Multi-Stage Pump Recirculation Valve for Work Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multiple stage rotary screw pumps used in oil and gas wells face inefficiencies due to uneven distribution of work across stages when handling multiphase fluids, leading to overheating and potential seizure, especially when the gas-to-liquid ratio changes, as existing designs fail to match swept volumes with fluid properties effectively.
Innovation Solution
A multiple stage pump assembly with pressure-controlled valves that re-circulate fluid from the outlet to the inlet, allowing for controlled power generation and distribution of work across stages, optimizing the design for specific gas-to-liquid ratios and accommodating variations in fluid composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If multiple stage pumps are used to generate high differential pressures, then the total pump differential pressure increases, but the work distribution becomes uneven across stages causing overheating and potential seizure
Solution Approach 1:
The patent employs pressure sensors in each stage that provide feedback signals to a control system. Based on this feedback, the control system adjusts the recirculation flow rates through controllable valves to balance the work distribution across stages. This feedback mechanism prevents any single stage from experiencing excessive pressure differential, thereby eliminating overheating and seizure risks while maintaining high total differential pressure.
Solution Approach 2:
The patent dynamically changes operational parameters (recirculation flow rates) based on real-time pressure conditions in each stage. By adjusting the recirculation rate for each stage individually, the system optimizes the pressure differential across each stage, ensuring even work distribution and preventing thermal overload while achieving the required total differential pressure.
2Stress or pressure
If multiple stage pumps are used to generate high pressures in multiphase fluids, then the discharge pressure increases, but the compressibility of gas causes uneven work distribution and inefficiency
Solution Approach 1:
Pressure sensors in each stage provide real-time feedback on the pressure differential experienced by that stage. The control system uses this feedback to calculate and adjust recirculation flow rates, ensuring that each stage processes a balanced volume of multiphase fluid. This prevents gas compressibility from causing work concentration in later stages, thereby maintaining high pumping efficiency while achieving high discharge pressure.
Solution Approach 2:
The patent utilizes hydraulic recirculation systems with controllable valves to manage fluid flow between stages. By controlling the recirculation of liquid phase fluid through each stage, the system compensates for gas compressibility effects, ensuring consistent work distribution across all stages and maintaining high productivity in multiphase pumping operations.
3Reliability
If the swept volume of pump stages is reduced to match decreasing gas volume, then the work distribution becomes more even, but the device complexity increases
Solution Approach 1:
The patent uses identical pump stages with standard swept volumes for all stages, maintaining simplicity in hardware configuration. Instead of designing custom swept volumes for each stage, the system achieves even work distribution by adding a recirculation system that adjusts flow rates. This multi-functional approach allows the same pump stage design to handle varying gas-to-liquid ratios effectively without increasing device complexity.
Solution Approach 2:
The patent introduces recirculation lines with controllable valves as intermediary flow paths between stages. These intermediaries allow adjustment of the effective flow through each stage without modifying the pump stage geometry itself. This approach achieves uniform work distribution while keeping the main pump configuration simple and standardized.
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 enables more even distribution of work across pump stages, increasing reliability and efficiency by sharing the burden of pressure generation, reducing the risk of overheating and seizure, and allowing the pump to handle varying gas-to-liquid ratios effectively.
Implementation Method 1
A multiple stage pump assembly with pressure-controlled valves that re-circulate fluid from the outlet to the inlet, allowing for controlled power generation and distribution of work across stages
Implementation Method 2
Rotary screw pumps, such as twin or triple screw pumps, are positive displacement pumps which use rotating screws to pressurise a fluid
Data Source
AI summary
Pump having a pump inlet, a pump outlet, at least two threaded rotors and a pressure controlled valve. The pressure controlled valve is capable of controlling re-circulation of fluid from the pump outlet to the pump inlet. The pressure controlled valve can be a control valve. A multiple stage pump assembly is also provided having least two pumps arranged in series, in which at least one of the pumps is the aforementioned pump.