降低钻井液水眼粘度的室内研究

利用 Casson 流变模式得到的钴井液的η_∞(习惯上称为水眼粘度)与钻进 V 直接相关.本文在室内研究了钻井液基础材料及30多种处理剂对低固相不分散聚合物钴井液η_∞的影响规律,为现场合理使用这种钻井液体系及降低水眼粘度提供了依据。

水眼粘度与喷速和钻速关系探讨

目前钻井工程计算钻头水力参数公式存在忽略泥策流变参数等问题。将工程和泥浆溶为一体，可推导出反映泥浆漉变参数的水眼粘度、水眼长度高度及流量系数的钻头水力参数计算武。文章根据粘度与喷速和秉压的关系，建立水眼粘度与机械钻速的关系武。水眼粘度低不仅能提高喷速，而且相对固相浓度和分散度低、密度低、初失水大等。综合反映出降低水眼粘度，提高机械钻速的问题。提出了江汉油田降低水眼粘度的途径。

聚合物低固相泥浆水眼粘度与钻速的回归关系

寻求水眼粘度与钻井速度二者之关系和钻井液性能参数对水眼粘度的影响，对陕甘宁盆地使用聚合物低固相钻井液的性能参数和该参数下获得的钻井速度数据进行统计和优选，应用一元线性回归分析法和最小二乘法，拟合得出了钻井速度与水眼粘度的关系的幂函数方程；密度和滤失量与水眼粘度之间的关系是幂函数方程；漏斗粘度和塑性粘度与水眼粘度的关系是一元直线方程，动塑比与水眼粘度二者之关系是一元二次方程．根据回归方程和回归曲线分析得出提高钻井速度合理选择钻井液水眼粘度和与此相配伍的其它钻井液性能参数的取值范围．为现场安全快速钻井提供选择钻井液性能参数的依据．

用蒙特卡罗方法计算恒磁场中流体的粘度

用蒙特卡罗方法研究了水分子体系的结构、内能与磁感应强度的关系。计算结果表明，外加磁场能影响水的内能及水的结构，水的粘度与磁感应强度呈多极值函数关系。

外加剂对金属硅粉-水系统流动性能的影响

考察了各种外加剂对金属硅粉-水系统粘度和流动性能的影响。对加入相同量不同种类的外加剂的试验结果表明,加入萘系磺酸盐UNF-5时对体系的降粘效果最好。同时外加剂的加入量以0.2%(按金属硅粉加入量外加计)时,金属硅粉-水系统的流动性最好。研究还表明,体系处于较强酸、碱度条件下对粘度均有不利影响,微酸性条件下体系粘度最低,流动性最好。

煤层气井注入/压降试井解释中参数的选取

为了避免煤层气井注入/压降试井解释中参数的选取对渗透率、表皮系数、调查半径及边界距离等结果造成多解,作者根据多年的实测经验,通过对现场实测数据的研究,并结合典型实测曲线分析,提出了水粘度、孔隙度、综合压缩系数、流体地层体积系数等参数的取值范围。结果表明,在试井分析过程中,合理的选择这些参数,有利于避免解释多解,能更准确、更实际地评价煤储层。

重力式卧式分离器分离效率影响因素分析

重力式卧式分离器的设计原理是油和水之间存在着相对密度差,当系统处于平衡状态时,油水混合物在一定的温度压力下就会形成一定比例的油相和水相。当相对密度小的组分处于层流状态时,密度大的组分会根据斯托克斯公式运动规律发生沉降。由斯托克斯公式可知,沉降速度与油和水的相对密度差成正比,与水的粘度成反比。通过增加水的密度,使油和水的相对密度差变大,同时使油液的粘度减小能够提升沉降的速度,进而提升分离效率。为验证这一理论,利用CFD软件按照不同边界参数模拟了油水分离的内部流场的浓度分布,分别研究了油水的相对密度差、水的粘度和入口流速对重力式油水分离器分离效率的影响。

Bond condition between surface layer and immediate layer in porous asphalt pavement

Through the shear tests on composite specimens using four different kinds of tack coat material （epoxy resin, SBS modified emulsified asphalt, SBS modified asphalt and H# bridge waterproof material）, the bond condition between layers of porous asphalt pavement under traffic load, temperature variation and moisture situation is evaluated. The test results show that the bond strength decreases with the rise in temperature, and the relationship between shear strength and temperature can be expressed by a logarithm curve at a high reliability. Under the action of traffic load, the value of shear strength of the mixture right under the centre of the wheel track is smaller than that of other parts of the pavement. It is also found that some effects concerning moisture have comparative effects on the bonding of the two layers. Given all the results achieved during the study, it will be quite rewarding to make rational comparisons during selecting the sound type of tack coat.

影响聚合物驱采收率因素研究

通过室内物理模拟驱油实验,研究了影响聚合物驱效果的3种主要因素:水油粘度比、地层渗透率、聚合物用量,并对聚合物驱的基本参数进行了优化。实验结果表明:当地下原油粘度为50.7mPa.s时,聚合物驱的合理水油粘度比区间为0.06～0.6;聚合物驱提高采收率的最佳地层渗透率为2.0μm2;水驱之后转注浓度为3000mg.L-1的聚合物段塞对提高采收率有较大影响,采收率增幅随着聚合物段塞体积的增大逐渐变小;同时聚合物的顿增油量有所下降。

Determination of undrained shear strength using piezocone penetration test in clayey soil for bridge foundation

In order to obtain the reasonable undrained shear strength Su for geotechnical analyses of bridge foundations in Yangtze River floodplain clayey soils, a site-specific study is conducted using the imported piezocone penetration test （CPTu） with dissipation phases at the Fourth Nanjing Yangtze River Bridge construction sites. Taking the values of Su from laboratory tests as references, several existing Su-predicted methods based on CPTu are compared and evaluated. To verify the presented cone factor Nk, additional test sites are selected and examined. The results show that the values of cone factors such as Nkt, Nke, and Nau, depend on the shear test mode and disturbance. Generally, the values of Nke show more scattering than those of Nkt and N△u. For the stratified and layered sediments of the Yangtze River floodplain, it is recommended using the net cone resistance qT to estimate Su and the preliminary cone factor values Nkt are from 7 to 16, with an average of 11. It is also confirmed that the CPTu test, as a new technique in site characterization, can present reasonable parameters for bridge foundations.

Viscosities of Pure Water, Acetic Acid ＋ Water, and p-Xylene ＋ Acetic Acid ＋ Water at Different Temperature and Pressure

The viscosities of pure water,the acetic acid+water binary system,and the p-xylene+acetic acid+ water ternary system at different concentrations were determined with a rolling-ball viscometer at temperatures from 313.15 to 473.15 K and pressures from 0.10 to 3.20 MPa.The viscosity data were fitted by a correlation equation for the estimation of the mixture viscosities.The average absolute deviations(AAD)of the correlation for binary and ternary systems are 2.48%and 1.77%,respectively.

Experimental study on viscosity characteristic of sewage in urban untreated sewage source heat pump system

To confirm the rheological characteristic of sewage in the research and application of urban sewage source heat pump system, the viscosity of sewage was investigated. The tube-type rheometer was used in this experimental study, and the sewage was treated as homogeneous non-Newtonian fluid. In addition, the relational expression between viscosity parameters was developed, and the function of apparent viscosity was obtained. It is concluded that the viscosity characteristic of sewage is influenced largely by complex mixture in sewage, and the sewage has the characteristic of sheared densification fluid.

Density, Viscosity, and Excess Properties for Binary Mixture of Diethylene Glycol Monoethyl Ether ＋ Water from 293.15 to 333.15 K at Atmospheric Pressure

Densities and viscosities were measured as a function of composition for binary liquid mixture of diethylerie glycol monoethyl ether [CH3CH2O（CH2）2O（CH2）2OH] ＋ water from 293.15 to 333.15 K at atmospheric pressure, with a capillary pycnometer and Ubbelohde capillary viscometer respectively. From the experimental data, the excess molar volume V^E, viscosity deviation △η, and the excess energy of activation for viscous flow △G^＊E were calculated. These data were correlated by the Redlich-Kister type equations to obtain the coefficients and standard deviations. The results showed a strong molecular interaction between diethylene glycol monoethyl ether and water.

Bubble size as a function of some situational variables in mechanical flotation machines

The specific results of the work investigating the effect of gas density and water temperature on bubble size were present.These were surrogate variables designed to investigate the effect of viscosity(varying water temperature) and altitude(varying gas density).The results show that there is a measurable but relatively small effect of gas density on bubble size.The D32 is revealed to increase proportionally as(ρ0/ρg)0.132.The projected impact on flotation kinetics at 4500 m versus sea level is small,of the order of 0.5% recovery loss for a bank of eight flotation cells.The effect of water temperature(4-40 °C) on bubble size is more significant than gas density.The relationship correlates with water viscosity values quite closely.A finding that D32 increases proportionally as(μ/μ20)0.776 highlights the importance of accounting for viscosity effects if,for example,large process temperature fluctuations or deviation from design/test conditions are expected.

Volumetric and Viscometric Studies of 4-Aminobutyric Acid in Aqueous Solutions of Salbutamol Sulphate at 308.15, 313.15 and 318.15K

Density （ρ） and viscosity （η） measurements were carried out for 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·L-1 aqueous salbutamol sulphate at T=308.15,313.15 and 318.15K.The measured values of density and viscosity were used to estimate some important parameters such as apparent molar volume Vφ,limiting apparent molar volume Vφ0,transfer volume △Vφ0,hydration number Hn,second derivative of infinite dilution of partial molar volume with temperature 2Vφ0/T2,viscosity B-coefficients,variation of B with temperature dB/dT,free energy of activation per mole of solvent △μ10＊ and solute △μ20＊,activation entropy △S20＊ and activation enthalpy △H20＊ of the amino acids.These parameters have been interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution.

Densities, conductivities, and viscosities of aqueous solutions of N-hexyl,methylpyrrolidinium bromide and N-butyl, methylpyrrolidinium bromide at different temperatures

The densities, conductivities, and viscosities were measured for ternary solutions of N-hexyl,methylpyrrolidinium bromide([PP1,6]Br)- N-butyl,methylpyrrolidinium bromide([PP1,4]Br)-H2 O and its binary subsystems [PP1,6]Br-H2 O and [PP1,4]Br-H2 O at(298.15, 303.15, 308.15, and 313.15) K, respectively. The results were used to test the predictability of the simple equations established for the prediction of density, conductivity,and viscosity of the mixed electrolyte solutions. The results show that the examined simple equations can offer good predictions for density, conductivity, and viscosity of the mixed ionic liquid solutions in terms of the corresponding properties of its binary subsystems of equal ionic strength.

Coupled effect of viscosity enhancing admixtures and superplasticizers on rheological behavior of cement paste

The coupled effect of viscosity enhancing admixtures(VEA)and superplasticizer(SP)on the rheological behavior of cement paste was investigated in this work.Two types of VEAs,including hydroxypropyl methylcellulose(HPMC)and Welan gum,and two types of SPs,i.e.polycarboxylate(PCA)and polynaphthalenesulfonate(PNS)were used as admixtures for cement paste.Rheological curves of cement paste and simulated pore solution containing VEA and SP were tested.Simulated pore solution test results show that molecules of different SPs may generate different effects on the viscosity of VEA solutions.Hershel-Bulkley(H-B)model was used to fit rheological curve of cement paste.Strong interaction between PNS and HPMC was observed in this work.

Wall Sticking of High Water-Cut, Highly Viscous and High Gel-Point Crude Oil Transported at Low Temperatures

Some crude oils with high water cut have the capability to flow below the oil gel point, while the oil particles adhere to the pipe wall in the form of paste, also called "wall sticking". Wall sticking is a serious problem during the pipeline transportation, leading to partial or total blockage of the pipeline and energy wastage. In this paper, a series of laboratory flow loop experiments were conducted to observe the wall sticking characteristics of crude oil with high water cut, high viscosity and high gel point at low transportation temperatures. The effects of shear stress and water cut on the wall sticking rate and occurrence temperature were investigated. Experimental results indicated that the wall sticking rate and occurrence temperature were lower under stronger shear stress and higher water cut conditions. A criterion of wall sticking occurrence temperature(WSOT) and a regression model of wall sticking rate were then established. Finally, the software was developed to calculate the pressure drop along the pipelines of crude oils with high water-cut. It was able to predict the wall sticking thickness of gelled oil and then calculate the pressure drop along the pipelines. A typical case study indicated that the prediction results obtained from the software were in agreement with actual measured values.

Excess Molar Volume, Viscosity and Heat Capacity for the Mixture of 1,2-Propanediol-Water at Different Temperatures

Experimental densities, viscosities and heat capacities at different temperatures were presented over the entire mole fraction range for the binary mixture of 1,2-propanediol and water. Density values were used in the determination of excess molar volumes, VE. At the same time, the excess viscosity was investigated. The values of VE and E were fitted to the Redlich-Kister equation. Good agreement was observed. The excess volumes are negative over the entire range of composition. They show an U-shaped-concentration dependence and decrease in absolute values with increase of temperature. Values of E are negative over the entire range of the composition, and has a trend very similar to that of VE . The analysis shows that at any temperature the specific heat of mixture is a linear function of the composition as x1 > 20%. All the extended lines intersect at one point. An empirical equation is obtained to calculate the specific heat to mixture at any composition and temperature in the experimental range.

Effect of Temperature on Volumetric and Viscometric Properties of Homologous Amino Acids in Aqueous Solutions of Metformin Hydrochloride

Density（ρ）and viscosity（η）are measured for glycine,DL-α-alanine DL-α-valine,and DL-α-leucine in 0.05,0.10,0.15 and 0.20 mol·L^-1aqueous metformin hydrochloride at 308.15,313.15 and 318.15 K.The measured values are used to estimate some important parameters,such as partial molal volume Vφ,standard partial molal volume Vφ^0,transfer volume ΔVφ^0,hydration number nH,the second derivative of infinite dilution of partial molal volume with respect to temperature,viz., ^2 Vφ^0 /T^2,viscosity B-coefficient,variation of B with temperature,viz., dB/dT,free energy of activation per mole of solvent Δμ1^＊0 and solute Δμ2^0＊ of the amino acids.These parameters are interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution.In addition,Vφ^0,0 ΔVφ^0,viscosity B-coefficient,ΔB and Δμ2 ^0＊ are split into group contributions（NH3^＋ COO ^-）and -CH2 of the amino acids using their linear correlation and their behavior is discussed.