Characterization and modeling of a crude oil desalting/dehydration plant by experimental design approach

Oil produced in most of oil fields is accompanied by water and dissolved salts, mainly NaCl, which can cause considerable operational problem. Therefore desalting and dehydration plants are often installed in crude oil production units to remove water soluble salts from an oil stream. This paper investigates experimentally effect of five parameters (demulsifying agent concentration, temperature, wash water dilution ratio, settling time and mixing time with wash water) on performance of desalting/dehydration process. The performance was evaluated by calculating the Salt Removal Efficiency (SRE) and Water Removal Efficiency (WRE) based on the five process parameters. In order to investigate effect of the parameters on desalting/dehydration efficiencies a 26-1 fractional factorial design with 5 other experiment at the center of the design for analysis of variance was applied. Based on the statistical analysis SRE was expressed by a model for the whole range of variables while WRE was expressed with two models, each is valid in a part of variable domains. The models were satisfactory evaluated with plant experimental data.

Keywords:

factorial design , desalting/dehydration process , crude oil treatment