Processes for analysis and optimization of multiphase separators, particularly in regard to simulated gravity separation of immiscible liquid dispersions

A computer implemented method to evaluate and control the separation performance of a separator for separating a multi-phase, multi-fluid stream consisting of gas and an immiscible liquid dispersion within an internal volume of the separator and outputting one or more streams of processed gas and one or more streams of processed liquids separated from the immiscible liquid dispersion, wherein the one or more streams of processed liquids are selected from the group consisting of a water outlet stream and an oil outlet stream, and wherein the immiscible liquid dispersion includes a continuous or dispersed gas phase, a dispersed liquid phase and a continuous liquid phase within an internal volume of the separator, the method comprising the steps of:

• receiving operational input parameters at a hardware processor of a controller computing device, wherein the processor is executing program code that is in the form of one or more software modules and stored in a non-transitory storage medium, and wherein the operational input parameters include:
• fluid property data for the immiscible liquid dispersion including one or more of density, viscosity and surface tension, and
• static or dynamic settling data for the immiscible liquid dispersion;
• generating, with the processor, a computational fluid dynamics (CFD) model of the separator, wherein generating the CFD model includes:
• modeling, a droplet size distribution for the dispersed liquid phase within the internal volume as a function of an initial droplet size distribution and the static or dynamic settling data, and
• generating a phase interaction model of a phase interaction between the dispersed liquid phase and the continuous liquid phase as a function of the fluid property data;
• determining, with the processor based on the CFD model, adjustments to one or more of the operational input parameters, wherein the adjusted one or more operational parameters are determined based on the CFD model to change a separation efficiency of the separator;
• controlling, with the processor, the separator according to the adjusted one or more operational input parameters, wherein the controlling step comprises sending, by the processor to the separator over a communication interface, a control signal configured to adjust a setting of one or more of a water outlet stream control valve, an oil outlet stream control valve, an operating temperature of the separator, a demulsifier chemical injection rate, an inlet control valve and a gas outlet control valve, as a function of the adjusted one or more operational input parameters;
• monitoring, with the processor, a liquid-liquid separation efficiency of the separator in real-time during operation of the separator using one or more sensors exposed to respective outlet streams, wherein the liquid-liquid separation efficiency is determined by measuring one or more of a fraction of water in the oil outlet stream and a fraction of oil in the water outlet stream;
• and
• dynamically performing, with the processor during operation of the separator based on the monitoring step, the receiving, generating, determining and controlling steps such that the monitored liquid-liquid separation efficiency of the separator is changed and the one or more streams of processed liquids separated from the immiscible liquid dispersion contain less than a prescribed amount of the immiscible liquid dispersion therein.