Articles

Geology

Evaluation of reservoir saturation and unrecovered reserves localization by pulse-code interference testing

Volkov Yu.V., Mingaraev R.A., Fatkulin M.R., Khaziev R.R., Andreeva E.E., Zinurov L.A.

DOI: 10.24412/2076-6785-2021-5-35-39

Abstract
In this paper, the method of pulse-code testing (PCT) on one of the squares of the fields of the Volga-Ural province to assess localized reserves of hydrocarbons (HC) and the feasibility of workovers and sidetracking to increase ultimate recovery up to value at field development plan. During the PCT, the following tasks were solved: the residual hydrocarbon reserves in the study area were estimated; the forecast indicators of liquid and oil after the sidetracking were calculated; the influence of the generator well Y1 on the surrounding wells was estimated.

Materials and methods
During PCT surveillance, downhole pressures were recorded at wells using zPas-20M quartz pressure gauges (with a resolution of 20 Pa) which is based on a temperature-stabilized quartz crystal. Furthermore, water injection rate of the injection well was measured using a portable flow meter. PCT is based on the Pulse-Code Decomposition (PCD) algorithms
a procedure for decomposing complex pressure responses at each well into different components, where each component correlates with the flow rate changes history of only one particular generating well.

Keywords
well testing, interference test, oil reservoir, transmissibility, diffusivity, reservoir evaluation, reserves localization

The mechanism of the indicator propagation in a terrigenous formation during tracer studies

Izotov A.A., Afonin D.G.

DOI: 10.24412/2076-6785-2021-5-31-34

Abstract
The tracer method of research is used in oil fields in the study of filtration flows in the reservoir. Studies reveal similar phenomena: a high speed of movement of labeled water for a porous medium, an uneven geometry of the distribution of flows over the area of the deposit. This still causes various hypotheses among researchers. Based on the geological and field analysis and research results, the concept of the indicator propagation in a terrigenous formation through technogenic fractures of auto-fracturing is proposed, which removes contradictions and combines hypotheses and facts. A method for calculating the parameters of cracks for the purpose of planning insulation works is proposed.

Materials and methods
Materials: analytical database, monthly operational reports on the deposits of the Russian Federation. Methods: geological and commercial analysis, graphical representation
of dependencies.


Keywords
tracer studies, flooding, waterlogging, auto-hydraulic fracturing

Forecast oil content of sakmarian sediments in the east side of Tatarstan Republic according to study core matherial of bio-testing wells

Khaziev R.R., Anisimova L.Z., Baranova A.G.

DOI: 10.24412/2076-6785-2021-5-24-27

Abstract
The trend of annually increasing oil production in the Volga-Ural oil and gas province requires increasing the mineral resource base by opening new fields or entering into development of hard-to-recover (unconventional) hydrocarbon reserves. One of this alternative sources of hydrocarbons is Permian bitumen, which is concentrated in the ufimian, kazanian and lower permian sediments in the south-east of Tatarstan. Prospects for the discovery of small bituminous deposits are also available in the eastern part of Tatarstan, where positive forecasts for hydrocarbon raw materials for the deposits were obtained according to lithological, tectonic criteria and the results of drilling test wells.

Materials and methods
Theoretical lithological-facies maps of the sakmarian deposits on the Tatarstan Republic. Practical maps with the results of drilling bio-testing wells. Object of research exploration areas on the territory of the eastern slope of the South Tatar arch.

Keywords
super-viscous oils, carbonate reservoir, sakmarian deposits, bio-testing wells, secondary mineralogy

Tectonic history of Beregovoye oil and gas field from the point of view of new geological and geophysical data (history of formation of structural forms of productive reservoirs)

Gorbunov P.A., Lebedev M.V., Yanevits R.B., Fishenko A.N., Dorohov A.R., Abrashov V.N.

DOI: 10.24412/2076-6785-2021-5-17-20

Abstract
This article completes the cycle of studies devoted to the paleotectonics of the Beregovoye field (Yamalo-Nenets Autonomous District). The article presents the results of studying the history of the formation of structural forms of productive reservoirs.

Materials and methods
Materials: the results of the structural interpretation of the seismic volume of the Beregovoye oil and gas field, including the results of structural mapping for the uppermost reflecting horizon E. Methods: Analysis of power maps according to the method of V.B. Neiman.

Keywords
Western Siberia, Beregovoe oil and gas field, tectonics, paleotectonic analysis, productive reservoirs, reflecting horizon E

A comprehensive approach to the efficiency evaluation of a block agent using laboratory core analysis

Kochetov A.V., Usoltsev A.V., Neklesa R.S., Bikmulin R.Z.

DOI: 10.24412/2076-6785-2021-4-40-43

Abstract
The use of a traditional well-killing fluid (water-salt mixture) may lead to a large liquid loss, which causes the increase in the amount of chemicals needed for operation, time expenditures and consequently the overall price of work.
In this study a series of formation damage tests were performed on core samples from Cenomanian formation at reservoir conditions in order to collect data about the effectiveness of several modern block agents presented on the market. The parameter of the fluid intake capacity, which defines the invasion zone characteristics of the near-wellbore formation, was examined for the purpose of a more consistent and complete analysis of the research data.
As a result: two block agents (Gelenix and MEX BLOCK) had low value of the fluid intake during the expose period (80 hours) and high value of the formation damage coefficient. That makes these two-block agent the most effective among the tested process fluids.


Materials and methods
Materials: rock (core samples) from Cenomanian formation, wellkilling brines, block agents (based on gelling fluids), oil samples from Cenomanian formation. Methods: the measurement of swelling capacity of oil-saturated / watersaturated samples, formation damage tests on block agents.

Keywords
block agents, core samples, permeability, formation damage coefficient, fluid intake capacity, oil saturation

Estimating minimum miscibility pressure and minimum oil swelling when displaced by associated petroleum gas for the conditions of an East Siberian field

Kobyashev A.V., Pyatkov A.A., Zakharenko V.A., Gromova E.A., Dolgov I.A.

DOI: 10.24412/2076-6785-2021-4-35-38

Abstract
A case study of the Severo-Danilovskoye field in East Siberia is presented to describe an experimental measurement of miscibility between oil and injected gas. The minimum miscibility pressure and the minimum oil swelling by associated petroleum gas are estimated. The slim tube displacement efficiency as a function of gas enrichment with C2C4 components is obtained. An approach to planning displacement conditions in a slim tube using correlations and an equation of state is presented.

Materials and methods
Materials: results of slim tube oil-gas displacement evaluation of the Severo-Danilovskoye field in East Siberia. Methods: estimation of the minimum miscibility pressure using Maklavani correlation and the state equation.

Keywords
minimum miscibility pressure, minimum oil swelling, equation of state, gas injection efficiency

The influence of tectonic processes on HC deposits formation at the Vankor cluster

Fateeva E.V., Buyakina I.V., Kantemirova N.A.

DOI: 10.24412/2076-6785-2021-4-30-33

Abstract
The influence of tectonic processes on the formation of hydrocarbon traps is studied on the example of the Vankor cluster. Geological and geophysical materials, as well as the difference in fluid contacts were analyzed to study paleotectonic activity, the periods of structures development intensity and to understand the features of structural and tectonic formation of hydrocarbon traps within the Lodochnoye Val. The presence of tectonically stressed zones within the Lodochnoye field and at the edges of Tagulskoye Lodochnoye Vankor uplifts has been confirmed.

Materials and methods
Materials: seismic data on the Vankor cluster, interpretation of logging data in the Lodochnoye field wells. Methods: maps, graphic images of structures depths vs. formation
period.

Keywords
paleotectonic analysis, separation zones, fluid contact levels, structures development, the Lodochnoye field

Tectonic history of Beregovoye oil and gas field from the point of view of new geological and geophysical data (history of tectonic development)

Gorbunov P.A., Lebedev M.V., Yanevits R.B., Fishenko A.N., Dorohov A.R., Abrashov V.N.

DOI: 10.24412/2076-6785-2021-4-24-28

Abstract
This article continues the cycle of studies devoted to the paleotectonics of the Beregovoye field (Yamalo-Nenets Autonomous District). The article presents the results of studying the history of tectonic development of the field.

Materials and methods
Materials: the results of the structural interpretation of the seismic volume of the Beregovoye oil and gas field, including the results of structural mapping for the uppermost reflecting horizon E. Methods: analysis of power maps according to the method of V.B. Neiman.

Key words
Western Siberia, Beregovoye oil and gas field, tectonics, paleotectonic analysis, reflecting horizon E

Tectonic history of Beregovoye oil and gas field from the point of view of new geological and geophysical data (seismogeological cross section)

Gorbunov P.A., Lebedev M.V., Yanevits R.B., Fishenko A.N., Dorohov A.R., Abrashov V.N.

DOI: 10.24412/2076-6785-2021-4-20-23

Abstract
This article opens a series of studies devoted to the paleotectonics of the Beregovoye oil and gas field (Yamalo-Nenets Autonomous District). The article provides general information about the object, as well as the characteristics of the seismic-geological cross section of the field.

Materials and methods
Materials: the results of the structural interpretation of the seismic volume of the Beregovoye oil and gas field, including the results of structural mapping for the uppermost reflecting horizon E. Methods: Stratigraphic well tie and correlation of seismic reflections, analysis of the structure of reflecting horizons.

Key words
Western Siberia, Beregovoye oil and gas field, tectonics, paleotectonics, seismogeological cross section, reflecting horizon E

Assessment of the generation potential of the bazhenov formation in the Khanty-Mansiysk autonomous okrug

Fedorova E.V.

DOI: 10.24412/2076-6785-2021-4-16-18

Abstract
The article studies and describes information about the features of the bazhenov formation. On the basis of the PetroMod software package, models were built that reflect the generation capabilities of the bazhenov formation in the Khanty-Mansiysk autonomous okrug, the corresponding conclusions about the prospects of the considered area.

Materials and methods
Vostochno-Surgutskoye field, basin analysis, PetroMod software.

Keywords
Bazhenov formation, Khanty-Mansi autonomous okrug, PetroMod, generation potential

Oil production

Study of the effect of a bimetallic catalyst based on iron and cobalt on the aquathermolysis process under thermal steam treatment of high-viscosity oil

Baygildin E.R., Sitnov S.A., Vakhin A.V., Nurgaliev D.K.

DOI: 10.24412/2076-6785-2021-5-46-51

Abstract
In this work, we studied the effect of bimetallic catalysts formed in situ from mixtures of oil-soluble iron and cobalt precursors in the process of aquathermolysis of heavy oil from the Ashalchinsky field. Based on the results of determining the group composition (SARA analysis) and viscosity-temperature characteristics, an improvement in the composition and an increase in the mobility of oil under the action of steam and a bimetallic catalyst is shown. It was found that the catalyst intensifies the destructive processes of resinous compounds, provokes the enrichment of the destruction products of the latter in the saturated and aromatic fractions with high molecular weight n-alkanes and polycyclic hydrocarbons, respectively. It was revealed that the proposed catalyst of the optimal composition is a mixture of individual and mixed oxides and sulfides of iron and cobalt (ferrospinels). Catalyst can be used at the Ashalchinsky field of heavy oil in conditions close to reservoir conditions (200 C, 10 bar), as a reagent providing an increase in the degree of oil recovery.

Materials and methods
Heavy oil of the Ashalchinsky field of the Republic of Tatarstan, SARAanalysis, viscometry, gas chromatography-mass spectrometry (GC-MS), catalyst active form, XRD.

Keywords
heavy oil, steam treatment, bimetallic catalyst, oil-soluble precursors, catalyst active form, in-situ upgrading, EOR

Revealing the direction of natural fracturing and cavernousness in order to optimize the field development parameters

Ponomarev M.D., Borkhovich S.Yu. , Mavliev A.R., Polozov M.B., Trubitsyna N.G.

DOI: 10.24412/2076-6785-2021-5-42-44

Abstract
This article evaluates the study of the direction of spread of natural fracturing and predominant direction of propagation of cavernousness of the carbonate reservoir of the Podol-Kashiro-Vereiskian object of the Elnikovskoye oil field. The studies are based on the analysis of information on the sampled core, tracer studies, the FMI method and the mutual influence of production/injection wells. The study identified the main directions of natural fractures and vugginess. These parameters must be taken for well coverage, in particular, adjusting the location of production/injection wells in order to prevent anticipatory water invasion, as well as when selecting candidates for geological and technical measures to increase the
final oil recovery factor.

Materials and methods
Based on the analysis of practical material on optimizing the conditions of the fields being developed in the territory of the Udmurt Republic.

Keywords
natural fractures, natural vugginess, development, oil field, carbonate reservoir rock, geological and technical actions, interference of wells

The experience of oil recovery using nonionic surfactants

Kozhin V.N., Gorodnov V.P., Kalinin E.S., Ryskin A.Y., Chernov E.N.

DOI: 10.24412/2076-6785-2021-4-46-52

Abstract
Nonionic surfactants provide benefits of possibility of large-scale production for oil industry demands. However, the laboratory and field tests
show their inferiority to anionic surfactants due to propensity for salting out when the reservoir temperature is higher than the cloud point of
the repressuring solution containing the nonionic surfactant. This paper describes the results of a field test of water solutions of alkylphenol
ethoxylates from different manufacturers, both with and without polyacrylamide, compared to the previous field tests of these reagents.
The innovative technologies for use of nonionic surfactants are based on their thermal salting out from the water solution and on the polyacrylamide
complex formation possessing high selectivity when moving in the reservoir, i.e. poor filtration into the watered and good filtration into the oilsaturated
areas.

Materials and methods
Materials: data on the field test of nonionic surfactants as a reagent
for improving reservoir oil recovery in Western Siberia and Urals-Volga
regions.
Methods: analysis of the results obtained when testing variety of technologies based on using aqueous nonionic surfactant solutions in
the oil fields of Western Siberia and Urals-Volga regions.

Keywords
nonionic surfactant, improving reservoir recovery, field tests

Seismogeological analysis as a tool of history matching: YNAO Case Study

Gorlanov A.A., Vorontsov D.Y., Schetinin A.S., Aksenov A.I., Ovchinnikova D.G.

DOI: 10.24412/2076-6785-2021-3-34-40

Abstract
The process of raising the gas-water contact (GWC) is inevitable during development of the reservoir. This leads to flodding of wells and reducing of daily gas production. Horizontal sidetracks and new horizontal drilling allows to maintain production at the required level. Mostly, the direction of the horizontal section of the well determines its efficiency. In difficult geological conditions, a detailed analysis of seismic data in the drilling area allows to reduce drilling risks and achieve planned starting rates. Accounting of seismic data in geological models is often limited by a low correlation coefficient between reservoir properties obtained from wells and seismic attributes. Simulation models use seismic data based on the assumptions made by the geological engineers.

Materials and methods
In this paper authors uses a iterative approach to geological modeling: implementations include in-depth analysis of seismic data and well performance dynamics. Modern software modules were used to automatically check the compliance of the geological implementation with the development history, as well as to assess the uncertainties. High correlation coefficients between well water cut and seismic attributes obtained. Authors developed a method for determining the presence of shale bodies and confluence windows of a massive gas reservoir with water-saturated volumes.

Keywords
geological modeling, simulation run, Pokurskaya suite, gas reservoir, cenomanian, horizontal wells, attribute analysis

The selection approach for the efficient development method gas-and-oil fields based on multialternative calculations

Potapov K.R., Polozov M.B., Trubicyna N.G., Borkhovich S.Yu.

DOI: 10.24412/2076-6785-2021-3-29-32

Abstract
The article describes the selection approach for the efficient development method of the vereiskian formation of the Chutyr field. To optimize the method, the filtration model of the vereiskian and bashkirian formations was prepared and historically matched. Based on multialternative calculations, the practical field development method was determined.

Materials and methods
Based on the analysis of practical material, the testing of the method of foam acid exposure in the conditions of developed fields in the territory of the Udmurt Republic.

Keywords
efficient system, development method, gas and oil field, filtration model, fluid flow model, multialternative calculations, modelling

Corrosion

Investigation of the protective effect of carbon dioxide corrosion inhibitors under dynamic conditions

Tsarkov A.Yu., Rodnova V.Yu., Nechaeva O.A.

DOI: 10.24412/2076-6785-2021-4-54-56

Abstract
The paper presents the influence of various factors on the rate of carbon dioxide corrosion of oil and gas field equipment, the characteristics of the inhibitors used in the companies are given. The corrosion rate of steel in a brine saturated with carbon dioxide at flow rates of 0,5 m/s and 2 m/s was investigated by the gravimetric method. The results of evaluating the protective effect of a water-soluble nitrogen-containing reagent are presented; the positive effect of the addition of a nitrogen- or phosphorus-containing surfactant is shown.

Materials and methods
Materials: industrial samples of nitrogen-containing corrosion inhibitors designed to protect equipment in oil and gas production systems, water-soluble nitrogen- and phosphorus-containing surfactants. Methods: measurement of the corrosion rate of a brine saturated with carbon dioxide under dynamic conditions based on the weight loss of steel-20 samples, comparative analysis of the protective effect of reagents.

Keywords
corrosion inhibitors, surfactants, carbon dioxide corrosion, gravimetric method for measurement the corrosion rate

Pipeline

Study of the influence of the water phase content in the transported water-oil emulsion on the thermal conductivity of the forming asphalt resoloparaphin deposits for the purpose of considering the technology applicable

Ilyushin P.Yu., Vyatkin K.A., Kozlov A.V., Votinova A.O.

DOI: 10.24412/2076-6785-2021-5-60-64

Abstract
The formation of organic deposits is one of the most common problems in the production and transportation of well products. In the fight against this complication, many modern methods are used, one of them is the Controlled Layer technology. One of the most important values considered when determining the technological efficiency of this technology is the thermal conductivity of organic deposits. In this work, laboratory studies were carried out to determine the nature and degree of change in the thermal conductivity of these deposits from the water content of the studied emulsion. Analyzing the results of laboratory studies, it becomes obvious that the high-water content of the transported emulsion increases the
thermal conductivity of deposits, which has an exceptionally negative impact on the technological efficiency of the technology under consideration.

Materials and methods
Materials: reservoir fluid samples from the target technological object, the Cold Finger installation, the Rheotest RN 4.1 rotary viscometer. Methods: research on the Cold Finger installation, the authors method for determining the thermal conductivity of organic deposits.

Keywords
controlled layer, asphalt-resin-paraffin deposits, thermal conductivity, intensity, water content

Effect of statistical dispersion of pipe wall thickness on the stress concentration factor from corrosion defect

Golofast S.L.

DOI: 10.24412/2076-6785-2021-3-50-55

Abstract
At the stage of assessing the technical condition of main pipelines, the stress concentration factor for stresses occurring in the pipe wall in the area of the identified corrosion defect is taken as a deterministic value. The models used to calculate this factor contain such a parameter as the pipe wall thickness, which is a random variable and has individual distributions even for pipes of the same range. Due to the presence of a functional relationship with the thickness of the pipe wall, the values of the stress concentration factor also obey distributions, the type of which depends on the statistical spread of the values of the pipe wall thickness. The necessity of taking into account the stress concentration factor in the calculation models as a random variable is justified by the example of assessing the strength reliability and the level of risk of linear sections of the main oil pipeline complicated by a corrosion defect.

Material and methods
The pipe wall thickness was measured using an ultrasonic thickness gauge of the DM2 model manufactured by Krautkrämer GmbH & CO (Germany). The processing of the measurement results and the calculation of the values of the reliability indicators are based on the methods of nonparametric statistics and the theory of reliability. The stress concentration coefficient is calculated on the basis of the
B31G standard.

Keywords
main oil pipeline, linear part, corrosion defect, stress concentration factor, strength reliability, failure probability

Method for predicting the value of the inter-treatment period of a linear pipeline

Ilyushin P.Yu., Vyatkin K.A., Kozlov A.V.

DOI: 10.24412/2076-6785-2021-3-44-48

Abstract
Pipeline transport is the main method of transportation of hydrocarbons. Based on the analysis of field data, it was determined that the intercleaning period of pipelines is associated with the time of year and reaches its peak in the spring. In the laboratory of Oilfield chemistry of the REC GiRNGM PNRPU, using the Cold finger installation, laboratory studies were carried out to determine the kinetic parameters of the formation of organic deposits in different months of the year. Analysis of the results of laboratory studies allows us to note that these parameters are nonlinear functions of temperature, but it is not possible to predict changes in the value of the MOS only on the basis of laboratory studies, which is why the authors of the article proposed the introduction of the value of the relative MOS. The introduction of this parameter will make it possible to predict the nature and extent of changes in the MOS of the pipeline on the basis of laboratory studies and using pipeline modeling in hydrodynamic simulators.

Material and methods
Analysis of commercial and theoretical information, conducting laboratory studies and modeling the process of paraffin formation.

Keywords
asphalt-resin-paraffin deposits, statistics of treatment measures, equipment of the Cold finger, inter-treatment period, hydrodynamic modeling, linear oil pipeline

Chemical technology

Efficiency of neutralizers comparative analysis for reducing the hydrogen sulphide content in oil to 20 million-1

Novikova N.V., Buldakova N.S.

DOI: 10.24412/2076-6785-2021-5-72-75

Abstract
Due to the stricter requirements for oil transferred for transportation by the main pipeline or processing, as well as high background values of hydrogen sulphide in the oils of the fields of Udmurtia, the selection of effective reagents was made. Laboratory studies of 6 grades of hydrogen sulphide neutralizers with different active bases on commercial oils of the preparation facilities of the Kiengopskoye, Mishkinskoye and Gremikhinskoye fields were carried out in accordance with the requirements of Rosneft Oil Company. It was determined that all six tested grades of reagents can achieve a hydrogen sulphide content of less than 20 million-1. The most effective grades of hydrogen sulphide neutralizers
have been established in the context of preparation facilities. As part of the tests, the absence of the influence of reagents in the studied dosages on the content of chloride salts in oil was confirmed.

Materials and methods
Laboratory studies of 6 grades of hydrogen sulphide neutralizers on commercial oils of the preparation facilities of the Kiengopskoye, Mishkinskoye and Gremikhinskoye fields were carried out in accordance with the requirements of Rosneft Oil Company. The results are in the form of figures and conclusions.

Keywords
hydrogen sulphide neutralizer, EAEU TR 045/2017, hydrogen sulphide neutralization, chemical method for reducing hydrogen sulphide in oil, oil, hydrogen sulphide