The effectiveness of surfactant solutions,polymers and nanosuspensions in capillary imbibition was studied comparatively.Two series of experiments on capillary imbibition with displacing liquids from cores saturated w...The effectiveness of surfactant solutions,polymers and nanosuspensions in capillary imbibition was studied comparatively.Two series of experiments on capillary imbibition with displacing liquids from cores saturated with low-viscosity(4.2 mPa s)and high-viscosity(28.9 mPa s)oil were performed.Water,a polymer solution of polyacrylamide,surfactant solutions(AES and SDS),as well as suspensions of spherical nanoparticles were considered as displacing fluids.The mass concentration of the substances varied from 0.05 to 0.25%.The rate of change in the volume of the displaced oil for 0.1%AES solution and suspension 1030 over time was greater than for other displacing liquids.The smallest increase in the volume of displaced oil was observed for the polymer solution.The coefficient of low-viscosity oil displacement from sandstone by water as a result of capillary imbibition was found to be 58%.When using surfactant solutions and suspensions,an increase in the oil displacement coefficient was observed:the SDS solution increased the capillary imbibition rate by 4%,and the suspension of SiO2 nanoparticles(10 nm)gave a 3%increase.The polyacrylamide solution reduced the capillary imbibition rate by 12%.In the series with higher oil viscosity,the effect of additives was more significant.The rate of capillary imbibition increased by 22%in the case of 0.1%SDS solution and by 24%for 0.1%SiO2 suspension(10 nm).The analysis of the factors influencing the displacement coefficient during capillary imbibition with solutions of surfactants,polymers and nanosuspensions was carried out.It has been shown that nanosuspensions are not inferior to surfactant solutions and leave polymer solutions far behind in terms of their positive effect on the oil displacement coefficient.展开更多
A systematic numerical investigation of slurry transport by drilling fluids modified with single-walled carbon nanotube(SWCNT)additives under laminar flow conditions of the suspension has been conducted.Across wide-ra...A systematic numerical investigation of slurry transport by drilling fluids modified with single-walled carbon nanotube(SWCNT)additives under laminar flow conditions of the suspension has been conducted.Across wide-ranging parameter variations corresponding to real wells and drilling modes,the effects of the mass flow rate of the drilling fluid,particle size of the slurry,ratio of inner to outer pipe diameters,eccentricity,rotational speed of the inner pipe,and well inclination angle on the efficiency of slurry particle transport by the modified fluids were examined.The influence of the additives on the concentration distribution of slurry particles and the velocity of the mixture in the annular channel,simulating the well,was studied.Mechanisms of the nanotubes'influence on slurry particle transport were identified.It was demonstrated that for all considered cases,the efficiency of particle transport by drilling fluids modified with nanotubes significantly increases with increasing additive concentration.The greatest effectiveness for improving wellbore cleaning was exhibited by a drilling fluid with an SWCNT concentration of 0.1 wt%.For this fluid,the ability to transport slurry increased by a factor of 3.4,while the pressure drop increased only by a factor of 1.8 compared to the baseline fluid.Furthermore,the addition of nanotubes was found to be most effective for horizontal wells with concentric pipe placement,at low rotational speeds of the drill pipe,and at high mass flow rates of the drilling fluid.展开更多
The paper presents the results of a systematic study of the influence of nano-additives of various concentrations,average sizes and composition on the temperature dependence of the viscosity and rheological behavior o...The paper presents the results of a systematic study of the influence of nano-additives of various concentrations,average sizes and composition on the temperature dependence of the viscosity and rheological behavior of water-based drilling fluids.Typical compositions of drilling fluids,such as water suspensions of various clay solutions and gammaxan-based polymer solutions,were considered.Hydrophilic nanoparticles of silicon and aluminum oxides were used as nano-additives at concentrations ranging from 0.25 to 3 wt%.The average nanoparticle size varied from 10 to 151 nm.The temperature of drilling fluids varied from 25℃ to 80℃.It is shown that the addition of nanoparticles to drilling fluids leads to a significant change in their rheological properties depending on the temperature.It was found that with increasing temperature,the yield stress and consistency index of drilling fluids with nanoparticles increase,while the behavior index,on the contrary,decreases.This behavior depends on the size of the nanoparticles.As the particle size increases,their influence on the temperature dependence of the drilling fluids’viscosity increases.In general,it is shown that the addition of nanoparticles makes the viscosity of drilling fluid more stable with regard to the temperature.This is an essential fact for practical application.展开更多
基金financed by Ministry of Science and Higher Education of the Russian Federation(project no.FSRZ-2020-0012).
文摘The effectiveness of surfactant solutions,polymers and nanosuspensions in capillary imbibition was studied comparatively.Two series of experiments on capillary imbibition with displacing liquids from cores saturated with low-viscosity(4.2 mPa s)and high-viscosity(28.9 mPa s)oil were performed.Water,a polymer solution of polyacrylamide,surfactant solutions(AES and SDS),as well as suspensions of spherical nanoparticles were considered as displacing fluids.The mass concentration of the substances varied from 0.05 to 0.25%.The rate of change in the volume of the displaced oil for 0.1%AES solution and suspension 1030 over time was greater than for other displacing liquids.The smallest increase in the volume of displaced oil was observed for the polymer solution.The coefficient of low-viscosity oil displacement from sandstone by water as a result of capillary imbibition was found to be 58%.When using surfactant solutions and suspensions,an increase in the oil displacement coefficient was observed:the SDS solution increased the capillary imbibition rate by 4%,and the suspension of SiO2 nanoparticles(10 nm)gave a 3%increase.The polyacrylamide solution reduced the capillary imbibition rate by 12%.In the series with higher oil viscosity,the effect of additives was more significant.The rate of capillary imbibition increased by 22%in the case of 0.1%SDS solution and by 24%for 0.1%SiO2 suspension(10 nm).The analysis of the factors influencing the displacement coefficient during capillary imbibition with solutions of surfactants,polymers and nanosuspensions was carried out.It has been shown that nanosuspensions are not inferior to surfactant solutions and leave polymer solutions far behind in terms of their positive effect on the oil displacement coefficient.
基金supported by the Russian Science Foundation(grant No.23-79-30022).
文摘A systematic numerical investigation of slurry transport by drilling fluids modified with single-walled carbon nanotube(SWCNT)additives under laminar flow conditions of the suspension has been conducted.Across wide-ranging parameter variations corresponding to real wells and drilling modes,the effects of the mass flow rate of the drilling fluid,particle size of the slurry,ratio of inner to outer pipe diameters,eccentricity,rotational speed of the inner pipe,and well inclination angle on the efficiency of slurry particle transport by the modified fluids were examined.The influence of the additives on the concentration distribution of slurry particles and the velocity of the mixture in the annular channel,simulating the well,was studied.Mechanisms of the nanotubes'influence on slurry particle transport were identified.It was demonstrated that for all considered cases,the efficiency of particle transport by drilling fluids modified with nanotubes significantly increases with increasing additive concentration.The greatest effectiveness for improving wellbore cleaning was exhibited by a drilling fluid with an SWCNT concentration of 0.1 wt%.For this fluid,the ability to transport slurry increased by a factor of 3.4,while the pressure drop increased only by a factor of 1.8 compared to the baseline fluid.Furthermore,the addition of nanotubes was found to be most effective for horizontal wells with concentric pipe placement,at low rotational speeds of the drill pipe,and at high mass flow rates of the drilling fluid.
基金supported by the Russian Science Foundation(grant No.17-79-20218-P).
文摘The paper presents the results of a systematic study of the influence of nano-additives of various concentrations,average sizes and composition on the temperature dependence of the viscosity and rheological behavior of water-based drilling fluids.Typical compositions of drilling fluids,such as water suspensions of various clay solutions and gammaxan-based polymer solutions,were considered.Hydrophilic nanoparticles of silicon and aluminum oxides were used as nano-additives at concentrations ranging from 0.25 to 3 wt%.The average nanoparticle size varied from 10 to 151 nm.The temperature of drilling fluids varied from 25℃ to 80℃.It is shown that the addition of nanoparticles to drilling fluids leads to a significant change in their rheological properties depending on the temperature.It was found that with increasing temperature,the yield stress and consistency index of drilling fluids with nanoparticles increase,while the behavior index,on the contrary,decreases.This behavior depends on the size of the nanoparticles.As the particle size increases,their influence on the temperature dependence of the drilling fluids’viscosity increases.In general,it is shown that the addition of nanoparticles makes the viscosity of drilling fluid more stable with regard to the temperature.This is an essential fact for practical application.
