Effectiveness of electrokinetic-enhanced oil recovery (EK-EOR): a systematic review

Abstract

Hydrocarbons continue to play an important role in providing affordable energy to meet rising energy demand. Amidst growing concerns on the environmental impact of oil and gas production processes, many researchers are increasingly exploring environmentally sustainable methods of extracting hydrocarbons from the reservoir. The introduction of direct current into the pore space activates mechanisms that enhance fluid flow, reduces produced water, decreases associated hydrogen sulfide production, and leaves no material footprint on the environment. Previous laboratory studies and field applications have reported varying degrees of success of the EK-EOR mechanism. However, the mechanism and effectiveness of this technique remain unclear. This systematic literature review provides an opportunity to critically evaluate laboratory results, establish a basis for the effectiveness of the EK-EOR mechanism and identify possible future research directions. In this study, 52 articles were identified and reviewed in a selection process that adhered to the PRISMA protocol. Data extracted from these articles were fed into the EK-EOR model, and Monte Carlo simulation (10,000 iterations) was used to determine the success rate of the EK-EOR process. Insights obtained from the simulation indicate that EK-EOR alone is not effective (with a success rate of 45%). Insights from published laboratory experiments indicate that interstitial clay affects the electro-osmotic permeability of reservoir rocks which determines the effectiveness of the EK-EOR mechanism. Salt deposition on the cathode and generation of gases (oxygen and chlorine at the anode) are significant limitations of the EK-EOR. The review concludes by identifying future areas of application of EK-EOR.