bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multizone Open Hole Gravel Pack Completion with Selective Production Capability in ACG Field
Authors: Susilo Yoliandri , Dharmadhikari Khsitij , Taha Sherif , Ismayilova Ayisha , Guliyev Ilkin , Jafarli Zaur , Kerimov Natig , Kerimova Ravana , Veliyev Samir , Whaley Kevin , Wallace Alex , Mammadov Elvin , Foster Mike 
Published: November 2023

Abstract
Azeri-Chirag-Gunashli (ACG) is a giant field located in the Azerbaijan sector of the Caspian Sea. The major reservoir zones are multi layers sandstone formations and weakly consolidated where Open Hole Gravel Pack (OHGP) completions have become the standard design for production wells. To date more than 170 high rate OHGPs have been completed that are producing comingled from multi-layered sandstone formation.
As the field matures, problems such as premature water and gas breakthrough are becoming increasingly common requiring the completion system to be inherently flexible to address such issues. The Multi Zone OHGP concept design has been developed to manage this increasing reservoir management complexity. Zonal isolation and selective production capability are achieved by installing combination of multiple Screen PBR and/or open hole packer in combination with seals unit and mechanical sliding sleeve in the inner string at the intermediate completion, and Inflow Control Valve (ICV) at the upper completion.
To date, two Multizone OHGP wells have been completed successfully. The Screen PBR system has proved to provide effective zonal isolation or baffling. This system allows flexibility to deal with unexpected reservoir surprise (wet/gas zone) that requires zonal isolation on day-1 without major changes in completion design, thus reducing rig time & operational cost.
This paper discusses design, execution, and result of the first two Multizone OHGP completions installed in the ACG Field. Installing multiple Screen PBR to provide baffling against crossflow is a novel concept. This technique does not compromise gravel pack quality or sand control integrity. The success seen with this technique makes a compelling case to further develop the concept on a larger scale in ACG and maximize field recovery.
Wellhead and Valve Technology Principles, Problems and Practices
Authors: Mugharbil M. K. , Mirza A. A. 
Published: November 2023

Abstract
Wellheads are complex equipment that connect the wellbore to the surface and execute multiple functions, such as pressure containment, load support, annulus access and wellbore sealing. These functions are essential for the safe and efficient operation of the well. The design of wellheads is based on the well conditions and operational requirements, such as pressure, temperature, flow rate, corrosivity, and service life. The wellhead design must comply with the relevant standards and specifications to ensure the quality and reliability of the device. The wellhead design must also use appropriate materials, dimensions and configurations to handle the expected loads and stresses that arise from the weight of the tubing, casing and equipment, as well as from the internal and external pressures and temperatures.
The effective management of fluid flow in or out of the wellbore is dependent upon the function of the wellhead valves, which serves as a crucial regulatory mechanism. They must be inspected and maintained regularly to ensure their functionality and integrity. Valve failures can have various causes, such as corrosion, erosion, debris, thermal expansion or improper operation. A prevalent issue affecting valves is referred to as the "stuck valve," which happens when the valve stem or disk cannot move freely due to friction or obstruction. The occurrence of a stuck valve has the potential to cause significant operational delays, safety hazards, and environmental risks.
When addressing a malfunctioning valve, a variety of tools and procedures may be implemented depending on the type and location of the valve. Some of the tools that can be used are valve wrenches, valve actuators, valve reamers and valve pullers. These tools can help to loosen or remove the stuck valve by applying force or torque to the valve stem or disk. Some of the procedures that can be used are applying lubricants or penetrants, tapping or heating the valve body, reaming the valve guide or removing the valve from the wellhead.
This paper aims to discusses the design, function and maintenance of wellheads and wellhead valves. It explains how wellheads and valves are essential and describes the common problems that can affect wellheads and valves, such as stuck valve, and how to fix them using different tools and procedures. It concludes by emphasizing the importance of wellhead and valve performance and safety for the well and the environment.
Integration of RCA and SCAL with Image Logs Leads to a Unique High Resolution Technique to Evaluate Laminated Clastic Reservoirs of Black Sea, Turkey
Authors: Isdiken Batur , Dutta Tanmoy , Yüce Ugur , Kiliç Mert 
Published: November 2023

Abstract
Deep water gas reservoirs in the Western Black Sea consist of highly laminated heterogeneous and complex sand/shale sequences. A petrophysical volumetric model was created by combining the triaxial induction resistivity data with the Thomas-Stieber (1975) sand-shale volumetric model to better evaluate low-resistivity pay zones in highly laminated shaly sand sequences. Although the results from this method are volumetrically almost correct, they are quite insufficient to deal with the distinctions between finely laminated sand, silt and shale.
In order to calculate volumetric petrophysical parameters, such as porosity and water saturation, which are linearly or non-linearly derived from the sand/shale fraction of the rock volume, accurate measurement of laminar shale volume in shaly sand sequences is an essential first step. Even though GIIP does not change much, the volumetric method presents a particular challenge in terms of continuity of gas bearing layers when there is water located in both above and below the gas-bearing sands. High-resolution wireline image tools with a vertical resolution of 0.5 cm can capture bed thicknesses and boundaries of these sand layers, enabling the determination of the net to gross sand ratio. However, imaging technologies by themselves are unable to determine precise porosity and water saturation. By statistically evaluating extensive volumes of core data (RCA and SCAL) and image logs, a new high-resolution methodology offers a simple and innovative method to compute porosity and saturation.
A partially cored reservoir section example is used to demonstrate the entire technique. This approach does not require standard log deconvolution. The uncertainty has been understood after comparing the results between the volumetric model and high-resolution model. By using the methods described in this paper, it is possible to position the perforation interval more precisely and reduce uncertainty for volumetric petrophysical calculations in complex highly laminated clastic reservoirs. The results show that low resistive laminated clastic reservoirs can be extremely productive, showing reservoir quality comparable to that of productive thick sands.
Using Deep Learning Algorithms to Monitor Well Performance and Restore Well Rate Dynamics
Authors: Yudin E. , Andrianova A. , Isaev D. , Kobzar O. , Mosyagin G. , Gudilov M. , Polinov M. , Shestakov A. , Ganeev T. 
Published: November 2023

Abstract
The main purpose of the work is to create a system for effective monitoring of well operation by analysing the data coming from sensors. This algorithm is focused on automation of intraday monitoring of unstable wells, as well as search for deviations in operation of wells and downhole equipment.
This paper applies an algorithm to reconstruct flow rate dynamics in an unstable wells based on deep learning models, specifically using a neural network model that learns from the large amount of information coming from telemetry sensors installed on wells and downhole equipment. In addition, static well data, such as well construction, PVT properties, and various data by results of well surveys, are also used. This approach allows all information from all wells in a particular field or group of fields to be used, and also allows the model to find complex relationships between parameters that sufficiently characterise well performance.
For wells with unstable working conditions, the approach presented in the work has a significant advantage, as it allows to form a sample with participation of a large number of wells on different regimes within the same method of exploitation, taking into account intentional or unintentional changes in operating regimes on these wells. The implementation of this algorithm achieved a convergence for unstable wells of up to 85% compared to the standard algorithms, which did not exceed 75% convergence. Despite the statistical model, this algorithm absorbed and summarised the vast expert experience of specialists, based on which the feature space was built, additional calculated parameters were added and parameters that did not affect the dynamics of well operation were removed from the sample. This algorithm has been successfully tested on gas lift unstable wells and has been translated to other artificial lifting methods, including complex periodic modes on ESP wells and wells operating modes under annular flow conditions. This algorithm helps field engineers solve challenges related to intraday analysis of well operations, such as regime control, wellbore understanding of deviations from planned operation modes, anomalies in operation and fast solution of production allocation problem.
The approach of building a general statistical model, compared to standard models that focus on knocking down each individual well, is a leap forward in the development of intraday stock analysis. With a timely trained model, the analysis is done extremely quickly on the entire field at once, and more importantly, quite efficiently. Where simple standard modeling approaches do not allow reproducing nonstationary processes with sufficient accuracy or take large amount of computing resources, the neural network is able to automatically filter data from all well telemetry, generalize features and identify complex patterns in the well operation behavior.
Scaling Issue in the Platform Area of Tengiz Field and Preventing Solutions
Authors: Myrzabayeva A. , Kydyrgazy A. , Sadyrbakiyev R. , Kalzhekov N. , Gaziz D. , Orazov B. , Williams D. , Lu H. , Yan C. 
Published: November 2023

Abstract
Even though most wells in the Tengiz Field produce virtually water free oil (less than 1% water cut), inorganic scales have been observed in many wells. Acid stimulation treatment programs for existing wells with deteriorated productivity include implementation of scale inhibitors, however this reactive approach might not always be the best way to proceed. The scope of the paper is to identify the main parameters which increase the probability of scale formation before a well is put on production and proactively treat such wells with scale inhibitors.
Previously Tengizchevroil (TCO) has conducted an extensive research project to reduce the need for frequent acid treatments while maintaining well deliverability at sustained rates. Compatibility and core flood tests have been performed to choose the best scale inhibitor, and an extensive surveillance program has been developed to track residual inhibitor concentration to timely plan subsequent stimulation treatments. This paper covers the next step of the study and includes analysis of the recent cases of scale formation including identification of similar properties between the cases to enable forecasting of the tendency of all new wells to encounter scale formation.
The study consists of three main steps – analysis of formation water and solid samples, analysis of open hole log data and analysis of production history for Tengiz and Korolev wells. The formation of precipitates is dependent on ion concentration in the water. Analysis of the water composition for each region and formation has been performed to identify which set of parameters increases the tendency to form scale. Solubility of inorganic salts is highly dependent on pressure and temperature changes taking place in the wellbore; therefore, the scale prediction study also includes these factors with the correlation to well region and reservoir properties each well penetrates. Weighted ranks for every parameter have been developed to rank a well after the drilling stage and make a proactive decision on whether scale inhibitor injection should be included in the primary acid stimulation treatment program, or if it should be considered only for reactive acid treatments in case of loss in well productivity.
This paper aims to share the best practices in scale inhibitor design, analysis of well parameters at the well completion stage and calculation of well tendency to scale formation. The decision tree for identification of well candidates for proactive scale treatments applicable for the Tengiz field presented in the paper can potentially be used in other carbonate fields.
Rejuvenating Profitability and Performance of Aging Gas Field through Multi-Pronged Strategy: System De-Bottlenecking, Well Optimization and Opex Management
Authors: Awase Azar , Memon Sikandar Ali , Zafar Jahangeer , Khan Zaeem Hasan , Noman Muhammad , Ejaz Muhtashim , Ali Mushtaque , Amjad Muhammad , Sirati Muhammad Attar 
Published: November 2023

Abstract
This paper presents a success case of optimizing a challenging mature gas field, producing at tail-end, with low reservoir pressure and increasing water gas ratio trend, complex surface network, and high operating cost. The situation demanded cost efficiency, novel strategies to optimize production and prudent decisions to safeguard reserves and sustain production.
S-Field was put on production in 2003 and peaked production of 460 MMscfd in 2007. In 2021, reservoir pressure dropped from 5400 to 300 psi, wells became critical and front-end compressors approached lower limits. Additionally, field was close to economic threshold, owing to late life conditions and high Opex. An integrated approach was taken to mitigate the challenges. A network modeling exercise with multiple sensitivities were performed to simulate the application of different deliq techniques (soap sticks, velocity string, CSI) and operating field with expanded compressor envelop. Subsequently, the strategy was implemented in phases to optimize the field.
Simulations performed for no further activity case with prevailing production technical limit suggested additional recoveries of only 4 Bscf for one year remaining. The simulated optimization cases predicted additional recoveries of around 20 Bscf with field life extension by 5 years. On top of production and reserves, the strategy envisaged significant improvement in field profitability by saving fuel gas (∼1 Bscf annual) and maintenance cost (2.5 $MM annual). The capital investment for the project was $10MM, with estimated project NPV of $17MM.
The project implemented in Oct 2021 with optimized compression scheme, smaller tubing size, velocity strings, and cost-effective foam injection. The actual field delivery was vigilantly monitored and till day additional volumes of 8 Bscf have been materialized and field is demonstrating very stable performance, closely matching the premise.
A novel aspect is that brown fields may be rejuvenated by expanding techno-commercial boundaries besides application of optimization techniques. At the stage where many operators would consider abandoning the fields, results driven strategy coupled with multidisciplinary inputs resulted in higher profits and additional recovery.
Determination of Environmental Conditions of Mesozoic Deposits of Kataton-Tengiz and Prorva Uplifts Based on the Study of Core Material
Authors: Pronin N. A. 
Published: November 2023

Abstract
To determine the environmental conditions of the Mesozoic deposits of the Karaton-Tengiz and Prorvinsky uplifts, the core samples derived from 22 wells in 8 fields were studied. The most useful information which allowed to draw a conclusion about environmental conditions were 19 wells from 5 fields (Fig.1). The core from the remaining 3 wells did not allow to obtain viable information, due to insufficient volume and lack of high-quality geophysical materials. Although the results obtained can be indirectly applied as a supplement and generalization of the information obtained. On the rest of the core, work was carried out on preparation, clarification of the true depth of occurrence, a lithological and sedimentological description was carried out with the construction of sedimentological columns, on the basis of which textural, structural features and bionomics were identified, enabling to fully interpret and determine the environmental conditions with the allocation of facies along the section. In addition, the results of earlier lithological studies of 2010-2020 were used to determine reservoir properties and their distribution, the results of geophysical studies, in particular logging curves GR and SP. Stratigraphic, age markers are obtained from the tabular data of previous projects, highlighted on the basis of correlation results. The studied core from wells reveals mainly sections of Jurassic and Cretaceous age.
Utilization of Digitalization Tools in Day-To-Day Operations at Tengiz
Authors: Rakhmetova D. , Batyrkhanova G. , Utebayeva D. , Su H. 
Published: November 2023

Abstract
Monitoring real time well performance is critical to not only maintain safe and reliable operations, but it is also crucial in meeting the yearly production targets. To track the current well rates Tengizchevroil (TCO) utilizes multiphase flowmeters (MPFM) which are installed on a group of wells (meter stations), usually consisting of 8-12 wells. However, there are some minor constraints in the current MPFM well testing process – wells can only be tested one-by-one with minimum 2-hour test durations, meaning that real time rates are only represented for one well only in the time of testing. When wells are not on test, TCO uses the theoretical rate (FTP rates or so called "flowing tubing pressure rates") determination process. This paper describes the application of digitalization tools in daily operations at Tengiz for production tracking and allocation process.
Prosper models are created and maintained for each well in TCO's operating well stock which are stored in Model Catalogue (DOF's model repository). Each month these Prosper models are updated and calibrated based on updated and reviewed well test data – engineers usually set new reservoir pressures or productivity index estimations to match the recent well test results. Revised models are later updated into the GAP integrated network model in Model Catalogue, and an automated workflow in DOF generates updated VLP/IPR tables with well rate trends as a function of varying wellhead pressure. The VLP/IPR tables are later uploaded into SCADA for integration with the real time monitoring tool, where based on current wellhead pressure the FTP rates are computed on a real-time basis for Operations to monitor.
The FTP update process also serves as a foundation for Field Production Allocation – a relationship of the cumulative daily production sourced from Plant intake gauges (actual Field production) to cumulative theoretical (FTP) Field rates. On average, TCO strives to keep the allocation factor in the range of 0.90-1.10 (+/- 10% error). This allocation process is done in Energy Components (EC).
The FTP and Allocation processes are foundational for short-term and long-term forecasting as the Well performance is used for day-to-day operations planning, maintaining, and ensuring enough production is feeding the Plants.
The end-to-end workflow is currently being streamlined to further automate where it makes sense; for example, leveraging DOF's capabilities to automate generating well test records from live real-time data, implementing a management by exception plug-in for the well test QA/QC, and semi-automating the Prosper model calibration process.
Real-Time Greenhouse Gas Emissions Visibility in Tengiz Production Operations
Authors: Tanzharikov Arman , Dairabayev Maxad , Kim Andrey , Sosa Jeremy , Bissembay Adilbek 
Published: November 2023

Abstract
Understanding the sources of GHG emissions and their visibility within the energy industry is crucial for developing effective mitigation strategies and achieving sustainability goals. This paper presents a comprehensive analysis of the data visibility of GHG emission sources in oil and gas production operations.
The study encompasses an extensive review of literature, industry reports, and technological frameworks to identify the primary sources of GHG emissions in oil and gas production. These sources include flaring, venting, fugitive emissions, combustion processes, etc. Each source is examined regarding its potential emissions, monitoring techniques, and data visibility. Moreover, highlights the challenges faced by companies in accurately measuring, monitoring, and reporting GHG emissions, such as technological limitations, data collection complexities, and the lack of standardized reporting frameworks.
In this paper, the author investigates the existing requirements and voluntary initiatives to improve data visibility and transparency. Furthermore, the paper presents emerging technologies and best practices to enhance GHG emissions data visibility. It discusses implementing advanced monitoring systems and emphasizes the importance of digitalization and data analytics in capturing, analyzing, and visualizing GHG emissions data for better decision-making and performance tracking. The findings of this paper shed light on the current best practices, potential limitations, and opportunities regarding GHG emissions data visibility in oil and gas production operations. The analysis underscores the need for stronger collaboration between industry stakeholders to establish consistent reporting frameworks and standards. It also emphasizes the importance of technological innovation and data-driven approaches to enable more efficient emissions monitoring and reduction strategies.
Overall, this paper serves as a comprehensive overview of GHG emission sources data visibility in oil and gas production operations. It provides valuable insights into the challenges faced by the industry, highlights potential solutions, and emphasizes the importance of enhanced data visibility for achieving sustainability goals in the context of climate change.
Creeping Claystone Formation in Absheron Field, Azerbaijan: Description, Issues and Mitigations for Future Wells
Authors: Kamalov K. , Mirzayev R. , Kilic A. 
Published: November 2023

Abstract
In Absheron appraisal well, a short section (16½″ × 20″) was dedicated to isolate the "Creeping Claystone" troublemaking interval.
The creeping shales correspond to a 6 meters thick shale layer compressed between two competent layers of anhydrite. This layer is saturated with water as it is impossible for the fluid to be expelled due to the enclosing anhydrite. The behavior of the shale layer is not considered as over pressured but only as a rheological effect.
Only 250 meters were drilled in 16½″ × 20″ section that included "Creeping Claystone" interval. The section was drilled in steps due to previous experienced borehole instabilities. Consequently, a 16½″ pilot hole was first planned to be drilled to TD (Total Depth), then being enlarged to 20″ size. Furthermore, the section was planned to be drilled with 1.67sg NABM (Non Aqueous Based Mud) mud, nevertheless, due to encountered problems with borehole stability, the mud weight was increased by steps up to 1.73sg.
Lots of problems were encountered while drilling, such as:
several mud overflows from header box in the shaker room after experiencing pack-offs; two SonicScope failures (tool could not withstand such borehole conditions); huge volume (3964.5 t) of cavings, cuttings and mud were recovered, filling 849 skips (4.3 t/skip average).
Eventually, 16″ liner was set and cemented at well section TD.