Box End Plunger High Compression Gas Lock Prevention
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Solution Overview
Problem
Downhole pumps in aging oil wells often experience gas locking, which reduces the differential pressure needed to open the traveling valve, leading to inefficient fluid extraction due to uncompressible volumes introduced by existing plunger designs, making it difficult to achieve high compression ratios.
Innovation Solution
A box end plunger design with a counterbore and a second valve comprising an insert, ball, seat, and seat plug with a pressure seal, where the seat plug couples to the plunger to form a box end, minimizing uncompressible volumes and maintaining a consistent outside diameter, allowing for high compression ratios even in gas-locked conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pin end plungers or box end plungers with external valves are used, then gas locking is minimized, but uncompressible volumes are introduced into the compression chamber making it difficult to achieve high compression ratios
Solution Approach 1:
The patent removes the traditional valve attachment methods (external threads, spacers, turned-down lengths) that created uncompressible volumes. The valve is integrated directly into the plunger end with minimal clearance, extracting the harmful uncompressible space from the compression chamber while maintaining gas locking prevention through the one-way valve mechanism.
Solution Approach 2:
The patent changes the geometric parameters of the plunger end by eliminating spacers and turned-down lengths, creating a compact box end configuration. This parameter change reduces the uncompressible volume while maintaining the valve's functional integrity, enabling higher compression ratios.
2Ease of manufacture
If traditional valve attachments with spacers and turned-down lengths are used, then valve assembly is simplified, but uncompressible compression chamber volume increases reducing compression efficiency
Solution Approach 1:
The patent merges the valve components (ball, seat, seat plug) directly into the plunger end structure, eliminating separate spacers and turned-down lengths. This integration reduces the overall volume of uncompressible space while maintaining assembly feasibility through a standardized box end configuration.
3Stress or pressure
If high compression ratios are achieved, then gas locking is overcome, but plunger wear increases reducing service life
Solution Approach 1:
The patent makes the plunger reversible by providing identical box end configurations at both ends. This dynamic design allows the plunger to be flipped after wear occurs on one end, extending the overall service life while maintaining the ability to achieve high compression ratios needed to prevent gas locking.
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 design achieves a higher compression ratio of about 45:1, minimizing gas lock issues and extending the plunger's wear life by allowing reversible use, thus enhancing the pump's efficiency and cost-effectiveness.
Implementation Method 1
The standing and traveling valves open and close by differential pressure. For example, when the plunger is dropped (the downstroke), the fluid in the compression chamber is pressurized by the plunger.
Implementation Method 2
when the plunger is dropped (the downstroke), the fluid in the compression chamber is pressurized by the plunger
Data Source
AI summary
A downhole pump has a barrel and a plunger. The barrel has a first one-way valve and the plunger has a second one-way valve. The plunger is of the box end type. The pump prevents or minimizes gas lock by achieving high compression in the compression chamber between the two valves. The second valve is located close to the bottom end of the plunger. In the second valve, the valve seat is in contact with the seat plug, which seat plug has a seal. Alternatively, the valve seat is incorporated into the seat plug, which seat plug also has a seal. The plunger lacks reliefs at the bottom end and thereby achieves tight tolerances with the barrel, further contributing to high compression.