Improve Soil Productivity Research Articles

Behavior of partially hydrolyzed polyacrylamide/polyethyleneimine reinforced with coal fly ash for preformed particle hydrogels

AbstractHigh water production and low oil recovery are attributable to reservoir heterogeneity, making extraction economically inefficient. To improve oil production, it is important to solve permeability issues, to allow a more uniform and efficient sweep. In recent years, several studies of preformed particle gel (PPG) have been performed reduce reservoir heterogeneity and enhance oil recovery. In this work, the effect of coal fly ash (CFA) on hydrolyzed polyacrylamide (PHPA) crosslinked with polyethyleneimine PPG were evaluated regarding thermal, rheological, and structural properties. The rheological results showed an increase in elastic behavior with the presence of CFA. Thermal analysis revealed degradation resistance of 271% with only 1.0% CFA. The swelling test proved that the presence of CFA supports the absorption of a brine solution. The results suggest a significant increase in properties assessed with small CFA contents due to a strong interaction between CFA and three‐dimensional polymer networks.

Effects of land use and cultivation time on soil organic and inorganic carbon storage in deep soils

The vertical distribution and exchange mechanisms of soil organic and inorganic carbon (SOC, SIC) play an important role in assessing carbon (C) cycling and budgets. However, the impact of land use through time for deep soil C (below 100 cm) is not well known. To investigate deep C storage under different land uses and evaluate how it changes with time, we collected soil samples to a depth of 500 cm in a soil profile in the Gutun watershed on the Chinese Loess Plateau (CLP); and determined SOC, SIC, and bulk density. The magnitude of SOC stocks in the 0–500 cm depth range fell into the following ranking: shrubland (17.2 kg m−2) > grassland (16.3 kg m−2) > forestland (15.2 kg m−2) > cropland (14.1 kg m−2) > gully land (6.4 kg m−2). The ranking for SIC stocks were: grassland (104.1 kg m−2) > forestland (96.2 kg m−2) > shrubland (90.6 kg m−2) > cropland (82.4 kg m−2) > gully land (50.3 kg m−2). Respective SOC and SIC stocks were at least 1.6- and 2.1-fold higher within the 100–500 cm depth range, as compared to the 0–100 cm depth range. Overall SOC and SIC stocks decreased significantly from the 5th to the 15th year of cultivation in croplands, and generally increased up to the 70th year. Both SOC and SIC stocks showed a turning point at 15 years cultivation, which should be considered when evaluating soil C sequestration. Estimates of C stocks greatly depends on soil sampling depth, and understanding the influences of land use and time will improve soil productivity and conservation in regions with deep soils.

Phase Behavior, Wettability Alteration, and Oil Recovery of Low-Salinity Surfactant Solutions in Carbonate Reservoirs

Summary Recent investigations have shown that treatment with injected brine composition can improve oil production. Various mechanisms have been suggested to go through the phenomenon; nevertheless, wettability alteration is one of the most commonly proposed mechanisms in the literature. Wettability alteration of the porous media toward a more favorable state reduces the capillary pressure, consequently contributing to the oil detachment from pore walls. In this study, phase behavior, oil recovery, and wettability alteration toward a more favorable state were investigated using a combination of formulations of surfactant and modified low-salinity (LS) brine. Phase behaviors of these various formulations were examined experimentally through observations on relative phase volumes. Experiments were performed in various water/oil ratios (WORs) in the presence of two different oil samples, namely C1 and C2. These experiments were conducted to clarify the impact of each affecting parameter; in particular, the impact of resin and asphaltene of crude oil on the performance of LS surfactant (LSS) flooding. Hereafter, the optimal formulation was flooded into the oil-wet micromodel. Optimum formulations increased the capillary number more than four orders of magnitude higher than that under formation brine (FB) flooding, thus causing oil recovery rates of 61 and 67% for oil samples C1 and C2, respectively. Likewise, the wettability alteration potential of optimized formulations was studied through contact angle measurements. Results showed that LS and LSS solutions could act as possible wettability alternating methods for oil-wet carbonate rocks. Using the optimum formulation resulted in a wettability alteration index (WAI) of 0.66 for sample C1 and 0.49 for sample C2, while using LS brine itself ended in 0.51 and 0.29 for oil samples C1 and C2, respectively.

Synthesis and characterization of aluminum citrate compounds and evaluation of their influence on the formation of hydrogels based on polyacrylamide

Aluminum citrate is used as a conformance control agent to improve oil production and excess water production. This paper discusses the formation of mono and polynuclear aluminum species from the synthesis of aluminum citrate and evaluates these compounds as crosslinkers in hydrogels for conformance control. The products obtained from the synthesis were characterized by Fourier-transform infrared spectrometry (FTIR), elemental analysis (CHN), scanning electron microscopy (SEM), and inductively coupled plasma–optical emission spectrometry (ICP-OES). The FTIR analyses indicated the presence of mononuclear aluminum citrate complexes at pH 3 and polynuclear species starting at pH 4. These results were corroborated by CHN and ICP-OES techniques, which revealed the variation of carbon, oxygen, hydrogen, and alumina precipitate levels as functions of pH variation. The focus of the study was to assess how these crosslinking agents perform in hydrogel formation under reservoir conditions. Rheological analysis showed that the values of tan (delta) of the hydrogel synthesized with aluminum citrate at pH 6 were lower than 0.1, indicating strong gels, while at pH 9, the values were above 0.1, indicating weak gels. These results are in agreement with those obtained by FTIR, which showed that at pH 6, the structures of the aluminum citrate complex were probably in the form [Al3(C6H5O7)3(OH)4(H2O)]4−. This structure appears to allow easier access to the aluminum orbital for the crosslinking process compared to the gel composed of aluminum citrate synthesized at pH 9 [Al3(C6H6O7)3(OH)4(H2O)5]4−.

Effects of land-use types on soil quality indices in ughoton community in Ovia north-east local government area, Edo state, Nigeria

The present study was conducted to examine the effects of different land-use types on soil quality indices. Surface soils were collected at 0-15 cm and 15-30 cm depth respectively from three land-use types: Cassava field, Oil palm, and Banana plantation. Samples were subjected to physical, chemical, and microbiological analyses using standard methods, and the result were subjected to descriptive statics. The extent of change in soil quality was assessed using soil quality indices as an index for soil fertility management. The result showed that oil palm plantation was highest in soil quality evaluated as compared to Banana and Cassava field. The fertility differences observed across the land use types were due to inherent soil properties such that farming practices that ensure accumulation of organic matter need to be encouraged in order to improve soil productivity. It is recommended that soil fertility management should be site-specific to enhance optimum yield and productivity.

Protected supersonic separator performance against variable CO2 content on natural gas processing: Energy and sustainability analyses

In offshore oil-and-gas fields with high CO2 content, oil-and-gas processing entails recycling CO2 to the field for enhanced oil recovery. Despite blocking fossil CO2 ingress into the biosphere and improving oil production, this entails increasing %CO2 in oil-and-gas with time, challenging the processing plant. Supersonic separator is a compact gas processing solution that can simultaneously adjust water and hydrocarbon dew-points. But, supersonic nozzles can only work if sonic-throat flow occurs. In this work a supersonic nozzle sized to a high-pressure 25%mol CO2 feed is submitted to varying %CO2 from 5%mol to 80%mol under constant feed temperature/pressure and molar flow rate. Varying %CO2 affects nozzle performance with three possible outcomes: (i) feed is insufficient to reach sonic-throat flow, entailing no supersonic processing; (ii) feed is at design condition (25%mol CO2) and nozzle works tightly; and (iii) sonic-throat flow is achieved with a fraction of the feed; i.e., there is no room to process the rest. These apparent shortcomings of supersonic gas processing are examined and a control-scheme based on manipulating feed-pressure is proposed to circumvent feed deficit/excess. With the proposed feed-pressure adjustment to protect supersonic separator operation, energy and sustainability assessments are conducted to evaluate environmental and gas-fired power generation impacts from the supersonic processing of feeds with varying %CO2. Feeds with 10%mol/15%mol/20%mol CO2 have highest sustainability-degrees.

Physical experiments and numerical simulations of viscosity reducer flooding for ordinary heavy oil

In order to overcome disadvantages of thermal recovery technologies such as high cost and air pollution, chemical flooding for ordinary heavy oil by viscosity reducer flooding was studied. The EOR mechanisms of viscosity reducer flooding to improve heavy oil recovery were studied by physical experiments and numerical simulation methods. First, the performance of the viscosity reducer was evaluated, then the injection characteristics and oil displacement performance were studied through core oil displacement experiments, the mechanism of oil recovery improvement by the viscosity reducer was studied through microscopic visualization experiments, and finally a comparison was made between indoor physical experimental results and numerical simulations. The results showed that the process of viscosity reducer flooding can form a stable oil-in-water emulsion. The process of water flooding can be divided into three stages: the starting pressure breakthrough stage, the rapid pressure decline stage, and the low pressure operation stage. Viscosity reducer flooding reduced the starting pressure gradient and the displacement pressure, while the oil recovery factor was increased by 12.4%, and the total recovery reached 46.6%. The main mechanism of improving oil recovery by a viscosity reducer is to reduce the crude oil viscosity and the residual oil saturation. By using the nonlinear mixing rule, the variation rule of crude oil viscosity with the viscosity reducer concentration was obtained, which can be directly applied to reservoir numerical simulations. A pilot test showed that the water cut was decreased and oil production was increased, which also reduced the injection pressure and gave all the production wells improved oil production.

Impact of Green Manuring and Crop Residues Incorporation along with Gypsum on Rehabilitation of Saline Sodic Soil and Yield of Direct Seeded and Transplanted Rice

A two years field study on rice was conducted to see the efficacy of gypsum to improve soil productivity with green manuring (GM) and crop residue (CR) incorporation and its impact on paddy yield of direct seeded rice and transplanted rice grown under saline-sodic soil..................................................Soil organic matter (SOM) intensity was also improved due to GM and CR incorporation particularly during the second year of crop harvest.

Influence of combined application of organic and inorganic amendments on nutrient status in a typic Haplaquept soil of West Bengal

Balanced nutrition based on soil test value is the key to sustain and improve soil productivity. Integrated management of organic, secondary and micronutrient inputs along with inorganic fertilizers in soils is required to prevent decline in soil fertility, crop productivity and sustainability. In present investigation is conducted to study the influence of farmyard manure (FYM), sulphur and zinc along with inorganic NPK fertilizers either alone or in combination on the nutrient availability in soil. Results revealed that use of FYM increased the organic carbon content and availability of nutrients over soil alone and soil treated with only inorganic fertilizers. Results further revealed that the beneficial effects of FYM got enhanced when it is applied along with S and Zn.

Improvement of oil production in low permeability deposits with a system of horizontal wells

The article describes an approach to the production of difficult to extract oil, confined to deposits with low poroperm properties, using a system of horizontal wells and hydraulic multistage fracturing. The main problems that arise during the development of the well are analyzed. A conclusion is reached on the possibility of continuing to apply the method based on the analysis of pilot tests.

Detailed analysis of the brine-rock interactions during low salinity water injection by a coupled geochemical-transport model

Enhanced Oil Recovery (EOR) methods have been widely used around the world to improve oil production from petroleum reservoirs. Recently, the injection of the low salinity/smart water has gained popularity among the EOR methods. Different mechanisms are believed to exist during low salinity/smart water injection, including dissolution, precipitation, and ion exchange at the rock surface. In this study, a coupled geochemical-transport model is presented for the detailed analysis and investigation of the interactions between brine, sandstone and carbonate rocks. The proposed model presents the coupling of a geochemical software (PHREEQC) and a species transport model. This coupled method makes it possible to model the dissolution, precipitation, and ion exchange caused by geochemical reactions during water flow through porous media. The results show that monovalent cations are released into the brine from the exchanger site, and divalent cations fill their position at the clay surface for the sandstone rock. The porosity and permeability changes are observed in the carbonate rock, where it can be important in the near injection area. The ion exchange results in the carbonate rocks show that the geochemical reactions move in a direction to disagree with the pH increase created by low salinity brine injection.

Interfacial Tension Measurement for Alkaline-Polymer Flooding Application for Oil from Fang Oilfield, Thailand

With the high demand of oil and gas consumption, oil is required for more production. Fang oilfield is one of the main oilfields in Thailand. An enhanced oil recovery method especially alkaline-polymer flooding is an essential technique to improve oil production. It involves an injection of alkaline to lower the interfacial tension (IFT) between oil and water and polymer for improving the mobility ratio to produce more oil. In Fang oilfield, a light oil recovery is improved by using the solution to reduce IFT of oil and water. In this study, sodium hydroxide (NaOH) and hydrolysed polyacrylamide (HPAM) are used as alkali and polymer to lower the IFT with different conditions. The aim of this work is to measure the IFT and to assess the effects of pressure, temperature, concentration and salinity on IFT reduction for oil from Fang oilfield. The results present that the concentration of the chemical plays a key role for IFT reduction accounting for 99.49 %. IFT decreases with an increase in temperature up to 49.30 %. The effect of pressure is insignificant for IFT reduction. Salinity can increase IFT for 94.74 % at the low alkali concentration while HPAM could be more benefit in other aspects such as the mobility control process. The outcome of this work can be used as a fundamental data to enhance more oil recovery with the new technique for Fang oilfield.

Impacts of Using some Fertilization Treatments in Presence of Salicylic Acid Foliar Spray on Growth and Productivity of Coriandrum sativum L. Plant

The present study was conducted during ( 2017-2018 and 2018-2019) seasons, at the Hort. Dept., Fac., of . Agric., Benha Univ., Egypt to study the effect of chemical fertilizers (NPK) as a full dose and biofertilization (Bio.) consisting of a mixture of (Nitrobein + Phosphorein) in the presence of Salicylic acid ( SA) foliar spray at 150 ppm in a single or combinations inbetween them on vegetative growth ,grain yield ,chemical constituents parameters and oil productivity of coriander plants comparison with control plants in both seasons. The results indicated that different treatments of NPK mineral fertilizer, biofertilization and salicylic acid treatments , either alone or mixed among them, resulted in a significant increase in the growth ,chemical constituents parameters and oil productivity in both seasons. The use of 100% NPK achieved the highest results in the characteristics of growth, yield and chemical composition, followed by the use of the treatment of 75%NPK +Bio.+SA, where it achieved a significant maximize in this concern,whereas the treatment of 75% NPK + Bio. ranked the third in this context as compared with untreated plants in both seasons. Also, the combined treatment of 75% NPK + Bio. + SA gave the highest values of oil productivity. Consequently, in order to achieve the highest values of growth and chemical constituents ,it is preferable to treate coriander with NPK at 100% or 75%NPK + Bio. + SA. Also, it is possible to treat coriander plant with 75% dose NPK +Bio. + SA to improve oil productivity.

Subsurface Sludge Sequestration in Cyclic Steam Stimulated Heavy-Oil Reservoir in Liaohe Oil Field

Summary There are a lot of sludges produced in oil production and storage processes in Liaohe Oil Field. Usually complicated chemical processes are involved in treating the sludge effectively and such surface-treatment processes are subject to high cost and environmental challenges. Therefore, the feasibility and performance of sludge injection into steam-stimulated wells, and sludge sequestration and associated heavy-oil-recovery improvement are investigated on the basis of results of laboratory research and field operation. The sludge originally produced from the reservoir comprises mainly water, some oil components, and solid phase such as mud and fine sand, and aggregation of the injected sludge components, except water, could block the void porous space. Actually, the sludge is buried into its origin, the reservoir. As the sludge is injected into the steamed reservoir through an enlarged pore at high injection pressure, the permeability of the formation could be significantly decreased (the permeability reduction rate could be more than 98% after sludge blocking in our experiments with sandpacked tubes), and the sludge blocking performance is related to the reactions of oil and solid separated from the sludge, including adherence to the sand surface, consolidation of the sands, and filling in the void porous space. Consequently, the sludge is stored in the steamed formation, and the water in the sludge is separated and produced. At the same time, steam conformance and heating efficiency could be improved by implementing a sludge blocking process, thereby significantly improving oil production. Sludge sequestration has been applied to 45 steamed wells in Shuguang Oilfield until 2018, and all the wells have been stimulated by 7–10 cycles of CSS process. The total sludge injection of the wells is up to 133,200 tons, and more than 15,000 tons of oil and solid separated from the sludge are deposited underground. At the same time, more than 20% increase in cyclic oil production on average is obtained by the sludge-injection process.

Toward Reservoir-on-a-Chip: Rapid Performance Evaluation of Enhanced Oil Recovery Surfactants for Carbonate Reservoirs Using a Calcite-Coated Micromodel

Enhanced oil recovery (EOR) plays a significant role in improving oil production. Tertiary EOR, including surfactant flooding, can potentially mobilize residual oil after water flooding. Prior to the field deployment, the surfactant performance must be evaluated using site-specific crude oil at reservoir conditions. Core flood experiments are common practice to evaluate surfactants for oil displacement efficiency using core samples. Core flood experiments, however, are expensive and time-consuming and do not allow for pore scale observations of fluid-fluid interactions. This work introduces the framework to evaluate the performance of EOR surfactants via a Reservoir-on-a-Chip approach, which uses microfluidic devices to mimic the oil reservoir. A unique feature of this study is the use of chemically modified micromodels such that the pore surfaces are representative of carbonate reservoir rock. To represent calcium carbonate reservoir pores, the inner channels of glass microfluidic devices were coated with thin layers of calcium carbonate nanocrystals and the surface was modified to exhibit oil-wet conditions through a crude oil aging process. During surfactant screening, oil and water phases were imaged by fluorescence microscopy to reveal the micro to macro scale mechanisms controlling surfactant-assisted oil recovery. The role of the interfacial tension (IFT) and wettability in the microfluidic device was simulated using a phase-field model and compared to laboratory results. We demonstrated the effect of low IFT at the oil-water interface and wettability alteration on surfactant-enhanced oil displacement efficiency; thus providing a time-efficient and low-cost strategy for quantitative and qualitative assessment. In addition, this framework is an effective method for pre-screening EOR surfactants for use in carbonate reservoirs prior to further core and field scale testing.

Below ground residues were more conducive to soil organic carbon accumulation than above ground ones

Long-term intensive cultivation generally affects even soil fertility by decreasing the soil organic carbon (SOC) content. The returning of maize residues to the soil is documented as an effective measure to increase SOC and improve soil productivity. However, limited information is available on the turnover and storage of organic carbon (C) caused by the addition of different maize residue types to soil with different soil fertility levels. For this purpose, a 540-day in-site field experiment was carried on soils with low and high fertility levels amended with three types of 13C-labeled maize residues (root, stem and leaf) in Northeast China. The abundances of 13C in the soil samples were measured on the 60th, 90th, 180th, and 540th days after incubation. The results showed that the residual rate of the residue-derived C was higher in the high-fertility (HF) soil than that in the low-fertility (LF) soil on the 60th day (an average of 56.6% vs. 52.37%, P < 0.05). At the end of the experiment, the content of the residue-derived C in the root-amended treatment (0.5 and 0.4 g kg−1 in the HF and LF soils, respectively) was higher than that in the stem-amended (0.4 and 0.3 g kg−1 in the HF and LF soils, respectively) and leaf-amended (0.4 and 0.3 g kg−1 in the HF and LF soils, respectively) treatments. The residual rates of the root-, stem- and leaf-derived C were 20.1%, 15.6%, and 15.4% in the LF soil and 20.4%, 18.3%, and 18.2% in the HF soil, respectively. The results revealed that the HF soil had higher capacity to retain exogenous residue C, and the residue-derived C contribution from below ground residues (roots) to SOC should be more important than that from above ground parts (leaves + stems) in a long-term period.

Yield, oil content, and fatty acid profile of flax (Linum usitatissimum L.) as affected by phosphorus rate and seeding rate

Flax (Linum usitatissimum L.) is an important cash crop for production of edible oil and biodiesel. Experiments were conducted on soils with medium levels of phosphorus (P) at BaiYin (BY) (in 2014 and 2015) and Ulanqab (Ula) (in 2012, 2014, and 2015) aimed at optimizing rate of P rate and seeding rate (SR) for flax seed yield and oil production. The experiments evaluated all combinations of three P fertilizer rates (0, 35, and 70 kg P2O5 ha−1) and three seeding rates (450, 750, 1050 seeds m−2) with 3 replicates, a split-plot arrangement in a randomized complete block design. Results showed P rate, SR, and their interaction significantly affected seed yield and oil yield, the P rate × environment (E) interaction was significant for palmitic, stearic, oleic, linoleic, and linolenic acid contents, and E significantly influenced oil content. Increased P rate significantly enhanced seed yield, linolenic acid content, and oil yield at the high SR, but not at the low SR. Additionally, the high SR produced greater seed and oil yields, and linolenic acid content compared to the low SR. Application of 35 kg ha−1 P2O5 and 1050 seeds m−2 resulted in higher oil productivity and linolenic acid content. These results indicate that appropriate P rate and SR can improve oil productivity and alter fatty acid profile of flax, and that the magnitude of these effects depends on the growing E. Maximum predicted oil yield was obtained with 50 kg P2O5 ha−1 and 1050 seeds m−2 based on regression analysis when averaged across the five environments. These findings could have important implications for sustainable intensification of flax production in the presence of variable and changing growing environments.

Effect of different organic composts and inorganic fertilizer on nodulation, nitrogen fixation and grain yields of soybean (Glycine max L.) under field conditions.

The study assessed the effects of composted corn wastes, poultry droppings and inorganic fertilizer on the number of nodules, nitrogen fixation and grain yields of soybean (Glycine max L.) under field conditions for 2 seasons. The experiments were conducted in the research sub-station of the Institute of Agricultural Research and Training, (IAR&amp;T), Ilora, Oyo State, South Western Nigeria: (Derived Savanna Agro-ecology). Six experimental treatments namely; composted corn wastes boiled with table salt, composted corn wastes boiled with water alone, composted un-boiled corn wastes, composted poultry droppings, NPK 20- 10-10 fertilizer and control were applied to a soil with low fertility status. Soybean (Glycine max L.) seeds were planted in a Randomized Complete Block Design (RCBD) and replicated 6 times. The plantings were carried out twice at two consecutive plantings. The number of nodules, amount of nitrogen fixed as well as grain yield were evaluated. The field trial results showed a higher number of nodules, nitrogen fixation and grain yield response when the un-boiled composted corn wastes (F3) and composted poultry droppings only (F4) were applied to the field compared to the other treatments. The number of nodules, nitrogen fixation and yield were significantly higher at the end of the second plantings compared to the first reflecting a residual effect of the composts. The study concluded that the application of composted corn wastes and poultry droppings especially when the seeds were inoculated with Rhizobium and mycorrhiza improved the number of nodules, N2 fixation and grain yield of soybean (Glycine max L.) even when no boiling treatment was applied to the corn wastes. It is therefore recommended that maize cobs be converted to composts for improved soil productivity.

Sunflower agronomy: 10 years of research in partnership within the “Sunflower” Technological Joint Unit (UMT) in Toulouse

In order to make more efficient plant breeding and gain in competitiveness, the sector of oil-protein crops decided to intensify agronomic research on sunflower crop. The “Sunflower” Joint Technological Unit (Unité Mixte Technologique (UMT) “Tournesol”, in French) was launched in the Toulouse area in 2006, associating closely INRA and Terres Inovia. First focused on improving oil production through an agronomic approach, the UMT was renewed in 2011 with a broader partnership and a more assertive orientation towards the development of decision-making tools. The objective of this paper is to highlight the relevance and productivity of this user-oriented research facility. The main results relate to (i) the co-construction of a simulation model (SUNFLO) that can be parameterized and manipulated by Terres Inovia engineers, (ii) the joint exploration of supra-field scales and new methods for agronomic diagnosis and yield forecasting based on remote sensing, (iii) the tuning and dissemination of operational decision rules, (iv) the production of essential knowledge on emergent and/or damaging fungal diseases, as well as on complex interactions between genotype, environment and crop management. After a concluding symposium in 2016, new requests for sunflower research were formulated by the participants. They also advocated for a diversification of crops to consider in order to better meet the needs of the whole oil-protein sector.

Potentials of Enzyme Enhanced Oil Recovery: A Review

In this paper, the progresses of understanding of the enzymes application in hydrocarbon production from extensive experimental and field studies are reviewed. Enzyme enhanced oil recovery 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. From the comprehensive review carried out in this study, we observed that most of the works done on enzyme enhanced oil recovery 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 reservoir. Furthermore, the challenges and future research directions for enzyme enhanced oil recovery applications have been pinpointed in this study. Having unfold the enhanced oil recovery potential of enzyme, a clarion call is thereby made for deeper studies on this emerging method of improving oil production. This study is relevant to the design and application of enzyme enhanced oil recovery process in both carbonate and sandstone reservoirs.