Self-Purging Multi-Phase Pump Filtration System
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Solution Overview
Problem
Multiphase pumps, particularly those used in oil field production, face significant wear and damage from abrasive solids like sand, leading to frequent shutdowns and component replacement due to the lack of effective filtration systems that can handle high-pressure environments.
Innovation Solution
The implementation of a system with at least two sand filters and a controller to periodically switch the flow path, allowing filters to collect solids upstream of the pump and automatically purge them downstream using high discharge pressure, reintegrating the solids into the process flow without requiring a low-pressure destination for purging fluid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If filters are installed upstream of the pump to prevent sand ingress, then pump reliability is improved, but the filters quickly fill with sand and require constant cleaning or cause clogs
Solution Approach 1:
The system employs periodic flow path switching between multiple filters, where one filter is in service while another is purged. This periodic alternation allows filters to be automatically cleaned without interrupting pump operation, resolving the contradiction between maintaining pump reliability and avoiding constant manual filter cleaning
Solution Approach 2:
The system uses the pump's own discharge pressure to automatically purge accumulated sand from the filters through flow path switching. This self-service mechanism eliminates the need for external cleaning equipment or manual intervention, allowing the system to maintain itself while continuing to protect the pump
2Reliability
If traditional filtration systems are used, then solids are removed from the process stream, but a low pressure destination is required for purged solids and flushing fluid which is often not available
Solution Approach 1:
The system extracts the filtration function from the traditional linear flow path and creates a parallel circuit with multiple flow paths. This allows solids to be temporarily removed upstream of the pump and then reintroduced downstream, eliminating the need for external low-pressure destinations while maintaining pump protection
Solution Approach 2:
The system dynamically switches between multiple flow paths using valves controlled by a controller. This dynamic reconfiguration allows the same filter to alternately serve as an upstream filtration element and a downstream purging element, eliminating the need for complex collection vessels and external disposal infrastructure
3Productivity
If narrow clearances are maintained in multiphase pumps to preserve volumetric efficiency, then production levels are maintained, but wear from abrasive sand becomes significantly more damaging
Solution Approach 1:
The system performs preliminary filtration of sand from the process stream upstream of the pump before the fluid enters the pump. This advance removal of abrasive particles prevents wear damage while the pump maintains its narrow clearances for optimal volumetric efficiency and production levels
Solution Approach 2:
The filter system acts as an intermediary between the sand-containing process stream and the pump. It temporarily holds and removes sand particles, allowing the pump to operate with narrow clearances without direct exposure to abrasive solids, thus protecting durability while maintaining productivity
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 effectively prevents solids from damaging the pump while avoiding the need for complex collection vessels and minimizing environmental impact by ensuring solids are not ingested by the pump, thus extending pump lifespan and reducing maintenance costs.
Implementation Method 1
the high discharge pressure of the process fluid flushes the sand out of the filter and toward the discharge pipeline
Implementation Method 2
the first filter collects sand and prevents it from entering the pump
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
An apparatus and method prevent entrained solids from entering a pump by directing a process stream through an active upstream filter that removes the solids, and then through a downstream idle filter where the process stream purges the filter of previously retained solids. The flow path is periodically switched to exchange the roles of the filters, so that none of the filters is saturated, and the solids remain in the process flow but bypass the pump. Any need for a low pressure destination for purged solids and purging fluid and/or any environmental impact of dumping process fluid and solids into the environment is thereby avoided. Partially opened valves can be used to divert only part of the downstream flow for filter purging. Selectable paths can be included for which no filters are purged. The downstream flow can be divided and used to simultaneously purge a plurality of idle filters.