Phase distribution and intrapore salt exchange during drilling mud invasion of an oil- and gas-bearing formation

As a result of drilling mud filtrate invasion of a formation saturated with oil, gas and natural water, the distribution of the immiscible phases and the electrophysical characteristics of the near-well zone change as compared with its initial state. Taking this change into account is necessary for successful interpretation of electrical well logging data. In this paper, on the basis of the equations of immiscible fluid flow through a porous medium and the system of transfer equations with account for instantaneous salt exchange between the filtrate and the natural water inside the pores, the regions of initial formation fluid saturations for which in the invasion zone the displacement fronts retain their relative position are determined.     

A Micromethod of Estimating the Reactivity of Cellulose to Acetylation

A micromethod was developed for estimating the reactivity of cellulose to acetylation by monitoring temperature variation in the process.     

First normal stress difference-temperature dependence for polystyrene and high-impact polystyrene melts

The method of reduced variables or superposition is applied to investigate the first normal stress difference (N₁)-temperature dependence over the shear rate (γ) range 10–1000 s^?1 for polystyrene (PS) and high-impact polystyrene (HIPS) melts, at temperatures of 180 C and above. These conditions are similar to those for industrial polymer processing. For PS, the first normal stress differences are obtained using Tanner's equation, leading to good agreement with values obtained by other authors and methods. For HIPS we have not found data in the literature for N₁ at shear rates above 10s^?1. In our case N₁ was obtained by measurements of entrance pressure losses. Correlations, based on master curves, are found for first normal stress difference in terms of shear rate and temperature. All samples follow the power law equation $\text{N}{}_1\text{= k}\text{γ}\text{?}{}^{\mathrm{m}}$, with values of m ranging from 0.50 to 0.64.     

1,1-双取代二茂铁化合物的13C核磁共振研究

Two 1,1'-disubstituted ferrocene organometallic compounds 1,1'-dihydroxy-methylferrocene (Ⅰ) and 1,1'-diformylferrocene (Ⅱ) have been synthesised. The ~(13)C NMR spectra in CDCl_3 solution have been determined and assigned. A theoritical calculation of ~(13)C NMR chemical shift based on our INDO/σ program has been applied to these two compounds which included d orbitals. These are the most complicated compounds up to now for the chemical shift calculation, It is satisfied for the trend between the theoritical calculation and experiment.     

高温煤气脱硫 Ⅰ．铁锌基脱硫剂脱硫工艺条件及硫化动力学

用自制的铁酸锌高温煤气脱硫剂研究了硫化氢浓度、硫化温度、空速对脱硫反应及脱硫剂物理性质的影响。结果表明：铁酸锌脱硫剂的反应活性随着Ｈ２Ｓ浓度及硫化温度的升高而升高，脱硫温度为５５０℃时，脱硫剂的硫容量最高，脱硫剂的物理性质基本保持不变；硫化空速为８５０ｈ￣（－１）时，空速和反应时间同时达到最大值。硫化反应可用未反应核收缩模型描述，得到了转化率与时间之间的动力学方程。     

Mapping dark matter with cosmic magnification

We develop a new tool to generate statistically precise dark matter maps from the cosmic magnification of galaxies with distance estimates. We show how to overcome the intrinsic clustering problem using the slope of the luminosity function, because magnification changes strongly over the luminosity function, while intrinsic clustering only changes weakly. This may allow precision cosmology beyond most current systematic limitations. The Square Kilometre Array is able to reconstruct the projected matter density map at smoothing scale approximately 10' with S/N > or = 1, at the rate of 200-4000 deg2 per year, depending on the abundance and evolution of 21 cm emitting galaxies. This power of mapping dark matter is comparable to, or even better than, that of cosmic shear from deep optical surveys or 21 cm surveys.     

Development of oil inclusions under the action of chemical reagents on the reservoir

Various conditions of formation of motionless closed hydrocarbon inclusions are considered: viscous instability of fluid displacement and inhomogeneous rock structure. Conditions of dynamic equilibrium of the inclusion in a water flow are given for one-dimensional and two-dimensional motion. Distributions of the oil content in inclusions of different shapes are numerically calculated. It is found that the amount of unrecovered oil depends on the ratio of the pressure gradients in the filtration flow of water pumped into the reservoir and the characteristic capillary pressure on the boundary of immiscible phases. It is demonstrated that the use of chemical reagents can substantially reduce the effect of capillary forces and promotes oil entrainment by the overall flow.     

Modeling of the Spectral Characteristics of Reflection Holograms in Photopolymeric Materials

The dependences of the spectral characteristics of reflection holograms on various parameters are investigated for the model of multilayered thin films and in the context of the Kotel'nikov theory of coupled waves. The practically important cases of the influence of the recording layer thickness shrinkage, the Bragg angle mismatch, and the recording of multicolored reflection holograms are considered. A comparative analysis of the experimental data and the results of computer modeling is made.