Application of physico-technological principles in demulsification of water-in-crude oil system

The presence of water-in-oil emulsion in petroleum industry presents serious pipeline challenges and flow problems such as corrosion, scaling and plugging of in-field flow lines plugging. These problems are attributed to the presence of asphaltene and resinous compounds in the crude oil. Application of a suitable approach for the treatment of crude oil emulsion remains a major concern in the petroleum industry. This paper discusses the use of light gasoline as diluents to reduce the viscosity o f a 17° API heavy crude oil emulsion. Several demulsification bottle tests were carried out. Addition of up to 25ml of gasoline led to an increase in API gravity of the crude oil from 17 to 24, indicating improved crude quality. The results also show increased water separation in response to corresponding increase in gasoline blending ratios which was most effective at gasoline blends between 5ml and 10ml. The crude oil and gasoline blend samples dosed with 2ppm of demulsifier chemical, NALCO EC2111A, a reduced injection rate from 5ppm, currently used on the operator's oilfield showed considerably higher rates of water separation with huge savings in demulsifier costs.