bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficiency Survey of a Drainage Wellbore and Well Placement in Gas Fields
Authors: Penigin Artem Vitalevich , Sergeev Evgeniy Ivanovich , Varavva Artem Igorevich , Yamaletdinov Airat Flurovich
Published: October 2021

The paper describes the assessment process of methods for the construction and operation of gas wells with a large water-gas ratio. One of the ways to tackle the issue of poor performance of high WGR wells is to drill a drainage wellbore with an ESP to lift accumulating water. In addition, various configurations of well placement through gas-bearing and water-bearing reservoirs have been considered.

To evaluate the efficiency of a drainage wellbore with an ESP installed for lifting water that comes from the main, productive, wellbore, industry-recognized non-stationary dynamic multiphase flow simulator was used, as well as a more refined tool, such as the physical simulator based on the finite volume method (computational fluid dynamics, CFD). A non-stationary dynamic simulator was also used to assess the impact of well placement through gas- and water-bearings reservoirs. Well data, fluid data, physical parameters were entered into the models and, by varying the input parameters, dependencies and results were obtained, allowing to draw a conclusion about the efficiency of each method, as well as about the software capabilities and limitations.

The applicability and technical efficiency of an additional drainage borehole with an ESP tto ensure stable operation / high productivity of the well strongly depend on the value of the water-gas ratio, the higher it is, the lower the efficiency of the method. In addition, efficiency also decreases with increasing gas rate. To assess the correctness of the calculation made with dynamic multiphase flow simulator, which is the industry standard, a verification calculation was also carried out on a physical simulator using the finite volume method, which shows the same trends, but with different absolute values. It also made it possible to assess the influence of the geometry factor on the distribution of flows, which could not be done by the non-stationary multiphase flow simulator. Apart from this, it was concluded that the location of a water-bearing reservoir in the last lower part of the wellbore is preferable, since then the impact on production is less than when it is located above the gas-bearing interval. Changing the well layout to a U-shaped one affects the dynamics of its operation insignificantly.

The study helps to answer the question about the efficiency of using a borehole with an ESP and about the degree of influence of drilling through gas- and water-bearing reservoirs using the example of a real field, as well as it presents the method of conducting such an assessment for other fields.
Solving the Problem of Operational Accounting of Well Drilling Results in a Full-Scale Model of Unique Gas Condensate Fields
Authors: Poushev Andrey Viktorovich , Mangushev Ruslan Railievich , Yakimov Sergey Anatolievich
Published: October 2021

Today, strategic planning of field development is based on full-field static and flow simulation models which are regularly updated as part of field surveillance programs and by integrating the actual results of drilling and testing of new production and exploration wells and integrated interpretation of seismic surveys and reservoir core and fluid laboratory analyses.

One of the key factors for the success of investment projects is how quick and flexible the decision-making process is. Therefore, in modern conditions, prompt integration of new data into full-field flow simulation models followed by their processing, analysis, and decision-making on adjusting the strategic goals is of particular relevance for oil and gas production companies.

For unique multi-reservoir fields containing dozens of reservoirs, hundreds of accumulations and wells, it is hardly possible to promptly update full-field static and flow simulation models within less than 6-12 months, therefore, the decisions are made in the absence of up-to-date models, which may lead to poor quality of production forecasts.

The purpose of the study was to develop an approach to the modeling of unique fields, which would allow prompt integration of new data in a full-field flow simulation model while keeping the level of detail without significant time input.
Residual Hydrocarbon Saturation in the Transition Zone and the Gas Cap
Authors: Cheremisin Nikolai Alekseevich , Shulga Roman Sergeevich , Zagorovskiy Alexey Anatolyevich , Gilmanov Yan Irekovich , Kochetov Alexey Valentinovich
Published: October 2021

The laboratory study of the formation of residual oil saturation in a gas cap after active gas production from it and the penetration of oil from the underlying oil reservoir is currently not regulated in any way. Residual oil saturation in the gas cap was taken and is accepted, as a rule, from the correlation dependences with reservoir properties obtained from experiments on oil displacement from to the limit oil-saturated core samples. The use of similar correlations for the transition zone significantly underestimates the mobile oil reserves in such zones

In this connection, the paper discusses the technology of physical modeling of the residual oil saturation in the gas cap after the penetration of oil into it and the issues related to the determination of the residual oil saturation in the transition zones of oil reservoirs. On a series of test experiments on core samples of a weakly consolidated reservoir of the Pokurovskaya formation carried out according to the method developed by the authors, it was shown that the values of residual oil saturation after the penetration of oil into the gas cap are significantly lower than for oil-saturated formations with similar properties.

It is shown that such studies will make it possible to clarify the possible irreversible oil losses during the advanced development of gas caps and to revise the approaches to the development of oil reservoirs of gas-oil and oil-gas fields. Laboratory modeling and study of the process of oil penetration into a gas cap and its subsequent displacement by water or gas is relevant for almost 10% of Rosneft's current reserves.
Application of Digital Rock Analysis for Evaluation of Gas-Condensate Transport
Authors: Dinariev Oleg , Evseev Nikolay
Published: October 2021

The computational method for gas-condensate phase permeabilities is presented using digital rock analysis. The proposed method combines: a) construction of high-resolution tomographic images of the pore space; b) development of compositional model of a gas-condensate mixture at pore-scale including rheology, fluid-fluid and fluid-rock interfacial tension coefficients, and thermodynamic and kinetic properties of fluid phases; c) 3D pore-scale modeling of multiphase transport and interfacial chemical component exchange using the density functional hydrodynamics numerical simulator.

This digital rock analysis workflow is applied to the gas-condensate transport at pore-scale. The numerical simulations are carried out using the 3D digital rock model constructed by X-ray microCT imaging of the rock pore structure. By specifying different gas and condensate fractions and injection rates it has been possible to obtain computationally 3D saturation distribution fields and the phase permeabilities. The results of 3D density functional hydrodynamic simulations provide the comprehensive description of gas-condensate mixture at pore-scale including hydrodynamic desaturation effects and phase transition kinetic phenomena. It is demonstrated that condensate distribution in pores, phase mobility thresholds and phase permeabilities are dependent on wettability properties and flow rates. It is shown that condensate composition in individual pores is also dynamically dependent on flow regimes. These results can be used in field development planning for the improved evaluation of condensate banking in the vicinity of production wells and condensate losses in the reservoir.
Application of High-Contrast µCT and FIB-SEM for the Improvement in the Permeability Prediction of Tight Rock Samples
Authors: Avdonin Alexander , Ebadi Mohammad , Krutko Vladislav
Published: October 2021

Digital rock analysis has proven to be useful for the prediction of petrophysical properties of conventional reservoirs, where the pore space is captured well by a modern µCT scanner with a resolution of 1-5 µm. Nevertheless, this resolution is not enough to accurately capture the pore space of tight (low-permeable) rock samples. As a result, derived digital rock models do not reflect the real rock topology, and permeability predictions yield unreliable results. Our approach deploys high-contrast µCT scanning technique and Focused Ion Beam milling combined with Scanning Electron Microscopy to improve the quality of digital rock models and, hence, the permeability prediction. This workflow is successfully applied to a low-permeable rock sample of Achimov deposits. The computed permeability compares well to the experimental value.
Environmental Monitoring and Control Over Production Wells Using Automated Control and Regulation Systems for Orenburgskoe Oil and Gas Field
Authors: Rogov Yuri , Rymarenko Konstantin , Mironositskii Alexei , Grishenko Sergey , Golubtsov Alexsandr , Kabanov Vasilii , Gusachenko Tatyana , Nukhaev Marat
Published: October 2021

Environmental stability and safety are becoming increasingly important in the world. Used to be mainly until recently under state control, the release and distribution of hazardous substances, wastes, and by-products is now monitored and regulated everywhere by enterprises, forced to establish special services that record and transmit information in the dispatch centers of the MES and other regulatory authorities of the Russian Federation. All the measures taken in this respect focus on safety improvement, ensuring occupational safety and accident prevention at enterprises, and safety of people, animals, and natural environmental location, which can be exposed to harmful and dangerous anthropogenic and natural factors.

Aiming to provide a comprehensive solution to the problem, the authors proposed the concept of environmental monitoring and control over oil and gas wells using automated control and regulation systems and presented the concept on the example of the Orenburgskoe oil and gas condensate field
3D Modeling of Stability of Mobile Jack-Up Rigs Under Seismic Impacts
Authors: Vasilev Ivan Alekseevich , Dubinya Nikita Vladislavovich , Nachev Viktor Andreevich , Alekseev Dmitry Aleksandrovich , Tikhotskiy Sergey Andreevich
Published: October 2021

The work is devoted to the study of the influence of external mechanical impacts on the stability of jack-up floating drilling rigs. Ensuring safety when working on jack-up floating drilling rigs (jack-up rigs) is one of the most important tasks at the initial stages of offshore hydrocarbon field development. The aim of the work is simulation of the stability of the rigs, which is in the operating mode, both in the absence of external effects acting on it, and when it is affected by various geodynamic processes. Calculation of jack-up rig stability in sea soil with complex viscoelastoplastic rheology under external mechanical influences was carried out using the finite element method. As a result of the work, the spatial distributions of stress and strain fields were determined both in the jack-up rig itself and in the area of the soil in the vicinity of its supports, in an equilibrium and disturbed state. The results of equilibrium static calculations made it possible to analyze the zones of localization of stresses and deformations in the jack-up rig with respect to stability: the structural elements that are most dangerous from the perspective of stability loss were identified. The analysis of the soil area in the vicinity of the jack-up rig supports made it possible to estimate the typical dimensions of the stress concentration zones arising during the jack-up installation and draw conclusions about the requirements on details and scalability of the model of mechanical properties needed for geomechanical modeling at specific objects. The obtained results of dynamic calculations - the response of theconsidered system to external influences simulating remote seismic processes - made it possible to study the process of loss of jack-up rig stability. The critical values of the parameters describing external influences were determined: in particular, the amplitudes of surface seismic waves leading to the loss of stability of the jack-up rig were found. The obtained results made it possible to formulate an algorithm for predicting seismic hazard during drilling in offshore conditions, based on numerical modeling of mechanical processes at specific locations.
Deep Geothermal Well Construction Problems and Possible Solutions
Authors: Gelfgat Mikhail Yakovlevich , Geraskin Aleksandr Sergeevich
Published: October 2021

The geothermal energy is one of the most promising sources of electricity on the planet; it is available almost anywhere on the continents and resources are inexhaustible. The realization of these possibilities requires solving the problems of deep wells (6-10 km) construction, when the lower horizons are practically impermeable crystalline basement rocks. For effective use of the Earth's heat, bottomhole temperatures must be within 200-300°C. World experience of such deep wells construction is very limited, some examples are given in this work.

Known schemes of geothermal energy application requires at least two wells construction - for cold fluid injection and superheated fluid production. The rock - circulating fluid heat exchange in the bottomhole requires drilling of inclined, horizontal, or multi-lateral boreholes and hydraulic fracturing application. Such technologies are widely used in the oil and gas fields, but not in crystalline rocks. The article presents an analysis of the prospects for the geothermal wells construction efficiency increasing by using modern directional drilling systems, drilling with casing, technologies for complications eliminating. The possibilities of using alternative hard rock drilling methods by enhancing the standard formation destruction with drill bits are discussed. These are hydraulic hammers, high-pressure abrasive and fluid jets, laser drilling. A fundamentally new plasma drilling technology is considered. The most serious limitation of alternative drilling prospects is the need of additional "supply lines" to the bottom: high-pressure fluid; electricity; a plasma forming agent, etc. In this regard, options are being considered for the development of continuous drill strings such as coiled tubing, umbilical, flexible composite systems like subsea pipelines. Some of technological solutions for deep geothermal wells construction, and implementation of petrothermal energy schemes for potential projects are proposed.

The paper provides an idea of the geothermal well construction technologies, which can ensure the implementation of advanced geo-energy schemes. The problems of geothermal engineering and possible solutions to overcome them, which will contribute to the development of geothermal energy, as the most effective option for decarbonization, are indicated.
An Example of Building a Petrophysical Model of Unconsolidated Gas-Saturated Laminated Sediments Using Advanced Wireline and Logging While Drilling Services
Authors: Bokarev Anton Yurievich , Yezersky Dmitriy Mikhailovich , Filimonov Anton Yurievich , Dubnitsky Ivan Romanovich , Vorobiev Vladislav Viktorovich
Published: October 2021

Productive deposits of the Turonian age as part of the Kuznetsovskaya Formation are cover the eastern part of Western Siberia (Figure 1), but until recently they were not of wide industrial interest.

Today, most of the gas reserves in Western Siberia are produced in the Cenomanian deposits, which are in the stage of declining production. The productivity of the deposits above Cenomanian layer has been established in many fields where the Cenomanian formations are productive. In general, in Western Siberia in the Turonian deposits, there are more than 3 trillion cubic meters of gas, which allows us to consider them as high-potential sources of gas reserves. The main difficulties in the industrial development of Turonian deposits are reduced permeability, high dissection, high content of clay fraction, high macro- and microheterogeneity of the reservoir, inconsistency of effective thicknesses in plan and section. In turn, the relatively low temperature of the reservoir predetermines the operation of the field in a mode close to hydration (Avramenko et all., 2019).

Under these conditions, a good petrophysical baseline is essential to assess the exploration potential of the assets and design the development of the reservoir. Shaly gas-saturated formations are not a simple object for petrophysical modeling. Adding to this the low quality of the core material caused by the weak cementation of shallow deposits, we get a very nontrivial problem. On the other hand, modern horizontal well development scenarios dictate their requirements for petrophysical models. In other words, the petrophysical model must maintain its stability for any well logging regardless of the well trajectory (vertical or horizontal) and the logging method conveyance (wireline or while drilling).

The authors of the paper carried out work on the development of a universal petrophysical model of the Turonian reservoir, for one of the fields in the region of the north of Western Siberia, based on a modern extended GIS complex.
Application of Machine Learning for Lithology-on-Bit Prediction using Drilling Data in Real-Time
Authors: Zhekenov Temirlan , Nechaev Artem , Chettykbayeva Kamilla , Zinovyev Alexey , Sardarov German , Tatur Olga , Petrakov Yuriy , Sobolev Alexey
Published: October 2021

Researchers base their analysis on basic drilling parameters obtained during mud logging and demonstrate impressive results. However, due to limitations imposed by data quality often present during drilling, those solutions often tend to lose their stability and high levels of predictivity. In this work, the concept of hybrid modeling was introduced which allows to integrate the analytical correlations with algorithms of machine learning for obtaining stable solutions consistent from one data set to another.
Propogation LWD Tool Analysing for Better Saturation Estimation in High Angle Horizontal Well Conditions
Authors: Mingazov Airat , Zhidkov Andrey , Nukhaev Marat
Published: October 2021

Multidepth electromagnetic logging tool is considered as traditional measurements of formation resistivity estimation while drilling. When considering data in wells with high angles trajectory, more than 70 degrees, the resistivity measurements could be affected by several factors associated with geological conditions and logging tool specifications. As the result, during water saturation estimation formation properties could be distorted, which will lead to significant effect of reservoir properties assessment and the design of the horizontal well completion.

Within the framework of this paper, various methods of influence on the resistivity readings will be considered, especially with cross boundary effects and reservoir formations with anisotropy. At the same time, propagation resistivity logging technologies while drilling with interpretation and boundary propagation technologies will be observed, which has tilted azimuthal oriented receivers for geosteering service of horizontal wells and additionally helps with take into account of boundary enflurane on standard resistivity logging.
Survey Management During Geosteering
Authors: Sabirov Ilnar Nailevich , Kristya Anton Vladimirovich
Published: October 2021

Geosteering is usually responsible for addressing geological uncertainties, such as the uncertainty in the position of the horizon structure or the structural dip angle. During drilling, the directional survey measurements are taken as true, whilst the uncertainties related to the instruments are not considered. Measurement errors cannot be completely excluded, but they can be reduced to a minimum (reducing the "ellipse of uncertainty" of measurements) by considering the variability of the Earth's magnetic field and the influence of the external factors on the tool (by employing quality control and correction of directional measurements), as a result, reducing the risks of crossing the fluid contacts by the wellbore.

This work is devoted to the methods of detecting and minimizing the inclinometer measurement error while drilling, as well as the application of the results for geological support of drilling. The article describes the principle of the methodology for correcting the inclinometer measurements while drilling and indicates the cases in which the correction method is applicable. The paper considers the prerequisites for using the measurement quality control method and tools to reduce the measurement error in these cases. The possibility of using the method of geomagnetic referencing IFR, as well as methods for correcting measurements of the telemetry system BHA Sag and MSA, to fulfill geological tasks is considered.

This paper provides an example of quality control of directional measurements after drilling a well with an extended horizontal section. In the course of the work, the values of measurement errors along the vertical and lateral were established at a large deviation from the wellhead of the considered well. Attention is focused on the analysis of the identified inclinometry errors, their consequences and impact on the geological drilling of the wellbore and considered an example of improving the quality of geological support using the method of correcting directional measurements while drilling.
Sectorial Scanning Electromagnetic Defectoscope: The Next Stage in Well Integrity Diagnostics
Authors: Ganiev Bulat , Lutfullin Azat , Karimov Ildar , Shaydullin Rinat , Nagimov Vener , Volkov Maxim , Vdovin Alexey , Trusov Alexander , Sviridov Alexander , Elkadi Antoine
Published: October 2021

The paper presents a new technology for the oil and gas industry for azimuthal electromagnetic scanning of the first tubular wall defects, the basis of which is a small-sized sector scanning tool that measures the pipe wall thickness. The paper presents the results of laboratoryand well tests, as well as the early field surveys using this technology. These constitute thebasis on which the actual sensitivity of the technology and its prospects in diagnosing well integrity are determined.
Remote Bed Boundary Detection Tool Data Interpretation Without Special Geosteering Support to Drill Horizontal Wells
Authors: Nazipov Danis , Shpakov Pavel
Published: October 2021

Today, one of the most modern and successful geosteering methods in terms of net to gross value (NTG) is a proactive geosteering.

The purpose of this article is to share the experience of using Remote Boundary Detection Tools to solve various geological problems and describe the ways of using the data from it.

The method provides the ability to detect the approaching boundary (usually reservoir top) with resistivity contrast before entering it with the bit or BHA sensors. It allows to adjust well trajectory proactively and, therefore, increase Net to gross ratio.

The article shows the ways to implement global experience in horizontal wells drilling and proposes ways to reduce the cost of well construction without elimination of High-Tech equipment in BHA.

The article explains the methods of interpreting the output data from the tool that can determine the approach to one or several boundaries with resistivity contrast.
Application of Artificial Neural Networks for Processing and Interpretation of Data from a Scanning Magnetic Introscope
Authors: Kosarev Victor Evgenevich , Yachmeneva Ekaterina Anatolevna , Starovoyto Aleksandr Vladimirovich , Kirgizov Dmitrii Ivanovich , Mukhamadiev Rustem Ramilevich , Sudakov Vladislav Anatolevich , Akhmetov Bulat Feliksovich , Savlenkov Aleksandr Borisovich
Published: October 2021

This paper presents the efficiency of using artificial neural networks for solving problems of processing and interpreting geophysical data obtained by scanning magnetic introscopy. Neural networks of various architectures have been implemented to solve the problems of processing primary material, searching for well structure objects,identifying casing defects. The analysis of the capabilities of neural networks in comparison with mathematical algorithms is carried out. To test machine learning algorithms and mathematical algorithms for processing, visualizing and storing the results, a software shell was created in which all tasks are solved using a set of tools. It was found that the use of artificial neural networks can significantly speed up the process of data processing and interpretation, as well as improve the quality of the results in comparison with individual mathematical algorithms. Nevertheless, the use of mathematical algorithms in solving some problems gives consistently better results. In particular, the problematic aspects were identified at the stage of interpretation when identifying defects. This is due to the presence of conventions in the isolation of defects by the operator at the stage of preparing data for training neural networks, which is a subjective factor and requires a deeper study.
Integrated Geomechanical Modeling and Hydraulic Fracturing Design: From Particular Cases to the Overall Result
Authors: Samoilov Mikhail , Pavlov Valeriy , Pavlyukov Nikolay , Timirtdinov Aleksandr
Published: October 2021

Objective and scope

The objective of the work is to present an adequate workflow for conditioning geomechanical data and hydraulic fracturing design, adjustment and simultaneous verification of a MEM and hydraulic fracture models. These approaches are relevant for greenfields and also can be used when changing field development systems: from vertical fracked wells to a system of horizontal wells with multistage fracs.

Methods, techniques, and process description

The paper provides examples of issues in hydraulic fracturing planning due to poor attention to the reliability and robustness of geomechanical data. Given the critically of data quality, the authors describe a holistic approach used in collecting, analysing and conditioning data for building a MEM (1D; if necessary, 3D) as the basis of a frac design.

Mini-frac is considered not only as a tool for setting the hydraulic fracturing design parameters, but also as a source of data for cross-calibration between the MEM and the hydraulic fracture models. Case studies of various HF models will demonstrate the influence of MEM-and-frac uncertainties and the tools for considering them in practical HF modelling. An approach to systematic clustering of input data for HF designs is described. The importance of measuring the fracture heights is stressed as a source of data for cross-calibration of HF and GM models.

Results and conclusions

The correct sequence of work, data consolidation and successive data refinement helps to maintain the database of elastic and strength properties of various target reservoirs, which proves the demand for core analysis and well logging, as well as geomechanical modelling. The improved quality of HF designs leads to better reliability of forecasts and proposed field development and individual wellwork strategies.

The close integration of GM studies and modelling with HF design building enhances the operation culture, accelerates and streamlines the HF model build and validation processes, which can be a pace-setting experience for other oil and gas industries that are GM data users.

Novelty and achievements

The TNNC and RN-CEPiTR teams work in close cooperation and provide GM and HF integration to assess the fracture height in the target reservoirs at the Company's assets in order to improve the quality of HF modelling. The uncertainty influence on the HF design is reducing, so as the risks of screen-out and the risks of breakthrough into undesirable zones.

The approach streamlines the engineering support for the hydraulic fracturing activity and understanding of the fracture parameters as the operations move from single-stage hydraulic fracturing to the optimized field development using horizontal wells with multi-stage hydraulic fracturing.
Evaluation of Accuracy and Uncertainty of ISO 13503-2 Proppant Testing
Authors: Makashova Galina , Yukhtarov Stepan
Published: October 2021

Proppant is one of the key aspects of a successful fracturing treatment and subsequent well production, and its quality is strictly controlled by ISO 13503-2, an international standard for proppant testing. Proppant suppliers, oilfield companies and their clients all around the world rely on the standard measurement procedures and limit values to ensure the quality of a product they produce or use for fracturing operations. ISO 13503-2 prescribes testing procedures; however, the standard does not contain information about uncertainty of final measurements. This information is essential for consistent quality assurance, for resolving inconsistencies between different laboratories, and for comparing properties of different products.

An interlaboratory study was organized to evaluate the precision of ISO 13503-2 proppant testing. Four proppant samples were distributed among proppant quality control laboratories all around the world; 17 laboratories participated in the study. The obtained test data were used to calculate repeatability and reproducibility standard deviations (in accordance with ISO 5725-2) and uncertainty of ISO 13503-2 test data (in accordance with ISO 21748).

The study showed that most proppant parameters measured using ISO 13503-2 methods yielded high uncertainty. For example, for turbidity and acid solubility values, the uncertainty was up to ±50%. Uncertainty of roundness and sphericity values was ±0.1 since the values are estimated by operator, making the test quite subjective. For crush resistance, the highest uncertainty among tested samples, ±40%, was observed for an HSP 30/50 sample measured at 15,000 psi stress. For absolute density, a systematic difference between values obtained using gas pycnometers from different manufactures was observed; also, the equipment differs by repeatability characteristics.

The results of the interlaboratory study allowed estimating the uncertainty of ISO 13503-2 test methods. It was shown that high measurement uncertainty for some critical proppant parameters should be considered for correct interpretation of the obtained test results.
Halite Precipitation in Brine Reservoirs: Prediction and Control by Numerical Model, Optimization of the Fresh Water Treatments and Well Production Regimes
Authors: Andryushchenko Aleksei Dmitrievitch
Published: October 2021

The aim of the work is to optimize the fresh water treatment design, frequency and production regimes (maximize NPV of the well operation) for wells with high NaCl content formation water (brines) production, which are very common for the Eastern Siberia, and forecast productivity index (PI) decline rates and production profiles for the wells by means of halite deposition model for brine flow in porous media united with fresh water treatment model and economic model.

New numerical halite deposition model for brine flow in porous media is developed based on Darcy's law and equation of halite precipitation dynamics from formation water taking into account the fresh water treatments, solubility of descipitated halite in the fresh water and permeability profile. It enables to predict deposited halite saturation (Shalite), dynamic porosity and permeability radially and versus time. Thus, we can forecast PI versustime and unite production and economic models,vary fresh water treatment design, frequency andproduction regimes for the given geological conditions and to determine treatment design, frequency and production regimes that brings the maximum NPV.PI decline rates and exploitation factor are calculated and analyzed for different scenarios of the fresh water treatment design, frequency and production regimes.

These main conclusions are made from the results of the work:
New Analytical Approach to Operational Assessment of Fractured Well Productivity with Variable Permeability
Authors: Yudin Evgeniy Viktorovich , Piotrovskiy George Aleksandrovich , Petrova Maria Vladimirovna , Roshchektaev Alexey Petrovich , Shtrobel Nikita Vladislavovich
Published: October 2021

Requirements of targeted optimization are imposed on the hydraulic fracturing operations carried out in the conditions of borderline economic efficiency of fields taking into account geological and technological features. Consequently, the development of new analytical tools foranalyzing and planning the productivity of fractured wells, taking into account the structuralfeatures of the productive reservoir and inhomogeneous distribution of the fracture conductivity, is becoming highly relevant.

The paper proposes a new approach of assessing the vertical hydraulic fracture productivityin a rectangular reservoir in a pseudo-steady state, based on reservoir resistivity concept described in the papers of Meyer et al. However, there is a free parameter in the case of modeling the productivity of a hydraulic fracture by the concept. The parameter describes the distribution of the inflow along the plane of the fracture. This paper presents a systematic approach to determining of the parameter. The resulting model allows to conduct an assessment of the influence of various complications in the fracture on the productivity index.

During the research a method of determining the free parameter was developed,it was based on the obtained dependence of the inflow distribution on the coordinate along the fracture of finite conductivity. The methodology allowed to refine existent analytical solution of the Meyer et al. model, which, in turn, allowed to assess the influence of different fracture damages in the hydraulic fracture on the productivity index of the well. The work includes the cases of the presence of fracture damages at the beginning and at the end of the fracture. A hydraulic fracture model was built for each of the types of damages, it was based on the developed method, and also the solution of dimensionless productivity ratio was received. The results of the obtained solution were confirmed by comparison with the numerical solutions of commercial simulators and analytical models available in the literature. The advantage of the methodology is the resulting formulas for well productivity are relatively simple, even for exotic cases ofvariable conductivity fractures.

The approaches and algorithms described in the paper assume the calculation of the productivity of a hydraulic fracture with variable conductivity and the presence of other complicatingfactors.The methodology of the paper can be used for analysis and diagnosis problems with formation hydraulic fracturing. The efficiency of the calculations allows using the presented methodology to solve inverse problems of determining the efficiency of the hydraulic fracturing operation.
Experience in Low Viscosity Guar-Free Fracturing Fluid Under Samotlor Field Conditions
Authors: Koplik Alexander Sergeevich , Kudrya Semen Sergeevich , Zolnikov Denis Alekseevich , Koltsov Rustam Albertovich , Kovalevskiy Alexey Vasilievich
Published: October 2021

Executive Summary

The recently developed Samotlor 2020 campaign includes a requirement to shift the Frac design to synthetic gelling agent (gellant) which would increase production, keep the reservoir clean and also reduce both capital and operational costs for each stage Frac stage (no need to heat up the water, an option to use the well water, no requirement to miniFrac performance, etc.). The key difference between guar-based gels and synthetic gels is a lower viscosity rating that results in a significant increase in the fracture length and an improved ability to transport high concentration of proppant due to its thixotropic properties (the ability of a substance to lower its viscosity as a result of a mechanical impact and grow its viscosity when still). When gel is destroyed throughout the fracture after the Frac is completed the synthetic option allows for a cleaner fracture and helps remove all residual matter from the fracture. Another important consideration is that guar shipments from India make Russian oil vulnerable to price, foreign exchange and availability fluctuations. If guar crops experience a bad year or Indian farmers determine that the market should be refocused on cotton or other areas (i.e. not guar), the guar prices in Russian would likely skyrocket.

The authors worked as a team to come up with a list of clear recommendations to develop both new and existing wells for Lower Cretaceous collectors of the Vartovsk and Megion suites such as AV1 (1-2) and BV8(0) to increase production and reduce capital costs. We have determined that Frac fluids based on synthetic modified polyacrylamide start to come to the front and hold a leading position in the area of production stimulation as previously happened to other effective methods such as polymer water flooding, drilling and cementing applications.
The combined effect of sowing methods, and nitrogen application rates on photosynthetic characteristics, and soil water consumption of wheat
Authors: NOOR HAFEEZ , Sun Min , Lin Wen , Gao Zhiq-iang
Published: October 2021

Sustainability of winter wheat yield under dryland conditions depends on Improvements in crop photosynthetic characteristics and, crop yield. Study the effects of sowing method and N-nitrogen rates on yield, selected sowing, and soil water storage, nitrogen translocation. Experiment comprised of three sowing methods: wide-space sowing (WSS), furrow sowing (FS), and drill sowing (DS) and seven nitrogen treatments: 0 kg ha− 1, 90 kg ha− 1, 180 kg ha− 1, 210 kg ha− 1, 240 kg ha− 1, 270 kg ha− 1 and 300 kg ha− 1.The results indicated that the sowing methods significantly affected the yield, and grain. The increase in grain yield was 25%, respectively. The photosynthetic traits, and leaf area index were highest under WS followed by FS. The plant height was highest under DS. I (WSS), and (II) (DS). Sowing method WSS with N level N240 significantly enhanced the Photosynthesis Rate, intercellular CO2, and transpiration rate .Our results indicated that implication of a proper sowing method coupled with enhanced nitrogen doses resulted in an increase in yield. WSS 240 kg ha− 1 enhances photosynthetic characteristics of flag leaves, and promotes to achieve high yield. The plants were improved, which ware beneficial to the improvement of sugar content.
Genome-Wide Association Study Identified Novel Genomic Loci Controlling Internode Lengths and Plant Height in Common Wheat under Different Nitrogen Treatments
Authors: Xing Piyi , Zhang Xia , Li Dandan , Wang Honggang , Bao Yinguang , Li Xingfeng
Published: October 2021

Nitrogen is an important nutrient for crop growth and development. Plant height-related traits can be affected by nitrogen supplementation. In this study, we performed a genome-wide association study (GWAS) on plant height, spike length, length of different internodes, and lodging resistance strength at the grain-filling stage based on a natural wheat population subjected to low nitrogen and normal (CK) treatments. GWAS analysis showed that a total of 86 quantitative trait locus (QTLs) were detected, including 13 QTLs for plant height, 10 QTLs for spike length, 19 QTLs for the length of the first internode from the top of the plant, 6 QTLs for the second internode length, 11 QTLs for the third internode length, 13 QTLs for the fourth internode length, and 14 QTLs for the fifth internode length. Compared to the CK treatment, the plant height, spike length, and fourth and fifth internode lengths were significantly affected by the low nitrogen treatment. A total of 18 QTLs responding to low nitrogen stress were detected, including three QTLs for the fourth internode length detected on 3A, 6A, and 6D chromosomes, eleven QTLs for the fifth internode length on 1A, 1B, 1D, 2A, 2B, 3A, 3B, 4A, 5B and 7B chromosomes, one QTL for spike length on 3A chromosome, and one QTL for plant height on 5B chromosome. These QTLs will enhance our understanding of the genetic basis of plant height responses to nitrogen deficiency and will benefit genetic reactions to nitrogen fertilization.
SARS-CoV-2 infection induces inflammatory bone loss in golden Syrian hamsters
Authors: Yeung Kelvin , Qiao Wei , Lau Hui En , Xie Hui Zhi , Poon Vincent , Chan Chris , Chu Hin , Yuan Shuofeng , Yuen Terrence , Chik Kenn Ka Heng , Tsang Jessica , Chan Chris Chun-Yiu , Cai Jian-Piao , Luo Cuiting , Yuen Kwok-Yung , Cheung Kenneth , Chan Jasper Fuk-Woo
Published: October 2021

Extrapulmonary complications of different organ systems have been increasingly recognized in patients with severe or chronic Coronavirus Disease 2019 (COVID-19). However, limited information on the skeletal complications of COVID-19 is known, even though inflammatory diseases of the respiratory tract have been known to perturb bone metabolism and cause pathological bone loss. In this study, we characterized the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on bone metabolism in an established golden Syrian hamster model for COVID-19. SARS-CoV-2 causes significant multifocal loss of bone trabeculae in the long bones and lumbar vertebrae of all infected hamsters. The bone loss progressively worsens from the acute phase to the post-recovery phase. Mechanistically, the bone loss was associated with SARS-CoV-2-induced cytokine dysregulation which upregulates osteoclastic differentiation of monocyte-macrophage lineage. The pro-inflammatory cytokines further trigger a second wave of cytokine storm in the skeletal tissues to augment their pro-osteoclastogenesis effect. Our findings in this established hamster model suggest that pathological bone loss may be a neglected complication which warrants more extensive investigations during the long-term follow-up of COVID-19 patients. The benefits of potential prophylactic and therapeutic interventions against pathological bone loss should be further evaluated.
Differential Brain and Cerebrospinal Fluid Proteomic Responses To Acute Prenatal Endotoxin Exposure
Authors: Muk Tik , Stensballe Allan , Dmytriyeva Oksana , Brunse Anders , Jiang Ping-Ping , Thymann Thomas , Sangild Per Torp , Pankratova Stanislava
Published: October 2021

Background
Chorioamnionitis (CA) is a risk factor for preterm birth and is associated with neurodevelopmental delay and cognitive disorders. Prenatal inflammation-induced brain injury may resolve during the immediate postnatal period, which is a time of rapid metabolic and brain remodeling. Cerebrospinal fluid (CSF) collected at birth may be a critical source of predictive biomarkers. Using pigs as a model of preterm infants exposed to CA, we hypothesized that prenatal lipopolysaccharide (LPS) exposure induces proteome changes in the CSF and brain both at birth and later.
Methods
Fetal piglets (103 days gestation of the full-term 117 days) were administered intra-amniotic (IA) lipopolysaccharide (LPS) 3 days before preterm delivery by caesarian section. CSF and brain tissue were collected on postnatal Days 1 and 5 (P1 and P5). CSF and hippocampal proteins were profiled by LC–MS-based quantitative proteomics. Neuroinflammatory responses in the cerebral cortex, periventricular white matter and hippocampus were evaluated by immunohistochemistry, and gene expression was evaluated by qPCR.
Results
Pigs exposed to LPS in utero showed changes in CSF protein levels at birth but not at P5. Complement protein C3, hemopexin, vasointestinal peptide, carboxypeptidase N subunit 2, ITIH1 and plasminogen expression was upregulated in the CSF, while the expression of proteins associated with axon growth and synaptic functions (FGFR1, BASP1, HSPD1, UBER2N, and RCN2), adhesion (Talin1), and neuronal survival (Atox1) was downregulated. Microglia, but not astrocytes, were activated by LPS at P5 in the hippocampus but not in other brain regions. At this time, marginal increases in complement protein C3, LBP, Hif1a, Basp1, Minpp1 and FGFR1 transcription indicated hippocampal proinflammatory responses.
Conclusion
A brief period of prenatal endotoxin exposure induces proteome changes in the CSF and brain at birth, but most changes resolve a few days later. The developing hippocampus has high neuronal plasticity in response to perinatal inflammation. Changes in CSF protein expression at birth may help to predict later structural brain damage in preterm infants exposed to variable types and durations of CA-related inflammation in utero.
On the dynamics and feasibility of transferred inference for diagnosis of invasive ductal carcinoma: A perspective
Authors: GM Harshvardhan , Sahu Aanchal , Gourisaria Mahendra Kumar , Singh Vijander , Balabantaray Bunil Kumar , Rodrigues Joel J.P.C.
Published: October 2021

It is generally noticed that increasing the number of convolutional layers in generic image classification procedures proves to be detrimental to model performance in terms of validation accuracy and loss. Apart from vanilla CNNs, we have state-of-the-art (SOTA) architectures such as ResNet50 (and its variants) which show that through the use of skip-connections, higher performance metrics are attainable through deeper architectures. However, most evaluative metrics converge on a log scale as we go deeper with diminishing gradient of the metrics' curves. Given these two contrasting speculations, in this paper, we implement various vanilla and SOTA CNNs for the diagnosis of one of the most common forms of breast cancer - invasive ductal carcinoma (IDC) - to examine and understand the feasibility of implementation of SOTA CNNs through transferred weights when juxtaposed with vanilla CNNs (and LeNet-5) of varying configurations in terms of their performance metrics and other parameters. In this paper, we solve the dual-objective of studying behavioural aspects of avant-garde CNN models (more specifically, VGG16, VGG19, ResNet50, ResNet50V2, MobileNetV2, and DenseNet121) and proper diagnosis of IDC through intermediate neural activations to critically evaluate and theorize the performance of different models. We notice that among all the models, only VGG16, VGG19, LeNet-5 and a selected vanilla CNN through an optimization procedure were the ones to attain the best metrics, shared amongst them.