Oil-Water Separation in Liquid-Liquid Hydrocyclones (LLHC)–Experiment and Modeling

Abstract

The data reveal that LLHCs can be used up to 10% oil concentrations at the inlet, maintaining high separation efficiency. However, the performance of the LLHC is best for very low oil concentrations at the inlet, below 1%. For low concentrations, no emulsification of the mixture occurs in the LLHC. However, high inlet concentrations, up to 10%, promote emulsification posing a separation problem in the overflow stream.An existing LLHC mechanistic model is modified and refined. The main modifications carried out are improved correlation for the swirl intensity that affects the axial and tangential velocity distributions, the flow reversal radius and the inlet factor.The required inputs for the model are: LLHC geometry, fluid properties, inlet droplet size distribution and operational conditions. The model is capable of predicting the LLHC hydrodynamic flow field, namely, the swirl intensity and the axial, tangential and radial velocity distributions of the continuous-phase. The separation efficiency and migration probability are determined based on droplet trajectory analysis. The flow capacity, namely, the inlet-to-underflow pressure drop, is predicted utilizing an energy balance analysis.The LLHC mechanistic model was tested against the present study data and additional data from the literature, especially from . Very good agreement is observed between the model predictions and the experimental data with respect to the swirl intensity, axial and tangential velocity distributions, migration probability and global separation efficiency. The developed LLHC model can be used for the design of field applications for the industry. v ACKNOWLEDGEMENTS

Theoretical background and the flow fields in downhole liquid-liquid hydrocyclone (LLHC)

“…3 included the semi angle, β, of the LLHC. By combining Caldentey and Erdal correlations, Gomez [6] ended up with Eq. 4 as the correlation for swirl intensity.…”

Recovery of Fresh Water Resources from Desalination of Brine Produced During Oil and Gas Production Operations

“…4,5,9,[46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64] This new technology in oil water separations is also being applied now to newer onshore fields to meet the onshore disposal criteria. 47,54,[58][59][60] Different technologies that are being employed in the industry for oil/water separations are:…”

“…Hydrocyclone Technology: For example, hydrocyclones, 9,13,21,46,47,50,52,54,56,58,59,60,62 have proven to be effective in high pressure and medium pressure oil systems. This technology is now considered to be the most reliable for offshore applications in meeting the required level of oil for discharge.…”

“…One potential attraction for aquifer recharge is that it could be used for water rights transfer from party to party. Such offsets are accepted in the Columbia River Basin where a one-to one-replacement of fresh water is required for permits to be issued for new fresh water usage (59). The major disadvantages to ASR are (1) the cost of injection of the fresh water into the underground formation and (2) the uncertainty of monitoring of water quality.…”

“…CBNG wells in southeast Kansas are now producing about 10 Bcf per year, and activity is strong. Arkansas CBNG production is just now beginning to increase [59].…”