston, and piston rod, the piston rod comprising first and second ends, the first end being external to the cylinder and having the capacity to be operatively connected to a sucker rod string or a sucker rod pump, the second end being positioned within a sealed cylinder chamber and attached directly or indirectly to the piston. The cylinder confining fluid within the cylinder chamber. The piston is coaxially positioned within the cylinder chamber such that the piston and cylinder share a central longitudinal axis. The piston and cylinder each comprise respective sidewalls, the respective sidewalls defining a lateral space between the piston and the cylinder. The lateral space and a piston conduit have the capacity to permit the fluid to move from a first chamber to a second chamber and to permit the fluid to move from the second chamber to the first chamber.