Anti-gas lock valve for reciprocating downhole pump
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Solution Overview
Problem
Downhole reciprocating pumps face inefficiencies and mechanical damage due to gas-locking, where gas interferes with the compression chamber, reducing productivity and requiring costly maintenance, especially in low-volume wells and those with high gas content, as conventional methods like adjusting pump settings or using an annulus are ineffective.
Innovation Solution
The implementation of a pre-valve system that compresses gassy fluids in the pump chamber and directs them into a staging chamber, using a drag sleeve to actuate the downhole chamber valve, allowing incremental fluid uptake and pressure increase until sufficient to overcome hydrostatic pressure, thereby preventing gas-locking and maintaining pump efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the pump operates in a gas-locked condition, then the pump continues to reciprocate without interruption, but no fluid is lifted and mechanical damage occurs to pump components and rod string
Solution Approach 1:
A pre-valve is introduced as an intermediary component between the compression chamber and the traveling valve. This pre-valve creates a staging chamber that accumulates and compresses gas incrementally, mediating between the gas-filled compression chamber and the traveling valve to prevent gas-locking while allowing continuous operation.
Solution Approach 2:
The pre-valve performs preliminary compression of gas in the staging chamber before the gas reaches the traveling valve. By pre-compressing the gas incrementally over multiple strokes, the system prepares the gas in advance to eventually open the traveling valve without causing mechanical damage during the process.
2Productivity
If conventional methods adjust pump settings or use an annulus to break gas lock, then gas locking may be temporarily relieved, but pump efficiency is reduced and maintenance costs increase
Solution Approach 1:
The pre-valve system is self-actuating and automatically manages gas accumulation and compression without requiring external intervention. The drag sleeve mechanism automatically opens and closes the pre-valve based on pressure differentials, eliminating the need for manual pump setting adjustments or complex annulus systems.
Solution Approach 2:
The pre-valve extracts the gas management function from the main pump operation. By separating gas compression into a dedicated staging chamber controlled by the pre-valve, the system removes the harmful effects of gas-locking from the main pumping action without requiring complex external systems.
3Productivity
If the compression chamber contains undissolved or dissolved gas, then the gas takes the place of liquid reducing pump efficiency, but the pump structure remains simple
Solution Approach 1:
The system segments the compression function by dividing it between the original compression chamber and the new staging chamber. The staging chamber handles gas accumulation and incremental compression, while the main compression chamber focuses on liquid pumping, separating gas management from liquid pumping operations.
Solution Approach 2:
The pre-valve system changes the pressure parameters incrementally by compressing gas in small increments in the staging chamber. This gradual parameter change allows gas to be compressed to sufficient pressure to open the traveling valve without requiring sudden pressure changes that would reduce efficiency or damage components.
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 solution enhances pump efficiency, reduces maintenance needs, and allows for continuous operation by overcoming gas-locking conditions, increasing liquid production and extending the life of pump components.
Implementation Method 1
compressing gassy fluid in the pump chamber and opening a downhole chamber valve between the pump chamber and a staging chamber
Implementation Method 2
The chamber valve is actuated by dragging against the barrel between open and closed positions
Implementation Method 3
allowing incremental fluid uptake and pressure increase until sufficient to overcome hydrostatic pressure
Data Source
AI summary
Method and apparatus overcoming gas-lock in reciprocating downhole pumps. On the downstroke of a plunger in a barrel, gassy fluid is compressed in the pump chamber between standing and travelling valves. Downhole plunger movement drags a sleeve over a mandrel for opening a chamber valve to a staging chamber located at a downhole end of the travelling valve for receiving at least a portion of the compressed and gassy fluid therein. On the upstroke, the chamber valve is dragged closed for sealably retaining the compressed gassy fluid therein while drawing an additional increment of fluid through the standing valve into the pump chamber. Continued downstroke and upstroke cycles increases pressure of the compressed gassy fluid in the pump chamber until it exceeds the hydrostatic head above the travelling valve for resumption of normal fluid pumping.