The rheological properties of two kinds of oil-based drilling fluids with typically composition were studied at pressures up to 138 MPa and temperatures up to 204 ℃ using the RheoChan 7400 Rheometer.The experimental ...The rheological properties of two kinds of oil-based drilling fluids with typically composition were studied at pressures up to 138 MPa and temperatures up to 204 ℃ using the RheoChan 7400 Rheometer.The experimental results show that the apparent viscosity,plastic viscosity and yield point decrease with the increase of temperature,and increase with the increase of pressure.The effect of pressure on the apparent viscosity,plastic viscosity and yield point is considerable at ambient temperature.However,this effect gradually reduces with the increase of temperature.The major factor influencing the rheological properties of oil-based drilling fluids is temperature instead of pressure in the deep sections of oil wells.On the basis of numerous experiments,the model for predict the apparent viscosity,plastic viscosity and yield point of oil-based drilling fluids at high temperature and pressure was established using the method of regressive analysis.It is confirmed that the calculated data are in good agreement with the measured data,and the correlation coefficients are more than 0.98.The model is convenient for use and suitable for the application in drilling operations.展开更多
High temperature rheological properties of fiber modified asphalt binders and impact of the type and content on such properties were studied.Three types of fiber,including polyester(PET),polyacrylonitrile(PAN) and cel...High temperature rheological properties of fiber modified asphalt binders and impact of the type and content on such properties were studied.Three types of fiber,including polyester(PET),polyacrylonitrile(PAN) and cellulose(CEL),a control content(0%) and four levels of fiber content(2%,4%,6% and 8% by total asphalt binder mass) were used with asphalt binders.The high temperature rheological properties,consisting of complex modulus(G*) and phase angle δ,were measured using SHRP's dynamic shear rheometer(DSR) between 46-82 ℃.Experimental results indicate that the changes of G* and tan δ of fiber modified asphalt binders with the increase of test temperature tend to slow down,and the temperature susceptibility is improved obviously compared to that of original asphalt binder.Fiber modification results in the increase of rutting parameter(G*/sin δ) at high temperatures,the decrease of temperature susceptibility,and further improved high temperature performance of asphalt binder.An excellent correlation exhibits between fiber content and high temperature performance of asphalt binder.Moreover,fiber type also has different influences on the improvement of G*/sin δ,G*/sin δ of PET and PAN fiber asphalt binders are both higher than that of CEL fiber,but G*/sin δ of CEL fiber is still higher than that of original asphalt.However,there is a critical fiber content when fibers start to interact with each other.Therefore,based on the critical fiber content and economic consideration,the optimum fiber contents for various fiber-modified asphalt binders are obtained.展开更多
The material properties of surface and powder, rheological property, and mineral composition were investigated by means of SEM, XRD, Malvern laser granulometer and rotary, viscometer. The influence of a admixture on u...The material properties of surface and powder, rheological property, and mineral composition were investigated by means of SEM, XRD, Malvern laser granulometer and rotary, viscometer. The influence of a admixture on ultra-fine cement rheological properties and its mechanism, were studied in material theories. The results show that the ultra-fine fly ash has a higher zeta potential, and improves flowability of ultra-fine cement paste, decreases flowability loss as time prolonging, improves compatibility between superplasticizers and cement because of the electrostatic repulsion, ball bearing effect, filling and dispersing effect of admixtures and delay-releasing effect of superplasticizers.展开更多
The effect of pan-milling on the rheological properties of high density polyethylene (HDPE) was studied. An innovative milling apparatus, viz. an inlaid pan-mill, was used. Melt indexer, capillary rheometer, Haake Rhe...The effect of pan-milling on the rheological properties of high density polyethylene (HDPE) was studied. An innovative milling apparatus, viz. an inlaid pan-mill, was used. Melt indexer, capillary rheometer, Haake Rheocord 90 single-screw extruder and Brabender rheometer were used to evaluate the rheological properties of HDPE. HDPE with higher initial molecular weight and larger particle size was easier to degrade under pan-milling stress, as indicated by the melt index. Pressure oscillation in capillary flow occurred at significantly higher shear stress and shear rate for milled HDPE than for unmilled HDPE. The apparent shear viscosity of HDPE decreased with increasing times of milling. After milling, the flow activation energy decreased and thus the sensitivity of viscosity to temperature was reduced. Die pressure and torque during single screw extrusion were reduced significantly after milling. Plasticizing time as measured in a Brabander mixer decreased markedly with increasing milling times.展开更多
In this paper,high cis-1,4 content hydroxyl-terminated polybutadiene(cis-HTPB)with different molecular weights was prepared through the oxidative cracking process using cis-butadiene rubber as raw material.Firstly,thi...In this paper,high cis-1,4 content hydroxyl-terminated polybutadiene(cis-HTPB)with different molecular weights was prepared through the oxidative cracking process using cis-butadiene rubber as raw material.Firstly,this article comprehensively compared the differences between cis-HTPB and conventional I-HTPB in terms of molecular weight distribution,functionality,viscosity,molecular polarity,and other physicochemical properties,which provided effective data support for its subsequent application.In addition,the reaction kinetics study showed that cis-HTPB with isocyanate curing agent has high reactivity,allowing it to be rapidly cured at low temperatures,and the cured elastomers had excellent mechanical properties,with tensile strength and elongation up to 1.89 MPa and 1100%,respectively.It was also found that cis-HTPB has extremely excellent low-temperature resistance,and the glass transition temperature(T_(g))of its cured elastomer is as low as-101℃.Based on the above studies,cis-HTPB is applied as a binder in composite solid propellants for the first time to investigate its practical performance,and the results indicated that cis-HTPB-based propellants have excellent process and mechanical properties.展开更多
To elucidate the high temperature rheological capability of graphene modified rubber asphalt,three contents of graphene and crumb rubber were prepared by a combination of mechanical agitation and high speed shearing m...To elucidate the high temperature rheological capability of graphene modified rubber asphalt,three contents of graphene and crumb rubber were prepared by a combination of mechanical agitation and high speed shearing machine,then used dynamic shear rheological test(DSR)and multiple stress creep recovery(MSCR)tests to evaluate.The hardness and softening point with rotational viscosity of samples raised with the addition of graphene,especially the addition of 0.04%.Dynamic shear rheological test revealedthat the dynamic shear modulus G*,rutting factor G*/Sin δ,and zero shear viscosity(ZSV)of graphene-modified rubber asphalt were greatly influenced along with graphene-increased,on the contrary,phase angle δ which characterize the viscoelastic ratio of asphalt decreased.Multiple stress creep recovery(MSCR)tests showed that the graphene-enhanced rubber asphalt had high-temperature stability through non-recoverable creep compliance(Jnr).Based on these findings,graphene-modified rubber asphalt binders with the addition of 0.04% graphene had good viscoelastic properties as well as high temperature rutting resistance performance.In the meantime,G*/Sin δ,ZSV,and Jnr100,Jnr3200 have good correlation,which can reveal the excellent high-temperature stability performance of asphalt.展开更多
To study the influence of fiber on the properties of asphalt mortar,the properties of lignin fiber,polyester fiber,and basalt fiber were summarized and analyzed respectively.The high-and low-temperature properties of ...To study the influence of fiber on the properties of asphalt mortar,the properties of lignin fiber,polyester fiber,and basalt fiber were summarized and analyzed respectively.The high-and low-temperature properties of fiber asphalt mortar were studied and analyzed by using three indexes,rutting factor and tensile fracture energy.The results showed that all three kinds of fibers could improve the performance of asphalt mortar to varying degrees,with lignin fiber demonstrating the best effect,followed by basalt fiber and polyester fiber.The type the fiber can be selected based on the required thermal stability and cost depending on the project type.展开更多
为满足海上深层超深层油气井压裂改造需要,保证压裂液的耐温和携砂能力,以丙烯酰胺、丙烯酸、2-丙烯酰胺-2-甲基丙磺酸以及疏水单体DM合成了一种耐高温高盐疏水缔合聚合物TH–200。采用红外光谱、核磁共振氢谱、热重对聚合物TH–200进...为满足海上深层超深层油气井压裂改造需要,保证压裂液的耐温和携砂能力,以丙烯酰胺、丙烯酸、2-丙烯酰胺-2-甲基丙磺酸以及疏水单体DM合成了一种耐高温高盐疏水缔合聚合物TH–200。采用红外光谱、核磁共振氢谱、热重对聚合物TH–200进行结构表征,并进一步评价了其作为压裂液稠化剂的主要性能。研究结果表明:聚合物TH–200为四元共聚合物,具有较好的热稳定性。该聚合物在海水中增黏速率达92%,具有较好的增黏抗盐性能,适合在海水等高矿化度水中使用,其分子间临界缔合质量分数在0.25%附近。分子动力学模拟显示AMPS单体浓度增加,聚合物链段的回转半径显著提升且受温度和矿化度的影响较小。海水配制0.1%溶液降阻率可达78%。1.0%聚合物TH–200+0.5%螯合调节剂+1.0%有机锆交联剂配制的海水基压裂液,在200℃、100 s^(-1)下剪切90 min后黏度为110 m Pa·s,表明其具有良好的延迟交联性能和耐温耐剪切性能,交联冻胶具有优异的携砂性能,可满足海上200℃储层压裂施工需求。展开更多
This work investigated the aging effects on the rheological properties of high viscosity modified asphalt(HVMA).First,the high-and low-temperature rheological properties were measured by a dynamic shear rheometer and ...This work investigated the aging effects on the rheological properties of high viscosity modified asphalt(HVMA).First,the high-and low-temperature rheological properties were measured by a dynamic shear rheometer and a bending beam rheometer,respectively.The aging mechanism was then tested using an Fourier transform infrared spectroscopy and a scanning electron microscope.Besides,a study was performed to compare the aging effects on the rheological properties of HVMA,crumb rubber modified asphalt(CRMA),and neat asphalt(SK-90).The experimental results showed that the effects of the long-term aging on HVMA exceeded those of short-term aging.The complex shear modulus of the HVMA was improved by the aging in the whole frequency range.The complex shear modulus of the HVMA after the long-term aging was larger than after the short-term aging.Thus,the aging improved the high-temperature viscoelastic performance of HVMA.With a decrease in temperature from-12℃to-24℃,the low-temperature viscoelastic performance of HVMA decreased since its stiffness modulus and low continuous grading temperature increase.Both of the short-and long-term aging of HVMA were caused by an oxidation reaction,while modifier swelling also happened after long-term aging.Compared to CRMA and SK-90,aging had a limited influence on the high-and low-temperature rheological properties of HVMA.展开更多
High viscosity asphalt(HVA)has been a great success as a drainage pavement material.However,the larger porosity of drainage asphalt mixtures weakens the cohesion and adhesion and leads to premature rutting,water damag...High viscosity asphalt(HVA)has been a great success as a drainage pavement material.However,the larger porosity of drainage asphalt mixtures weakens the cohesion and adhesion and leads to premature rutting,water damage,spalling and cracking.The purpose of this study was to investigate the rheological properties of HVA prepared using different high viscosity modifiers through conventional tests,Brookfield viscosity tests,dynamic shear rheometer tests and bending beam rheometer tests.The conventional performance results demonstrated SBS+rubber asphalt(SRA1/2)exhibited excellent elastic recovery and low-temperature flexibility.The 60℃ dynamic viscosity results indicated TPS+rubber asphalt(TRA)had the excellent adhesion.The rotational viscosity results and rheological results indicated that SRA-2 not only exhibited excellent temperature stability and workability,as well as excellent resistance to deformation and rutting resistance,but also exhibited excellent low-temperature cracking resistance and relaxation performance.Based on rheological results,the PG classification of HVA was 16%rubber+asphalt for PG76-22,20%rubber+asphalt for PG88-22,TRA and SRA-1/2 for PG88-28.From comprehensive evaluation of the viscosity,temperature stability and sensitivity,as well as high/low temperature performance of HVA,SRA-2 was found to be more suited to the requirements of drainage asphalt pavement materials.展开更多
基金Project(50574061) supported by the National Natural Science Foundation of ChinaProject(IRT0411) supported by the Changjiang Scholars and Innovative Research Team,Ministry of Education
文摘The rheological properties of two kinds of oil-based drilling fluids with typically composition were studied at pressures up to 138 MPa and temperatures up to 204 ℃ using the RheoChan 7400 Rheometer.The experimental results show that the apparent viscosity,plastic viscosity and yield point decrease with the increase of temperature,and increase with the increase of pressure.The effect of pressure on the apparent viscosity,plastic viscosity and yield point is considerable at ambient temperature.However,this effect gradually reduces with the increase of temperature.The major factor influencing the rheological properties of oil-based drilling fluids is temperature instead of pressure in the deep sections of oil wells.On the basis of numerous experiments,the model for predict the apparent viscosity,plastic viscosity and yield point of oil-based drilling fluids at high temperature and pressure was established using the method of regressive analysis.It is confirmed that the calculated data are in good agreement with the measured data,and the correlation coefficients are more than 0.98.The model is convenient for use and suitable for the application in drilling operations.
基金Project(2004243) supported by the Science and Technology Key Project of Hubei Province,China
文摘High temperature rheological properties of fiber modified asphalt binders and impact of the type and content on such properties were studied.Three types of fiber,including polyester(PET),polyacrylonitrile(PAN) and cellulose(CEL),a control content(0%) and four levels of fiber content(2%,4%,6% and 8% by total asphalt binder mass) were used with asphalt binders.The high temperature rheological properties,consisting of complex modulus(G*) and phase angle δ,were measured using SHRP's dynamic shear rheometer(DSR) between 46-82 ℃.Experimental results indicate that the changes of G* and tan δ of fiber modified asphalt binders with the increase of test temperature tend to slow down,and the temperature susceptibility is improved obviously compared to that of original asphalt binder.Fiber modification results in the increase of rutting parameter(G*/sin δ) at high temperatures,the decrease of temperature susceptibility,and further improved high temperature performance of asphalt binder.An excellent correlation exhibits between fiber content and high temperature performance of asphalt binder.Moreover,fiber type also has different influences on the improvement of G*/sin δ,G*/sin δ of PET and PAN fiber asphalt binders are both higher than that of CEL fiber,but G*/sin δ of CEL fiber is still higher than that of original asphalt.However,there is a critical fiber content when fibers start to interact with each other.Therefore,based on the critical fiber content and economic consideration,the optimum fiber contents for various fiber-modified asphalt binders are obtained.
基金Funded by the Science Foundation of the Science and Technology Department of Hubei Province(No.200029031).
文摘The material properties of surface and powder, rheological property, and mineral composition were investigated by means of SEM, XRD, Malvern laser granulometer and rotary, viscometer. The influence of a admixture on ultra-fine cement rheological properties and its mechanism, were studied in material theories. The results show that the ultra-fine fly ash has a higher zeta potential, and improves flowability of ultra-fine cement paste, decreases flowability loss as time prolonging, improves compatibility between superplasticizers and cement because of the electrostatic repulsion, ball bearing effect, filling and dispersing effect of admixtures and delay-releasing effect of superplasticizers.
文摘The effect of pan-milling on the rheological properties of high density polyethylene (HDPE) was studied. An innovative milling apparatus, viz. an inlaid pan-mill, was used. Melt indexer, capillary rheometer, Haake Rheocord 90 single-screw extruder and Brabender rheometer were used to evaluate the rheological properties of HDPE. HDPE with higher initial molecular weight and larger particle size was easier to degrade under pan-milling stress, as indicated by the melt index. Pressure oscillation in capillary flow occurred at significantly higher shear stress and shear rate for milled HDPE than for unmilled HDPE. The apparent shear viscosity of HDPE decreased with increasing times of milling. After milling, the flow activation energy decreased and thus the sensitivity of viscosity to temperature was reduced. Die pressure and torque during single screw extrusion were reduced significantly after milling. Plasticizing time as measured in a Brabander mixer decreased markedly with increasing milling times.
基金the support from the Open Research Fund Program of Science and Technology on Aerospace Chemical Power Laboratory(Grant No.STACPL120221B03)the National Natural Science Foundation of China(Grant No.22175059).
文摘In this paper,high cis-1,4 content hydroxyl-terminated polybutadiene(cis-HTPB)with different molecular weights was prepared through the oxidative cracking process using cis-butadiene rubber as raw material.Firstly,this article comprehensively compared the differences between cis-HTPB and conventional I-HTPB in terms of molecular weight distribution,functionality,viscosity,molecular polarity,and other physicochemical properties,which provided effective data support for its subsequent application.In addition,the reaction kinetics study showed that cis-HTPB with isocyanate curing agent has high reactivity,allowing it to be rapidly cured at low temperatures,and the cured elastomers had excellent mechanical properties,with tensile strength and elongation up to 1.89 MPa and 1100%,respectively.It was also found that cis-HTPB has extremely excellent low-temperature resistance,and the glass transition temperature(T_(g))of its cured elastomer is as low as-101℃.Based on the above studies,cis-HTPB is applied as a binder in composite solid propellants for the first time to investigate its practical performance,and the results indicated that cis-HTPB-based propellants have excellent process and mechanical properties.
文摘To elucidate the high temperature rheological capability of graphene modified rubber asphalt,three contents of graphene and crumb rubber were prepared by a combination of mechanical agitation and high speed shearing machine,then used dynamic shear rheological test(DSR)and multiple stress creep recovery(MSCR)tests to evaluate.The hardness and softening point with rotational viscosity of samples raised with the addition of graphene,especially the addition of 0.04%.Dynamic shear rheological test revealedthat the dynamic shear modulus G*,rutting factor G*/Sin δ,and zero shear viscosity(ZSV)of graphene-modified rubber asphalt were greatly influenced along with graphene-increased,on the contrary,phase angle δ which characterize the viscoelastic ratio of asphalt decreased.Multiple stress creep recovery(MSCR)tests showed that the graphene-enhanced rubber asphalt had high-temperature stability through non-recoverable creep compliance(Jnr).Based on these findings,graphene-modified rubber asphalt binders with the addition of 0.04% graphene had good viscoelastic properties as well as high temperature rutting resistance performance.In the meantime,G*/Sin δ,ZSV,and Jnr100,Jnr3200 have good correlation,which can reveal the excellent high-temperature stability performance of asphalt.
文摘To study the influence of fiber on the properties of asphalt mortar,the properties of lignin fiber,polyester fiber,and basalt fiber were summarized and analyzed respectively.The high-and low-temperature properties of fiber asphalt mortar were studied and analyzed by using three indexes,rutting factor and tensile fracture energy.The results showed that all three kinds of fibers could improve the performance of asphalt mortar to varying degrees,with lignin fiber demonstrating the best effect,followed by basalt fiber and polyester fiber.The type the fiber can be selected based on the required thermal stability and cost depending on the project type.
文摘为满足海上深层超深层油气井压裂改造需要,保证压裂液的耐温和携砂能力,以丙烯酰胺、丙烯酸、2-丙烯酰胺-2-甲基丙磺酸以及疏水单体DM合成了一种耐高温高盐疏水缔合聚合物TH–200。采用红外光谱、核磁共振氢谱、热重对聚合物TH–200进行结构表征,并进一步评价了其作为压裂液稠化剂的主要性能。研究结果表明:聚合物TH–200为四元共聚合物,具有较好的热稳定性。该聚合物在海水中增黏速率达92%,具有较好的增黏抗盐性能,适合在海水等高矿化度水中使用,其分子间临界缔合质量分数在0.25%附近。分子动力学模拟显示AMPS单体浓度增加,聚合物链段的回转半径显著提升且受温度和矿化度的影响较小。海水配制0.1%溶液降阻率可达78%。1.0%聚合物TH–200+0.5%螯合调节剂+1.0%有机锆交联剂配制的海水基压裂液,在200℃、100 s^(-1)下剪切90 min后黏度为110 m Pa·s,表明其具有良好的延迟交联性能和耐温耐剪切性能,交联冻胶具有优异的携砂性能,可满足海上200℃储层压裂施工需求。
基金supported by the National Key R&D Program of China(Grant No.2018YFB1600200)the Fok YingTong Education Foundation(Grant No.161072)+1 种基金the Youth Top-notch Talent Support Program of Shaanxi Provincethe Fundamental Research Funds for the Central Universities(Grant No.300102219317)。
文摘This work investigated the aging effects on the rheological properties of high viscosity modified asphalt(HVMA).First,the high-and low-temperature rheological properties were measured by a dynamic shear rheometer and a bending beam rheometer,respectively.The aging mechanism was then tested using an Fourier transform infrared spectroscopy and a scanning electron microscope.Besides,a study was performed to compare the aging effects on the rheological properties of HVMA,crumb rubber modified asphalt(CRMA),and neat asphalt(SK-90).The experimental results showed that the effects of the long-term aging on HVMA exceeded those of short-term aging.The complex shear modulus of the HVMA was improved by the aging in the whole frequency range.The complex shear modulus of the HVMA after the long-term aging was larger than after the short-term aging.Thus,the aging improved the high-temperature viscoelastic performance of HVMA.With a decrease in temperature from-12℃to-24℃,the low-temperature viscoelastic performance of HVMA decreased since its stiffness modulus and low continuous grading temperature increase.Both of the short-and long-term aging of HVMA were caused by an oxidation reaction,while modifier swelling also happened after long-term aging.Compared to CRMA and SK-90,aging had a limited influence on the high-and low-temperature rheological properties of HVMA.
基金The work described in this paper is supported by the National Natural Science Foundation of China under Grant No.51778136Technology Research and Development Project of China Railway under No.J2019G003.
文摘High viscosity asphalt(HVA)has been a great success as a drainage pavement material.However,the larger porosity of drainage asphalt mixtures weakens the cohesion and adhesion and leads to premature rutting,water damage,spalling and cracking.The purpose of this study was to investigate the rheological properties of HVA prepared using different high viscosity modifiers through conventional tests,Brookfield viscosity tests,dynamic shear rheometer tests and bending beam rheometer tests.The conventional performance results demonstrated SBS+rubber asphalt(SRA1/2)exhibited excellent elastic recovery and low-temperature flexibility.The 60℃ dynamic viscosity results indicated TPS+rubber asphalt(TRA)had the excellent adhesion.The rotational viscosity results and rheological results indicated that SRA-2 not only exhibited excellent temperature stability and workability,as well as excellent resistance to deformation and rutting resistance,but also exhibited excellent low-temperature cracking resistance and relaxation performance.Based on rheological results,the PG classification of HVA was 16%rubber+asphalt for PG76-22,20%rubber+asphalt for PG88-22,TRA and SRA-1/2 for PG88-28.From comprehensive evaluation of the viscosity,temperature stability and sensitivity,as well as high/low temperature performance of HVA,SRA-2 was found to be more suited to the requirements of drainage asphalt pavement materials.
