This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to wa...This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to water.The interest of this paper is to shed light on the thermomechanical and above all water effects of heavy fuel oil on a sample of silty clayey soil.To achieve this,we used heavy fuel oil added in different proportions to silty clayey soil,to make sample of bricks on which tests were carried out.At the end of the experimental tests carried out on materials made(bricks)with our soil sample,it appears that heavy fuel oil moderately reduces the mechanical resistance of bricks and slightly increases thermal diffusion through them.On the contrary,we note a very good water resistance of the bricks thanks to the heavy fuel oil,in particular their water absorption by capillarity.This confirms that the mixture of heavy fuel oil and a silty-clayey soil used as a coating makes it possible to prevent the infiltration of water into the walls of raw soil constructions.However,its use as a construction material does not guarantee very good mechanical resistance,and slightly increases thermal diffusion.展开更多
It is known that increasing the injection pressure reduces the breakup length and the droplet size.Adding pulses,on the other hand,helps to atomize the liquid into finer droplets,similar to airassisted injectors but w...It is known that increasing the injection pressure reduces the breakup length and the droplet size.Adding pulses,on the other hand,helps to atomize the liquid into finer droplets,similar to airassisted injectors but without altering the airtofuel concentration.To further reduce the droplet size and breakup length,a novel injector type,called''Pulsed PressureSwirl"(PPS),is introduced in this work,which is a combination of pressureswirl and ultrasonic pulsed injectors.A pressureswirl atomizer was designed and fabricated specifically for Mazut HFO(Heavy Fuel Oil).The droplet formation process and droplet size distribution have been studied experimentally(by shadowgraphy high speed imaging)and numerically(with the opensource VolumeofFluid code Gerris).Changing liquid injection pressure effect on the spray angle and film thickness has been quantified.These simulations have been used to study the primary breakup process and quantify the droplet size distributions,using different injection pulse frequencies and pressures.The numerical results have revealed that the new injector concept successfully produces finer droplets and results in a decrease in the breakup length,especially when applying high pulse frequencies,with no significant changes in the spray angle.展开更多
The Carboniferous volcanic reservoir in the Chepaizi Uplift became an exploration hot target in recent years for its substantial amount of oils discovered. However, most of the Carboniferous heavy oils were biodegrade...The Carboniferous volcanic reservoir in the Chepaizi Uplift became an exploration hot target in recent years for its substantial amount of oils discovered. However, most of the Carboniferous heavy oils were biodegraded to PM7 or higher with orders of magnitude variation in oil viscosities. Two oil groups (I and II) exactly corresponding to the western and eastern Chepaizi Uplift were distinguished according to their source diagnose. Furthermore, three oil families (II1, II2 and II3), with the biodegradation level of PM7, PM8–8+, PM9+, respectively, were classified based on molecular compositions and parameter-stripping method of strongly bioresistant parameters. Allowing for this extremely high biodegradation case, more biodegradation refractory compound class were added to establish a refined Manco scale to quantitatively evaluate the biodegradation extent. Refined Manco number (RMN2) positively correlated with the oil density, NSO contents, and absolute concentrations of diasteranes and gammacerane, negatively correlated with the absolute concentrations of diahopane, summed tricyclic terpanes and pentacyclic terpanes. This refined scale showed higher resolution than the PM one to differentiate the biodegradation extent of Carboniferous heavy oils from the Chepaizi Uplift, especially those with same PM values but different oil viscosities.展开更多
Liaohe super-heavy crude oil was separated into its components, namely saturates, aromatics, resins, and asphaltenes (SARA), by the group separation method. Several solvents were used to extract different forms of m...Liaohe super-heavy crude oil was separated into its components, namely saturates, aromatics, resins, and asphaltenes (SARA), by the group separation method. Several solvents were used to extract different forms of metallic elements from crude oil. The metallic elements, such as calcium, nickel, iron and manganese, in crude oil, SARA and extract samples were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results demonstrate that the contents of calcium, nickel, iron, and manganese gradually increase in saturates, aromatics, resins, and asphaltenes, suggesting that the abundance of the four metallic elements in asphaltenes is much higher than that in the other groups. For example, the content of calcium in asphaltenes reaches a maximum of 7,920 pg/g. Among the SARA components of Liaohe super-heavy crude oil, resins account for more than 50 wt%, suggesting that the total amount of the four metallic elements are higher in the resin component than in other components. The four metallic elements mainly exist in the form of organic metallic compounds in crude oil. Further analysis shows that calcium and manganese elements exist mainly as metal salts of petroleum acids, and the majority of the iron and all the nickel exist mainly as metalloporphyrin and non-metalloporphyrin compounds.展开更多
In this study, petroleum acids were extracted from the super-heavy oil of Liaohe oilfield, North-east China, by using acetic acid, and their structural components and properties were investigated by using FT-IR and MS...In this study, petroleum acids were extracted from the super-heavy oil of Liaohe oilfield, North-east China, by using acetic acid, and their structural components and properties were investigated by using FT-IR and MS. Moreover, the trace metal contents in the super-heavy oil sample before and after acetic acid treatment were also measured in this work. The results showed that naphthenic acids were the main component of petroleum acids in Liaohe super-heavy oil, and the content of naphthenic acids with double rings was higher than that of other naphthenic acids. It can be concluded that petroleum acids in Liaohe super-heavy oil mainly consist of naphthenic acids, with a carbon number of around 11–69 and containing one to six naphthenic rings and/or one to two aromatic rings, and mainly exists in form of metal salts of petroleum acid. The molecular weight of petroleum acids is in the range of 190–1000.展开更多
The air oxidation of super-heavy oil at low temperature was studied in laboratory and its influences on oil viscosity, component and steam sweep efficiency before and after air-injection were analyzed. The feasibility...The air oxidation of super-heavy oil at low temperature was studied in laboratory and its influences on oil viscosity, component and steam sweep efficiency before and after air-injection were analyzed. The feasibility, operation mode and air flooding effect at the late stage of steam assisted gravity drainage(SAGD) were investigated by numerical simulation. The experimental results show for vertical-horizontal well pair SAGD test area of Xing VI Formation in Block Du 84 of Liaohe Oilfield, the low temperature oxidation occurred between 150-250 ?C(steam chamber temperature), the oil viscosity increased greatly after low temperature oxidation, consequently, the oil displacement efficiency dropped sharply. Three development methods in the late stage of SAGD were simulated, i.e., steam + air low temperature oxidation, only air low temperature oxidation and only air high temperature oxidation. By comparing production dynamic curves and residual oil distribution etc., high temperature oxidation reduced the heat loss in late stage of SAGD, recovered the residual oil effectively, and prolonged reservoir development time.展开更多
Combustion of heavy fuels is one of the main sources of greenhouse gases, particulate emissions, ashes, NOxand SOx. Gasification is an advanced and environmentally friendly process that generates combustible and clean...Combustion of heavy fuels is one of the main sources of greenhouse gases, particulate emissions, ashes, NOxand SOx. Gasification is an advanced and environmentally friendly process that generates combustible and clean gas products such as hydrogen. Some entrained flow gasifiers operate with Heavy Fuel Oil(HFO) feedstock. In this application, HFO atomization is very important in determining the performance and efficiency of the gasifiers.The atomization characteristics of HFO(Mazut) discharging from a pressure-swirl atomizer(PSA) are studied for different pressures difference(Δp) and temperatures in the atmospheric ambient. The investigated parameters include atomizer mass flow rate( _m), discharge coefficient(CD), spray cone angle(θ), breakup length(Lb), the unstable wavelength of undulations on the liquid sheet(λs), global and local SMD(sauter mean diameter) and size distribution of droplets. The characteristics of Mazut sheet breakup are deduced from the shadowgraph technique. The experiments on Mazut film breakup were compared with the predictions obtained from the liquid film breakup model. Validity of the theory for predicting maximum unstable wavelength was investigated for HFO(as a highly viscous liquid). A modification on the formulation of maximum unstable wavelength was presented for HFO. SMD decreases by getting far from the atomizer. The measurement for SMD and θ were compared with the available correlations. The comparisons of the available correlations with the measurements of SMD andθ show a good agreement for Ballester and Varde correlations, respectively. The results show that the experimental sizing data could be presented by Rosin-Rammler distributions very well at different pressure difference and temperatures.展开更多
This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate: n-C10 to n-C15 were lost...This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate: n-C10 to n-C15 were lost gradually in 24 weeks and the relative abundance of alkanes with long chains (〉n-C19) increased markedly. The aromatic compounds with less than two tings (except C4N) were completely lost in 24 weeks and CnP and CnD became the main aromatics in the heavy fuel oil after 24 weeks. The ratios of n- C1/Pristane (Pr) and n-C18 Phytane (Ph) were suitable for identifying lightly weathered (3 weeks) heavy fuel oil. The ratios of n-ClT/n-C18 and Pr/Ph were suitable for identifying moderately weathered heavy fuel oil (12 weeks); the ratios of C2D/C2P and C3D/C3P did not change significantly in 24 weeks and were more suitable for identifying moderately weathered heavy fuel oil (24 weeks).展开更多
In this work,particulate matter(PM) emissions from a large two-stroke,low-speed marine diesel engine were investigated when the engine was operated with low-sulfur heavy fuel oil(HFO) at various loads.Particle samples...In this work,particulate matter(PM) emissions from a large two-stroke,low-speed marine diesel engine were investigated when the engine was operated with low-sulfur heavy fuel oil(HFO) at various loads.Particle samples were collected in situ from the engine exhaust to determine the detailed physical and chemical properties.The nanostructure and morphology of the nanoparticles were analyzed using transmission electron microscopy images(TEM).The results show that volatile organic carbon(OC) accounts for more than 80% in the HFO particles and leads to an increase in particle size.The thermodynamic conditions of a low-speed engine favor the behavior of capturing the soluble organic components.A large number of spherical char HFO particles with aerodynamic diameters of 0.2 μm-0.5 μm and a suspected inner metal core were detected.The two peak aerodynamic diameters of the HFO nanoparticles are 15 nm and 86 nm.The morphological differences among the HFO nanoparticles in varied engine conditions represent the formation process from primary nascent particles to mature graphitized particles caused by thermodynamics.The above study will be valuable for understanding the characteristics of PM emissions from low-sulfur HFO to achieve the ship PM emissions reduction target.展开更多
In water-lubricated pipeline transportation of heavy oil and bitumen, a thin oil film typically coats the pipe wall. A detailed study of the hydrodynamic effects of this fouling layer is critical to the design and ope...In water-lubricated pipeline transportation of heavy oil and bitumen, a thin oil film typically coats the pipe wall. A detailed study of the hydrodynamic effects of this fouling layer is critical to the design and operation of oil-water pipelines, as it can increase the pipeline pressure loss (and pumping power requirements) by 15 times or more. In this study, a parametric investigation of the hydrodynamic effects caused by the wall coating of viscous oil was conducted. A custom-built rectangular flow cell was used. A validated CFD-based procedure was used to determine the hydrodynamic roughness from the measured pressure losses. A similar procedure was followed for a set of pipe loop tests. The effects of the thickness of the oil coating layer, the oil viscosity, and water flow rate on the hydrodynamic roughness were evaluated. Oil viscosities from 3 to 21300 Pa s were tested. The results show that the equivalent hydrodynamic roughness produced by a wall coating layer of viscous oil is dependent on the coating thickness but essentially independent of oil viscosity. A new correlation was developed using these data to predict the hydrodynamic roughness for flow conditions in which a viscous oil coating is produced on the pipe wall.展开更多
The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to ...The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to measure diffusion coefficients of natural gas in Venezuela foamy oil at high pressures, and a new method for deter- mining the diffusion coefficient in the foamy oil was de- veloped on the basis of experimental data. The effects of pressure and the types of the liquid phase on the diffusion coefficient of the natural gas were discussed. The results indicate that the diffusion coefficients of natural gas in foamy oil, saturated oil, and dead oil increase linearly with increasing pressure. The diffusion coefficient of natural gas in the foamy oil at 20 MPa was 2.93 times larger than that at 8.65 MPa. The diffusion coefficient of the natural gas in dead oil was 3.02 and 4.02 times than that of the natural gas in saturated oil and foamy oil when the pressure was 20 MPa. However, the gas content of foamy oil was 16.9 times higher than that of dead oil when the dissolution time and pressure were 20 MPa and 35.22 h, respectively.展开更多
文摘This study focuses on the use of heavy fuel oil in construction in Burkina Faso.Mixed with silty and/or clay soil,it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to water.The interest of this paper is to shed light on the thermomechanical and above all water effects of heavy fuel oil on a sample of silty clayey soil.To achieve this,we used heavy fuel oil added in different proportions to silty clayey soil,to make sample of bricks on which tests were carried out.At the end of the experimental tests carried out on materials made(bricks)with our soil sample,it appears that heavy fuel oil moderately reduces the mechanical resistance of bricks and slightly increases thermal diffusion through them.On the contrary,we note a very good water resistance of the bricks thanks to the heavy fuel oil,in particular their water absorption by capillarity.This confirms that the mixture of heavy fuel oil and a silty-clayey soil used as a coating makes it possible to prevent the infiltration of water into the walls of raw soil constructions.However,its use as a construction material does not guarantee very good mechanical resistance,and slightly increases thermal diffusion.
文摘It is known that increasing the injection pressure reduces the breakup length and the droplet size.Adding pulses,on the other hand,helps to atomize the liquid into finer droplets,similar to airassisted injectors but without altering the airtofuel concentration.To further reduce the droplet size and breakup length,a novel injector type,called''Pulsed PressureSwirl"(PPS),is introduced in this work,which is a combination of pressureswirl and ultrasonic pulsed injectors.A pressureswirl atomizer was designed and fabricated specifically for Mazut HFO(Heavy Fuel Oil).The droplet formation process and droplet size distribution have been studied experimentally(by shadowgraphy high speed imaging)and numerically(with the opensource VolumeofFluid code Gerris).Changing liquid injection pressure effect on the spray angle and film thickness has been quantified.These simulations have been used to study the primary breakup process and quantify the droplet size distributions,using different injection pulse frequencies and pressures.The numerical results have revealed that the new injector concept successfully produces finer droplets and results in a decrease in the breakup length,especially when applying high pulse frequencies,with no significant changes in the spray angle.
基金This work was funded by the National Natural Science Foundation of China(Grant No.42072172,41772120)the Shandong Province Natural Science Fund for Distinguished Young Scholars(Grant No.JQ201311)+1 种基金the SDUST Research Fund(Grant No.2015TDJH101)Associated editor Jie Hao and seven anonymous reviewers were deeply acknowledged for their critical comments and helpful suggestions,which greatly improved the early version of this manuscript.
文摘The Carboniferous volcanic reservoir in the Chepaizi Uplift became an exploration hot target in recent years for its substantial amount of oils discovered. However, most of the Carboniferous heavy oils were biodegraded to PM7 or higher with orders of magnitude variation in oil viscosities. Two oil groups (I and II) exactly corresponding to the western and eastern Chepaizi Uplift were distinguished according to their source diagnose. Furthermore, three oil families (II1, II2 and II3), with the biodegradation level of PM7, PM8–8+, PM9+, respectively, were classified based on molecular compositions and parameter-stripping method of strongly bioresistant parameters. Allowing for this extremely high biodegradation case, more biodegradation refractory compound class were added to establish a refined Manco scale to quantitatively evaluate the biodegradation extent. Refined Manco number (RMN2) positively correlated with the oil density, NSO contents, and absolute concentrations of diasteranes and gammacerane, negatively correlated with the absolute concentrations of diahopane, summed tricyclic terpanes and pentacyclic terpanes. This refined scale showed higher resolution than the PM one to differentiate the biodegradation extent of Carboniferous heavy oils from the Chepaizi Uplift, especially those with same PM values but different oil viscosities.
基金supported by the National Natural Science Foundation of China (No. 20576075 and 21206194)
文摘Liaohe super-heavy crude oil was separated into its components, namely saturates, aromatics, resins, and asphaltenes (SARA), by the group separation method. Several solvents were used to extract different forms of metallic elements from crude oil. The metallic elements, such as calcium, nickel, iron and manganese, in crude oil, SARA and extract samples were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results demonstrate that the contents of calcium, nickel, iron, and manganese gradually increase in saturates, aromatics, resins, and asphaltenes, suggesting that the abundance of the four metallic elements in asphaltenes is much higher than that in the other groups. For example, the content of calcium in asphaltenes reaches a maximum of 7,920 pg/g. Among the SARA components of Liaohe super-heavy crude oil, resins account for more than 50 wt%, suggesting that the total amount of the four metallic elements are higher in the resin component than in other components. The four metallic elements mainly exist in the form of organic metallic compounds in crude oil. Further analysis shows that calcium and manganese elements exist mainly as metal salts of petroleum acids, and the majority of the iron and all the nickel exist mainly as metalloporphyrin and non-metalloporphyrin compounds.
基金the National Natural Science Foundation of China (Grant No. 20576075)
文摘In this study, petroleum acids were extracted from the super-heavy oil of Liaohe oilfield, North-east China, by using acetic acid, and their structural components and properties were investigated by using FT-IR and MS. Moreover, the trace metal contents in the super-heavy oil sample before and after acetic acid treatment were also measured in this work. The results showed that naphthenic acids were the main component of petroleum acids in Liaohe super-heavy oil, and the content of naphthenic acids with double rings was higher than that of other naphthenic acids. It can be concluded that petroleum acids in Liaohe super-heavy oil mainly consist of naphthenic acids, with a carbon number of around 11–69 and containing one to six naphthenic rings and/or one to two aromatic rings, and mainly exists in form of metal salts of petroleum acid. The molecular weight of petroleum acids is in the range of 190–1000.
基金Supported by the China National Oil and Gas Major Project(2016ZX05012-002)
文摘The air oxidation of super-heavy oil at low temperature was studied in laboratory and its influences on oil viscosity, component and steam sweep efficiency before and after air-injection were analyzed. The feasibility, operation mode and air flooding effect at the late stage of steam assisted gravity drainage(SAGD) were investigated by numerical simulation. The experimental results show for vertical-horizontal well pair SAGD test area of Xing VI Formation in Block Du 84 of Liaohe Oilfield, the low temperature oxidation occurred between 150-250 ?C(steam chamber temperature), the oil viscosity increased greatly after low temperature oxidation, consequently, the oil displacement efficiency dropped sharply. Three development methods in the late stage of SAGD were simulated, i.e., steam + air low temperature oxidation, only air low temperature oxidation and only air high temperature oxidation. By comparing production dynamic curves and residual oil distribution etc., high temperature oxidation reduced the heat loss in late stage of SAGD, recovered the residual oil effectively, and prolonged reservoir development time.
文摘Combustion of heavy fuels is one of the main sources of greenhouse gases, particulate emissions, ashes, NOxand SOx. Gasification is an advanced and environmentally friendly process that generates combustible and clean gas products such as hydrogen. Some entrained flow gasifiers operate with Heavy Fuel Oil(HFO) feedstock. In this application, HFO atomization is very important in determining the performance and efficiency of the gasifiers.The atomization characteristics of HFO(Mazut) discharging from a pressure-swirl atomizer(PSA) are studied for different pressures difference(Δp) and temperatures in the atmospheric ambient. The investigated parameters include atomizer mass flow rate( _m), discharge coefficient(CD), spray cone angle(θ), breakup length(Lb), the unstable wavelength of undulations on the liquid sheet(λs), global and local SMD(sauter mean diameter) and size distribution of droplets. The characteristics of Mazut sheet breakup are deduced from the shadowgraph technique. The experiments on Mazut film breakup were compared with the predictions obtained from the liquid film breakup model. Validity of the theory for predicting maximum unstable wavelength was investigated for HFO(as a highly viscous liquid). A modification on the formulation of maximum unstable wavelength was presented for HFO. SMD decreases by getting far from the atomizer. The measurement for SMD and θ were compared with the available correlations. The comparisons of the available correlations with the measurements of SMD andθ show a good agreement for Ballester and Varde correlations, respectively. The results show that the experimental sizing data could be presented by Rosin-Rammler distributions very well at different pressure difference and temperatures.
文摘This paper presents the experimental results of composition changes of heavy fuel oil by stmulating weathering in static seawater under natural environmental conditions. The results indicate: n-C10 to n-C15 were lost gradually in 24 weeks and the relative abundance of alkanes with long chains (〉n-C19) increased markedly. The aromatic compounds with less than two tings (except C4N) were completely lost in 24 weeks and CnP and CnD became the main aromatics in the heavy fuel oil after 24 weeks. The ratios of n- C1/Pristane (Pr) and n-C18 Phytane (Ph) were suitable for identifying lightly weathered (3 weeks) heavy fuel oil. The ratios of n-ClT/n-C18 and Pr/Ph were suitable for identifying moderately weathered heavy fuel oil (12 weeks); the ratios of C2D/C2P and C3D/C3P did not change significantly in 24 weeks and were more suitable for identifying moderately weathered heavy fuel oil (24 weeks).
基金supported by the Science & Technology Commission of Shanghai MunicipalityShanghai Engineering Research Center of Ship Intelligent Maintenance and Energy Efficiency under Grant 20DZ2252300。
文摘In this work,particulate matter(PM) emissions from a large two-stroke,low-speed marine diesel engine were investigated when the engine was operated with low-sulfur heavy fuel oil(HFO) at various loads.Particle samples were collected in situ from the engine exhaust to determine the detailed physical and chemical properties.The nanostructure and morphology of the nanoparticles were analyzed using transmission electron microscopy images(TEM).The results show that volatile organic carbon(OC) accounts for more than 80% in the HFO particles and leads to an increase in particle size.The thermodynamic conditions of a low-speed engine favor the behavior of capturing the soluble organic components.A large number of spherical char HFO particles with aerodynamic diameters of 0.2 μm-0.5 μm and a suspected inner metal core were detected.The two peak aerodynamic diameters of the HFO nanoparticles are 15 nm and 86 nm.The morphological differences among the HFO nanoparticles in varied engine conditions represent the formation process from primary nascent particles to mature graphitized particles caused by thermodynamics.The above study will be valuable for understanding the characteristics of PM emissions from low-sulfur HFO to achieve the ship PM emissions reduction target.
基金support of the NSERC Industrial Research Chair in Pipeline Transport Processes (held by RS Sanders)Canada’s Natural Sciences and Engineering Research Council (NSERC)the Industrial Sponsors (Canadian Natural Resources Limited, Fort Hills LLP, Nexen Inc., Saskatchewan Research Council Pipe Flow Technology CentreTM, Shell Canada Energy, Syncrude Canada Ltd., Total E&P Canada Ltd., Teck Resources Ltd. and Paterson & Cooke Consulting Engineers Ltd.)
文摘In water-lubricated pipeline transportation of heavy oil and bitumen, a thin oil film typically coats the pipe wall. A detailed study of the hydrodynamic effects of this fouling layer is critical to the design and operation of oil-water pipelines, as it can increase the pipeline pressure loss (and pumping power requirements) by 15 times or more. In this study, a parametric investigation of the hydrodynamic effects caused by the wall coating of viscous oil was conducted. A custom-built rectangular flow cell was used. A validated CFD-based procedure was used to determine the hydrodynamic roughness from the measured pressure losses. A similar procedure was followed for a set of pipe loop tests. The effects of the thickness of the oil coating layer, the oil viscosity, and water flow rate on the hydrodynamic roughness were evaluated. Oil viscosities from 3 to 21300 Pa s were tested. The results show that the equivalent hydrodynamic roughness produced by a wall coating layer of viscous oil is dependent on the coating thickness but essentially independent of oil viscosity. A new correlation was developed using these data to predict the hydrodynamic roughness for flow conditions in which a viscous oil coating is produced on the pipe wall.
基金financial support from the Major Subject of National Science and Technology (2011ZX05032-001)the Fundamental Research Funds for the Central Universities(NO.11CX06022A)
文摘The diffusion coefficient of natural gas in foamy oil is one of the key parameters to evaluate the feasibility of gas injection for enhanced oil recovery in foamy oil reservoirs. In this paper, a PVT cell was used to measure diffusion coefficients of natural gas in Venezuela foamy oil at high pressures, and a new method for deter- mining the diffusion coefficient in the foamy oil was de- veloped on the basis of experimental data. The effects of pressure and the types of the liquid phase on the diffusion coefficient of the natural gas were discussed. The results indicate that the diffusion coefficients of natural gas in foamy oil, saturated oil, and dead oil increase linearly with increasing pressure. The diffusion coefficient of natural gas in the foamy oil at 20 MPa was 2.93 times larger than that at 8.65 MPa. The diffusion coefficient of the natural gas in dead oil was 3.02 and 4.02 times than that of the natural gas in saturated oil and foamy oil when the pressure was 20 MPa. However, the gas content of foamy oil was 16.9 times higher than that of dead oil when the dissolution time and pressure were 20 MPa and 35.22 h, respectively.