bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of Jurassic Clastic Reservoirs in the Sudochi Depression of the East Ustyurt Basin (Uzbekistan) Based on the Results of Seismic Reservoir Characterization
Authors: Shaikhina D. , Yessalina S. , Muratov A. , Muminov M. , Gulamov R. , Mallaev S. 
Published: May 2024

Abstract
The goal of the current work is a detailed study of the reservoir architecture, stratigraphy, and properties of Uzbekneftegas (UNG) assets within the Sudochi depression of the East Ustyurt basin, that is urged by low success rates of drilling and declined gas production. Until today, the approach to drilling exploration and production wells was based on the concept of conformably layered reservoirs, that has changed dramatically as a result of the current work.
Limitations in data quality and availability was the most challenging aspect of this study. Image processing of the seismic data in the color domain has increased the resolution of the seismic data. Together with spectral decomposition, chromatic extraction yields valuable results in analysis of seismic facies, a tool for automatic well tie allowed to extract the wavelets of best shapes and time-depth relationships (TDR) in optimal time. Rock physics study was performed and justified the feasibility of acoustic inversion. A post-stack inversion was performed to describe reservoir properties and distribution. Application of seismic reservoir characterization techniques and integration of the other domain data resulted in the interpretation of the depositional environment, geometry, and quality of Jurassic reservoirs.
As a result of the successful implementation of the mentioned tools, the reservoirs of East Ustyurt basin are seen to be represented by alluvial and fluvial deposits, which are traced and predicted in inter-well space. This information was a valuable input to geological and dynamic models. Different overprints of paleodepositional settings on the reservoir architecture, heterogeneity, and facies distribution of each study area can explain why drilled wells were not identically productive. Eventually, consideration of the seismic reservoir characterization results has significantly changed the location of planned exploration and production wells and led to drilling successful wells with high production rates.
The novelty of the work is in the results obtained for the South-Eastern part of Ustyurt basin, specifically the Berdakh high and the Sudochi depression. We have interpreted paleogeographic development in Jurassic period, the reservoir architecture, quality and facies distribution by seismic reservoir characterization tools and integrated analysis of other data, that has not been extensively studied and published before. This study can contribute to the development of the region.
CFD-DEM Simulation Analysis of the Effect of Sweep Stages on Proppant Placement within Rough Fracture
Authors: Song Xianzhi , Yang Zhichao , Zhou Mengmeng , Xu Zhengming , Zhou Qianqian , Abderrahmane Hamid Ait , Wang Bin , Zheng Yong 
Published: May 2024

Abstract
Hydraulic fracturing is a conventional measure to enhance recovery. Proppant transportation as a critical technology of hydraulic fracturing can maintain the effect of production enhancement. A validated Computational Fluid Dynamics - Discrete Element Method (CFD-DEM) method is used in this paper to study the generation condition of blocky dune and the impact of proppant placement in rough fractures during the sweep stages. The results indicate that medium-sized aperture proppants have more possibility of generating blocky dune. These blocky dunes possess distinctive properties that can lead to complications, such as the plugging of fractures. Intriguingly, this phenomenon is unique to proppant transport within rough fractures. Contrary to initial predictions, concentration, and injection velocity exert minimal influence on the genesis of blocky dunes. Dunes formed at lower injection velocities should be subjected to water scouring at higher velocities. Additionally, a critical velocity threshold, determined by the fracture's characteristics, exists for the injection velocity during the sweep stage. If the velocity dips below this critical threshold, the sweep stages lose their effectiveness. This investigation elucidates the generative conditions of blocky dunes and their properties about rough fractures during sweep stages, offering valuable insights for the optimization of proppant placement strategies in practical engineering scenarios.
Fault Pattern and Structure Configuration of Apsheron Sill, South Caspian Basin, New Insight from High Quality OBN Seismic
Authors: Dengyi Xiao , Rouis Lamia , Xiaoliang Li , Khdhaouria Mourad , Aldrin Rondon , Ameish Giamal , Qingfeng Huang , AlDahmani Abdulla , Oweini Tarek , Gibrata Muhammad , Qiang Li , Xin Chen , Kongzhi Huang , Bo Wang 
Published: May 2024

Abstract
As one of the major oil-producing belts in the South Caspian basin, the Apsheron Sill holds tens of structure-related reservoirs which are closely originated with the tectonic evolution and performed complex fault patterns. Previous study paid high attention to the east Azerbaijan area with reporting lots of case study, however, the west Cheleken peninsula is still in high ambiguity.
To enhance understanding of the east Apsheron ridge, an integrated study is conducted mainly based on new acquired 3D OBN seismic in Cheleken concession. The AI-based technology is adopted to illustrate the complex fault system for the first time with using huge database of similar structure cases. Seismic geometrical attributes and RGB fusion method are used to demonstrate the fault assemblage. Analogue study was also carried out between the Cheleken faults and physical stimulation, aiming to better understand the geometrical and kinetic feature. Furthermore, the structure reconstruction technique is used to capture the strati-structure evolution.
According to this study, two typical fault patterns are identified, positive flower structure cut in the middle-deep red series, and negative flower structure bearing in Apsheron-middle red bed series. The flower structure sometimes shows the schematic of complex palm-tree. These two sets of structure patterns represents the trans-pression in early-middle Pliocene and trans-extension in the late Pliocene-Pleistocene. Some detached faults cut from Apsheron stratigraphic interval and terminated at CH1 shale which related to the later regional extension and strain releasing. In Cheleken concession, two fault belts are identified, Zhdanov in the north and Lam in the south. Some transform faults occurs between these two belts to accommodate the lateral strata shearing or rotation. In the map view, fault assemblage performs feature of en-echelon and horsetail spray, which represents the dextral strike-slip of Apsheron Sill. Typically, the Lam and Zhdanov reservoirs are fault-derived structure with continuous growth from middle Pliocene to late Pleistocene. Occurrence of mud volcano in the concession indicates the faults are still active.
For the first time, this study gives systematic illustration on the fault pattern and structure configuration of the east Apsheron Sill in terms of good image OBN seismic. The enhancement in structure feature could facilitate the current producing and help de-risk drilling hazards. Furthermore, it would also provide new insight for adjacent reservoirs from the aspect of regional tectonic understanding and structure configuration.
Unlocking Potential: Re-Accessing Left-Behind Potential in GS365 Field GoS, Egypt: Navigating Through Challenging Historical Data, Compositional Gradient Reservoir, Multi-Layer Stacked Reservoir, and Complex Structure Setting
Authors: Rashad O. M. , Samaha A. A. , Emam M. , El-Ghalid M. , Fargal M. , Kamal O. , Ibrahim N. 
Published: May 2024

Abstract
GS365 oil field sits in the southern Gulf of Suez faced significant challenges in development plan: limited historical data, restricted accessibility, and single mudline producer from thin oil rim overlain by a sizeable gas cap. This presented challenges for both geological and reservoir engineering teams, including defining reservoir geobodies, estimating fluid contacts, optimizing well spacing, infill drilling, and maximizing recovery. Well engineering faced the additional challenge of managing gas cusping and maximizing reserves through trajectory and perforation design.
To overcome these challenges, this study employed a comprehensive approach integrating static and dynamic reservoir modeling. Key uncertainties addressed included reservoir pressure, fluid contacts, reservoir quality variations, and aquifer description. Lack of dynamic data due to limited accessibility necessitated utilizing surface parameters like wellhead pressures and temperature as model control points. Production uncertainties from limited surveillance data were addressed through historical data analysis, Prosper modeling, fluid characterization and PLT interpretation. A 3D model was built and history matched to refine the estimated oil initially in place (STOIIP) range. This integrated approach yielded valuable insights for infill drilling and optimizing target location selection to manage uncertainties.
A slanted well design was chosen to maximize reservoir contact and minimize gas cusping while maintaining low drawdown pressure. Post-drilling results exceeded expectations: encountered pressures were on the high side, and new sands with virgin pressure were discovered, indicating untapped potential in the reservoir of interest. Revisiting the initial gas-oil contact (GOC) with updated pressure data and detailed fluid characterization revealed a shallower GOC by +100 ft, leading to an increase in STOIIP estimates. Accessing the shallower reservoirs was as prognosis, highlighting its importance in field development and potentially influencing future infill well strategies.
This study demonstrates the successful reviving of untapped potential in mature field through a data-driven approach addressing uncertainties in historical data, reservoir characterization, production performance, and pressure assessment. By integrating deep analysis, 3D simulation modeling, and cross-checking with analytical methods, this study validates the effectiveness of the applied methodologies and strategies. This approach offers valuable insights for maximizing recovery from similar challenging reservoirs, contributing to long-term production sustainability in aging fields.
Enhancing Electric Submersible Pump Producer Run Life with Cost-Effective GRE Lined Tubing Completion
Authors: Shah Alaa , Wagh Sachin , Patra Milan , Mubarak Jamayel , Radhakrishnan Gokulnath , Rajendran Kailas 
Published: May 2024

Abstract
Electric Submersible Pump (ESP) is extensively used by Kuwait Oil Company (KOC) for the producer wells. In the Minagish field (West Kuwait) of KOC, Corrosion related issues in ESP producer wells have been observed due to increasing water cut (WC), H2S, and CO2. KOC embarked on a trial in the Minagish field to install Glass Reinforced Epoxy (GRE) lined tubing for ESP completion in a candidate well having increasing WC, CO2, and H2S. The installation was done in 1 well, and the well has been producing without any issues for more than 2 years, thereby increasing the Mean-Time-before-Failure (MTBF) and contributing to sustained production as compared to when the well was completed with Carbon steel tubing.
Corrosion in the tubing can lead to loss of tubing metal wall or corrosive scale formation. In several cases, holes in tubing were formed, causing the produced fluid to recirculate within the wellbore, altering the ESP performance and loads.
The GRE liner acts as a protective isolating layer between the carbon steel tubing and the produced fluid. Because of their inert nature, GRE liners are unaffected by the produced fluids. Moreover, the smooth surface provides flow assurance benefits by eliminating corrosion and mitigating deposit formation.
Experience based on other fields within KOC has shown that GRE lined tubing can be re-used without any issue for the ESP producer wells as the system provides protection to the thread connection area by using Corrosion Barrier Rings (CBR). These help KOC reduce the operating expenditure (OPEX) during workover jobs to replace the ESP pump and reuse the same GRE lined tubing. The company plans to expand GRE-lined tubing application for ESP producers with feed-thru packer PAD completion and wells with retrievable ESP.
Impact of Injection Velocity on Wormhole Generation Due to CO2 Sequestration
Authors: Mirzayev Elvin , Ramadan Mustafa Al , Aljawad Murtada Saleh , Ibrahim Ahmed Farid , Al-Yousif Zuhair , Almajid Muhammad , Yaseri Ahmed Al 
Published: May 2024

Abstract
Carbon dioxide (CO2) could be potentially stored in deep saline carbonate aquifers, taking advantage of its solubility in brine. Nevertheless, wormholes will be created due to the reactivity of carbonic acid with limestone. This research targets revealing the impact of live brine (i.e., sc-CO2 soluble in brine) injection velocity on the efficiency and shape of generated wormholes.
Core samples of limestone, measuring 1.5 × 3 inches and exhibiting permeability values ranging from 2 to 3 mD, along with porosity values ranging from 15 to 17%, were chosen for the study. Following the coreflooding experiments, the samples underwent scanning to observe both the generation of wormholes and alterations in the pore structure. CO2 was mixed with 120,000 ppm salinity brine at 60 °C and 2,000 psi at a 30:70 ratio and injected into the core samples. The effect of injection velocity was analyzed by injecting live brine at 0.25, 1, and 5 cc/min. 700 mL of CO2-saturated brine were injected for all the experiments.
The analysis showed a porosity increase due to the creation of wormhole from the injection of live brine. A significant increase has been seen in permeability due to created half or continuous wormholes. Furthermore, as the injection increased from 0.25 cc/min to 1 cc/min, less live brine was needed to create the wormhole. On the other hand, the increase in flow rate from 1 to 5 cc/min siginificantly increased the required volume. These results indicated an optimum injection velocity to be at 1 cc/min with the PVBT of 18. In summary, the study revealed that the injection of live brine induces the formation of a wormhole, resulting in changes to the porosity and permeability of the rock.
The novelty of this study lies in its application to CO2 storage, specifically in exploring the influence of injection rate on the sequestration process. This study marks the pioneering effort to comprehend the impact of CO2 injection velocity on wormhole generation and to identify the optimal conditions for such processes.
Experimental Study on the Mechanical Properties of Matrix and Laminae Planes in Shale
Authors: Zhuo Renyan , Ma Xinfang , Zou Yushi , Zhang Shicheng 
Published: May 2024

Abstract
The mechanical properties of laminae planes have an essential effect on the nucleation and propagation of hydraulic fractures. Previous studies mainly focused on the strong anisotropic mechanical characteristics of laminae shale. However, the effective experimental data on the mechanical properties of matrix and laminae planes is generally limited. Therefore, a series of rock mechanics tests were conducted on laminae shale to study the difference in mechanical properties between matrix and laminae planes. The tested shale samples were subsurface full-diameter cores from the Fengcheng Formation in Mahu Sag. Specimens with different laminae orientations were drilled in directions perpendicular and parallel to laminae planes. The triaxial compression strength tests, direct shear tests, and Brazilian tests were carried out on the specimens. The results showed that the tensile strength, shear strength, cohesion, and friction angle of the specimens loaded parallel to laminae planes were lower than those of the shale matrix. It demonstrated that the laminae planes are weak planes of shale in terms of mechanical strength. However, the normal stiffness and shear stiffness of the laminae planes were higher than those of the shale matrix, indicating that laminae planes are not prone to elastic deformation. Two types of failure modes were observed in the Brazilian test. For the specimens loaded parallel to laminae planes, the fractures propagated along the loading diameter without branching fractures. For the specimens loaded perpendicular to laminae planes, the fractures deviated from the loading diameter and suppressed the propagation of main fractures, which resulted in secondary fractures along the laminae planes. It was concluded that the laminae planes, as the weak planes of shale, lead to the mechanical properties changing with the loading direction relative to the direction of laminae planes and also change the propagation path of the fractures. For fractures propagating along the normal or oblique direction of the laminae plane, the propagation pathways usually offset to the direction of laminae planes or direction parallel to laminae planes, which produces curved propagation pathways and branch fractures. The mechanical properties of laminae planes in shale provide necessary data support for numerical simulation of hydraulic fracture propagation, fracture geometry prediction, and fracture initiation pressure prediction.
Research on Flow Field Characteristics Measurement in Variable Cross-Section Annulus Using Particle Image Velocimetry (PIV)
Authors: S. Zhou Y. , F. Qu C. , W. Zhang H. , Zhang H. , Jiang L. , Liu Z. S. , Shen J. Y. , Zhang Z. Z. , Zheng R. 
Published: May 2024

Abstract
The actual downhole annulus is irregular, a variable cross-section geometry, due to the difference between the diameter of tool joints, tubing collars or downhole tools and the inner pipes. With the increasing of well depth, it is difficult to predict the annulus pressure loss accurately due to the effect of variable cross-section geometry. Research on flow field characteristics in variable cross-section annulus is the theoretical foundation of accurate prediction on annulus pressure loss. However, there is still few research on flow field characteristics in variable cross-section annulus by experiment, especially by using PIV technology. PIV has become an efficient method for complex flow field visualization and analyzation.
The results show that there is separated reattachment flow in the irregular annulus which mainly occurred in the downstream of the expansion. The separated reattachment flow has low velocity, but vortex mainly occurred in this area. The disturbance range of streamlines caused by expansion structure is shorter in the upstream than in the downstream. The first and second modes contain 82% energy contribution in the irregular annular flow field. And the first mode can effectively restore the large-scale structure. With the mode increases, it is found that the small-scale structure is mainly distributed in the shear layer of the separated and reattached flow downstream of the variable cross- section geometry.
Keys Unlock Drilling Performance by Using New Automated Technologies in Directional Drilling
Authors: Nesaif Jawad , Al-Meer Ali , Albalawe Moalla , Fakhrylgayanov Ayrat , Osman Ahmed , Alabdullah Mansour , Gassas Reema , Ovwigho Efe , Franco Nata , Almakhamel A , Almomen M , Alkhalifah Meshal , Alotaibi Saleh 
Published: May 2024

Abstract
The vision of the oil and gas industry is to be fully automated. However, directional drilling is still using conventional methods that mainly depend on the directional drillers with their experience, decisions, competencies, skills, and motivations. Moreover, measuring-while-drilling (MWD) has also seen minimal automation, as directional surveys are still taken conventionally, which requires the involvement of MWD engineers. Such operations are dependent on the personnel therefore exposed to human error and inefficiency.
The automated directional drilling and surveying system is a solution designed to automatically drill directional wells with rotary steerable systems (RSS). The system is pre-fed the planned well trajectory, and once engaged while drilling, uses its control algorithms and directional surveys to control the RSS tool, while correcting the trajectory as drilling progressed by constantly updating the target inclinations and azimuths in a closed loop system. Meanwhile, the automated surveying system takes directional surveys "on-the-fly" and without the MWD engineer’s intervention, automatically feeding the surveys to the directional drilling system in real time, resulting in full directional drilling automation.
The system was first deployed worldwide in the Middle East, and it improved the directional drilling performance in directional drilling operations, especially drilling with complex directional well profiles. Furthermore, the system reduced the downlink frequency by 63% in each hole section and reduced wellbore tortuosity by 10%, while improving rate of penetration (ROP) by 35% when compared to the field average ROP. In addition, the automated directional surveying reduced drill-string stationary time, ultimately reducing rig flat time and differential sticking risks, while providing a higher survey frequency and density when compared to conventional surveying systems. The high survey data frequency and density feature also reduced well position uncertainty, thereby improving well placement within target reservoirs while reducing wellbore tortuosity and improving anti-collision management. On the environmental aspect, the automated system improved drilling performance and ROP in the directional sections and, overall, reduced the drilling rig operating time, thereby reducing the associated average rig CO2 emission.
The automated directional drilling and directional survey systems can be integrated with both new and existing drilling technologies. This will achieve full automation with the ability of supervision in directional drilling for optimizing oil and gas well delivery operation.
Application of Cold CO2 Injection in High Skin Factor Depleted Reservoirs: A Review
Authors: Khan Fahad , Mahmoud Mohamed , Raza Arshad , Patil Shirish , AlTammar Murtadha J. , Al Shafloot Talal 
Published: May 2024

Abstract
Subsurface storage of carbon dioxide (CO2) in geological media is now an effective strategy to address the climate change issue. Upon CO2 injection, thermal, hydrological, mechanical, and chemical processes take place in a storage media which may affect the storage performance. Specifically, the subsurface thermal changes during CO2 injection impact bottom hole pressure, stresses, fracture initiation, and thus, well-bore characteristics. Depleted reservoirs with a high skin factor can pose significant operational complications in achieving favorable CO2 injectivity. Keeping in view the thermal stress, and the usage of CO2 in a very cold CO2 state in the early stage of storage, the concerns of stimulation can be mitigated, offering the benefit of improved injectivity.
This work aims to provide a comprehensive overview of CO2 utilization and storage in high-skin factor-depleted reservoirs. Firstly, we will introduce the physical properties of CO2. Next, we will present storage operational aspects and challenges related to injectivity. Moreover, we will shed light on an overview of depleted reservoirs and the factors that contribute to a high skin factor, along with its quantification. Finally, we will discuss the role of very cold CO2 injection in high skin factor-depleted reservoirs to overcome injectivity challenges. In short, this review aims to summarize the striking developments in subsurface CO2 utilization and storage in challenging reservoirs, thereby helping to de-risk the injection operation.