Polyacrylamide microspheres have been suc- cessfully used to reduce water production in reservoirs, but it is impossible to distinguish polyacrylamide microspheres from polyacrylamide that is used to enhance oil recov...Polyacrylamide microspheres have been suc- cessfully used to reduce water production in reservoirs, but it is impossible to distinguish polyacrylamide microspheres from polyacrylamide that is used to enhance oil recovery and is already present in production fluids. In order to detect polyacrylamide microspheres in the reservoir pro- duced fluid, fluorescent polyacrylamide microspheres P（AM-BA-AMCO）, which fluoresce under ultraviolet irradiation, were synthesized via an inverse suspension polymerization. In order to keep the particle size distribu- tion in a narrow range, the synthesis conditions of the polymerization were studied, including the stirring speed and the concentrations of initiator, NaaCO3, and dispersant. The bonding characteristics of microspheres were deter- mined by Fourier transform infrared spectroscopy. The surface morphology of these microspheres was observed under ultraviolet irradiation with an inverse fluorescence microscope. A laboratory evaluation test showed that the fluorescent polymer microspheres had good water swelling capability, thus they had the ability to plug and migrate in a sand pack. The plugging rate was 99.8 % and the residual resistance coefficient was 800 after microsphere treatment in the sand pack. Furthermore, the fluorescent microspheres and their fragments were accurately detected under ultra- violet irradiation in the produced fluid, even though theyhad experienced extrusion and deformation in the sand pack.展开更多
In this paper, cationic polyacrylamide microspheres （CPAM） were synthesized using acrylamide （AM） and methacryloyloxyethyl trimethyl ammonium chloride （TMAEMC） as monomers, ammonium sulfate as dispersant, poly（...In this paper, cationic polyacrylamide microspheres （CPAM） were synthesized using acrylamide （AM） and methacryloyloxyethyl trimethyl ammonium chloride （TMAEMC） as monomers, ammonium sulfate as dispersant, poly（acryloyloxyethyl trimethyl ammonium chloride） （PAETAC） as dispersion stabilizer, and ammonium persulfate as initiator. The synthetic method was dispersion polymerization. The effects of monomer ratio （AM/TMAEMC）, dispersant concentration, and dispersion stabilizer dosage on dispersion polymerization were systematically studied to determine the optimal preparation conditions. The structure and viscosity of the synthesized polymer were characterized by FTIR and capillary viscometry, respectively, and the particle sizes and distribution of the polymer microspheres were characterized by microscopy and dynamic light scattering, respectively. Finally, flow tests were conducted to measure the permeability reduction performance of the microspheres at various concentrations in sand packs with different permeability. Results show that CPAM emulsion of a solids content of 1 wt% has excellent performance in low-to-medium permeability formations （〈 1,000 mD）, and the efficiency may reach above 90%.展开更多
The first pilot test of polyacrylamide microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants(Sa/c)was carried out for a high-temperature,high-salinity,and highhardness sandstone res...The first pilot test of polyacrylamide microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants(Sa/c)was carried out for a high-temperature,high-salinity,and highhardness sandstone reservoir to demonstrate the potential of this novel technique to improve oil recovery.A critical micelle concentration(CMC)of 4.82 mg/L,an ultralow interfacial tension(IFT)of 8104 mN/m,and a high oil solubilization of 22 were obtained.Static and dynamic adsorptions of Sa/c on natural core containing 15 wt%clay were reduced to about 2.20 and 0.30 mg/g-core,respectively,with the addition of adsorption inhibitor(AI).Since June 2014,the pilot test of PMAS was carried out in a Sinopec reservoir with a temperature of 87C,a salinity of 260,393 mg/L,and a hardness of 6,401 mg/L.Twelve cycles of alternative injection of 0.0125 PV Sa/c with a concentration of 0.1%and 0.0125 PV polyacrylamide microsphere with a concentration of 0.2%were conducted at an injection rate of 0.1 PV/yr,for a total of 0.3 PV chemical injection.As a result,the net daily oil production increased from 0 t to 6.5 t,and the water cut decreased from 96.3%to 93.8%,leading to an ultimate improved oil recovery of 6.3%original oil-in-place.展开更多
基金supported by the National Natural Science Foundation of China (No.21273286)Doctoral Program Foundation of the Education Ministry (No.20130133110005)
文摘Polyacrylamide microspheres have been suc- cessfully used to reduce water production in reservoirs, but it is impossible to distinguish polyacrylamide microspheres from polyacrylamide that is used to enhance oil recovery and is already present in production fluids. In order to detect polyacrylamide microspheres in the reservoir pro- duced fluid, fluorescent polyacrylamide microspheres P（AM-BA-AMCO）, which fluoresce under ultraviolet irradiation, were synthesized via an inverse suspension polymerization. In order to keep the particle size distribu- tion in a narrow range, the synthesis conditions of the polymerization were studied, including the stirring speed and the concentrations of initiator, NaaCO3, and dispersant. The bonding characteristics of microspheres were deter- mined by Fourier transform infrared spectroscopy. The surface morphology of these microspheres was observed under ultraviolet irradiation with an inverse fluorescence microscope. A laboratory evaluation test showed that the fluorescent polymer microspheres had good water swelling capability, thus they had the ability to plug and migrate in a sand pack. The plugging rate was 99.8 % and the residual resistance coefficient was 800 after microsphere treatment in the sand pack. Furthermore, the fluorescent microspheres and their fragments were accurately detected under ultra- violet irradiation in the produced fluid, even though theyhad experienced extrusion and deformation in the sand pack.
基金financial support from the National Natural Science Foundation of China (Grants Nos. 51203186, U1362101 and 51173203)the Converging Research Center Program funded by Korean Ministry of Education (2013K000415)the Project of Science and Technology Program for Basic Research of Qingdao (No. 121-4-7-(6)-jch)
文摘In this paper, cationic polyacrylamide microspheres （CPAM） were synthesized using acrylamide （AM） and methacryloyloxyethyl trimethyl ammonium chloride （TMAEMC） as monomers, ammonium sulfate as dispersant, poly（acryloyloxyethyl trimethyl ammonium chloride） （PAETAC） as dispersion stabilizer, and ammonium persulfate as initiator. The synthetic method was dispersion polymerization. The effects of monomer ratio （AM/TMAEMC）, dispersant concentration, and dispersion stabilizer dosage on dispersion polymerization were systematically studied to determine the optimal preparation conditions. The structure and viscosity of the synthesized polymer were characterized by FTIR and capillary viscometry, respectively, and the particle sizes and distribution of the polymer microspheres were characterized by microscopy and dynamic light scattering, respectively. Finally, flow tests were conducted to measure the permeability reduction performance of the microspheres at various concentrations in sand packs with different permeability. Results show that CPAM emulsion of a solids content of 1 wt% has excellent performance in low-to-medium permeability formations （〈 1,000 mD）, and the efficiency may reach above 90%.
文摘The first pilot test of polyacrylamide microsphere alternate surfactant flood(PMAS)with mixtures of anionic-cationic surfactants(Sa/c)was carried out for a high-temperature,high-salinity,and highhardness sandstone reservoir to demonstrate the potential of this novel technique to improve oil recovery.A critical micelle concentration(CMC)of 4.82 mg/L,an ultralow interfacial tension(IFT)of 8104 mN/m,and a high oil solubilization of 22 were obtained.Static and dynamic adsorptions of Sa/c on natural core containing 15 wt%clay were reduced to about 2.20 and 0.30 mg/g-core,respectively,with the addition of adsorption inhibitor(AI).Since June 2014,the pilot test of PMAS was carried out in a Sinopec reservoir with a temperature of 87C,a salinity of 260,393 mg/L,and a hardness of 6,401 mg/L.Twelve cycles of alternative injection of 0.0125 PV Sa/c with a concentration of 0.1%and 0.0125 PV polyacrylamide microsphere with a concentration of 0.2%were conducted at an injection rate of 0.1 PV/yr,for a total of 0.3 PV chemical injection.As a result,the net daily oil production increased from 0 t to 6.5 t,and the water cut decreased from 96.3%to 93.8%,leading to an ultimate improved oil recovery of 6.3%original oil-in-place.
