The Effect of Removal of Oil and Suspended Solids in the Production Water by Gravimetric Separation and Chemical Treatment Using Adequate Dosage of Coagulating and Flocculating Agents

Abstract

Abstract The aim of this study was to determine the removal effect of oil and suspended solids present in the production water from the oil and gas industry. Two treatment processes were proposed – oil skimming and chemical sedimentation. In both cases, experimental tests were developed to characterize each process. In the oil skimming process, a time of 0.22 hrs was obtained experimentally for the separation of oily-aqueous phases. The average size of the oil droplet in the formation water was 300 microns, obtained by Gaussian distribution. The chemical sedimentation process was designed by dosing coagulant and flocculant, selected through experimental jar tests. The selected chemicals were tannic resin as coagulant and a latex emulsion as flocculant in concentrations of 4 mg/L and 6 mg/L, respectively. The sizing of the settling equipment was carried out based on the solid settlement curve. The designed processes removed 96% of residual oils and 98% of the suspended solids present in the formation water, generating an effluent suitable for the secondary recovery of oil.

Keywords

• production water, oil skimming, floculation, coagulation, chemical precipitation.