Composite Sucker Rod Inspection via Destructive Pull Test
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a lack of effective methods for inspecting and reconditioning used composite sucker rods, such as fiberglass reinforced plastic rods, which are lighter and cause less stress on machinery, but their reliability is unproven, leading to the need for new rods in downhole operations.
Innovation Solution
A method involving cleaning, visual and non-visual inspections, and a destructive pull test to determine the elasticity of the non-metallic body, using organic compounds like kerosene for cleaning, magnetic flux leakage inspection, and a computer program to assess the rod's suitability for re-use by measuring tension force and distance, ensuring the rod meets specified parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If fiberglass sucker rods are used instead of metal rods, then weight is reduced and stress on machinery is lowered, but reliability is unproven and inspection methods are lacking
Solution Approach 1:
The patent applies parameter changes by establishing specific elasticity parameters (such as elongation percentage under specified load) that composite sucker rods must meet to be considered reliable for reuse. By defining and measuring these physical parameters through pull tests, the patent transforms the unproven reliability of composite rods into quantifiable, verifiable metrics, thereby resolving the contradiction between using lighter composite materials and ensuring their reliability.
2Reliability
If a comprehensive inspection method is developed for composite sucker rods, then reliability can be proven and reuse becomes viable, but inspection complexity and time requirements increase
Solution Approach 1:
The patent applies preliminary action by performing a destructive pull test during the initial inspection process to establish baseline elasticity parameters before the rod enters service. This preliminary characterization of the rod's mechanical properties allows for faster subsequent inspections and creates a reference standard that speeds up future reliability assessments, thereby reducing overall inspection time while maintaining reliability verification.
Solution Approach 2:
The patent transforms the complex reliability assessment into a specific, measurable parameter change - the elasticity parameter measured during pull testing. By focusing on this single critical parameter (elongation percentage) rather than attempting to assess all possible reliability aspects, the patent simplifies the inspection process while still providing meaningful reliability verification, thus resolving the time-reliability contradiction.
3Loss of time
If visual inspection alone is used for composite sucker rods, then inspection time is minimized, but detection precision of internal defects is insufficient
Solution Approach 1:
The patent introduces an intermediary mechanical test (the pull test) that mediates between the simple visual inspection and comprehensive reliability assessment. This intermediary test applies controlled stress to the rod and measures the resulting elasticity parameters, providing indirect detection of internal defects and structural integrity issues that visual inspection cannot detect, while still being relatively quick to perform.
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
This method allows for the reliable re-use of composite sucker rods by ensuring they meet specified elasticity parameters, reducing the need for new rods and minimizing downtime in oil extraction operations.
Implementation Method 1
washing the sucker rod with an organic compound
Implementation Method 2
pressure washing the sucker rod
Implementation Method 3
magnetic flux leakage inspection
Implementation Method 4
performing a destructive pull test of the non-metallic body to determine if the composite body is amenable to re-use
Implementation Method 5
measuring tension force and distance
Data Source
AI summary
The disclosure relates to reconditioned sucker rod, particularly to the sucker rods already used in the mechanical deep-pumping extraction of oil. The sucker rod comprises metal rod ends and a non-metallic body. The method of remanufacturing of reconditioned sucker rod includes subjecting used non-metallic sucker rods to a destructive pull test.