Experimental Investigation of Electrokinetic Assisted Hybrid Smartwater EOR in Carbonate Reservoirs

Abstract

Abstract Smartwater flooding is a promising oil recovery technique, demonstrating positive results in many laboratory and field tests, by altering salinity and ionic composition of injection water. Injection of smartwater in carbonate reservoirs has gained interest due to its potential feasible application, taking advantage of improved oil recovery. Electrokinetic enhanced oil recovery (EK-EOR) is another rising technology that involves passing low D.C. current through the reservoir between a subsurface anode and cathode in the producing well. It has demonstrated a number of advantages including fluid viscosity reduction, permeability enhancement and reduced water cut. Our formulation aimed at advancing their combined mechanisms through a novel hybrid EOR. This study is the first attempt to present the experimental work on Smartwater Flooding integrated with the application of Electrokinetics (EK). The effects of total salinity, reducing monovalent ions (Na+ and Cl-) and spiking of multivalent anions (SO42-) on the crude oil/brine/rock interaction were studied. Zeta potential tests were integrated with core flooding experiments systematically designed to identify the optimum ionic concentration and current density. Optimization of current density was essential for controlling both Cl2 gas generation and formation damage. EK showed positive effects with our designed Smartwater, when optimum currentdensity was induced, allowing earlier production and incremental displacement efficiency of 2.4-6%.