bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated Study of Tar Mat Formation Through Structural Restoration and Basin Modelling in an Oil Field Offshore Abu Dhabi, UAE and Qatar
Authors: Katabuchi M. , Holloway D. , Rayner M. , Richards F. 
Published: November 2024

Abstract
A Tar Mat Zone (TMZ) is present in the Upper Jurassic reservoir in a studied field; these features are commonly observed in other fields in the Middle East. Since the tar mat is widely distributed in the field and acts as a pressure barrier, understanding of its formation and distribution is important for field development. To investigate the structural development history of the TMZ, tar formation mechanism and its distribution, integrated structural restoration and basin modelling studies were conducted.
A total of eleven horizons were used for structural restoration to constrain the timing of the reservoir and TMZ geometry. A total of fifteen 2D lines were utilized to build a pseudo-3D structural restoration and to analyze the restoration results. In addition, a basin modelling study was conducted to confirm that the timing of tar mat formation inferred from the structural restoration study to ensure a consistent interpretation in terms of thermal history and hydrocarbon migration timing.
The timing of the onset of folding of the reservoir was interpreted to be between 150 Ma and 120 Ma and for TMZ between 120 Ma and 108 Ma, which is earlier than estimates from simple horizon flattening. In addition, the current TMZ geometry can be reconstructed based on the results of the structural restoration. Then the reconstructed TMZ geometry can be utilized as a trend to estimate the TMZ surface, especially in areas without wells. The basin modelling results indicate that the source rock (Oxfordian to Kimmeridgian) to the southeast of the field became oil mature during the Early Cretaceous and oil expulsion commenced during the Aptian. Importantly, this is synchronous with or later than the trap formation in the field defined by the structural restoration study, enabling hydrocarbons to be trapped in the rapidly growing structure. Slowing of oil expulsion rate from 116 Ma to 92 Ma coincided with the onset temperature of thermochemical sulphate reduction (TSR) of anhydrite with hydrocarbons in the reservoir. It is likely that TMZ was formed by the TSR-related process of hydrocarbon alteration and sour gas production on a paleo-oil water contact during this period.
This integrated approach revealed not only the geometry of TMZ distribution from evaluating the structural evolution of the field, but also the timing and mechanism of TMZ formation from the thermal history, which complemented each other to provide a more robust, reliable, and reasonable interpretation.

Keywords
Tar Mat; Upper Jurassic Reservoir; Structural Restoration; Basin Modeling; Thermochemical Sulphate Reduction
Reducing CO2 Emissions in Drilling Operation with 3D Mapping Technology
Authors: Al-Khalifa Nasser Faisal , Al-Qazweeni A. E. M. , Al-Dhafeeri Ahmad Dekheel , Joshi D. , Pasaribu I. , Purohit Siddhartha , Al-Hassan Ahmed 
Published: November 2024

Abstract
Kuwait reported has 89 million metric tons of CO2 emissions as per the 2020 world report published by United Nation (UN). The oil and gas sector significantly contributes to the country's economic growth while simultaneously serving as a major source of CO2 emissions. The country's national oil company has established an objective to reduce CO2 emissions in alignment with national goals. To achieve this, advancements in technology that can both minimize CO2 emissions and enhance productivity are essential.
In Kuwait, the operator employed ultradeep azimuthal resistivity (UDAR) technology within a carbonate reservoir that has a production history spanning over 57 years. The primary objective of utilizing UDAR 3D reservoir mapping was to reduce unnecessary operations, such as the drilling of a pilot hole, which would otherwise consume additional energy. By eliminating these superfluous activities, the initiative aims to contribute to the minimization of carbon emissions through decreased energy consumption.
The elimination of the pilot hole and the cement operation saved approximately 10 operational days per well. The rig energy saving from reduced fuel consumption amounted to approximately 230 metric tons CO2 / well. This reduction of the CO2 emissions through 3D reservoir mapping, established a new milestone and supported the nation’s goal of achieving full carbon neutrality by 2050.
Field Experiences: CO2 HuffnPuff Test at the Minami-Aga Depleted Onshore Oil Field in Japan
Authors: Koga Hiroaki , Akai Takashi , Kayamoto Yudai , Nakashima Toshinori 
Published: November 2024

Abstract
A huff‘n’puff CO2 injection test was conducted in a depleted onshore oil field in Japan. This pilot test was conducted to evaluate the effectiveness of CO2-enhanced oil recovery, assess the technical validity of various monitoring tools used for detecting CO2 behavior in the reservoir, and gain operational experience with CO2 injection.
The pilot test was conducted in a newly drilled well. Extensive geological information, including wireline logging and core sample acquisition, was collected before the pilot test and used to characterize the pilot test area and design the test procedures. Approximately 100 tons of high-purity CO2 purchased from industry was transported to the site via trucks and injected into the newly drilled test well.
CO2 injection last two days, during which a pump and heater at the site were used to maintain CO2 in a dense liquid phase at the well-head condition. The well was then left to a soaking period for 23 days before being brought back into production for 5 days. A clear increase in oil production rate was observed after CO2 injection. In addition, a production logging tool and a pulsed neutron reservoir saturation tool revealed the CO2 flow paths and areas of residual oil remobilization.
This study presents the pilot test results, including the injection and production profiles, in situ CO2 monitoring with wireline tools, and evaluation of well deliverability based on pressure transient analysis at each test sequence.
Finite Element Analysis for Pipeline Leak Containment System
Authors: Farag A. 
Published: November 2024

Abstract
In this paper, the finite element analysis (FEA) for a proposed secondary containment assembly (Envirolock) intended to protect the environment from pipelines leaks was carried out. The assembly, composed from a Fiber Reinforced Polymer (FRP), aims to protect the most susceptible locations on pipelines where corrosion, dents and cracks could cause pipeline leaks to occur. The FEA was conducted to investigate the mechanical capacity of the system under hoop and longitudinal pressures.
In the current study, the system was under full pressure emanating from a leak from the carrier pipe into the secondary containment liner. To explore the resistance capability of the containment system, which is composed of three layers (two polyurea and one carbon fiber), against internal pressure, finite element models were developed. Two separate finite element models for mid-pipe and end cap segments were created. System failure was defined as material failure, where failure pressure being the pressure at the onset of material failure in any layer.
The FEA results indicated that the strength and failure of the mid-pipe segment under internal pressure is dominantly controlled by the carbon fiber layer. The failure of this layer will consequently lead to the failure of the polyurea layers. The carbon fiber makes the system capable of sustaining internal pressure (hoop stresses) up to 86 MPa. For the end cap FEA model, several consecutive trials and modifications were prototyped, and finite element models were created accordingly. The final design of the end cap has a cone-shaped geometry that is reinforced by different numbers and directions (acting in hoop and longitudinal directions), of carbon fiber layers wound over the surface of the end cap assembly. Based on the FEA results, the end cap segment of the containment system can sustain internal pressure of 21.5 MPa to 27 MPa depending on the number of CF layers. These results indicated that the containment system is safe to be used for most operating pressures of liquid and gas pipelines without compromising the assembly. The results of this FEA were used to finalize the design. The system passed ASME PPC-2 certification testing, the results of which can be used to finetune these FEA models.
As more stringent rules and government regulations are enacted to enhance the protection of the environment, pipeline operators need to be proactive regarding public safety and the protection of the environment from pipeline leaks. This system is a risk mitigation tool containing pipeline leaks until further actions are implemented by pipeline operators. It also has the advantage of being a low-cost solution that can be installed on new or existing pipelines.
Predictive Modeling of Clay-Bound Water in Carbonate Reservoirs Using Machine Learning Techniques
Authors: Tariq Zeeshan , Abid Muhammad , Mustafa Ayyaz , Alkhowaildi Mustafa , Mahmoud Mohamed 
Published: November 2024

Abstract
The pore structure in carbonate rocks is intricate and heterogeneous, encompassing both intra-particle and inter-particle porosities. Ignoring the presence of clay-bound water during the assessment of hydrocarbon recovery in these reservoirs can lead to inaccurate recovery factor estimates. Conventional well logging techniques often struggle to accurately measure clay-bound water in such complex lithologies. Although Nuclear Magnetic Resonance (NMR) can measure microporosity independently of the rock matrix and mineralogy. However, NMR is very expensive to measure, and not widely available in conventional wells. In this study, we propose an approach utilizing supervised machine learning (ML) techniques to predict clay-bound water using readily available well logs. We have used a dataset comprising of 6000 samples collected from multiple wells within a carbonate reservoir to develop and validate ML models. Five different machine learning techniques were employed, including, Long Short-Term Memory (LSTM) networks, Recurrent Neural Networks (RNN), Gated Recurrent Units (GRU), extreme gradient boosting regressor (XGBoost), and Gradient Boosting Regressor (GBR). Model performance was evaluated using the coefficient of determination (R²) and mean absolute percentage error (MAPE). The results demonstrate that our ML tools can effectively predicts clay-bound water content using well log data, offering a significant time and cost-saving over traditional methods. Among the tested models, the LSTM network emerged as the top-performing algorithm, achieving an impressive R² value of 0.980 and a MAPE of 3%, indicating its superior ability to capture the complex relationships within the data. The GRU and RNN models also performed well, with R² values exceeding 0.95, while the XGB and GBR models provided moderate predictive accuracy. This study highlights the potential of machine learning techniques in enhancing reservoir characterization by providing a cost-effective and accurate alternative to traditional methods for estimating clay-bound water. By relying solely on well log data, our approach eliminates the need for expensive direct measurement methods, thereby offering a practical solution for reservoir engineers and geoscientists working in complex carbonate systems.
Geothermal Plays Feasibility and Potential in a Transform Basin: A Case Study from Southern Vienna Basin
Authors: Eleslambouly A. , Aldhanhani O. , Fathy A. , Zeynalli M. , Alsuwaidi M. 
Published: November 2024

Abstract
Austria aims to diversify its energy resources and decrease its dependence on hydrocarbons through reliance on less CO2 emission resources. The transform Vienna Basin in Central Europe is well known for its rich history of hydrocarbon resources, yet its geothermal potential remains underexplored. The basin is characterized by a moderate geothermal gradient (22° C/km) and possesses a favorable geological setting, making it a promising prospect for geothermal energy exploitation. The current work investigated the southern part of the Vienna Basin's geothermal potential using a combination of legacy oil and gas wells and regional seismic lines. Each geological key level was evaluated using an integrated geological and geophysical characterizing approach to highlight possible systems within the basin. We also evaluated the subsurface conditions to identify, map, and allocate the highest potential geothermal resources in the basin. Additionally, we allocated economically feasible high-potential locations for optimal energy production scenarios within the basin. Lastly, a thorough economic assessment addressing different geothermal power plant options was carried out with different economic indicators such as, Net Present Value (NPV), Internal Return Rate (IRR), Discounted Payback Period (DPP), and Profitability Index (PI). We employed a combination of geological, geophysical, and basin modeling techniques to estimate the property spatial distribution within the basin. Moreover, we attest to the subsurface conditions for geothermal production using numerical models to estimate the production capacity of the basin and economics feasibility. Our results indicated that the Vienna Basin has a significant untapped geothermal potential, with several viable energy production scenarios. The Karpatian aquifer reservoirs present optimal conditions for geothermal production, though they face challenges related to permeability. Enhancing reservoir conditions through stimulation techniques was therefore needed to maximize their geothermal production potential. Overall, the system was found to have a low - moderate plant output (227,952,720 kWh/yr on average) utilizing a binary-cycle system for electricity production. Electricity production is expected to be profitable based on a 25–30 years life span and payback within an almost 8-year period. The Geothermal energy development in the Vienna Basin can contribute significantly to the region's energy mix, reduce greenhouse gas emissions, and promote sustainable development. Our findings highlight the favorable potential plays for geothermal harvesting or heating and cooling applications in the Vienna Basin. Additionally, the current research offers forward-looking recommendations, aiding strategic decision-making in the geothermal industry.
Line Drive or Not? Lessons Learned From Waterflood Field Case in Middle East Carbonate Reservoirs
Authors: Ilyasov I. , Suleiman M. , Alobeidi O. , Aldhuhoori H. 
Published: November 2024

Field X is situated onshore in the southwestern part of the Abu Dhabi Emirate. Historically, five appraisal wells were drilled between 1961 and 1995. Drilling activities resumed in 2006 to further appraise additional reservoirs identified within the Field X structure. The field has been producing since 2007 for testing purposes. It was officially commissioned and commenced production in Q1 2013, peaking at 22 MBOPD from the A and B reservoirs. In 2020, the C reservoir was brought to production, providing promising oil in place to offset the decline in the A and B reservoirs. All wells are currently flowing naturally.
The target field is an elongated, low-relief structure with a NNE-SSW strike direction. During the Late Permian to Middle Cretaceous, the Arabian Plate was positioned along the passive margin of the Neo-Tethys (Murris, 1980). The reservoir rocks were deposited on an extensive shallow-marine ‘mega-platform’ several hundred kilometers wide on the southern Tethys margin. These formations are characterized by alternating porous and dense carbonate units, indicative of deposition in transgressive and regressive cycles. The formation is subdivided into seven reservoir zones, with contacts between intervals typically marked by very tight or low-permeability carbonates that hydraulically isolate these reservoirs. Each porous reservoir zone is separated by a dense carbonate zone.
Scaling E-Fuels - A Solution for Deep Decarbonizing the Mobility Sector
Authors: Schwappach D. , Hannan S. Yasir 
Published: November 2024

Abstract
As we navigate the adverse effects of climate change and looming pressure on industries globally to adhere to their pledged to climate goals, the urgency to accelerate decarbonization across various sectors becomes ever more apparent. The decarbonization of the transport industry via electrification has been greatly developed for road mobility. However, for "Hard-to-abate" transport sectors such as shipping and aviation, synthetic fuels, or e-fuels, offer a promising solution with their energy-dense nature, ease of storage, and compatibility with existing global infrastructure. However, despite their potential, the path to wide-scale production is not without challenges. This paper aims to outline the barriers that must be overcome to facilitate a broader adoption of e-fuels.
Alternative Method for Estimating Liquefaction-Induced Settlement of Shallow Foundation PLEM Using Finite Element Analysis
Authors: Nattapoom K. , Chao T. , Sompop S. , Patraporn W , Apisit T 
Published: November 2024

Abstract
Settlement of subsea structures, such as Pipeline End Manifolds (PLEMs), is typically calculated using conventional software or analytical methods for non-liquefied soil conditions. However, these methods do not effectively address realistic structural settlement behaviors under liquefied soil conditions induced by seismic activities. Recent publications have introduced simplified procedures for estimating liquefaction-induced settlement, but these are tailored primarily for onshore structures and do not extend to subsea applications. Additionally, specialized software in geotechnical engineering has limited capability to model the penetration of shallow foundation structures through liquefied soil layers during seismic conditions.
This study proposes an alternative method using Finite-Element-Analysis (FEA) to model and analyze the settlement of subsea structures, specifically PLEMs, in liquefied soil conditions caused by earthquake ground motions. The shallow foundation part of PLEMs, called mudmat, and soil layers were modeled. The soil model was defined based the density, the shear modulus, and pressure as a function of volumetric strain. The Smooth Particle Hydrodynamics (SPH) technique was employed to capture large deformations under dynamic conditions like earthquakes. Simultaneously, settlement of mudmat under the same conditions was reproduced using geotechnical engineering software to validate the proposed approach. The result from the studied FEA revealed greater settlement than traditional geotechnical engineering software in liquefied soil during seismic conditions. This comparison demonstrates the advantages and limitations of each approach, highlighting the enhanced capability of FEA when utilizing the SPH technique to capture the complex behavior of subsea structure in liquefied soils. Consequently, it provides more realistic results for design proposes.
Introducing New Dissolvable Perforating Particles to Optimize Abrasive Perforation
Authors: Kharrat Wassim , Hamdi Abdullah , Rajab Mohammed , Samuel Mathew 
Published: November 2024

Abstract
Coiled tubing (CT) abrasive perforation offers a valuable alternative for explosive based perforation methodology. This technique employs fluids containing abrasive material, which are jetted at high pressure through specially designed downhole tools' nozzles, creating clean tunnels connecting the wellbore to the reservoir without causing perforation damage like traditional perforating guns. Sand is the preferred abrasive material in the traditional methods as it is the cheapest besides the fact that it causes significantly less damage to CT pipe and abrasive perforating tools compared to all other artificial solids like bauxite or ceramics. The conventional abrasive perforation requires a cleanout operation using gelled fluids with adequate annular velocity and viscosity at bottom hole temperature.
In this paper, the abrasive perforating performance of a novel dissolvable perforating particles (DPP) is compared in a yard test with that of conventional 100 mesh and 20/40 mesh silica sand. The effectiveness factors are the punches' outer diameters in a 4.5 inches casing and a cement block, and the penetration depth through the cement block.
The DPP delivers entry hole size and tunnel penetration length comparable to the ones obtained using sand while eliminating the need to be cleaned out of the wellbore. Therefore, the optimized abrasive perforation reduces (1) the operational time and carbon emission, (2) the risk of CT pipe stuck due to highly deviated wells, high bottomhole temperature and low cleanout annular velocity, (3) water and gel consumptions, and (4) CT pipe fatigue caused by cleanout reciprocations. The DPP is applicable in both carbonate and sandstone formations as it is soluble in a dissolver, which is dissolving carbonates and not causing any clays' destabilization.
Contrary to the traditional explosive perforation, the dynamic underbalance eliminates the crushed zone and the residual rock and charge debris, which makes it a clean perforating technique same as the abrasive perforating method. However, after stopping the need for any cleanout, the optimized abrasive perforation supersedes not only with zero logistical challenges but mainly with the reduction of wellbore tortuosity thanks to its larger diameter holes and surface contact with the reservoir, which enable both: better hydrocarbons production and hydraulic fracturing treatments in very tight formations after significantly decreasing its breakdown pressures.