The article is devoted to the study of thermoelectrical element. The model of thermoelectrical element of Earth’s crust was developed. Long-lived deep faults with graphite ores inside are the basis of the element, they provide continuous electrical connection between the upper part of Earth’s crust and the mantle. Temperature difference between them can reach 1 000 ⁰С and more because of geotemperature gradient. That is why Seebeck effect causes thermopower and thermoelectrical currents moving directly upwards to arise. And that is the reason why natural electric potentials of high intensity up to –2…–10 V are fixed over graphitized rocks because of presence of thermopower. There was found a mathematical solution to quantify them. Stationary observation of those thermopotentials can help study Earth’s tense zones and control the dynamics of thermal deep processes, which are often connected with volcanic activity and seismic events.

The article is devoted to the problem of improving the substantiation of the diagnostics of production Jurassic and Neocomian reservoirs in the West Siberian basin. We have formed the complex of geochemical investigations of core material to solve this problem. It includes extraction of bitumen with its material composition detection, thermal desorption and analysis of retained hydrocarbons. Using the obtained data, we have carried out a comparative analysis of Jurassic sediment intervals in two wells within one field. We studied the quantitative and qualitative characteristics of the hydrocarbon core fluid, determined the geochemical criteria of its mobility in reservoir conditions, namely the ratio of the naphthenic component to n-alkanes. Also, we carried out inter-well correlation of the relations of n-alkanes and isoprenoids, established the facies conditions of sedimentogenesis and oxidation-reduction conditions of the initial stage of organic matter fossilization. Based on the chromatograms of retained gases we determined the efficiency criteria of the interval such as benzene/n-hexane and toluene/n-heptane. Conclusions about the saturation of the studied intervals were confirmed by inspection test record. The results of the work showed that complex geochemical studies of the core can significantly increase the reliability of the diagnosis of the drilled sediments saturation.

The article is devoted to the issue of geological modelling. The sedimentational environment of Tyumenand Frolov suites productive deposits is reconstructed using complex regional analysis of seismic and well data. Detailed facial models are built for UKand AS₃ reservoir group. Concordant structural model, reservoir properties mapping, saturation recognition, oil-water contacts estimation, and pool contouring are made for oil initial resources evaluation.

The issue of vertical wells curvature is important, especially when conducting wells in complex geological conditions of drilling, due to the increasing depth of the wells and the corresponding rise in the cost of drilling. The cause of this circumstance lies in the large time and financial costs while flattening of the bent wells. Moreover, it should be noted that during the subsequent drilling of a curved well the risk of key-seating and the corresponding complications increases. That is why large oil field service companies and drilling enterprises are paying more and more attention to solving the problem of vertical wells curvature.
This article is devoted to investigation the effect of rotation of the drill string on the deflecting force on the bit while drilling a vertical well in a rotary way. We suggest using of eccentric drill collars for drilling vertical wells in difficult geological conditions. Also, we create an expression for the dynamic milling force on the bit, taking into account the usage of an eccentric drill collar in the composition of bottom-hole assembly.

It has been repeatedly noted in the literature that the physic-chemical properties of oil extracted at different stages of exploitation can vary significantly. We have investigated a modification of the Buckley — Leverett model (BL model) in our previous works to study the influence of oil viscosity change on the solutions of twophase filtration problems. In this model the change in oil viscosity was modeled using the dependence of the viscosity ratio on dynamic water saturation. The solutions to the linear displacement problem at a given total filtration rate were analyzed.
This article considers a modification of the two-phase isothermal Muskat — Leverett model (ML model), which takes into account capillary forces. The influence of oil viscosity change in the process of oil production on the structure of the solution is studied numerically a case study of the problem of radial displacement with a given pressure drop.

The development of oil and gas condensate fields is accompanied by phase transformations of reservoir mixtures, i.e. the when the bottomhole pressure drops below the dew point pressure, the liquid condensate becomes versatile and enters the gas phase. Retrograde condensate leads to a decrease in phase permeability in the bottomhole. As a result, it also leads to a decrease in production levels is reduced both by gas and natural gas liquids. The article considers this challenge and its possible solutions by the method of unsteady-state conditions well efficiency, on which the hydraulic fracturing was carried out. The issue of well efficiency is urgent in conditions abnormally high reservoir pressure and considerable condensate yield.

During the late stage of gas field development, the solution of specific issues is required to increase the flow rates of wells and reduce their water cut. The accumulated experience in the development of gas and gas condensate fields indicates that the most effective way to remove water accumulating in wells is to introduce foaming compositions based on surfactants to the bottom of the wells. The most technologically advanced application was the use of solid and liquid surfactants. The installation of smaller diameter tubing in the wells ensured the removal of fluid from the bottom of the well, but after several months of operation the conditions for removing the liquid from the bottom of the well deteriorate. Technologies for using concentric elevator systems and plunger elevators are used on a single number of wells. The main technology for removal of liquid from the bottom of gas wells is currently the technology for processing bottom holes with solid surfactants.

The article deals with a hypothetical model of the molecular structure of degassed and gas-saturated oils developed on the basis of the J. I. Frankel’s hole theory of liquid. Based on this model, the author of the article obtained semiempirical dependences for calculating compressibility factors of degassed and gassaturated oils. The fact that the obtained dependences are based on the noted model gives the necessary physical validity to them and the specific physical content to the empirical parameters contained in them. As a result, semi-empirical dependences become theoretical. Corresponding calculations confirm that their scope broadens as the types of oils and conditions for their finding.

When determining the operability of the sealing elements, it is necessary to take into account the overall movement of the packer during operation, which it passes before the damage of the sealing elements when fixing the leakage failure in the annulus. It should be noted that as the frequency and the amplitude of the pressure of injected liquid pulses increase, the distance travelled increases proportionately. According to preliminary calculations, the average leakage volumes of injected fluids are in the range 0,005 ... 0,1 cm³/m² with the prevalence of possible leakages at the level of 0,05 cm³/m². As a result of preliminary calculations, it was found that the average performance of mechanical packers in the case of nonstationary waterflooding impulse before identifying significant leaks was 30,000...50,000 km. It should be taken into account that with increasing frequency and amplitude of the pressure of pulses in the injected fluid, the operability and longevity of the packer seal reduce. The article suggests recommendations for improving the reliability of packers for long-term pulsed water injection into injection wells.

Currently, a large number of Cenomanian gas storages inWestern Siberiaare at the final stage of development. Gas production from such storage is accompanied by the accumulation of different types of liquid at the bottomhole. One of the methods of solving this problem is the introduction of a foaming agent into the well. To date, there are no computational models that allow us to predict with a high level of accuracy the pressure loss in the tubing of a gas well working with surfactant in the flow. The existing few computational models were created on the basis of bench studies under atmospheric conditions, and the results obtained by them have significant errors. For the study and modelling of gas-liquid flows with surfactant taking into account the influence of pressure, temperature, water-gas ratio and other key parameters, an "Experimental facility to simulate gas-liquid flow and dynamic processes in the tubing of a gas well" was developed and implemented.

This article aims to numerically investigate the stress-strain state of the tank at the appearance a local area of inhomogeneity in the soil foundation. We have established the size of the zone of influence of the inhomogeneity area of the base on the work of the tank wall. Also, we have formulated proposals to adjust the requirements of the Russian regulatory and technical documentation.

Today evaluation of the technical assessment of the linear part of main gas pipeline is one of the most important tasks of pipeline operation. However, many assessment methodologies provide only a partial picture of the technical condition and don’t take into account the conditions for pipeline laying. This article discusses the improvement of methods for technical assessment of main gas pipelines.

The article deals with the operating conditions of Sobolevo — Petropavlovsk-Kamchatsky gas pipeline. Much attention is given to technical assessment of aboveground crossings of this gas pipeline. We report key climatic conditions and other factors affecting gas pipeline operation. Also, we present the results of aboveground crossings partial monitoring and detect the matters of their condition significant degradation.

Conducting thermal calculations of "hot" oil pipelines through which high-viscosity and high-sticking oils are transported is one of the main ones. Determining the rate of cooling of oil in a stopped pipeline is of practical importance. According to the cooling rate, the time to safely stop the "hot" pipeline is calculated. This is the time at which the "hot" oil pipeline doesn’t freeze and the station’s pressure is enough to overcome the shear stresses arising during the cooling f high-viscosity and high-sticking oil. Oil cooling in underground stopped pipelines depends on the temperature of the soil around it. Installed heat stabilizers designed to cool the soil can affect the cooling rate of the "hot" pipeline.
We have carried out a numerical experiment using modern tools of mathematical modelling. The experiment showed that the installed soil heat stabilizers near the underground "hot" pipeline have an impact on the process of cooling oil. These stabilizers have reduced the time to safely stop the pipeline.

Elements of drilling equipment are subjected to random loads with very high amplitudes during operation. Classical methods of probabilistic calculation of gearings don’t allow us to estimate the probability of their failure taking into account the real operational data obtained by telemetry when these data cannot be described by standard distribution laws. The offered technique is based on application of methods of non-parametric statistics therefore it is free from these restrictions. All its stages are realized in the Mathcad mathematical processor.
The article describes the technique of failure probability of gearing of drilling rig top drive system in accordance with criterion of bending endurance of teeth. Results of its realization for failure probability assessment of gearing at its operation in the heavy loading mode agree well with failure statistics. Also, the technique allows us to determine the probability of gearing failure for any load distribution laws during operation, including, when the loading mode is defined by sample.

Investigations were carried out to study the state of the soil in the territory of the Shetpe South chalk deposit and in the area of the Caspian Cement plant in October 2018. 20 soil samples were taken. Samples were taken from a depth of 0–20 cm. The presence of heavy metals in the soil was determined by atomic absorption spectrometry using AAC MGA-915M (Lumex, Russia), their content was compared with background values and with existing maximum allowable concentrations. The total soil pollution indicator or Z_C , using the background, was used to study the state of the soil. The indicators of the soil pollution index were calculated to improve the diagnostic performance of the study area. The calculation of the total soil pollution indicator showed that the value of Z_C for all sites was from 3,58 to 5,26 units. The soils are characterized as non-hazardous (Z_C < 16), and the assessment of the condition of the soil is biased due to taking into account only heavy metals with K_C < 1. The soil pollution index calculations showed that the majority of soil samples at sites PP-1, PP-2 and PP-3 have indicators of soil pollution index > 1, which characterizes the soil as "polluted". At site PP-4 (control) the soil pollution index is 0,74, the soils are "clean". Statistical processing in the environment Statistica 10 showed that the Kruskal — Wallis criterion is statistically significant only for Ni and As (p < 0,05) for soil samples at site PP-2 (at the site of transportation of chalk and dumps). Maps were performed using satellite imagery and using of Google Maps, Mapinfo Professionalv. 12.