A method for operational forecasting of fires is proposed that enables the sequential implementation of five procedures. The method development is necessary to predict early fires in premises in order to take measures to prevent them from escalating into an uncontrolled combustion phase ‒ a fire. As a result of research, it was found that a short-term forecast of the recurrence of increments of the air conditions by one step, based on the current measure of recurrence, is an effective indicator of early fires in premises. At the same time, it was found that before the moment of ignition of the material, the state of the air environment is characterized by dynamic stability, which is described by an irregular and time-dependent random change in the recurrence of the states of the vector of current increments of the state of the air environment. The values of the indicated levels of recurrence of the state increments are determined by the probability levels of 0.67 and 0.1, respectively. The probability of recurrence of state increments of 0.67 is characteristic of a larger number of measured states. When the material is ignited, the dynamics of the probability of recurrence of state increments change abruptly. There is a transition from two to one level of recurrence, close to zero probability ‒ the loss of dynamic stability (in the region of count 250). Further dynamics are characterized by the appearance of separate random recurrent increments corresponding to the instability of the air environment in the premises. In the course of the experiment, it was found that the accuracy of predicting a fire by the proposed method ranges from 4.48 % to 12.79 %, which generally indicates its efficiency. The obtained data prove useful in the development of new systems that early warn of fire in premises, as well as in the modernization of existing systems and means of fire protection of premises

This paper reports a study into the errors of process forecasting under the conditions of uncertainty in the dynamics and observation noise using a self-adjusting Brown's zero-order model. The dynamics test models have been built for predicted processes and observation noises, which make it possible to investigate forecasting errors for the self-adjusting and adaptive models. The test process dynamics were determined in the form of a rectangular video pulse with a fixed unit amplitude, a radio pulse of the harmonic process with an amplitude attenuated exponentially, as well as a video pulse with amplitude increasing exponentially. As a model of observation noise, an additive discrete Gaussian process with zero mean and variable value of the mean square deviation was considered. It was established that for small values of the mean square deviation of observation noise, a self-adjusting model under the conditions of dynamics uncertainty produces a smaller error in the process forecast. For the test jump-like dynamics of the process, the variance of the forecast error was less than 1 %. At the same time, for the adaptive model, with an adaptation parameter from the classical and beyond-the-limit sets, the variance of the error was about 20 % and 5 %, respectively. With significant observation noises, the variance of the error in the forecast of the test process dynamics for the self-adjusting and adaptive models with a parameter from the classical set was in the range from 1 % to 20 %. However, for the adaptive model, with a parameter from the beyond-the-limit set, the variance of the prediction error was close to 100 % for all test models. It was established that with an increase in the mean square deviation of observation noise, there is greater masking of the predicted test process dynamics, leading to an increase in the variance of the forecast error when using a self-adjusting model. This is the price for predicting processes with uncertain dynamics and observation noises.

The choice of the optimal trajectory of horizontal and directional wells, the placement of frac-ports for multistage hydraulic fracturing, taking into account prepared input data (using geological and geomechanical modeling with the rock properties anisotropy), provide optimization of hydraulic fracturing operations and field development. Formation T contains more than 3 trillion m3 of gas, and is already an object of close attention of the largest oil and gas companies. The unique character of the object is due to the high reservoir compartmentalization of the collector and low permeability. Therefore, the main development strategy for the reservoir is to drill low-angle and horizontal wells, followed by multistage hydraulic fracturing. The main goal of multistage hydraulic fracturing is to join productive intervals and at the same time avoid undesirable fracture breaks into neighboring layers. To achieve this goal, several tasks were solved: creation of a petrophysical and geological basis for geomechanical modeling, creation 1D and 3D geomechanical models taking into account the rock properties anisotropy due to the high layering of the reservoir, and preparing input data for hydraulic fracturing design. For the qualitative creation of the geomechanical model at the observation wells of the field, an expanded complex of special well logging studies has been performed, borehole measurements of reservoir pressure and minimum horizontal stress have been carried out according to the results of stress tests, core sampling and research to determine petrophysical and mechanical properties. The analysis of the obtained information revealed the features of the stress state along the section and reservoir area, which were taken into account in the design of hydraulic fracturing. Geomechanical modeling was carried out in a uniform work procedure, which made it possible to unify the result, improve the quality of calculations and forecast parameters for horizontal wells.

This paper theoretically substantiates research into the spectral features of the dynamics of the main dangerous parameters of a gas environment when igniting materials in a laboratory chamber. Studying such spectral features is based on the calculation of the direct discrete Fourier transform for discrete measurements, equal in number, over the current intervals of observation of the hazardous examined parameter of the gas medium before and after the material is ignited. In this approach, a Fourier discrete transform makes it possible to determine the instantaneous amplitude and phase spectra for the time intervals under consideration. This makes it possible to explore the peculiarities of the distribution of amplitudes and phases of harmonic components in the spectrum of the dynamics of dangerous parameters of the gas environment before and after the ignition of materials. The results of experimental studies established that the nature of the amplitude spectrum is low-informative and not sensitive enough to fires. The main contribution to the amplitude spectrum of the dynamics of the investigated hazardous parameters of the gas environment in the chamber is made by the frequency components in the range of 0–0.2 Hz. The contribution to the amplitude spectrum of frequency components over 0.2 Hz is insignificant and decreases with increasing frequency. It is established that from the phase spectrum, the nature of the random scattering of phases for frequency components exceeding 0.2 Hz is informative. It was found that the nature of the phase spread for these frequency components in the spectrum depends on the type of ignition material. The results reported here could prove useful when devising new effective technologies for detecting fires in the premises of objects in various fields to protect against fires. This is explained by the fact that for the detection of fires in the premises, high-frequency components are important, characterized by the increase in dangerous parameters of the gas environment

In 2009, OJSC "Samotlorneftegas" began performing two-stage fracture stimulations in newly drilled and sidetracked wells. The wells were treated zone-by-zone, with frac fleets doing two or more frac jobs. Slotted filter intervals were treated first. Then they were plugged off with bridge plugs or proppant for the next interval to treat. After two frac jobs, the bottom-holes were cleaned and the wells were started. The success of the method consisted in an increased oil production at an early stage of production (around 40 tons per day from newly drilled wells) and in a slower decline in flow rates throughout the first year of production (around 35%) as compared to directional wells. There was only one disadvantage - a longer shut-in period (up to 60 days), which, with low formation pressures, can lead to a lower oil increment due to saturation of the formations with flush fluids. In mid 2011, the multistage stimulation technologies did not find improvement for a number of reasons: No multistage fracturing equipment on the market. No such equipment was built in Russia and oil companies showed little interest in a large-scale application of purpose-built multistage fracturing completion systems;Lack of multistage fracturing experience;Significant geological and technological risks involved, when using these technologies to improve production to expected levels and enhance the cost effectiveness of these projects;Little experience in horizontal drilling with the drilling conditions being difficult to make large enough holes to accommodate multistage fracturing systems (MSFS). No effective annular isolation techniques. In the first half of 2011, special ball-activated sleeves were delivered to the Russian market from abroad. However, OJSC "Samotlorneftegas" continued using an interesting multistage fracturing technique employing the use of burst port collars and cup-to-cup (C2C) tools. The technology was being improved for 4 years. Owing to the improvement efforts, a unique 29-stage frac job was performed at the beginning of 2016.