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Durkin S.M.,Ukhta State Technical University
Neftyanoe Khozyaistvo - Oil Industry

This article is devoted to the improvement of the methods of well tests interpretation for heavy oil field with fractured reservoirs. Creation of the numerical mathematical model of the well, draining fractured porous reservoir is presented. The developed model will allow to describe the well tests and to identify the type of filtration flow characteristic of fractured reservoirs. Source

Kobrunov A.I.,Ukhta State Technical University
Izvestiya, Physics of the Solid Earth

Analytical properties of the solutions of the inverse problem of gravimetry are studied in the context of the approximative approach and method of linear integral representations. A new effect of the inheritance of specific analytical properties in the solutions, which is named the effect of hidden equivalence, is revealed and investigated. This effect significantly influences the interpretation informativity in the complex models of a medium, and it should be taken into account in the geological interpretation of gravity data. Hidden equivalence is studied for both linear and nonlinear inverse problems. As an example of a nonlinear problem, the inverse problem of structural gravimetry is analyzed. The correlation between the boundary equations and boundary values of the harmonic functions is demonstrated. Methods are suggested to allow for the effects that occur by expanding the approximative approach for complex conditions (the models of the media with spatially distributed parameters) by the dynamical and criterion principles. © 2014 Pleiades Publishing, Ltd. Source

Gerzhberg Yu.M.,Ukhta State Technical University
Neftyanoe Khozyaistvo - Oil Industry

This work is devoted to prevent BHA differential sticking as a result of its sticking to well's wall. We give the methodology and some research results of various factors influence on BHA sticking to a crust by means of contact area determination and the interaction force of pipes with a crust. We show the most significant actions to prevent BHA differential sticking of the boring tool when the boring tool stops working. Source

Gerzhberg Yu.M.,Ukhta State Technical University
Neftyanoe khozyaystvo - Oil Industry

Article is devoted to an integrated approach to design BHA. We consider the issues of its tension at different situations along with its hole path characteristics, we determine the safety coefficient on fatigue resistance, prevention of a holding strap, depressurization of threaded connections. Fundamentals of methodology and examples of configurations complex calculation with the use of computer programs are shown here. Use of several additional centralizers (over lower full-measured) with a diameter, which is significantly smaller, than a bit allows to increase efficiency of regulation of the well path 10-20% and to reduce holding strap forces at its sticking with preservation of optimum mass of the weighted pipes. Source

Multivariate predictive analysis is a widely used tool in the petroleum industry in situations in which the deterministic nature of the relationship between a variable that requires prediction and a variable that is used for the purposes of such prediction is unknown or very complex. For example, to perform a sweet-spot analysis, it is necessary to predict potential oil and gas production rates on a map, using various geologic and geophysical attribute maps (porosity, density, seismic attributes, gravity, magnetic, etc.) and the initial oil and gas production rates of several control or training wells located in the area of interest.We have developed a new technology that allows for building a stable nonlinear predictive operator by using the combination of a neural network, a genetic algorithm, and a controlled gradient method. The main idea behind the proposed technology is to combine stochastic and deterministic approaches during the construction of the predictive operator at the training stage. The proposed technology avoids many disadvantages of the genetic algorithm and gradients methods, such as a high level of dependency on the initial values; the phenomenon of over-fitting (overtraining), which results in creation of an operator with unstable predictability; and a low speed of decreasing error during iteration, and, as a result, a low level of prediction quality. However, the above-mentioned combination uses the advantages of both methods and allows for finding a solution significantly closer to a global minimum for the objective function, compared to simple gradient methods, such as back propagation. The combination of these methods together with Tikhonov regularization allows for building stable predictions in spatial or/and time coordinates. © 2016 Society of Exploration Geophysicists. Source

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