Enhancing oil recovery by electric current impulses well treatment: A case of marginal field from Oman: A case of marginal field from Oman

Electro-enhanced oil recovery (EEOR) methods have the smallest carbon footprint, among which the electric current impulses method is the most economic. Its performance requires minimal surface facilities, no auxiliary equipment, downhole tools or hazardous materials. Stopping oil production or pulling the tubing out of the well for placing the downhole tools are not required either. The period of treatment session is short (12–24 h). The electricity consumption of 150–200 kW is lower than for any other methods. Prior to the abandonment of an oil field in Oman, treatment with the electric current impulses was applied to marginal wells to clean up the near borehole zone and improve well production characteristics. 7 wells were treated in pairs as cathode and anode in two successive electrical treatments, which were carried out with a difference of 4 months. In the period after the second electrical treatment, only five wells were in operation. Two of them, wells 5 and 12 were treated in both electrical treatments. The results of electrical treatments were thoroughly analysed due to the overlap of simultaneous operations that could mask the effect of electrical treatment. The incremental oil production compared to the forecast was evaluated using reservoir simulation and decline curve analysis. In wells after the second electrical treatment, the increase in oil production rate (OPR) by 36% was in Well 5 and by 25% in Well 1. There was no noticeable effect in Well 12, probably because it was located at the very edge of the reservoir structure. The effect of electrical treatment was also observed in untreated nearby wells. An increase of 11% in OPR was observed in Well 23 and 64% in Well 7. The effect of the electrical treatment was also observed in the form of heavy oil and wax flowing in slugs from three treated wells, which increased the total consumption of demulsifier from 12 to 20 L per day. It has been demonstrated that this method has great potential for cleaning the near wellbore space and increasing oil production.