Superimposed Standing Valve for Rod Pump Gas Locking
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Solution Overview
Problem
Conventional rod pumps face inefficiencies due to gas locking and premature wear from sand and silt accumulation, as they often operate with the standing valve closed during half the cycle and are prone to energy wastage and component wear from gas and sediment settling during shutdowns.
Innovation Solution
An improved superimposed standing valve design that isolates head pressure from the pump components during the downstroke, allowing oil and gas to flow on both up and downstrokes, and prevents sand and silt from settling back into the pump by maintaining a fluid seal, thereby increasing efficiency and extending pump lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pump operates with a conventional standing valve that closes during the downstroke, then the pump structure remains simple, but the pump efficiency decreases because no oil enters the pump chamber during approximately one-half of the pump cycle
Solution Approach 1:
The standing valve is divided into two independent valves: a conventional standing valve and a superimposed standing valve. The conventional standing valve handles flow during the upstroke, while the superimposed standing valve handles flow during the downstroke. This segmentation allows oil to enter the pump chamber during both strokes, doubling the productive time without requiring a completely new valve design
Solution Approach 2:
The superimposed standing valve is nested within the conventional standing valve assembly. The superimposed valve is positioned above the conventional valve and shares the same basic structure and mounting location. This nesting approach increases functionality while minimizing additional space requirements and maintaining relative structural simplicity
2Reliability
If the pump allows oil and gas to enter the pump chamber during both upstroke and downstroke, then gas locking risk is reduced, but the valve mechanism complexity increases
Solution Approach 1:
The valve system is segmented into two independent standing valves that operate during different strokes. The superimposed standing valve specifically addresses gas locking by allowing gas-oil mixture to enter during the downstroke when the conventional valve would be closed, thereby preventing gas accumulation that leads to gas locking
Solution Approach 2:
The superimposed standing valve opens in advance during the downstroke to allow gas and oil to enter the pump chamber before the upstroke begins. This preliminary action prevents gas from accumulating to problematic levels and ensures the pump chamber is properly filled with a manageable fluid mixture before the lifting stroke
3Use of energy by moving object
If the pump shuts down frequently to save energy costs, then energy consumption decreases, but sand and silt settle onto and reenter the pump causing premature wear
Solution Approach 1:
The superimposed standing valve maintains a fluid seal in the annulus between the valve and the valve seat during pump shutdown periods. This preliminary protective action prevents sand and silt from settling onto critical pump components such as the plunger and traveling valve, thereby extending component lifespan while allowing frequent shutdowns for energy savings
Solution Approach 2:
The fluid seal created by the superimposed standing valve acts as an intermediary barrier between the pump interior and the tubing contents during shutdown. This barrier prevents direct contact between sand-silt-laden fluid and sensitive pump components, reducing wear while allowing the pump to remain stationary
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 improved superimposed standing valve enhances rod pump efficiency by ensuring the standing valve remains open during both strokes, reducing gas locking risks, and preventing sediment accumulation, leading to increased operational efficiency and extended component life.
Implementation Method 1
During the upstroke, oil and gas flow freely from the pump outlet, into the central manifold, through the slanted passageways and out the plurality of openings, thereby forcing the valve cylindrical sleeve to move from the closed position to the open position
Implementation Method 2
The polished rod properly dimensioned with respect to the honed inner surface of the central passage enables the polished rod to reciprocate with respect to the top cylinder while simultaneously maintaining a fluid seal to preclude the passage of oil from the tubing downward through the central passage
Implementation Method 3
as the plunger moves downward during the downstroke, the pump chamber decreases in volume and causes the pressure in the pump chamber to exceed the head pressure from fluid in the tubing above the pump and allows the traveling valve to open and oil to pass into the pump chamber above the traveling valve
Implementation Method 4
As the plunger moves upward, pressure decreases in the pump chamber allowing formation pressure to exceed pressure in the pump chamber, which in turn, causes the standing valve to open and oil to enter into the pump chamber through the open standing valve
Data Source
AI summary
The present invention is an improved superimposed standing valve and related method of harvesting oil and gas using a conventional rod pump equipped with the improved superimposed standing valve. The present invention includes a valve cylindrical sleeve disposed between a top cylinder and a main standing valve such that the valve cylindrical sleeve can slide along the top cylinder a fixed valve stroke. A plurality of openings are sealed and unsealed by the movement of the valve cylindrical sleeve. The present invention isolates the pump from the head pressure of the oil and gas inside of the tubing thereby enabling the standing valve of the pump to remain open on both the upstroke and the downstroke. As a result, the improved superimposed standing valve increases pump efficiency and reduces the risk of gas locking. Its cylindrical sealing surfaces also prevent solid formation particles from gravitating downward into the pump chamber.