Increasing costs associated with separators - often in difficult, remote applications - drives the desire to improve separator selection and avoid oversizing the device by improving confidence in separator performance predictions. Accurate predictions of separation performance of a dispersed phase depend upon accurate estimates of entrainment and size distribution of the dispersed droplets entering the separator. For relatively efficient separation devices, the performance prediction is highly sensitive to the small end of the size distribution. A common practice is to characterize the droplet field with a two-parameter distribution based on predictions of two large droplet sizes such as the maximum and median droplets. This approach allows small errors associated with the predictions of large droplets to produce large errors in the small end of the distribution and can significantly compromise the performance prediction.
This presentation will discuss a modified two-parameter methodology in which the minimum droplet size that can be created from available energy along with the maximum droplet size that can survive in the flow are used to characterize the droplet size distribution. Evaluations of this methodology over a range of dispersion suggest that the approach can be universally applied to dispersions of liquid in gas, liquid in liquid, and gas in liquid.
Gene E. Kouba is a senior research consultant in Chevron’s Energy Technology Company and works closely with Advanced Production Systems, Flow Assurance, and Compact Modular Production Systems teams. His areas of interest include measurement, transport, separation, and modeling of multiphase flows.
Recent efforts have focused on methodologies for predictions of the following: smallest entrained droplet size, foam characterization, separator performance, probability of sand transport, sand bed removal rate, and improvements to “top-kill” well killing operations. He has developed and deployed several designs of compact separators and flow conditioning devices.
Kouba received B.S. and M.S. degrees in mechanical engineering from Oklahoma State University, Ph.D. in petroleum engineering from the University of Tulsa and currently holds memberships in SPE, ASME, and Sigma Xi.