The main advantages of the use of ionic liquids in enhanced oil recovery are their tunability and stability in harsh environmental conditions. In this work, a comprehensive review of ionic liquids proposed to improve ...The main advantages of the use of ionic liquids in enhanced oil recovery are their tunability and stability in harsh environmental conditions. In this work, a comprehensive review of ionic liquids proposed to improve current chemical oil recovery methods has been presented, focusing on core flooding experiments. With an almost infinite number of possible ionic liquids, the amount of experiments carried out up to now has been very limited. However, results are promising, with additional recovery after secondary flooding of up to 32% of the original oil in place. Most formulations with ionic liquids have been proposed for sandstone reservoirs, the number of studies with carbonate cores being very scarce. The possibilities of a new room temperature surface active ionic liquid, 1-decyl-3-methylimidazolium triflate,for this application were analyzed. It was shown that it is able to drastically reduce the water/oil interfacial tension. An optimized formulation was proposed for carbonate reservoirs. After secondary flooding with brine, an additional recovery of 10.5% of original oil in place was achieved at room conditions. A combination of the proposed method followed by a polymer flooding step with polyacrylamide led to a lesser but still significant recovery, reducing the costs associated to the ionic liquid.展开更多
A common assertion is that alkaline solution aids oil mobilization by generating in situ soap,or by lowering interfacial tension(IFT)to ultra-low values in synergy with surfactants.This study takes a different approac...A common assertion is that alkaline solution aids oil mobilization by generating in situ soap,or by lowering interfacial tension(IFT)to ultra-low values in synergy with surfactants.This study takes a different approach that involves the alkaline dissolution of detrital quartz grains of sandstone reservoirs to create pathways for oil migration and accumulation.Quartz dissolution via alkaline injection will result in changes in permeability and porosity.This study performed high-pH core flooding on Berea sandstones using core displacement equipment.Silica molybdate spectrophotometry was applied to measure the amount of dissolved silica.Inlet and confining pressure variations were also observed.The molar concentration of NaOH varied at 0.5 M and 1.0 M.The results show higher initial silica dissolution for 0.5 M NaOH(˃200mg/L)compared to 1.0 M NaOH(20 mg/L),which can be attributed to the presence of pre-existing dissolved silica and precipitates in the system prior to the first injection phase.Nonetheless,a steady quartz dissolution rate of 0.4 mg/L/hr for 20 h was only achieved at 1.0 M.Conversely,an abrupt drop in quartz dissolution to below 0 mg/L was recorded for 0.5 M NaOH after 3 h of dissolution.At higher molar concentration of injected alkaline solution,both confining and inlet pressures increased from 8 and 5 bars to 12 and 11 bars as a result of the increased secondary phase of(hydr)oxides or precipitates in the pores.Thus,it can be inferred that the effect of alkaline solution on quartz dissolution is strongly dependent on molar concentration.展开更多
Different methods of enhanced oil recovery have been used to produce trapped oil.One of these methods is carbonated water injection in which CO2 contained water is injected in reservoirs in order to decrease free CO2 ...Different methods of enhanced oil recovery have been used to produce trapped oil.One of these methods is carbonated water injection in which CO2 contained water is injected in reservoirs in order to decrease free CO2 injection mobility,increase water viscosity and store/remove produced greenhouse CO2 gas safely.Another enhanced oil recovery method is smart water injection at which the ions in brine are modified in order to make controlled reactions with distributed ions on the surface of rock to cause more hydrocarbon recovery.Therefore,combination of these two methods may also have a great effect on enhancing oil recovery or may result in recovery factor less than each method used alone.In this paper hybrid smart carbonated water injection method is investigated to study its applicability in oil recovery using core flooding setup.The experimental core flooding setup was designed to perform different types of EOR methods for the sake of recovery comparison with the new hybrid method.The effect of both brine content and volume of CO2 is determining in hybrid EOR assessment.The main findings of this work show that the hybrid smart carbonated water results in the highest recovery factor in comparison to the most well-known EOR methods for carbonate cores.展开更多
Matrix acidizing is usually conducted on sandstone reservoirs to increase hydrocarbon production.Mineralogy plays an important role in designing acidizing treatments to enhance the production of oil and gas from sands...Matrix acidizing is usually conducted on sandstone reservoirs to increase hydrocarbon production.Mineralogy plays an important role in designing acidizing treatments to enhance the production of oil and gas from sandstone reservoirs.The most common acid in practice to acidize sandstone formation is mud acid after the pre-flush acid stage.The main aim of the pre-flush acid stage is to dissolve positive ions like calcium,potassium,sodium,etc,which can cause precipitation reactions during the mud acid stage.This research is aimed to investigate the reaction mechanism of a new pre-flush acid combination(hydrochloric acid and acetic acid)with sandstone formation.Core flooding experiments were performed to react acid with the core samples(6 in×1.5 in)under high pressure and temperature(HPHT)condi-tions(80℃and 1000 psia).Analytical techniques such as Tescan Integrated Mineral Analysis(TIMA)have been used to illustrate the effect of these acids on sandstone formation.TIMA analysis showed that the new acid combination was effective in dissolving various minerals(ankerite,magnetite)and cations(calcium,magnesium,sodium,and iron).15%HCl proved to be more effective in the dissolution of different particles from sandstone core samples.It dissolved 32.8%of the initial number of particles present inside the sample while the dissolving power of 5%CH_(3)COOH:10%HCl is 26.7%.Subsequently,the number of pores increased by the application of 15%HCl is 22%while that by 5%CH_(3)COOH:10%HCl is 21.8%.Density analysis showed that both acid combinations removed heavy particles effectively,whereas 5%CH_(3)COOH:10%HCl proved more efficient in dissolving calcium ions which is very important for pre-flush acidizing.展开更多
基金the Ministry of Science and Innovation and State Research Agency for financial support throughout project PGC2018-097342-B-I00, including European Regional Development Fund。
文摘The main advantages of the use of ionic liquids in enhanced oil recovery are their tunability and stability in harsh environmental conditions. In this work, a comprehensive review of ionic liquids proposed to improve current chemical oil recovery methods has been presented, focusing on core flooding experiments. With an almost infinite number of possible ionic liquids, the amount of experiments carried out up to now has been very limited. However, results are promising, with additional recovery after secondary flooding of up to 32% of the original oil in place. Most formulations with ionic liquids have been proposed for sandstone reservoirs, the number of studies with carbonate cores being very scarce. The possibilities of a new room temperature surface active ionic liquid, 1-decyl-3-methylimidazolium triflate,for this application were analyzed. It was shown that it is able to drastically reduce the water/oil interfacial tension. An optimized formulation was proposed for carbonate reservoirs. After secondary flooding with brine, an additional recovery of 10.5% of original oil in place was achieved at room conditions. A combination of the proposed method followed by a polymer flooding step with polyacrylamide led to a lesser but still significant recovery, reducing the costs associated to the ionic liquid.
基金Norhana Yahya for facilitating the research under the Alpha Matrix research group,UTP(Cost Centre:015LC0-149).
文摘A common assertion is that alkaline solution aids oil mobilization by generating in situ soap,or by lowering interfacial tension(IFT)to ultra-low values in synergy with surfactants.This study takes a different approach that involves the alkaline dissolution of detrital quartz grains of sandstone reservoirs to create pathways for oil migration and accumulation.Quartz dissolution via alkaline injection will result in changes in permeability and porosity.This study performed high-pH core flooding on Berea sandstones using core displacement equipment.Silica molybdate spectrophotometry was applied to measure the amount of dissolved silica.Inlet and confining pressure variations were also observed.The molar concentration of NaOH varied at 0.5 M and 1.0 M.The results show higher initial silica dissolution for 0.5 M NaOH(˃200mg/L)compared to 1.0 M NaOH(20 mg/L),which can be attributed to the presence of pre-existing dissolved silica and precipitates in the system prior to the first injection phase.Nonetheless,a steady quartz dissolution rate of 0.4 mg/L/hr for 20 h was only achieved at 1.0 M.Conversely,an abrupt drop in quartz dissolution to below 0 mg/L was recorded for 0.5 M NaOH after 3 h of dissolution.At higher molar concentration of injected alkaline solution,both confining and inlet pressures increased from 8 and 5 bars to 12 and 11 bars as a result of the increased secondary phase of(hydr)oxides or precipitates in the pores.Thus,it can be inferred that the effect of alkaline solution on quartz dissolution is strongly dependent on molar concentration.
文摘Different methods of enhanced oil recovery have been used to produce trapped oil.One of these methods is carbonated water injection in which CO2 contained water is injected in reservoirs in order to decrease free CO2 injection mobility,increase water viscosity and store/remove produced greenhouse CO2 gas safely.Another enhanced oil recovery method is smart water injection at which the ions in brine are modified in order to make controlled reactions with distributed ions on the surface of rock to cause more hydrocarbon recovery.Therefore,combination of these two methods may also have a great effect on enhancing oil recovery or may result in recovery factor less than each method used alone.In this paper hybrid smart carbonated water injection method is investigated to study its applicability in oil recovery using core flooding setup.The experimental core flooding setup was designed to perform different types of EOR methods for the sake of recovery comparison with the new hybrid method.The effect of both brine content and volume of CO2 is determining in hybrid EOR assessment.The main findings of this work show that the hybrid smart carbonated water results in the highest recovery factor in comparison to the most well-known EOR methods for carbonate cores.
文摘Matrix acidizing is usually conducted on sandstone reservoirs to increase hydrocarbon production.Mineralogy plays an important role in designing acidizing treatments to enhance the production of oil and gas from sandstone reservoirs.The most common acid in practice to acidize sandstone formation is mud acid after the pre-flush acid stage.The main aim of the pre-flush acid stage is to dissolve positive ions like calcium,potassium,sodium,etc,which can cause precipitation reactions during the mud acid stage.This research is aimed to investigate the reaction mechanism of a new pre-flush acid combination(hydrochloric acid and acetic acid)with sandstone formation.Core flooding experiments were performed to react acid with the core samples(6 in×1.5 in)under high pressure and temperature(HPHT)condi-tions(80℃and 1000 psia).Analytical techniques such as Tescan Integrated Mineral Analysis(TIMA)have been used to illustrate the effect of these acids on sandstone formation.TIMA analysis showed that the new acid combination was effective in dissolving various minerals(ankerite,magnetite)and cations(calcium,magnesium,sodium,and iron).15%HCl proved to be more effective in the dissolution of different particles from sandstone core samples.It dissolved 32.8%of the initial number of particles present inside the sample while the dissolving power of 5%CH_(3)COOH:10%HCl is 26.7%.Subsequently,the number of pores increased by the application of 15%HCl is 22%while that by 5%CH_(3)COOH:10%HCl is 21.8%.Density analysis showed that both acid combinations removed heavy particles effectively,whereas 5%CH_(3)COOH:10%HCl proved more efficient in dissolving calcium ions which is very important for pre-flush acidizing.
