bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimization of Stress & Strain Tensors Computational Algorithm While Constructing 3D Geomechanical Model of the Field
Authors: Mylnikov Danila , Melnichuk Dmitrii , Korelskiy Evgeny , Petrakov Yuriy , Sobolev Alexey 
Published: September 2020

Abstract
This work is dedicated to studying the numerical description of oil & gas field mechanical behavior. The algorithm is proposed for the stress and strain tensor distribution computation within the assumption of infinitesimal elastic strains. The proposed algorithm is verified and demonstrated to be potentially more effective than the algorithms currently used in industry for the same problem solution. The proposed algorithm is based on finite volume method with two-grid solution scheme. After algorithm verification versus COMSOL software, it is applied to geomechanical model construction for a particular oilfield located in Russia. The model is successfully constructed and the model quality check is passed.
Elemental Study of Single Fractures Conductivity Using 3D Prototyping and Nuclear Magnetic Resonance
Authors: AlSinan Marwah Mufid , Gao Jun , Kwak Hyung Tae , Satrawi Mustafa 
Published: September 2020

Abstract
Fluid flow in fractures is of great interest in the oil and gas industry due to its numerous applications in naturally and hydraulically fracture reservoirs. In order to resolve a fracture's conductivity, its structural and hydraulic properties must be analyzed extensively. Advancements in Real-time Nuclear Magnetic Resonance (NMR) tests and 3D-printing technology impelled them to become valuable analytical tools. This paper takes a multi-disciplinary approach to improve empirical studies of flow in fractures.
A resin core-plug of parallel-plate fracture model was created. The fracture design has a well-known theoretical solution which was used to validate experimental results. To increase fluid susceptibility to NMR measurements, fractures were replicated 6 times in each plug. X-ray micro-computed tomography images were conducted to evaluate the manufacturing quality and geometrical parameters.
NMR T2 relaxation time and saturation profiles were conducted to monitor the flood front and asses the fracture volume. The NMR pore volume can be substituted in the cubic law equation to obtain the fracture permeability.
3D printing technology provides a non-destructive and efficient method of controlling geometrical parameters in the designed models. In addition, 3D printing is flexible regarding the manufacturing material, which allows control of surface wettability. All of these factors would improve the quality of model studies, including the current study of the impact for different geometrical factors on fracture conductivity
Metrology and Standardization in Geomechanical Modeling
Authors: Ravilov Nikolay , Tatur Olga , Chettykbayeva Kamilla , Sobolev Alexey , Petrakov Yuriy , Ocheretyanyy Anton 
Published: September 2020

Abstract
The paper presents an algorithm for estimating the error of the 1D geomechanical model taking into account the measurement errors of the instruments and the correlation dependencies used. The sensitivity analysis of the resulting error to the quality of the source information was also performed. A confidence parameter has been introduced to assess the contribution of a measurement to the calculations. An approach is proposed for the transition from the convergence of correlation dependencies to the error of the correlation used.
The application of this methodology allows at the initial stage to draw a conclusion about the quality of simulation results and take measures to increase the reliability of calculations.
Plastic Instability of Vikulovskaya Suite
Authors: Toropetsky Konstantin Victorovich , Borisov Gleb Alexandrovich , Samoilov Mikhail Ivanovich , Zharkov Artem Vladimirovich 
Published: September 2020

Abstract
This paper considers methodology aspects for constructing one-dimensional (1D) geomechanical models and stability calculations for the case of viscoplastic behavior of rock under stress with a case study of the Vikulovskaya sandstone from the Em-Egovskoe Field in West Siberia.
Advanced Method of Controlled Core Scratching as a Source of Geomechanical Data
Authors: Toropetsky Konstantin Victorovich , Borisov Gleb Alexandrovich , Samoilov Mikhail Ivanovich , Eltsov Igor Nikolaevich 
Published: September 2020

Abstract
The established practice of geomechanical testing includes the procedures of core sampling and marking, as well as core plug drilling out and testing. The key challenge is that a selection of core plugs is physically or economically limited. The classical core analysis offers a limited and discrete data set. Along with that, the tests carried out on a set of core plugs are dependent upon the core quality and the accuracy of selection of the core plugs sharing identical properties. These constraints impair accuracy and reliability of geomechanical models.
This paper describes controlled core scratching (CST) as a method of geomechanical testing of full-size cores. Physically, the CST method is based on resistance measurements of the of full-size cores to scratching. Depending on the cutter penetration depth and the core sample scratching rate, the force characterizes unconfined compressive strength (UCS) and/or fracture resistance of the rock.
The principal CST advantage is that it provides accurate and diverse continuous geomechanical rock properties. The application of the CST method enhances comprehensive core analysis accuracy, synthetic physical & mechanical parameters reliability and, therefore, geomechanical modeling precision. In practice, the CST method applied in conjunction with the classical geomechnical core analysis enhances the quality of drilling, completion, frac'ing, and field development support in general.
This paper presents a comparative study of geomechanical models that incorporate synthetic curves for unconfined compressive strength (UCS), Brazilian tensile strength (BTS) and cohesion strength (CS), derived from the CST and well logging data, using a well that is drilled through halocarbonates and clastics as an example. The comparative study of the CST-based and log-based geomechanical models demonstrated that the CST-based model outputs robust correlations and detailed distinctive curves of physical & mechanical properties and clear stratification boundaries.
Multi-Objective Optimization as a Tool for Scenario Modeling of a Company's Portfolio
Authors: Zhigach Sergei Alexandrovich , Yudina Elizaveta Nikolaevna 
Published: September 2020

Abstract
The aim of the work is to create a scenario modeling technique based on adaptation of metaheuristic multi-objective optimization algorithms to construct Pareto-optimal investment portfolios taking into account multiple restrictions on the company's portfolio.
Investment portfolio is a tool for company's resources management. The process of portfolio construction through a combination of individual investment projects aims to optimize available resources utilization. Currently, there is no single approach to determining the optimal portfolio, since portfolio requirements depend on a particular company. Due to its simplicity in terms of implementation, approaches based on the ranking of projects according to individual technical and economic indicators are widely used. However, if a company needs to take into account several indicators, then this approach is not applicable. An effective solution to this problem is to create a technique that allows to find Pareto-optimal portfolios.
In this work, the problem statement and analysis of existing solving approaches were carried out. Based on that, methodology of scenario modeling of a company's portfolio was created. The posed problem belongs to the class of NP-hard problems and for its efficient solving it is necessary to use metaheuristic algorithms. These algorithms include genetic algorithms, variable neighborhood search, bees algorithm, etc. Genetic algorithm NSGA-II is widely used for solving multi-objective optimization problems due to its high performance and ease of use. This algorithm was adapted to solve proposed problem. Based on it, a methodology was developed for the formation of Pareto-optimal investment portfolios, taking into account financial and infrastructural restrictions. Testing of the methodology was carried out on a dataset of synthetic projects simulating real investment projects. Various combinations of this projects simulated investment portfolios. The optimization objectives were maximization of net present value (NPV), maximization of cumulative oil production and minimization of total investments. In order to control the quality of the results obtained using genetic algorithm, the problem was also solved by using variable neighborhood search. However, the quality of the results obtained using genetic algorithm was higher. Analysis of the results allows us to consider the use of multi-objective optimization as a tool for forming a pool of investment portfolios, which provides flexible company management.
In the proposed work, it is shown that the problem of scenario-based modeling of company's investment portfolio can be considered as a multi-objective optimization problem. Based on the existing metaheuristic algorithms, a Pareto-optimal investment portfolio search methodology has been developed. Proposed methodology can effectively solve the problem of managing company resources.
Bolshekhetskaya Depression Concept Selection Study
Authors: Mamedov Emil Adalatovich , Lysov Alexey Gennadyevich , Avchikhanov Arsen Sultanovich 
Published: September 2020

Abstract
A concept has been developed for gas, gas-condensate and oil fields exploitation planning in the Arctic region, taking into account the limitations of the existing external and internal infrastructure. The work was carried out as part of an integrated project management system to determine business opportunities and initiate the transition of field development projects to the pre - project development phase (Pre - FEDD).
The paper considers the formations and geological structures of the Bolshekhetskaya Depression in the license areas: License area "Nakhodkinskiy"Licensed area "Pyakyakhinsky"License area "South Messoyakhsky"License area "Halmerpayutinsky"License area "Salekaptsky"Licensed area "West Tazovsky"License area "Vareisky"
The choice of the profile of the horizontal section of the well is one of the main issues in the design and affects not only the final gas and condensate recovery, but also helps to clarify the geological structure of the formation during the well construction, as well as include all productive layers in the development, reduce the risk of complications during operation. Usage of longer horizontal wells will reduce drill footage; to increase the flow rate and profitability of wells; it is more rational to use formation energy due to lower values of depression on the formation and correspondingly reduced losses of condensate in the formation.
Method for Optimal Well Pattern Estimation for Oil Rim Fields
Authors: Nekhaev Sergey Aleksandrovich , Perevozkin Igor Vladimirovich , Reshetnikov Dmitriy Anatolevich , Samolovov Dmitriy Alekseevich 
Published: September 2020

Abstract
The effective development of thin oil rims by horizontal wells is an urgent area of technological development of oil and gas companies in the context of an increase in the portfolio of new fields with significant reserves of free gas. A key feature of the development of oil rims is gas coning and therefore it is necessary to limit the productivity of wells, which leads to a high sensitivity of project profitability to reservoir properties, economic conditions and the development system. For successful development it is necessary to optimize all the components of the project – wells count, downhole equipment, transport system.
Some works relating to the theory and methodology of developing oil rims describe approaches to calculating the optimal well spacing [Khasanov et.al.], the number of wells per bush [Samolovov, Mozhchil et.al.], and ground facility [Povyshev et.al.]. Special cases of comparing different well placement systems are widely represented in the literature, for example, in [Sugaipov et.al.]. An increase in the share of oil rims production leads to the need to find common solutions to such optimization problems.
In this paper, we consider the question of determining the optimal location of wells by systematic selection of an in-line or radial development system. When horizontal wells are placed on oil rims in the form of an in-line development system, optimal conditions are created for the uniform production of oil reserves, since the distance between the horizontal wells is the same for all cross sections of the well and the gas cone is formed uniformly along the direction of the horizontal wells. However, when combining well trajectories into one bush, in this case there is a need for large reach from the wellhead or in a small number of wells in the bush. When horizontal wells are placed on oil rims in radial development system, optimal conditions are created to minimize well reach, however, interference occurs between wells in the reservoir due to the distance between wells changing along the direction of the horizontal wellbore. The purpose of the work is to determine the conditions under which in-line or radial well placement is optimal.
Promising Methods for Increasing the Efficiency of Exploitation of Thin Low-Pressure Gas Deposits with Underlying Water
Authors: Urvantsev Roman Vadimovich , Ibragimova Dina Renatovna 
Published: September 2020

Abstract
The main problem of exploitation of thin low-pressure gas deposits with underlying water is the constantly increasing water cut. As a result, this leads to wells liquid loading and the impossibility of further work. Various technologies exist to solve this problem. In this paper, we consider technologies based on the principle of removing water from the bottom of the wells with its further disposal. An analysis of literary sources containing experience in the application of various technologies at analogous facilities has been performed. In addition, the conditions under which produced water is removed from the bottom hole are evaluated.
A feasibility study of technologies applicability was carried out in the context of unique gas field, the main reserves of which are associated with Cenomanian deposits.
All calculations were performed on the hydrodynamic model including the gas-gathering system option.
The Balance Between Oil and Gas Options in Case of J2-6 Oil Rim Development of Novoportovskoye Field
Authors: Varavva Valentina , Bogdanov Evgenii , Chameev Igor , Sherstoboev Evgenii , Isakov Kirill , Virt Vitaliy , Shorokhov Aleksei , Kashapov Denis 
Published: September 2020

Abstract
The paper considers gas option beginning and forcing in case of U2-6 reservoir of oil and gas condensate Novoportovskoye field, which is an underlaying-typed oil rim with a massive gas cap. Based on conducted analysis the recommendations for the further gas option development with oil production losses minimization and gas production maximization were formulated.
Production Enhancement in Deep Sour Gas Field: A Case Study in China
Authors: Guo Hongzhi , Li Huigeng , Weng Zhiyong , Tao Ke , Wang Dong 
Published: September 2020

Abstract
Puguang is the biggest sour gas field in China with 17% H2S and 9% CO2 concentration and is the major gas sources for the pipeline from Sichuan to Shanghai. It's important to keep the gas wells healthily and steadily producing. However, the production is continually declining due to water coning, scale buildup and formation pressure dropping. It's urgent to perform well intervention effectively and economically to increase the well production.
Production logging in multiple wells identified that inflow zones were less than 30% of perforation interval because of formation invasion and perforation tunnel plugging from initial completion. To release the potential productivity from nonproducing zones, reopening the perforations is critical to reverse the trend of production decline. To pass through the 3.5-in tubing with minimal restriction of 2.7-in and to effectively perforate the 7-in production casing and the carbonate formation, a 2.5-in spiral-exposed perforation system was finally selected as the optimized solution that can achieve the deepest formation penetration compared with conventional carrier system from simulations with rock-based perforation model.
The spiral-exposed perforation system was modified to be H2S resistant, and wellbore dynamic simulation was conducted to minimize the gun shock to avoid gun drop during detonation. The detailed job design and risk mitigation plan were made as well to avoid any failure in such a highly corrosive environment with well depth up to 6,000 m. The first reperforation job was conducted successfully, and the well production increased 130,000 m3/day or 22.8%, and afterward, production logging confirmed that zonal production had significantly improved from the newly perforated interval. Then another seven wells were reperforated with an interval of 30 m to 45 m and average 100,000 m3/day gas production increment or 20% per well was achieved. It's proven that reperforation with redesigned exposed perforation system is the effective and economical way to increase production in the Puguang gas field.
This paper illustrates how and what we do for exposed system improvement, candidate well selection, planning, and executing the through-tubing exposed perforation in such extremely challenging conditions. It also discusses lessons learnt and recommendations for future well intervention to steadily increase the well production in the Puguang gas field.
Digital Core Analysis – Innovative Approach for EOR Agent Screening at Pore-Scale for Achimov Rocks
Authors: Yakimchuk Ivan , Evseev Nikolay , Korobkov Dmitry , Dinariev Oleg , Ridzel Olga , Khan Vladimir , Semkov Vyacheslav , Zhonin Alexander , Kravets Dmitry 
Published: September 2020

Abstract
The digital core analysis technology with direct hydrodynamic modeling based on the density functional method was applied for the first time for the EOR screening and evaluation of the EOR agent efficiency at pore scale for Achimov reservoir rocks. The technology consists of scanning core samples by X-ray microtomography (microCT), constructing the corresponding digital core models of the pore space geometry, and performing multiphase hydrodynamic modelling at the pore scale based on the density functional method (DFT).
The required spatial resolution of digital models for the studied sample was about 1 μm, and the size of the representative elementary volume on which multiphase hydrodynamic modeling was performed was 750 × 750 × 750 voxels.
Despite the extremely low permeability values (less than 1 mD) of the test sample, digital core analysis allowed a series of digital experiments to calculate the absolute permeability, the creation of residual water saturation using different approaches (simulation of the laboratory protocol and geological process) and the determination of oil displacement when injecting various EOR agents (formation water, carbon dioxide and smart water). For the first time, the dependence of the displacement coefficient both on the method of modeling the initial conditions (residual water saturation) and on the type and mechanism of the considered EOR agents for Achimov reservoir rocks was studied.
Core Column Filtration Testing Supplemented by Measurements of Oil Optical Properties
Authors: Burkhanov Ramis Nurutdinovich , Lutfullin Azat Abuzarovich , Ibragimov Ildar Ilyasovich , Maksyutin Alexander Valeryevich 
Published: September 2020

Abstract
The composition and properties of oil change during its flow through the reservoir, which is associated with the high molecular weight resins and asphaltenes retained in the pores. Oil is retained in the thinnest capillaries and narrow contacts of hydrophilic mineral grains (capillary-retained oil) and as a film on the surface of hydrophobic minerals (oil films). To confirm this, core analysis tests were performed on three pre-prepared core columns made up of standard core samples with different porosity ϕ, absolute permeability k, irreducible water saturation Swir and other properties. Oil was flowing through the column and displaced by water with pre-determined physical properties. The properties of the core specimens, oil and water, as well as the thermobaric conditions of flow experiments were selected so that they corresponded to the reservoir conditions of the Pashian horizon of the Romashkinskoye oilfield of the Republic of Tatarstan. In the case of the mature Romashkinskoye oilfield, the relevant objective is to quantify and localize the remaining reserves of capillary-retained oil and oil films and substantiate effective technologies for their extraction. To prove that the composition of oil change during flow through porous media, the light absorption coefficient of oil kla was investigated that depends on the relative content of resins and asphaltenes in the oil. Oil was studied using a photometer in a continuous mode during the entire period of oil displacement test. Oil samples were collected and subjected to preparation at the inlet and outlet of the core column, their optical density D, light absorption and transmission coefficients were measured in vitro, and statistical data were processed. It has been found that regular changes in the oil kla occur both at the stage of the core column saturation with oil (a regular decrease), and as oil is displaced from the core samples by water (a regular increase). The identified patterns are the function of the rock and oil properties, the established rate of the column saturation with oil and oil displacement by water, and the amount of residual and displaced oil. The obtained data have shown the promising outlook for continuing laboratory experiments to study not only changes in the properties of oil when it is displaced by water, simulating the development processes, but also those occurring in the column as it is saturated with oil, simulating the processes of primary migration and accumulation of oil in a natural reservoir.