Rag Layer Electrostatic Coalescence for Transformer Protection
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Solution Overview
Problem
Gas oil separation plants (GOSP) face issues such as transformer tripping, inefficient energy usage, off-specification crude oil production, high operating costs, and inefficient manual operations due to the growth of emulsion rag layers in desalters and dehydrators, which can lead to safety hazards and contamination.
Innovation Solution
The continuous withdrawal and treatment of a slip stream from the emulsion rag layer using a restricted orifice into a three-phase separation vessel with fully insulated electrostatic electrodes to break the emulsion, reducing the growth of the rag layer and preventing off-specification crude oil products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual monitoring and infrequent draining of rag layer is used, then operational simplicity is maintained, but transformer short-circuiting and tripping occur due to rag layer growth
Solution Approach 1:
The system uses the rag layer itself to trigger the drainage process. When the rag layer reaches a certain level, it automatically activates the pump to drain the layer, eliminating the need for manual monitoring while preventing transformer short-circuiting. The rag layer acts as both the problem source and the triggering mechanism for its own removal.
Solution Approach 2:
The system implements a feedback mechanism where the rag layer level (or lack thereof) controls the pump operation. The absence of rag layer prevents pump activation, while the presence of rag layer at critical levels triggers automatic drainage, creating a self-regulating system that maintains reliability without manual intervention.
2Reliability
If demulsifier injection is increased by 25% to stabilize operation, then crude oil specifications are met, but operating costs increase
Solution Approach 1:
The system extracts and removes the rag layer containing concentrated emulsifiers and contaminants before they can interfere with the dehydrator operation. By continuously removing this problematic layer, the system maintains specification compliance without needing to over-inject demulsifier, thereby reducing chemical consumption and operating costs.
3Reliability
If continuous monitoring and frequent manual draining of rag layer is implemented, then transformer short-circuiting is prevented, but operational efficiency decreases
Solution Approach 1:
The system eliminates the need for continuous manual monitoring by implementing automatic pump control that responds to rag layer presence. The system serves itself by using the rag layer condition to trigger appropriate action, maintaining transformer reliability while eliminating the productivity loss associated with frequent manual interventions.
4Reliability
If multiple stages and units are used for pressure reduction, then flash vaporization is prevented, but device complexity increases
Solution Approach 1:
The system performs preliminary removal of the rag layer containing emulsifiers and contaminants before the crude oil undergoes pressure reduction and vaporization processes. By eliminating this problematic layer in advance, the system ensures stable vapor separation in subsequent stages without needing to add additional complexity to handle rag layer interference.
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 approach reduces the risk of transformer short-circuiting, minimizes demulsifier and wash water consumption, increases desalter capacity, lowers capital costs, and maintains stable crude oil specifications by controlling the water level without relying on interface level measurements.
Implementation Method 1
conveying the rag layer to a separation device, the separation device operable to effect electrostatic coalescence on the rag layer to separate oil and water
Data Source
AI summary
Systems and methods for treating a rag layer in a gas oil separation plant. The method includes withdrawing the rag layer from a vessel proximate an oil water interface; conveying the rag layer to a separation device, the separation device operable to effect electrostatic coalescence on the rag layer to separate oil and water; and recycling separated oil from the separation device back to the gas oil separation plant process.