bluuebunny/crossref_metadata_2025 huggingface dataset:
Well Integrity Analysis to Assess SCP Inside Hig Temperature Gas Wells
Authors: Ramasamy R. , Siew C. , Shaleh F. Arief , Prakaash M.
Published: November 2024

Frequent cases of high temperature (HT) gas wells experiencing annulus pressure have driven the development and implementation of advanced modelling and analyses techniques to assess the severity of the sustained casing pressure (SCP), its impacts on to the wells' cement and casings. The potential root cause of this build-up is also identified and rationalized. Two case studies are presented here based on their individual nature of the SCP incident and severity, and the most effective mitigations have been proposed and successfully implemented to maintain continuous productions without any need for any additional costly well intervention activities.

Real-time pressure and temperature data are heavily relied upon to provide data to assess the SCP issues affecting the wells. Based on the obtained data, the impact of the annulus pressure magnitude and frequency of the build-up are assessed against the casings' allowable material limits. Once the casing integrity is confirmed and mapped against the maximum pressure limits, the cyclic pressure ranges are evaluated to assess the casing fatigue capacity and to determine the pressure bleeding intervals. The cement integrity checks are carried out based on the obtained data to check the annulus pressure magnitude and if the casing-cement interface (or cement bond) are breached. This will also help streamline potential root causes for the pressure build-up and provide insights into any remedial measures which can be taken or if the in-operation mitigations are still an effective option.

For the two HT gas wells being assessed, the root causes are identified with sound rationalisations provided by the real-time data coupled with the analyses which are carried out. The mitigation plan to bleed-out on weekly basis is also found to be effective and safe which maintains the casings' fatigue life throughout the wells' intended production life, whilst having adequate load resistance to prevent any structural failures.

The introduction of advanced numerical modelling to evaluate annulus cement integrity during SCP events have proved to be crucial in determining the remaining effectiveness of the anulus cement, in addition to obtaining the extent of the cement damage / cracks from the prediction during the continuous pressure build-up and subsequent bleeding-out cycles which may occur as rapid as every week. This has proven to provide insights and confidence into safe continuous production without needing for costly interventions etc.
Virtual Voyages: Exploring the Potential of VR/AR in Marine Education and Training
Authors: Naqvi Syeda Mahwish , Rasool Shahzad , Haider Fakiha , Naqvi Faiza , Zehra Mehkar
Published: November 2024

Objective

Technology is revolutionizing every sphere of life and marine education, and training is also expecting a change. This study explores the potential of Virtual and Augmented Reality in marine education and training, aiming to look into investigate the various stakeholders' perspectives and experiences on the use of this new technology. The use of VR/AR technologies provides interactive and immersive experiences, revolutionizing traditional approaches of learning and education within the marine-related fields. By conducting informal interviews and discussions with marine trainers, educators, students, industry professionals, and VR/AR developers, this study explores the perceptions, needs, opportunities and challenges surrounding the use of VR/AR in marine education and training.

Procedure

Study employed a qualitative approach, allowing for in-depth exploration and analysis of insights and perspectives of the participants. Participants are selected on the basis of their expertise in marine-related fields, making sure a diverse range of perspectives and insights are captured. Data is collected through informal interviews with stakeholders, during which note-taking is conducted to capture the responses, observations and reflections of the selected participants. These notes provided detailed accounts of opinions, experiences, and suggestions of stakeholders regarding the use of VR/AR technologies in marine education and training.

Results

Findings from the study offered a wide range of insights with regard to regarding the use of VR/AR in marine education and training. Participants articulate eagerness for the potential of these technologies to boost the learning outcomes, engagement, and practical skills acquisition in marine-related disciplines. However, challenges such as technological barriers, cost considerations and the need for customized content and training modules are also identified. Stakeholders also emphasize the significance of innovation, collaboration and ongoing professional development to capitalize on the benefits of VR/AR within the context of marine education and training.

Novelty/Contribution

By and large, this study contributes important qualitative insights into the current knowledge stream and future directions of VR/AR integration in marine education and training. By capitalizing on the perspectives and experiences of stakeholders, educators, trainers, policymakers and technology developers can make informed decisions; develop targeted interventions, andcultivate collaboration to exploit the full potential of VR/AR technologies in advancing marine education and training initiatives.
Generative AI Powered Virtual Data Rooms for Energy
Authors: Tishechkin D. , Gubanov Y. , Gibson R. , Tribbey S.
Published: November 2024

In the ever-evolving Oil & Gas (O&G) industry, National Oil Companies (NOCs) are central to the management and distribution of critical energy resources. A key aspect of their operations involves conducting bidding rounds to attract investments and forge partnerships for the exploration and development of oil and gas fields. Historically, this process required physical data rooms where interested parties could access confidential information related to the bids. However, with the rise of cloud technology, this practice has been transformed by the introduction of virtual data rooms (VDRs), which offer "a faster, more cost-effective, and efficient way to manage data and information during licensing and bidding rounds" (1).

Generative AI, a subset of artificial intelligence, involves models that can generate new data based on patterns learned from existing data. This technology presents remarkable potential in various applications and could "transform the human-machine interaction in the oil and gas industry" (3). When applied to Virtual Data Rooms, Generative AI augments existing processes by extracting summaries from automated document analysis. Gen AI will enhance search and retrieval of data, compared to traditional keyword-based search. Generative AI search functionality significantly improves by understanding data context and intent, allowing for more accurate and relevant search results. Organizing and categorizing documents in a VDR can be a daunting task, particularly during large transactions where the volume of data is overwhelming. Generative AI assists by automatically categorizing and organizing documents based on their relevance.
Optimized Water Management Life Cycle Strategy for a Giant Offshore Field
Authors: Chen Peng , Alyan Mohand Ahmed , AlHarbi Manal Saeed
Published: November 2024

Water management plays a vital role in the oil and gas industry since it is an important injectant to maintain reservoir pressure in addition to being a by-product of oil crude production which needs to be separated. Optimal water management is critical for maximizing production profitability and hence minimizing total water life-cycle costs. This paper presents an integrated water management life cycle strategy for one of the largest offshore oilfields in the world.

The subject field is currently injecting seawater under matrix injection mode. Reservoir souring, scale modelling, core-flood tests, etc. were conducted to evaluate water compatibility, scaling risk and water specification required for properly designing the surface facilities to process raw seawater for injection without negatively affecting reservoir performance.

The field's rock quality varies in different regions: permeability is higher in the east region and gradually deteriorates towards the west area. Different water injection strategies are applied to address the variance based on lab study results: in the east part, sea water is filtered down to 2µm before injecting to subsurface to avoid formation damage. Whereas in the west part average permeability is around 1mD which poses huge difficulties in terms of water injectivity and its development. The traditional approach of wellbore cleaning and stimulation coupled with an innovative solution of removing sulphate from the seawater to reduce SrSO4 scale risk are implemented to address these sea water injection complications.
Expanding the Utilization of Low-Cost Light Workover Unit's LWU Operational Envelopes, Yields a Substantial Upturn in Rig Resources Allocations Efficiency and Well Cost Economics
Authors: Youssef M. , Al Rahma R. , Al Reyami M. , Al Wahedi K.
Published: November 2024

Embarking on an initiative to expand the Low-Cost Light Workover Units (LWU) operational envelopes.

By utilizing the LWU units to perform well integrity evaluation and Lower completion with Inflow Control Devices (ICD) installations in Workover wells, the perspective of operational excellence allows to maximize the operational scope of low cost LWU replacing Higher cost Heavy Rigs utilization and Activity. Consequently, improving well delivery economics, business plan budget and resource allocating to drilling activities.

The main objective of deploying this practice and approach is mainly to utilize light work over rigs to run ICD lower completion in old producing wells, which are saving a big drilling units days and rental cost that led to optimize well production. Hence, controlling water shut off and water cut percentage in production is a big gain.

The practice was optimized, and the learning curve was developed to provide optimum procedures for those wells that can be generalized as retrieval of old completion string, verification of well integrity in terms of cement casing through corrosion logs and pressure testing. In addition, a key factor is drifting the open hole through proper accessibility run using Non-Damaging Fluid (NDF) and optimized Bottom Hole Assembly (BHA) after conducting engineering analysis and simulation studies for the well trajectory and actual survey, close supervision and mutual engineering / operations follow up for execution of lowering the lower completion.

By following this proven practice, we successfully delivered three wells in same field with +/- 5500 ft of ICD lower completion for a gas lift and ESP producing wells on light Work Over rig with multiple limitations such as: limited Hook load capacity hence minimum "Margin of Overpull" availability that was challenging for freeing stuck situations while lowering lower completion strings, as well having one mud pump available in rig equipment added another burden to work with possibility of differential sticking while pump is under mechanical failure.

Moreover, practice can be spread to other fields that can make a significant rig days’ saving and cost saving of rental bigger units.

This practice leads to enhanced utilization of light work over rigs for running long ICD lower completion exceeding 5000 ft of lateral holes in existing producing wells saving us big rig days and rental cost and even sustainable less carbon footprint for optimizing production rate and decreasing water cut ratio from these reservoirs.
Shale Swelling Inhibitor Utilizing Taro Root, Alginate, and Activated Carbon from Waste Material
Authors: ur Rahman Saad , Siddiqui Rida , Mustafa Muhammad , Lalji Shaine MohammadAli , Ali Syed Imran , Abbasi Faiq Azhar
Published: November 2024

This research explores eco-friendly methods to prevent shale swelling while drilling. It evaluates the effectiveness of using alginate, taro root, and activated carbon from waste materials as additives to drilling fluids in Pakistan's shale formations. This study optimizes the inhibition of a chosen drilling fluid through various experiments, including immersion tests, determination of contact angles, rheological properties, HPHT (high pressure and high temperature) filtration loss. Equipment such as a mortar grinder, sieve shaker, pH meter, heating oven, hydraulic compactor, and ImageJ software were used for analysis. Taro root, activated carbon, and alginate showed promise as additives for enhancing water-based drilling fluids. Optimal particle size and mass fraction solutions of taro root reduce shale collapse and filtration-induced mud loss. Activated carbon purifies water, lowering impurity levels and stabilizing drilling by mitigating clay swelling. Alginate improves mud rheological properties. Both alginate and taro root reduce fluid loss and friction, providing a thin filter cake and lubricity. These additives offer a green, environmentally friendly alternative for inhibiting clay swelling. This innovative approach utilizes waste material for swelling inhibitor in drilling fluids. It contributes to the existing literature by demonstrating its inhibitory properties, improving drilling mud characteristics, and offering an environmentally friendly alternative for clay swelling inhibition. These insights support the petroleum industry's pursuit of sustainable and eco-friendly drilling practices.
Extending The Life of MPFMs for Maximizing Value and Minimizing Downtime
Authors: Benlizidia I. , Faraj A. S. , Ruwaili E. H. , Kaipov Y.
Published: November 2024

The use of Multiphase Flow Meters (MPFM) has been increasing in the last decades in different well monitoring applications. It is important to extend the working life of this equipment as they have reached the end of life and yet can properly operate before it has to be discarded for technical and obsolescence reasons.

During the early stage of project development, MPFMs are selected and sized based on forecasted well production. At the later production stage of field development, usually flow-rates decline. As a result, the differential pressure through Venturi based MPFM will go below the minimum threshold, to maintain good metrological performances, it then requires to change to a smaller size MPFM.

This paper discusses the design, qualification, and field-test of a new methodology of extending the operating envelope of the MPFM using insert to ensure that the well monitoring data remain accurate and reliable without compromising the safety and integrity of the installation.

The insert venturi application developed is named the LRE "low-rate extender" tool because it reduces the cross-sectional area at the venturi throat, which increases the differential pressure for low flow rates and maintains the measurement accuracy.

The project was launched by first decommissioning one sample MPFM from the wellsite and sending it to the product center to build the customized tool and ensure all mechanical constraints and considerations are tackled on the spot.

Once the insert venturi device has been manufactured and duly inspected, the validation phase started through flow-loop testing. The performance of the MPFM with LRE is expected to be similar to MPFM without it. 328 test points were tested at four pressure levels with a water-liquid ratio (WLR) ranging from 0 to 100 % and a gas-volume fraction (GVF) from 0 to 100 % to prove the accuracy of MPFM with LRE. The validation considered the accuracy in total mass rate, liquid and gas rates, and WLR.

The last phase consisted of field trials, where comparison tests have been performed at different flow regimes between permanent MPFM with LRE and mobile MPFM of smaller Venturi size, the test has been extended for 6 months to monitor the MPFM with LRE long-term reliability.

The article discusses the new development of a retrofittable tool to extend the life of the MPFMs. It is a cost-effective solution and its workflow of design and validation can be applied to other MPFMs using the same measurement methodology facing similar flow measurement challenges.
Leveraging on the Subsurface Integrated AI-Enabled Well Planning Automation
Authors: Majumdar C. , Konwar D. , Chatterjee C.
Published: November 2024

Digital transformation has revolutionized the drilling domain, yet the subsurface domain has largely operated in isolation. Despite realizing substantial value, its impact was somewhat diminished due to traditional, non-digital communication and information exchange methods.

The integration of digital drilling planning solutions with subsurface modules has transformed well engineering processes, enabling seamless communication and real-time updates. These integrated workflows optimize well planning and execution, effectively addressing challenges associated with manual data transfer and bottlenecks. Embracing AI-enabled subsurface integration ensures effective data utilization, breaking down traditional silos and enhancing collaboration, leading to superior well designs and improved outcomes for IOCs and NOCs. This approach highlights a niche opportunity for true integration of liberated data within domain-driven workflows.
Electrical Tomography Sensors - Interface Level Measurements Inside Desalters and Dehydrators
Authors: Kallinen Johanna , Voutilainen Arto , Cyriac Sinoj , Nissinen Antti
Published: November 2024

In crude oil process vessels, precise control of oil and water levels is vital. In oil refining, high-voltage electrostatic coalescers create strong electric fields for desalting and dehydration, which may disrupt electrical level measurements. Stilling wells improve measurement conditions and shield devices from external electrical interference. This paper proposes enclosing electric tomography- based level measurement technology within a perforated stilling well to counteract high-voltage grid effects. Electrical Tomography (ET) enables comprehensive real-time monitoring of material distributions in various environments, such as pipes, tanks, and vessels. The ET probe sensor provides information on liquid levels within separators, identifying water-emulsion, emulsion-oil and oil-gas interfaces. The probe sensor is confined by a rather narrow stilling well to investigate its effects on measurement accuracy. The stilling well, with an inner diameter of 91.3 mm, accommodated a probe with a diameter of 59.0 mm. The system was tested with 11 different configurations of stratified liquids so that its level measurement capabilities were assessed with water, emulsion, oil and gas. In general, ET measurements within stilling wells are very localized since the proximity of the metal wall of the stilling well affects the electric interactions between the electrodes. The test results showed that the measured information still contains a sufficient amount of information so that the conductivity profile and subsequent interface levels can be estimated with good accuracy. The Root Mean Square Error (RMSE) across all interface levels in the entire series of test cases was 20.6 mm. This equates to approximately 1% of the length of the measurement area. This is of the same order of magnitude as in standard test measurements in identical conditions but without the stilling well. Electrical Tomography is well-suited for real-time measurement of various interface levels in challenging operating conditions where good repeatability and time-resolution are needed. This study demonstrated that Electrical Tomography based level measurements are successful even when installed in narrow stilling wells, without significant impact on measurement accuracy.
Managing Operation of LNG Plant with Tube-Leaked Cryogenic Heat Exchanger
Authors: Setiadi Bugi , Rahardian Reza
Published: November 2024

This paper describes how Tangguh LNG successfully managed tube-leaked on main cryogenic heat exchangers (MCHE) without compromising safety or production. It shows systematic methods to maintain production with adequate mitigation measures without increasing risk on safety and business. The scope covers daily monitoring to identify and diagnose anomalies, risk evaluation for continued operation, tactical plans for safe operation, including difficult startup after unexpected trip, and internal inspection to verify the tube leakage. The leakage of MCHE tubes was detected as anomalies in daily surveillance, as shown by the continuous rise of methane composition and compressor suction pressure. Investigation was carried out to locate the leakage source. Risk assessment was conducted to evaluate the feasibility of continued operation, agree on the control measures, and rectification plans. Tactical strategies were established, including periodic liquid draining and venting, management of refrigerant composition and scrub column pressure. Tangguh also managed to handle a challenging situation with an unplanned trip during this condition. Special instructions for startup, including exchanger cooldown were prepared to safely restart the plant. Tangguh managed to keep operating safely with a tube leaked MCHE until the scheduled shutdown period, saving the business from losing around $50M. The key to this success was the tactical strategies during both start-up and normal operation. Investigation revealed that the leak was triggered by rapid cooldown in the previous startup, which caused thermal shock. To prevent the leaks, the cooldown should be controlled within the maximum rate. Internal inspection verified leaks in the feed gas circuit at various locations, and repairs were done. The paper summarizes that proper cooldown during startup is vital for preserving the integrity of the cryogenic heat exchanger. If leakage happens, systematic methods, including comprehensive surveillance analysis, solid risk assessment, and tactical strategies, should be applied to evaluate if continuing operation is reasonable. The paper uses Tangguh LNG's distinctive experience in managing tube-leaked cryogenic heat exchanger safely to develop systematic methods to prevent unexpected shutdown, which can be useful for other LNG operators. The paper also highlights the importance of proper cooldown during startup to preserve the cryogenic heat exchanger integrity.
Optimized Design of Collision Free Wells: A Comprehensive Approach to Various Trajectory Types
Authors: Singh Umesh , Pathan Rizwan , Joshi Amol , Cavé Adrien , Baume Antonin
Published: November 2024

The primary objective of this research is to design collision free and economical well trajectories in a crowded brownfield oil and gas field with numerous legacy wells. This design includes various types of trajectories, such as directional and sidetrack wells. Another key goal is the strategic positioning of Electrical Submersible Pumps (ESPs) along the wellbore trajectories to enhance production efficiency and reduce drilling costs. The research also emphasizes operational safety and environmental management by avoiding collisions with existing wells. The approach involves developing a comprehensive method for generating optimized well trajectories in oil and gas drilling operations. This method incorporates the minimum curvature method and evolutionary modeling techniques to dynamically adjust and optimize trajectories. Geological, engineering, and operational parameters are integrated to develop trajectories that minimize drilling complexity and cost. Safety constraints are included in the optimization process to ensure collision avoidance with existing wells, thereby safeguarding operational integrity and preventing environmental hazards such as oil spills. The developed optimization method was tested in live oil and gas fields, specifically involving the design of 36 wells in Africa. The solutions resulted in significant length savings of 3.3 km and a substantial 13- fold reduction in collision risks. Additionally, the method successfully generated various safe sidetrack and deepening well trajectory designs accepted by drilling engineers. It also achieved automated ESP placement within the well trajectories. These results demonstrate the method’s effectiveness in optimizing various well trajectories, minimizing drilling complexity, and adhering to safety constraints. The research findings highlight both the cost effectiveness and safety improvements achieved. Overall, this research significantly advances well trajectory design methodologies. It introduces a novel approach for generating collision free, optimized well trajectories of different types, including vertical, directional, and specialized sidetrack and deepening well trajectories. The method can also optimize ESP placement within the trajectories. Unlike traditional methods that depend heavily on a designer’s experience and intuition, this approach utilizes evolutionary modeling techniques to dynamically generate well trajectories. By incorporating geological, engineering, and operational parameters, the method aims to minimize drilling complexity and cost while ensuring adherence to safety constraints.
Palm Oil Biomass to Drop-In Fuels as Alternative to Traditional Jet Fuels: Large-Scale Process Modelling and Techno-Economic Assessment
Authors: Alareeqi S. , Alkhatib I. I. I. , Vega L. F.
Published: November 2024

Palm oil-based biorefinery has the potential to generate renewable drop-in fuels based on a UAE-viable biomass resource. The objective of this work is to reduce the process scalability cost through implementing a "self-H2 supply-consumption" strategy. We have coupled the thermodynamic properties of effective BEA zeolite-based material evaluated using reactive molecular dynamics simulations to large- scale process modeling for producing drop-in fuels. Technoeconomic assessment (TEA) was implemented to quantify the process feasibility for commercialization. A sustainable aviation fuel (SAF) with a 76.75% wt. of undecene (C11H22) and a HHV of 44.96 MJ/kg was achieved. The deoxygenation reactor incurred the largest segment (76.1%) of the total capital investment marked as $6.71 million. Other equipment in line were the heating/cooling heat exchangers ($1.38 million, 15.6%), followed by the distillation column ($0.414 million, 4.7%). Exploring variations attributed to parameter sensitivity, the OPEX was found heavily reliant on the feedstock cost, which was optimized considering industrial symbiosis from a local palm oil production refinery. Compared to biomass-to-fuel processes in literature, this work reports a cost-competitive MFSP with a 3.38 $ L-1 for SAF production.

Graphical Abstract
Power Transformer Reliability Assurance Program
Authors: AL Dhaheri Ahmed , Srihariraju B.
Published: November 2024

Power transformers are vital components in electrical power systems, utilized for varying voltage to the required transmission and distribution levels. These assets are highly valued and susceptible to degradation from regular operations, abnormal conditions, including overloading, harmonics, short circuits, and environmental factors. Ensuring the reliability and fault-free operation of transformers is essential to prevent extensive power system interruptions with potential to disrupt business continuity. This paper details a comprehensive transformer health assessment program implemented at ADNOC GAS - Ruways & Sulphur Division, employing advanced techniques for testing and diagnostics. The main objective of assessing transformer health condition in accordance with international standards such the Institute of Electrical and Electronics Engineers "IEEE", the International Electrotechnical Commission "IEC" and Council on Large Electric Systems "CIGRE" is to establish prioritization criteria for transformer overhaul based on the severity of issues and transformer criticality. This comprehensive approach enhances planning strategies to proactively carry out transformer overhauls to prevent inadvertent failure, reduce downtime, extend transformer lifespan, improve availability and system reliability.
Reduce CO2 Emission in Gas Flare
Authors: Rengarajan Stalin , Alkatbi Sultan Muhayer
Published: November 2024

In industrial processes, particularly in oil and gas operations, managing emissions while maximizing efficiency is of paramount importance. The ever-increasing focus on environmental sustainability has led to innovative solutions for minimizing greenhouse gas emissions, notably carbon dioxide (CO2), during routine operations like gas flaring. One such cutting-edge solution involves an integrated system designed to harness fresh air, advanced sensor technology, and effective water treatment to significantly reduce CO2 emissions. This article outlines the essential materials and installation processes involved in this innovative system, highlighting its functionality and the underlying principles that make it effective.

At the core of this system is a Variable Speed Drive System (VSDS) motor-controlled suction blower fan, which plays a crucial role in enhancing combustion efficiency by fostering optimal air supply to the flare head. This is complemented by a sealed water tank equipped with inlet and outlet valves, a level sensor, and a pressure gauge to monitor and control operational parameters. A dedicated smoke passage mixture pipeline ensures the controlled transfer of gas emissions to the water tank for subsequent treatment.

Equipped with CO2 sensors strategically positioned to monitor gas levels throughout the system, this setup allows for real-time adjustments based on the concentration of CO2 in the smoke mixture. The setup employs a nebulization nozzle that fine sprays the smoke mixture into the water, facilitating the absorption of CO2 and minimizing harmful emissions. The water tank design is not only efficient but also functional, featuring a conical base that simplifies the removal of CO2-saturated water and enables easy maintenance.
Innovative Practices for Electrical Submersible Pump (ESP) Efficiency: New Gas Lift Mandrel (GLM) Deployment Techniques
Authors: Al Hinai S. , Al Saadi F. , AL Salmi A. , Al Lawati M. , Galin N. , Soliman A. , Al Hinai M. K.
Published: November 2024

Gas lock is one of the key challenges that Electrical Submersible Pumps (ESPs) faces in oil wells with high Gas Oil Ratio (GOR). For wells with ESP packer or wells with no continuous gas bleed-off through the annulus, gas accumulates below the packer until it reaches the pump intake, creating what is known as gas lock. As a result, ESP motor temperature increases (due to no cooling fluid), causing ESPs to trip. As a mitigation for this challenge, the innovative idea of ​​installing Gas Lift Mandrel (GLM) below the ESP packer deployed to enable continuous gas bleed-off from the annulus to tubing above the ESP. As a results, oil deferent reduced, ESP run life extended and intervention cost avoided.

Oil wells with gas lock issues or gas lock potential were selected using ESP historical running parameters and production testing data. Selected wells were attended by a well pulling hoist (WPH) where GLMs were installed. Side pocket mandrels with dummy valves were installed by WPH below the ESP packer and slick line later replaced the dummy valves with gas lift valves (GLV). these valves are set to open at the minimum differential pressure between annulus and tubing where gas will be bled off automatically before reaching the ESP intake. Hence, preventing gas lock phenomena.

The idea has already been implemented in more than 25 ESP wells in more than seven different fields. Better ESP efficiency, reduction in oil deferment and extended ESP run life was evident. The opening and closing of the valve were noticed in the ESP trend where it was seen as spikes in pump discharge, electrical current, and THP. To confirm the opening and closing of the valves, two memory density gauges were installed, above and below the GLM. The opening of the valve was confirmed by a sharp drop in density at the above valve only (indicating gas flow from annulus to tubing above the ESP, though the GLM).

Installing GLM in ESP wells to prevent the gas lock issue is a new novel approach that combines both low cost and highly efficient practices. The cost of GLM is low, the installation has no complexity when compared to some other existing solutions that are designed to bleed the gas from below the packer. It also serves as an SSD where the GLV can be retrieved by slick line if needed for any reason.
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

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

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

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

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

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

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.