In crude oil transportation, adhesion of oil on pipe wall can cause partial or total blockage of the pipe. This process is significantly affected by wall sticking occurrence temperature(WSOT). In this work, an efficie...In crude oil transportation, adhesion of oil on pipe wall can cause partial or total blockage of the pipe. This process is significantly affected by wall sticking occurrence temperature(WSOT). In this work, an efficient approach for estimating WSOT of high water-cut oil, which can agree well with the actual environment of multiphase transportation pipeline, is proposed. Based on the energy dissipation theory, it is possible to make comparison of average shear rates between the stirred vessel and the flow loop. The impacts of water content and shear rate on WSOT are investigated using the stirred vessel and the flow loop. Good agreement has been observed between the stirred vessel and the flow loop results with the maximum and the average absolute deviations equating to 3.30 °C and 2.18 °C, respectively. The development of gathering scheme can enjoy some benefits from this method.展开更多
In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil...In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil with high water fraction was studied in a flow experimental system of the X Oilfield.Four distinct flow patterns were identified by the photographic and local sampling techniques.Especially,three new flow patterns were found to occur below the pour point of crude oil,including EW/O&W stratified flow with gel deposition,EW/O&W intermittent flow with gel deposition,and water single-phase flow with gel deposition.Moreover,two characteristic temperatures,at which the change rate of pressure drop had changed obviously,were found during the change of pressure drop.The characteristic temperature of the first congestion of gel deposition in the pipeline was determined to be the safe temperature for the non-heating gathering and transportation of high water cut crude oil,while the pressure drop reached the peak at this temperature.An empirical formula for the safe temperature was established for oil-water flow with high water fraction/low fluid production rate.The results can serve as a guide for the safe operation of the non-heating gathering and transportation of crude oil in high water fraction oilfields.展开更多
In order to solve the problems related with processing low-quality Liaohe highly sour crude, the Liaohe Petrochemical Company has explored the possibility in optimizing the processing of highly sour crude by adopting ...In order to solve the problems related with processing low-quality Liaohe highly sour crude, the Liaohe Petrochemical Company has explored the possibility in optimizing the processing of highly sour crude by adopting different process schemes depending upon the properties of the highly sour crude. The Liaohe naphthenic-base crude oil with low freezing point is earmarked for manufacture of naphthenic lube oils and heavy traffic paving asphalt, while the extra-heavy Liaohe crude with high acid number is routed directly to delayed coking unit coupled with corresponding corrosion preventing measures, resulting in tackling the problem of equipment corrosion arising from refining of Liaohe highly sour crude to obtain light distillates from Liaohe heavy crude through a short process scheme.展开更多
Removal of water contained in extra-viscous crude oil is quite difficult because of the high viscosity and high resins content of heavy oil.The microwave technology was introduced for the separation of water from high...Removal of water contained in extra-viscous crude oil is quite difficult because of the high viscosity and high resins content of heavy oil.The microwave technology was introduced for the separation of water from high-viscosity crude oil in the presence of sodium acetate.The decrease in zeta-potential of interface and the viscosity of crude oil are responsible for the accelerated separation of water under microwave irradiation.The influences of the concentration of sodium acetate in sample,irradiation pressure,irradiation time and irradiation power on the separation efficiency were investigated.The optimum technological condition for the refining process was determined.Upon treating the sample 1 (with a water concentration of 50%),the water removal rate was 98.44%,when the optimum conditions were identified to be a sodium acetate concentration of 2%,an irradiation pressure of 0.1 MPa,an irradiation time of 2 min,and an irradiation power of 225 W,with the recovery of sodium acetate reaching 97.88%.Upon treating the sample 2 (the concentration of water was 20%),the water removal rate was 93.85%,when the optimum conditions were determined to be a sodium acetate concentration of 3%,an irradiation pressure of 0.1 MPa,an irradiation time of 4 min,and an irradiation power of 375 W,with the recovery of sodium acetate reaching 93.54%.By using this method,the dehydration efficiency was increased rapidly.展开更多
Experiments on surface-active polymer flooding for enhanced oil recovery were carried out by detection analysis and modern physical simulation technique based on reservoirs and fluids in Daqing placanticline oilfield....Experiments on surface-active polymer flooding for enhanced oil recovery were carried out by detection analysis and modern physical simulation technique based on reservoirs and fluids in Daqing placanticline oilfield.The experimental results show that the surface-active polymer is different from other common polymers and polymer-surfactant systems in molecular aggregation,viscosity and flow capacity,and it has larger molecular coil size,higher viscosity and viscosifying capacity,and poorer mobility.The surface-active polymer solution has good performance of viscosity-increasing and viscosity retention,and has good performance of viscoelasticity and deformability to exert positive effects of viscosifying and viscoelastic properties.Surface-active polymer can change the chemical property of interface and reduce interfacial tension,making the reservoir rock turn water-wet,also it can emulsify the oil into relatively stable oil-in-water emulsion,and emulsification capacity is an important property to enhance oil washing efficiency under non-ultralow interfacial tension.The surface-active polymer flooding enlarges swept volume in two ways:Microscopically,the surface-active polymer has mobility control effect and can enter oil-bearing pores not swept by water to drive residual oil,and its mobility control effect has more contribution than oil washing capacity in enhancing oil recovery.Macroscopically,it has plugging capacity,and can emulsify and plug the dominant channels in layers with high permeability,forcing the injected fluid to enter the layer with medium or low permeability and low flow resistance,and thus enlarging swept volume.展开更多
基金financially supported by the National Natural Science Foundation of China(NNSF,Grant No.51534007)。
文摘In crude oil transportation, adhesion of oil on pipe wall can cause partial or total blockage of the pipe. This process is significantly affected by wall sticking occurrence temperature(WSOT). In this work, an efficient approach for estimating WSOT of high water-cut oil, which can agree well with the actual environment of multiphase transportation pipeline, is proposed. Based on the energy dissipation theory, it is possible to make comparison of average shear rates between the stirred vessel and the flow loop. The impacts of water content and shear rate on WSOT are investigated using the stirred vessel and the flow loop. Good agreement has been observed between the stirred vessel and the flow loop results with the maximum and the average absolute deviations equating to 3.30 °C and 2.18 °C, respectively. The development of gathering scheme can enjoy some benefits from this method.
基金financially supported by the National Natural Science Foundation of China (Grant No.51674281)the Opening Fund of Shandong Provincial Key Laboratory of Oil&Gas Storage (Study on low temperature flow characteristics of oil and water in gathering pipeline)the Transportation Safety and the Fundamental Research Funds for the Central Universities
文摘In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil with high water fraction was studied in a flow experimental system of the X Oilfield.Four distinct flow patterns were identified by the photographic and local sampling techniques.Especially,three new flow patterns were found to occur below the pour point of crude oil,including EW/O&W stratified flow with gel deposition,EW/O&W intermittent flow with gel deposition,and water single-phase flow with gel deposition.Moreover,two characteristic temperatures,at which the change rate of pressure drop had changed obviously,were found during the change of pressure drop.The characteristic temperature of the first congestion of gel deposition in the pipeline was determined to be the safe temperature for the non-heating gathering and transportation of high water cut crude oil,while the pressure drop reached the peak at this temperature.An empirical formula for the safe temperature was established for oil-water flow with high water fraction/low fluid production rate.The results can serve as a guide for the safe operation of the non-heating gathering and transportation of crude oil in high water fraction oilfields.
文摘In order to solve the problems related with processing low-quality Liaohe highly sour crude, the Liaohe Petrochemical Company has explored the possibility in optimizing the processing of highly sour crude by adopting different process schemes depending upon the properties of the highly sour crude. The Liaohe naphthenic-base crude oil with low freezing point is earmarked for manufacture of naphthenic lube oils and heavy traffic paving asphalt, while the extra-heavy Liaohe crude with high acid number is routed directly to delayed coking unit coupled with corresponding corrosion preventing measures, resulting in tackling the problem of equipment corrosion arising from refining of Liaohe highly sour crude to obtain light distillates from Liaohe heavy crude through a short process scheme.
基金the financial support of Liaoning Province Education Department Project(2004D06)
文摘Removal of water contained in extra-viscous crude oil is quite difficult because of the high viscosity and high resins content of heavy oil.The microwave technology was introduced for the separation of water from high-viscosity crude oil in the presence of sodium acetate.The decrease in zeta-potential of interface and the viscosity of crude oil are responsible for the accelerated separation of water under microwave irradiation.The influences of the concentration of sodium acetate in sample,irradiation pressure,irradiation time and irradiation power on the separation efficiency were investigated.The optimum technological condition for the refining process was determined.Upon treating the sample 1 (with a water concentration of 50%),the water removal rate was 98.44%,when the optimum conditions were identified to be a sodium acetate concentration of 2%,an irradiation pressure of 0.1 MPa,an irradiation time of 2 min,and an irradiation power of 225 W,with the recovery of sodium acetate reaching 97.88%.Upon treating the sample 2 (the concentration of water was 20%),the water removal rate was 93.85%,when the optimum conditions were determined to be a sodium acetate concentration of 3%,an irradiation pressure of 0.1 MPa,an irradiation time of 4 min,and an irradiation power of 375 W,with the recovery of sodium acetate reaching 93.54%.By using this method,the dehydration efficiency was increased rapidly.
基金Supported by China National Science and Technology Major Project(2016ZX05010002-004 and 2016ZX05023005-001-003)China Postdoctoral Science Foundation(2019M651255)National Natural Science Foundation of China(51804078).
文摘Experiments on surface-active polymer flooding for enhanced oil recovery were carried out by detection analysis and modern physical simulation technique based on reservoirs and fluids in Daqing placanticline oilfield.The experimental results show that the surface-active polymer is different from other common polymers and polymer-surfactant systems in molecular aggregation,viscosity and flow capacity,and it has larger molecular coil size,higher viscosity and viscosifying capacity,and poorer mobility.The surface-active polymer solution has good performance of viscosity-increasing and viscosity retention,and has good performance of viscoelasticity and deformability to exert positive effects of viscosifying and viscoelastic properties.Surface-active polymer can change the chemical property of interface and reduce interfacial tension,making the reservoir rock turn water-wet,also it can emulsify the oil into relatively stable oil-in-water emulsion,and emulsification capacity is an important property to enhance oil washing efficiency under non-ultralow interfacial tension.The surface-active polymer flooding enlarges swept volume in two ways:Microscopically,the surface-active polymer has mobility control effect and can enter oil-bearing pores not swept by water to drive residual oil,and its mobility control effect has more contribution than oil washing capacity in enhancing oil recovery.Macroscopically,it has plugging capacity,and can emulsify and plug the dominant channels in layers with high permeability,forcing the injected fluid to enter the layer with medium or low permeability and low flow resistance,and thus enlarging swept volume.
