Enhanced oil recovery(EOR)by means of polymer flooding is an important technology for the strategic development of offshore oilfields in China.Hydrophobically associating polyacrylamide(HAPAM)has been recently propose...Enhanced oil recovery(EOR)by means of polymer flooding is an important technology for the strategic development of offshore oilfields in China.Hydrophobically associating polyacrylamide(HAPAM)has been recently proposed as a new flooding agent.The solubility of HAPAM is low,which is the bottleneck for further improving the oil recovery through polymer flooding in offshore oilfield.Stirred tanks have been used on offshore platforms to enhance HAPAM dissolving.But there is little literature on the study of HAPAM dissolving characteristics in stirred tanks.In this paper,effects of temperature,salinity,stirring speed,impeller type and stirring method on the dissolution of HAPAM are reported.The experimental results manifest that the dissolving rate of HAPAM increases with temperature and stirring speed,but the viscosity of the polymer solution decreases.There is an optimal range of salinity for polymer dissolving.Combining the operation mode of up-pumping with varying stirring speed,hydrofoil impeller can accelerate the dissolution of HAPAM and maintain a high solution viscosity.展开更多
In the middle of the last century,American scientists put forward the concept of capillary number and obtained the relation curve between capillary number and residual oil through experiments.They revealed that the co...In the middle of the last century,American scientists put forward the concept of capillary number and obtained the relation curve between capillary number and residual oil through experiments.They revealed that the corresponding residual oil saturation decreased with increasing of capillary number;after capillary number reached up to a limit,residual oil saturation would become stable and did not decrease.These important achievements laid a theoretical base for enhanced oil recovery with chemical flooding.On the basis of the theory,scholars developed chemical flooding numerical simulation software UTCHEM.During the numerical simulation study of combination flooding,the authors found that as the capillary number is higher than the limit capillary number,the changes of the residual oil saturation along with the capillary number differ from the classical capillary number curve.Oil displacement experiments prove that there are defects in classic capillary number experimental curve and it is necessary to mend and improve.Capillary number‘calculation’curve is obtained with a method of numerical simulation calculation and a complete description of capillary number curve is provided;On this basis,combination flooding capillary number experimental curve QL is obtained through experiments,which is different from the classical capillary curve;and based on which,an expression of corresponding combination flooding relative permeability curve QL is given and the corresponding relative permeability parameters are determined with experiments.Further oil displacement experiment research recognizes the cause of the singular changes of the capillary number curve."Combination flooding capillary number experimental curve QL"and"combination flooding relative permeability curve QL"are written in combination flooding software IMCFS,providing an effective technical support for the application of combination flooding technical research.展开更多
文摘Enhanced oil recovery(EOR)by means of polymer flooding is an important technology for the strategic development of offshore oilfields in China.Hydrophobically associating polyacrylamide(HAPAM)has been recently proposed as a new flooding agent.The solubility of HAPAM is low,which is the bottleneck for further improving the oil recovery through polymer flooding in offshore oilfield.Stirred tanks have been used on offshore platforms to enhance HAPAM dissolving.But there is little literature on the study of HAPAM dissolving characteristics in stirred tanks.In this paper,effects of temperature,salinity,stirring speed,impeller type and stirring method on the dissolution of HAPAM are reported.The experimental results manifest that the dissolving rate of HAPAM increases with temperature and stirring speed,but the viscosity of the polymer solution decreases.There is an optimal range of salinity for polymer dissolving.Combining the operation mode of up-pumping with varying stirring speed,hydrofoil impeller can accelerate the dissolution of HAPAM and maintain a high solution viscosity.
文摘In the middle of the last century,American scientists put forward the concept of capillary number and obtained the relation curve between capillary number and residual oil through experiments.They revealed that the corresponding residual oil saturation decreased with increasing of capillary number;after capillary number reached up to a limit,residual oil saturation would become stable and did not decrease.These important achievements laid a theoretical base for enhanced oil recovery with chemical flooding.On the basis of the theory,scholars developed chemical flooding numerical simulation software UTCHEM.During the numerical simulation study of combination flooding,the authors found that as the capillary number is higher than the limit capillary number,the changes of the residual oil saturation along with the capillary number differ from the classical capillary number curve.Oil displacement experiments prove that there are defects in classic capillary number experimental curve and it is necessary to mend and improve.Capillary number‘calculation’curve is obtained with a method of numerical simulation calculation and a complete description of capillary number curve is provided;On this basis,combination flooding capillary number experimental curve QL is obtained through experiments,which is different from the classical capillary curve;and based on which,an expression of corresponding combination flooding relative permeability curve QL is given and the corresponding relative permeability parameters are determined with experiments.Further oil displacement experiment research recognizes the cause of the singular changes of the capillary number curve."Combination flooding capillary number experimental curve QL"and"combination flooding relative permeability curve QL"are written in combination flooding software IMCFS,providing an effective technical support for the application of combination flooding technical research.
