Laboratory Studies to Determine Suitable Chemicals to Improve Oil Recovery from Garzan Oil Field (original) (raw)
Related papers
Journal of Engineering and Technological Sciences, 2015
Water injection has been employed in the Tempino oil field since 1996. The current oil recovery factor is 35% of OOIP. Even though the pressure is still high, the oil production rate has declined rapidly and the water cut is approaching 89%. In order to mobilize the oil from the reservoir more effectively, surfactant flooding is one of the solutions that can reduce residual oil saturation. Interaction between crude oil and compatible surfactant generates microemulsion, as an indication of low interfacial tension. Hence the oil is expected to move out of the pore throat easily. In this research, thirty types of surfactants were evaluated. The hydrophilic lipophilic balance (HLB) was calculated and the interfacial tension (IFT) with the reservoir fluid was measured. HLB criteria were established as an indicator of low IFT, which was then tested for Berea core flooding. The results indicate that an HLB between approximately 2.7 and 3.1 (on Davies' Scale) or greater than 11.5 (on Griffin's Scale) gives low IFT (~10 -3 dynes/cm). This characteristic is possesed by surfactant ethoxy carboxylate with a linear hydrophobic structure. This surfactant produces a high incremental oil recovery according to Berea core flood tests. The AN2NS and AN3 surfactants recovered 90% and 86% of OOIP respectively.
Journal of Petroleum Exploration and Production Technology
The paper focuses on the behaviour of nonionic surfactants (NISs) for enhanced oil recovery (EOR) processes with special reference to its applicability in the reservoirs of Upper Assam. The present work specifically studies three NISs, viz. Tergitol 15-s-7(Tg7), Tergitol 15-s-9 (Tg9) and Triton X 405(TX), based on their surface tension (ST), dynamic interfacial tension, hydrophilic-lipophilic balance, emulsion stability, aqueous stability, particle size analysis and phase behaviour. Simultaneously, crude oil from an oil field of upper Assam Basin was characterized based on API gravity, kinematic and dynamic viscosities, pour point and acid number. Core flood studies were conducted in the reservoir core to determine the recovery of crude oil during secondary water flood and EOR by NISs. It was observed that Tergitol 15-S-7 when mixed with Triton X-405 (Tg7TX) had the least interfacial tension (IFT) as compared to individual NIS and their mixtures. The recovery was found to be as high as 25.67% after secondary water flood from the original oil in place when Tg7TX followed by chase water was used as an exotic fluid for EOR. This work is an attempt to identify NISs mixtures for EOR for Upper Assam Basin.
Review of Surfactant Enhanced Oil Recovery in Carbonate Reservoirs
Advances in Petroleum Exploration and Development, 2013
About half of proven conventional oil reserves are in carbonate reservoirs. Due to complex structures, formation heterogeneities and oil-wet/mixed wet conditions, etc., the oil recovery factor in carbonate reservoirs is very low. There is increasing interest in improve oil recovery using surfactants, as the surfactant EOR has the potential after other EOR methods have been tried. This paper reviews the models of wettability alteration using surfactants and upscaling models related to oil recovery in carbonate reservoirs. Chemicals used in carbonate reservoirs are reviewed. The field cases where surfactants were used to stimulate oil recovery are analyzed.
Petroleum Science, 2011
Reservoir wettability plays an important role in various oil recovery processes. The origin and evolution of reservoir wettability were critically reviewed to better understand the complexity of wettability due to interactions in crude oil-brine-rock system, with introduction of different wetting states and their infl uence on fl uid distribution in pore spaces. The effect of wettability on oil recovery of waterflooding was then summarized from past and recent research to emphasize the importance of wettability in oil displacement by brine. The mechanism of wettability alteration by different surfactants in both carbonate and sandstone reservoirs was analyzed, concerning their distinct surface chemistry, and different interaction patterns of surfactants with components on rock surface. Other concerns such as the combined effect of wettability alteration and interfacial tension (IFT) reduction on the imbibition process was also taken into account. Generally, surfactant induced wettability alteration for enhanced oil recovery is still in the stage of laboratory investigation. The successful application of this technique relies on a comprehensive survey of target reservoir conditions, and could be expected especially in low permeability fractured reservoirs and forced imbibition process.
Laboratory study of salinity and surfactant concentration effects on oil recovery
MATEC Web of Conferences, 2017
This paper perfoms a discussion of the result from two laboratory tests of surfactant injection. The first test is focused on the influence of salinity that varies between 5000 ppm-9000 ppm with a concentration of 1% surfactant to the value of density, viscosity, interfacial tension, and Recovery Factor. The second test is performing the influence of surfactant concentration that varies between 0.1%-1% with a value of 5000 ppm salinity to the value of residual oil saturation, density, viscosity, and interfacial tension. The result of the first test shows that along with the increase of salinity levels, the increase in viscosity and density will occured as well. However, variations in salinity does not affect to the value of interfacial tension. Meanwhile, on Recovery Factor testing, the Recovery Factor optimal value of 61.53% was obtained when the salinity levels 6,000 ppm. The result of the second test showed that the addition of surfactant concentration lead to a decrease in the residual oil saturation and interfacial tension, but it may cause an increase in density and viscosity.
Evaluation of the Impacts of using Single and Combined Low Cost Surfactants on Enhanced Oil Recovery
2020
Due to the high cost of most surfactants used in the oilfield enhanced oil recovery, this study was conducted to evaluate the impacts of using single and combined low cost surfactants (Teepol and Tween 80). In the study oil and water wet porous media were subjected to water flooding followed by surfactants. Water flooding operations yielded an average recovery factor of 46.42 % and 52.59 % and an average displacement efficiency of 49.3% and 55.2 % for oil wet and water wet systems respectively. After water flooding operations and subsequent surfactant flooding with Teepol (anionic surfactant), a recovery factor of 64.69% and 73.52 % and a displacement efficiency of 69.33% and 72.82% were obtained for oil wet and water wet systems respectively. The water flooding and the subsequent surfactant flooding operations with Tween 80 (nonionic surfactant) resulted to the displacement efficiencies and recovery factors of 73.27% and 76.89% and 67.60% and 77.33% for the oil wet and water wet sy...