bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Velocity Model Calibration on The Reservoir Volume in Kashagan Carbonate Oil Field
Authors: Taikulakov Y. , Schreuder S. 
Published: November 2023

Abstract
There are a variety of reasons that require calibrating a seismic velocity model to enhance and refine geological, structural, lithological, and stratigraphical aspects. It might be a human factor at the seismic processing stage, interpretation problems related to the presence of noise in the seismic data, or simply a facies variation within one geologic unit. Therefore, seismic velocity calibration is extremely important to complete as part of the overall interpretation procedure.
Development of Novel Metering Equipment
Authors: Isaev A. A. , Takhautdinov R. Sh. , Malykhin V. I. , Sharifullin A. A. , Aliev M. M. ogly 
Published: November 2023

Abstract
The gas-oil ratio (GOR) is one of the critical properties of the oil produced from a reservoir that is subject to development, study and monitoring. Sheshmaoil Management Company LLC (Republic of Tatarstan) employs a portable metering unit of UZGF-1-4.0 type to determine the GOR in oil, as well as the flow rates of oil and water [1–3]. The measurement technique has been certified and included in the State Register of the Russian Federation under the No. MN 759-2017. This unit's drawback is the placement of the measuring instruments on a semi-trailer, which requires a truck to transport it. N 2016, the engineers of Department for Innovations and Examinations were assigned the task to develop a portable metering unit that could be installed on the chassis of a UAZ-type vehicle. In 2019, a Well Stream Metering Unit (BIPS) was developed and tested (Fig. 1).
The BIPS consists of 0.05 m3 metering tank (separator) with an upper feed of well products through the DN 50 line (Fig. 2). The fluid is drained from the tank via the bottom line DN 50.
The BIPS is almost three times smaller than the UZGF unit in terms of overall dimensions, therefore it is used on the UAZ car chassis (Fig.3).
Simulation-Based Methodology for Optimization of Infill Well Locations in a Mature Oilfield
Authors: Levchenko P. , Iskakov E. 
Published: November 2023

Abstract
Identifying promising areas for the placement of new wells in a mature oilfield presents a challenging task, requiring a complex integrated analysis of geological and production data. Full field reservoir simulation model reflects all relevant information about subsurface properties and historical production, making it a great tool to quickly evaluate relative performance of potential infill locations. However, evaluation of all possible scenarios and well patterns for infill drilling using dynamic simulator can be a time-consuming and computationally prohibitive process.
Historically, this problem was commonly addressed by leveraging optimization algorithms such as "Genetic Algorithm", "Particle Swarm Optimization" or "Ensemble based optimizations". These algorithms help to minimize the required number of simulation runs for assessing optimal well placement to a few hundred cases. However, a significant drawback of these approaches is their lack of transparency, when the final recommended scenario with the best well performance might lack a coherent underlying rationale. For example, it could be unclear why all infill wells should be drilled in a certain region of the oilfield or positioned very close to other offset producers.
This paper introduces an innovative approach to streamline the selection process for drilling infill wells. By conducting a focused set of simulation runs, our method employs a unique design that enables enhanced post-processing of the results. This leads to the generation of clear visualizations highlighting the most promising areas within the field. The effectiveness of this methodology has been demonstrated through its application in determining optimal infill producer locations within the Korolev oilfield in Western Kazakhstan.
A Practical Guide to Repurposing Existing Pipelines to Hydrogen Operation
Authors: Wynne D. P. , Naib Sameera , Mirzoev Gaffar 
Published: November 2023

Abstract
The realization of a hydrogen (H2) economy will require pipeline transportation to move H2 from production areas to end uses. Stakeholders have identified existing pipeline infrastructure as playing a key part in a new H2 transportation network. This paper provides a guide for operators to repurpose pipelines safely and identifies efforts in the Caspian Sea region to realize the hydrogen economy.
Converting existing pipelines will require a deep understanding of the integrity threats they currently face and what new threats will arise following the introduction of H2. Due to differences in operation, age, manufacturer and construction quality, each pipeline faces different integrity threats and should have a tailored integrity management program to mitigate risk. The conversion guide developed is therefore integrity-led and takes a holistic perspective. It details how to account for the impact of H2 on key pipeline steel mechanical properties and what approaches can be taken to quantify and mitigate the impact, including appropriate material testing programs and defect assessment methodologies.
With an emphasis being given to safety and maximum utilization, the conversion guide provides operators with a practical framework for converting existing pipelines that is not available in current codes.
Fast-Track Verification Methods for Optimizing the Strategy and Scope of a Static Model Rebuild
Authors: Issayev Duman , Correa Mora Francisco , Bibolova Assem , Makedonov Andrey , Bishop James , Kydyrgazy Adilet , Tlepbergenov Nurbolat 
Published: November 2023

Abstract
Oil field production forecasts rely heavily on an accurate characterization of the subsurface. Static geological models are computer-based three-dimensional representations of the subsurface that approximate the reservoir properties and are the basis for dynamic simulation and subsequent field development decisions. With the advent of new data acquisition technologies, the prompt availability of additional information can potentially impact the validity and reliability of existing geological models. This case study introduces accelerated verification methods to evaluate the scope of a static model rebuild to accommodate business decisions.
Recent development efforts in the Tengiz oil field have led to the acquisition of new data, including the drilling of new wells and well log acquisition, reprocessing of seismic data, and microseismicity. Drilling new wells has provided valuable information about the reservoir's petrophysical properties. Specifically, high-resolution well logs, including wellbore images, helped derive valuable information about lithology, porosity, and fluid saturation, leading not only to a more accurate petrophysical interpretation but also help to define local variations of reservoir quality, allowing for more precise reservoir characterization. Reprocessed seismic data has improved image quality and event positioning, enabling improved structural mapping and seismic mega-amplitude detection. New wells with drilling data, wireline and production logs also provided additional information about fracture orientations, aperture, and density.
A fast-track, fit-for-purpose geological model was built through effective communication and collaboration among multidisciplinary teams and using fit-for-purpose quantitative and qualitative techniques, including 2D methodologies, statistical analysis, and geostatistical modeling. The main seismic horizons were reinterpreted from newly reprocessed seismic. New wellbore data was prioritized based on available logs and the existing data coverage. Matrix porosity and water saturation were calculated using a multimineral inversion model; fracture orientations were picked from image logs and fracture intensity and porosity were quantified. Quality control included statistical and variogram analyses before porosity propagation in a 3D model, which allowed for assessing a change in matrix and fracture porosity and pore volume in the model. A standard data-driven dual-porosity dual-permeability property modeling workflow was leveraged with microseismicity data to define effective fracture regions for the discrete fracture network model. These fast-track modeling approaches, developed in a time-efficient period, enabled the maturation of techniques to be applied in a future next-generation static model and provided valuable insights for reservoir management and production optimization in the Tengiz oil field.
Grouping of Gas Lift Wells Based on their Interaction
Authors: Mammadov A. V. , Sultanova A. V. , Mammadov R. M. 
Published: November 2023

Abstract
The operation of wells by the gas lift method is in the conditions of a contradiction between the volumes of injected compressed gas and the production of wells. As already mentioned, the existing method of individual selection of gas-lift wells operating modes based on the lowest specific gas flow rate has a number of disadvantages; the designated optimal mode is optimal only for a short period of time, since the existing hydrodynamic connections along the reservoir and the interconnections along external feed lines lead to a redistribution of fluid flows inside the reservoir and gas flows in the feed lines. The instability of the optimal mode is also caused by the presence of all kinds of random interference, for example, equipment failures, especially in Western Siberia. In addition to the above, since the existing system for automating the operating modes of gas-lift wells is based on individual studies, due to the lack of proper metering installations that provide the necessary accuracy of measurements, the operation of wells included in a common pipeline and the operation of the "main ~ well-regulator" system (A.V.Mamedov, B.A.Osmanov, M.S.Askerov, 2004, A.Kh.Mirzadzhanzade, I.M.Ametov, 1983).
There is a need to find ways to bring gas-lift wells to optimal operating conditions, which is especially important in conditions of a shortage of compressed working agent volumes, when the available gas resources do not ensure the operation of wells with maximum fluid extraction (Bakhtizin R.N., Khasanov M.M., Efendieva N.N., 1993).
The solution to this problem is possible by dividing the entire fund of gas-lift wells into separate groups, taking into account their interaction and the characteristic features of the main technological parameters of individual wells, followed by assigning an operating mode for groups of wells as a whole.
Research on the Formation Gravity Displacement Window
Authors: Tao Zhenyu , Fan Honghai , Liu Yuhan , Fu Jin , Ye Yuguang , Zhou Fei , Yin Wen , Sun Yanshuai , Wang Jinxing 
Published: November 2023

Abstract
Formation gravity displacement refers to the phenomenon of "overflow and leakage" in the same crack due to the difference in density between the drilling fluid and the formation fluid. In order to restrain the leakage accident caused by gravity displacement, this paper studies the formation gravity displacement window, studies the conditions of gravity displacement, and puts forward the corresponding solutions. In summary, this paper develops the wellbore-formation gravity displacement experimental device, carries out gas-liquid gravity displacement critical point experiments, summarizes and analyzes the formation gravity displacement window, and fits the critical point pressure curve of the gravity displacement window based on the results of constant pressure experiments. The existence of formation gravity displacement window was verified through computer simulation. The error between the fitting formula and the measured value is less than 10%, it can reflect the relationship between the gravity displacement window and the density difference, which is of guiding significance for on-site gravity displacement suppression and pressure-controlled drilling.
Evaluating the Optimal Logging Suite for Sandstone Reservoirs in the South Caspian Basin
Authors: Shiriyev J. , Ismailzadeh E. , Aliyev N. , Pashayev N. , Aliyev F. , Sultanov A. 
Published: November 2023

Abstract
The South Caspian Basin is known for its significant hydrocarbon reserves, particularly in sandstone reservoirs. Accurate reservoir characterization and evaluation are crucial for this region's successful exploration and production activities. Choosing the appropriate well logging suite is vital decision in obtaining comprehensive data on reservoir properties, including lithology, porosity, permeability, and fluid saturation. The paper focuses on identifying the best well-logging suite to evaluate sandstone reservoirs in the South Caspian Basin effectively. Our research aims to compare and analyze different well-logging techniques to determine the optimal combination and provide a list of prerequisite core measurements for accurate reservoir characterization. The study systematically evaluates commonly used well-logging tools such as gamma ray, resistivity, neutron, density, sonic logs, and infrequently used NMR logs based on the ability to provide accurate measurements, cost-effectiveness, and compatibility with the local environment. The strengths, limitations, and applicability of each logging tool in sandstone reservoirs is assessed based on existing wellbore data and core samples. Additionally, production history enhances the reliability of the findings. To attain the outlined objectives, a comprehensive literature review and case studies from analogous sandstone reservoirs is conducted. The analysis considers the regional geological setting, reservoir heterogeneity, and fluid properties. The outcomes of this research aid exploration and production companies operating in the basin in making informed decisions regarding the well-logging tool selection that will optimize data acquisition, minimize uncertainties, and improve reservoir characterization accuracy, ultimately contributing to better reservoir management practices and higher hydrocarbon recovery.
Seismic Anisotropy Analysis of Fractured Reservoirs
Authors: Chichinina T. , Avila-Carrera R. , Bezkhodarnov V. 
Published: November 2023

Summary
Vertical fractures cause azimuthal anisotropy. To predict the fractures’ azimuth, we use anisotropy analysis of four seismic attributes: NMOA, AVOA, QVOA and Shear-Wave-Splitting (SWS). Namely: the first NMOA-attribute means "Normal-Move-Out velocity versus Azimuth". The second attribute AVOА stands for "Amplitude Versus Offset and Azimuth". The amplitude is understood as the reflection coefficient of the longitudinal (PP) wave. In the SWS analysis, we separate two shear waves from each other (S1 and S2). The S1 -wave has its polarization vector parallel to the plane of the fractures, and the other (S2) is perpendicular. The delay time Δt between the S1-wave and the S2 -wave is proportional to the fracture concentration. Regarding the NMOA, the unequal time of arrival of the PP-wave in different azimuths is due to the velocity anisotropy induced by fractures. The azimuthal variation of the NMO velocity is described by the NMO ellipse. The spatial time-field surface for the reflected PP-wave can be represented as a hyperboloid with an elliptical section, which is the so-called NMO ellipse. The minor axis of the ellipse points to the fractures’ azimuth (α0). In addition, the AVOA attribute is used for fracture characterization. The azimuthal variation of the AVO gradient can be represented as an ellipse, whose minor axis (Bmin) shows the fracture direction azimuth. We can estimate the concentration of fractures by the value of its major axis (Bmax). We apply an integrated approach, that is, the analysis of four anisotropy attributes: NMOA, AVOA, SWS and QVOA. The QVOA-attribute means "Q Versus Offset and Azimuth". Q is a quality factor. The inverse (the reciprocal) of the quality factor 1/Q is a measure of the attenuation of the seismic-wave energy. When analyzing the azimuthal variation of an anisotropy attribute, it is considered that a fractured reservoir can be represented as a model of a transversely isotropic medium with a horizontal axis of symmetry (HTI). With regard to the latter QVOA method, we come to the conclusion that in order to achieve the highest accuracy in the angle of the fracture-direction estimation, it is best to use our new "canonical" formula derived for the Q−1(θ, φ)-attenuation function, which gives the highest accuracy in estimating the azimuth of the fracture direction compared to its former approximations. In the former version of QVOA method, we used a simplified approximation formula of the attenuation (Q−1(θ, φ)) in the form A + Bx + Cx2, (where x = sin2θcos2(φ − φ0), as well as its truncated approximation A + Bx. However, to achieve the highest accuracy in estimating fracture direction, it is best to use our new "canonical" formula of Q−1(θ, φ)-function, which gives the best accuracy in estimating the azimuth angle of fractures’ direction compared to those simple approximations. Thus, our improved QVOA method gives an excellent absolute accuracy of more than 0.25 degrees.
Reduction of Oil Losses from Evaporation at Oil Collection Points
Authors: Mammadzada N. M. 
Published: November 2023

Abstract
During the filling and emptying of the tanks at the oil collection points, the transfer of petroleum products from one tank to another, and the storage of petroleum products in tanks, evaporation losses of petroleum products occur, and ecology and the environment are polluted. In order to reduce evaporation losses in the tanks, the gas spaces should be connected with the collector pipe. For the condensation of oil vapors, the collector connecting the gas spaces of the tanks should be connected to the drainage capacity by passing through the overflow crude oil collection or formation water collection tanks. Steam passing through the tank condenses as a result of cooling.
Ecology and environmental protection are the most important issues in the collection, transportation and storage of extracted oil and gas. Ecology and environmental protection is about reducing losses in the transportation and storage of oil. There may be quantity and quality losses in petroleum products. In quantitative losses, the consumption of petroleum products increases, and in quality losses, their composition changes. Quantitative losses are caused by leaks in the flange joints of fittings, pump casings, erosion of tanks and pipes during transportation of oil products, as well as evaporation of oil products in tanks. Evaporation losses account for 75% of total losses [1].
Evaporation losses of petroleum products occur as they are stored in tanks, filled and unloaded, and transported from one tank to another. In tanks filled with petroleum products, a complex evaporation process always occurs, resulting in oil losses. Oil losses are inevitable during the "breathing" of tanks [2, 3]. Small "breathing" is accompanied by the temperature difference between day and night, and large "breathing" is accompanied by filling the tanks with petroleum products.
Subsea Water Treatment and Injection to Optimize Production and to Reduce Cost
Authors: Hegdal T. 
Published: November 2023

Abstract
Water injection is normally used as the preferred drainage mechanism and to optimize oil recovery. Moving water treatment and injection close to the subsea wellhead, as close to the reservoir as possible, enables flexible, cost-efficient, and robust field development. The short distance the water travels and the unique approach to water treatment make the subsea solution attractive, with reduced energy and chemical consumption. Moving water treatment and injection to the seabed saves significant weight and space topside and enables unmanned or low-manned operations.
The subsea approach and technology offer new ways to develop and optimize existing fields. Implementing and expanding water injection on existing fields are possible with minimal interruption to ongoing operations and practically no production shutdown required. The modular approach and flexibility enable more freedom to manage the subsurface uncertainties, mitigate risk, and pursue upsides throughout the life cycle of the field. Subsea water treatment and injection, combined with subsea chemical storage, enable an all-electric solution for sophisticated injection water for enhanced oil recovery with a high potential to increase value on brown and green fields.
Treating seawater at the seabed has several inherent advantages, such as effective disinfection through long-time chlorine soak and removal of particles via sedimentation without topside processing equipment. SWIT is a modular system that can be adapted to all water requirements and is based on Seabox as the initial conditioning step where microbes are killed and particles are settled out.
The quality of water injected into an oil reservoir impacts the water produced together with the oil and gas. Thorough disinfection to mitigate reservoir souring and H2S generation is a prerequisite. Further tailoring of the chemistry of the injection water to mitigate any compatibility issues between raw seawater and formation water is critical for many reservoirs and operations to avoid precipitation of solids and scaling. The subsea seawater treatment technology offers some unique capabilities to improve this.
Subsea water treatment enables processing capacity increases without impacting the existing topside. This reduces weight, avoiding topside modification and associated shutdowns, cost, and environmental footprint compared to a traditional topside solution. Long-term maintenance-free and unmanned operations reduce logistics and hence improve safety.
This paper discusses conceptually how the quality of water injected into the reservoir impacts oil recovery and overall flow assurance from a life-of-field perspective. Subsea chemical storage and pigging are also discussed and may play an important role in flow assurance and production optimization.
Enhancing BHA Tendency Modeling Accuracy Using Hybrid Physics and Machine Learning
Authors: Suryadi H. , Yu T. , Boualleg R. 
Published: November 2023

Abstract
Directional drilling capabilities continue pushing for a more challenging 3D wellbore path with higher dogleg severity. The ability of the planned BHA to drill the wellbore as per the planned trajectory determines the well's success. Drilling program critical decisions require an accurate prediction of BHA tendency. Inaccurate modeling results lead to failures in execution, such as the inability to deliver the planned trajectory, the failure to reach the target reservoir or the compromise of the well production result.
Physical modeling has been extensively used in well planning to simulate the drilling process, optimize the design, and identify potential risks. The drilling process, including BHA steering tendency, is complex, with multiple parameters involved. Physical modeling cannot accurately model all parameters and minimize various uncertainties. This limitation leads to a reduction in modeling result accuracy.
In recent years, artificial intelligence or machine learning has been the most popular technology to unlock the full potential of data across industries. We need novel methodologies to integrate traditional physics-based modeling with state-of-the-art machine learning techniques to solve complex science and engineering problems such as drilling simulations.
The physics-based approach of BHA tendency modeling is based on static and dynamic finite element analysis. This approach is often a good solution if the physics model is accurately calibrated. Yet, it requires deep domain knowledge and accurate formation, bit, and steering tools data and may incur a high computational cost.
The machine learning (ML) model is based on learning algorithms that find relationships between various parameters and actual tendency results in a training dataset. The limitation of the ML model is that it requires big historical data to get accurate modeling. Merging the two principles of physics and machine learning combines the best of the two worlds, resulting in higher accuracy, better scalability, and computational cost efficiency.