Potentials of Enzyme Enhanced Oil Recovery: A Review

Abstract

In this paper, we review the progress in understanding enzyme applications in hydrocarbon production from extensive experimental and field studies.

Enzyme enhanced oil recovery (EEOR) is an emerging method of improving oil production in an environmentally friendly way, but the mechanisms underlying this process are not clearly understood. Also, detailed studies on enzyme enhanced oil recovery applications are not readily available.

Enzymes are NOT all created equal!

From the comprehensive review carried out in this study, we observed that most of the works done on EEOR processes were not properly detailed and the different experimental procedures adopted makes coherent understanding of the process difficult.

Evident however in all the studies from the laboratory experiments and field applications, is the capacity of enzyme to improve oil production from both sandstone and carbonate rocks. Also, we have identified and highlighted the physicochemical properties of the enzymes commonly used for enhanced oil recovery and their effects on oil recovery process in order to improve the understanding of their applicability in relevant hydrocarbon reservoirs.

Furthermore, the challenges and future research directions for EEOR applications have been pinpointed in this study. Having unfolded the enhanced oil recovery potential of enzymes, we call for deeper studies on this emerging method of improving oil production. This study is relevant to the design and application of EEOR process in both carbonate and sandstone reservoirs.

Bacteria is many sizes bigger than proteins and nanotubes.

Key Findings Across Enzyme EOR Studies

Across the laboratory studies compiled in this review, enzyme treatment consistently improved oil recovery in both core-flooding and spontaneous imbibition experiments:

• Nasiri et al. tested 1% GreenZyme-brine on Berea sandstone cores in tertiary mode, recording 42% OOIP recovery with 10 pore volumes of water injection on one core, and 47% OOIP on a second, with an additional 2% OOIP recovered over untreated brine in spontaneous imbibition tests.

• Udoh et al. found that 1 wt% enzyme in low salinity brine added 1.86% and 6.28% incremental recovery over low salinity flooding in post-tertiary and tertiary modes respectively, while secondary-mode enzyme-low salinity flooding reached 82.76% total recovery in carbonate core plugs.

• Comparable enzyme-based studies by Feng et al. and Wang et al. reported recoveries ranging 12-21% and 90-95% respectively across different core and concentration setups, underscoring how much lab results vary by rock type, concentration, and test design.

Field-Scale Results

The review also compiles field implementations of enzyme EOR spanning several basins:

• Prue Ranch (Anacacho) Oilfield, Frio County, Texas: average daily oil production doubled from 4.34 to a peak of 8.81 bbl/day following enzyme treatment.

• Dagang oilfield, China: water cut dropped from 85% to 54% and oil recovery increased by 41.6 bbl/day, attributed to unplugging low-permeability layers.

• Mann Field, Salin sub-basin, Myanmar: two treated wells produced incremental recoveries of 530 and 1,636 barrels of oil within thirteen and nine months respectively.

Across these cases, the mechanisms most often identified are interfacial tension reduction, wettability alteration toward more water-wet conditions, and, in some field settings, degradation of long-chain alkanes and paraffin content in the produced oil.

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Sources & Credits

Tinuola Hannah Udoh, Lucas Evangelista.

Petroleum Science and Engineering, Vol. 4, No. 2, 2020, pp. 51-63. Read the source →