Hydrodynamic Model for the Evolution of an Invaded Zone in Borehole Drilling

The evolution of an invaded zone during borehole drilling in water- and oil-saturated sand formations is studied by mathematical modeling of hydrodynamic processes in porous media filled with a two-component fluid. The use of hydrodynamic modeling to interpret high-frequency electromagnetic logs makes it possible to construct consistent geoelectric and hydrodynamic models for formations with different fluid saturations. The results obtained are in good agreement with geological and geophysical data.     

Method of Probabilistic Convolutions for Interpreting Data of Electromagnetic Logging

A new method is proposed for processing the data of electromagnetic logging in wells. The method is based on the hydrodynamic analysis of drilling mud filtrate penetration into the oil stratum, determination of the field of electrical resistances of the near-well zone with its subsequent averaging by convolutions with a kernel in the form of a logarithmically normal distribution of probe sensitivity.     

Effective method for the synthesis of azolo[1,5-a]pyrimidin-7-amines

Chemistry of Heterocyclic Compounds - Condensation of aminoazoles with (2E)-(3-morpholin-4-yl)acrylonitrile and 3,3-diethoxypropionitrile was used to synthesize a series of...     

Heterogeneous Metal Oxide Coatings with Magnetoactive Nickel,Cobalt, and Iron Phases Formed by the Method of Pulsed Microplasma Oxidation for Radiation Absorption in the Middle and Near-IR Regions

Russian Physics Journal - Heterogeneous coatings with high ability to absorb electromagnetic radiation in the middle (4000–400 cm–1) and near-IR regions (11000–2000 cm–1)...     

Alkenyl derivatives of 5-nitro-2-pyridone: Synthesis and halocyclization

Alkylation of 5-nitro-2-pyridone by alkenyl halides in acetone in the presence of K₂СО₃ proceeds with generation of a mixture of N- and О-derivatives with N-isomer prevailing. 1-Allyl- and 1-methylallyl-5-nitro-2-pyridone react with halogens with the formation of 2-halomethyl-6-nitro-2,3-dihydrooxazolo[3,2-a]-pyridinium halides. 1-Prenyl-5-nitro-2-pyridone reacts with bromine with the formation of 3-bromine-2,2-dimethyl-7-nitro-3,4-dihydro-2Н-pyrido[2,1-b][1,3]oxazinium bromide, and with iodine giving 2,2-dimethyl-7-nitro-3,4-dihydro-2Н-pyrido[2,1-b][1,3]oxazinium triiodide.     

A new approach to synthesis of 3,3‐dialkyl‐3,4‐dihydroisoquinoline derivatives

The synthesis of 3,3‐dialkyl‐3,4‐dihydroisoquinolines via heterocyclization in three‐component reaction of an activated arene with isobutyraldehyde and nitriles is described. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:486–493, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20049     

Invasion Zones in Lateral Drilling

A mathematical model for mud filtrate invasion in lateral drilling is proposed. The main assumption is that the difference in density between the invading and formation fluids is insignificant. Gravitational asymmetry of the invasion front is determined, and it is established that with time one of its points becomes abnormal and the entire invasion zone loses convexity. The main reason for the asymmetry is the density difference. If a lighter drilling mud is injected, the front floats up if the mud is heavier, the front floats down. The abnormal point of the front appears below or above the borehole, depending on the drilling mud weight. In the case where the mud is lighter than the formation fluid, the point of the front directly under the center of the borehole has the special property that with time it is less advanced downward than the neighboring left and right points of the front if the advance is reckoned from the horizontal axis through the center of the borehole. This property is the most pronounced for a small pressure difference between the borehole and formation equal to a certain critical value: under such conditions, the indicated point of the front does not move at all. For large pressure differences, the frontal advance is nearly equal in all directions.