Research on ultrasonic demulsification characteristics and parameter optimization of condensate oil emulsion

Abstract

As natural gas wells advance through the mid to late stages of extraction, foam drainage processes are employed to sustain production capacity, leading to the formation of significant condensate emulsions. This study examines the effects of key factors on separation efficiency during ultrasonic dewatering of two representative condensate emulsions with varying viscosities, using single-factor and orthogonal experiments. The droplet size distribution was assessed using a microscopic observation system before and after demulsification. Results indicate that ultrasonic demulsification is an effective method for treating condensate emulsions and improving recovery rates. Optimal parameters were determined as 0.5 W/cm², 20 kHz, and a processing time of 20 mins, achieving complete dewatering (100 %) for separated oil samples alongside a notable separation efficiency of 83.1 %. Importantly, increases in sound intensity and processing time initially enhanced separation efficiency but subsequently led to a decline. Frequency exerted the most substantial influence on separation efficiency, followed by sound intensity, processing time had the least effect. Furthermore, under identical conditions, the first oil sample demonstrated a separation efficiency that was 17.4 % greater than that of the second sample. In practical terms, reducing emulsion viscosity can enhance ultrasonic separation efficiency.