bluuebunny/crossref_metadata_2025 huggingface dataset:
Ranking Geological Models Using Dynamic Lorenz Coefficient: Application for CO2 Sequestration in Saline Aquifers
Authors: Aldaif H. , Hoteit H.
Published: November 2024

Concerns regarding climate change and global warming have intensified over the past decade. One of the main strategies to mitigate the rise in global temperatures is CO2 sequestration in geological formations. Reservoir simulators are the tools to evaluate the behavior of CO2 while being sequestered in the aquifers. However, the reliability of the simulation runs relies on the accuracy of the geological model, which is often associated with various uncertainties. Developing multiple realizations of the geological model is a common practice in the industry, which is typically adopted to incorporate uncertainties. There is a practical limitation to conduct detailed simulation studies for all the geological models. Ranking geological models using certain indicators is key to perform detailed studies on selective cases that capture the range of subsurface uncertainties. Dykstra-Parsons coefficient of variation (VDP) and static Lorenz coefficient (Lc) are common static indicators that are used in the ranking process. The main advantage of using VDP and Lc is that they can be easily and quickly calculated. However, studies have shown that dynamic Lorenz coefficient (DLc) is a superior tool to rank geological models and quantify heterogeneity. Numerous studies have examined the impact of aquifer heterogeneity on CO2 trapping mechanisms. However, existing research typically employs static indicators to assess aquifer heterogeneity, such as the coarse grain to fine grain ratio, sand to shale ratio, Dykstra-Parsons coefficient, and coefficient of variation. These static measures inadequately capture the spatial connectivity between reservoir grids and layers. Additionally, other studies compare homogeneous models with a single heterogeneous model without adequately quantifying the level of heterogeneity. In this study, the Sequential Gaussian Simulation method was utilized to generate multiple simulation models with varying levels of heterogeneity. The heterogeneity of these models was quantified using dynamic data from rapid streamline simulation runs and assessed with the dynamic Lorenz coefficient. Alongside a homogeneous model, four models with increasing heterogeneity (DLc values of 0.2, 0.4, 0.6, and 0.8) were analyzed. Sensitivity analyses were conducted on factors such as water salinity, wettability, injection rate/volume, and completion interval. Depending on the completion interval, the increased heterogeneity can enhance both solubility and residual trapping while reducing the amount of mobile CO2. This study uses dynamic data obtained from fast streamline simulations to quantify heterogeneity through the dynamic Lorenz coefficient, providing a more accurate measure of spatial connectivity of the reservoirs/aquifer and utilize that information to assess the impact of heterogeneity on different trapping mechanisms of CO2 in saline aquifers.
A Comprehensive Methodology for Assigning Capillary Pressure and Relative Permeability Curves to Reservoir Rock Types with Limited Laboratory Data
Authors: Carvalho A. , Valsardieu B. , Balthazar A.
Published: November 2024

Accurate characterization of capillary pressure and relative permeability curves is crucial for reservoir modelling and production optimization. However, in many cases, laboratory measurements are only available for reservoir rocks of better quality, leaving those of lower quality lacking essential data. This paper proposes a methodology that combines log data and laboratory measurements to assign capillary pressure and relative permeability curves to different reservoir rock types, even when laboratory data is limited. The suggested methodology was successfully applied to sandstone reservoirs in a northern Africa field.

First, all cored sample depths are converted to the corresponding log depths, and each sample is assigned to the most probable reservoir rock type (RRT) identified in the petrophysical analysis. Subsequently, Pc values are transformed into height above the free water level (HAFWL) curves, and these undergo a thorough screening process to filter out less confident samples. Higher confidence HAFWL curves are then grouped according to their respective RRTs. The subsequent step involves defining a reference synthetic Sw vs. HAFWL curve for those RRTs with assigned laboratory data. For the RRTs lacking laboratory data synthetic curves are then obtained by using log-identified irreducible water saturation (Swi) values above the transition zone. Finally, this part of the process concludes with the validation of the reference curves by comparing them to Sw profiles obtained from log interpretation.

Next, attention shifts to kr data, beginning with curves pre-processing. This entails determining endpoints and Corey coefficients for all supplied curves to construct analytical kr curves. The subsequent step involves an innovative screening technique of kr curves based upon the use of cross-plots between petrophysical parameters and kr curve endpoints. This process serves two primary purposes: firstly, it allows filtering anomalous samples and categorise representative curves per RRT, and secondly, it identifies trends in the cross-plots. The latter will enable the creation of synthetic kr curves for RRTs lacking laboratory data.

In summary, the proposed methodology offers a systematic approach to assign Pc and kr curves to reservoir rock types, effectively leveraging available laboratory data while addressing data gaps for less characterized rocks. Emphasis is placed on innovative screening techniques for kr curves. By incorporating synthetic curves and validating against log data, this methodology enhances the accuracy and reliability of Pc and kr curves, thereby supporting improved reservoir characterization and simulation studies for optimized hydrocarbon recovery.
Structure Characteristics and Deep Shearing in M Field, South Iraq, First Evidence from 3D Seismic and Integrated Gravity Study
Authors: Dengyi Xiao , Jiawen Song , Yanlin Huang , Jianlin Li , Xin Chen , Qunli Qi , Min Zhao , Bo Wang , Pengpeng Ye , Ziping Lu , Pengfei Zhang
Published: November 2024

The South Iraq is one of the most prolific hydrocarbon-producing regions in the world. Most of fields in this area are elongated in N-S, NW-SE and characterized as four-way dip closure. The kinetic and dynamic mechanisms of these structures are reported as deep salt diapir or regional shear but lack clear evidence in field scale. To robust understanding of structure origination and growth, a dedicated study with the integration of seismic and gravity illustration was carried out.

This study was conducted based on high-quality 3D seismic as well as field-scale gravity investigation in M field. Tectonically, this field locates in transition zone of N-S trending and NW-SW trending. The basement depth and tectonic lineament were delineated through gravity-based inversion with different scenarios to figure out the influence of Hormuz salt. Under the recognition of gravity, faults in Jurassic and Cretaceous were interpreted according to dedicated seismic interpretation through geometric attributes and AI techniques. Geometric, kinetic as well as dynamic mechanisms of structure were organically analysed. The anticline growth history is also quantitatively demonstrated through 2D seismic horizon flattening and 3D paleo-structure reconstruction. These understandings of fault features, anticline evolution history as well as basement condition give a clear delineation on the generation and growth procedure of M field.

Generally, two sets of faults develop in M field and are separated by Gotnia anhydrite. The fault systems are generated in same stress regime and show different patterns. The Jurassic faults perform as sinistral trans-compression with two N-S trending major faults and eighteen NW-SE subordinate faults. The Cretaceous faults distribute as right-stepping en echelon series. The Gotnia formation adjusts the deformation differentiation through ductile flow and results in the lateral thickness variation. The coincidence of Cretaceous anticline crest and Jurassic fault-constraint area indicated the contribution of fault activity to growth of the anticline. Paleo-structure through 2D horizon flattening and 3D methods indicated the continuous growth of since the early Cretaceous.

Conclusively, this is the first time to explicitly display the fault configuration in South Mesopotamian basin and prove the dextral shearing of Jurassic formation in 3D seismic and gravity. The study provides insight into the relationship between tectonic movement and field growth. The achievement of this study would enhance the understanding of hydrocarbon accumulation in South Mesopotamian basin and give inspiring information on hydrocarbon accumulation.
Green Acid Transformative Technology for Sustainable Oil Production, Reservoir Management and Operational Efficiency in UAE Hydrocarbon Recovery
Authors: Ghahgarokhi R. Barati , Alhajeri Mubarak M. , Tsau Jyun-Syung , Rowley S.
Published: November 2024

This paper introduces the groundbreaking application of a novel, low-corrosion, deep-penetrating, environmentally green acid designed for high-temperature Gulf reservoirs. The green acid exhibits various beneficial properties, including low corrosion rates with stainless steels and wireline materials, improved interfacial tension, and deeper penetration into carbonate rocks under reservoir conditions. The acid's performance was evaluated through interfacial tension measurements, corrosion testing, reaction rates with different materials, and matrix acidizing experiments. The results demonstrated lower corrosion rates, improved permeability, and potential for deeper penetration compared to similar HCl-based products with results pass the minimum requirement presented by the industry. The matrix acidizing experiment results revealed a permeability increase of 2,671 times for a limestone core with an initial permeability of 1.74 mD, which indicate that the green acid achieves approximately 2.5x greater permeability enhancement compared to 15% HCl. The green acid is non-corrosive, non-fuming, non-toxic, and biodegradable, making it a cost-effective and environmentally friendly alternative for reservoir applications.
Surviving the Flame: Ensuring Facilities Safety with Fire Survivability Study
Authors: Ali Z. , Ngah W. Wan
Published: November 2024

Traditionally facilities blowdown is normally designed for emergency depressurization to 100 psig or half of design pressure, whichever is lower, within 15 minutes as per recommended by API RP 521 (referred to as legacy method in this paper). API RP 521 criterion was developed based on pool fire and applies to carbon steel vessel with wall thickness of 25.4mm and more. This paper addresses the adequacy of legacy API 521 guidance for application to cases which differs from the criterion to reduce the risk of catastrophic equipment failure especially for jet fire impingement scenarios. The process systems are studied in detail to bridge the gaps and resolve the safeguarding limitations for facilities in operations which were designed based on legacy method, if any. Furthermore, this paper also provides further insight on the design aspects to meet the blowdown requirement. The findings from the study will be elaborated and recommendations proposed to solve any problems will be discussed.
Enhancing Enterprise-Wide Information Retrieval through RAG Systems Techniques, Evaluation, and Scalable Deployment
Authors: Palaniappan Somasundaram , Mali Rohit , Cuomo Luca , Vitale Mauro , Youssef Ali , Madathil Athira Puthanveetil , Murugesan Malathi , Bettini Alessandro , De Magistris Giovanni , Veneri Giacomo
Published: November 2024

Organizations in the Oil and Gas Industry deal with a vast repository of knowledge dispersed across various structured and unstructured data sources. The process of retrieving information for a particular task can be time-consuming and necessitates the involvement of multiple subject matter experts. Large Language Models (LLMs) supported by Retrieval Augmented Generation (RAG) systems can help expedite information retrieval and processing. However, Enterprise-scale LLM implementation faces challenges, that include confidentiality, scalability, handling hallucinations, handling domain data, feedback, and model improvement.

In this technical paper, we describe an optimized RAG system using LLMs for accelerated information retrieval from vast, highly confidential sources. We present the software architecture, the data flow that facilitates the application's ability to gather feedback for model fine-tuning and the techniques used to optimize our solution for accuracy, scalability, throughput. In the proposed architecture, the LLM-as-a-service component generated an average throughput of 989 tokens per second for summarization tasks involving up to 2500 tokens per request when run on A100 GPUs (40 GB). In the Oil & Gas Industry, the application allows Field Service Engineers to directly retrieve technical details about machinery, details from maintenance manuals etc and helps design teams to speed up information retrieval. This has resulted in an estimated improved productivity in the range of 20% and a positive impact on Customer Relationship, Time to Serve and Cost of Quality.
Harnessing Generative AI for Interactive System Failure Diagnostics: A User-Centric Approach to Streamlined Problem Solving and Maintenance
Authors: Vitale M. , Youssef A. , Mishra P. , Shetty S. , Sharma M. , Vanzo G. , Veneri G. , Vieri L. , Bettini A.
Published: November 2024

Industrial machinery, including gas turbines and compressors, plays a critical role in driving key industries such as energy, fertilizer, and refineries. However, unplanned events can have far-reaching consequences, resulting in substantial production losses, increased emissions, and significant financial burdens. This work introduces a novel framework that leverages generative artificial intelligence for automated Root Cause Analysis (RCA) in turbomachinery. Facing the challenges of traditional RCA, which is expert-intensive and time-consuming, our work adopts a Large Language Model (LLMs) and information retrieval methods to translate natural language descriptions of failures into structured insights. A comprehensive knowledge base, populated with operational log data and expert- validated solutions, empowers the LLM to perform in-context learning and iterative diagnosis. By employing a hybrid search mechanism, our work identifies the most probable failure symptom and guides the user through a series of questions to pinpoint the root cause. Ultimately, the system generates a comprehensive troubleshooting report containing the root cause, mitigation strategies, and relevant references, enabling efficient and informed corrective actions. This approach promises to significantly reduce reliance on domain experts given the limited expertise available in the industry and address the entry-level gab, and improve the speed and accuracy of RCA, leading to enhanced operational efficiency and cost savings in industries reliant on high-performance turbomachinery.
Optimizing Indonesia PSC Framework Strategies for Renewable Energy Initiatives
Authors: Putra Iswahyudi Sondi , Hariandy Pityt Puty
Published: November 2024

Renewable energy initiatives are of utmost importance on a worldwide level, as they address environmental concerns and promote sustainable development. Customizing these activities to the unique characteristics of each country is crucial for attaining success. Developed nations place a higher importance on technological advancements and the integration of power grids, whereas undeveloped countries prioritize making electricity accessible to all and implementing decentralized energy systems. The importance lies in the reduction of carbon emissions, ensuring energy independence, and fostering economic growth. Countries should use their unique resources, such as solar, wind, or hydropower, in order to maximize their impact. The implementation of various renewable energy solutions demonstrates the growing international collaboration and demonstrates a shared commitment to a greener and more resilient future.

Indonesia, adopting a fiscal framework known as a Production Sharing Contract, aims to achieve net zero emissions by the year 2060. The energy sector, which is responsible for the highest level of emissions, including those from oil and gas, has implemented a program aimed at reducing these emissions. The government entity responsible for managing the PSC contract, SKK Migas, has a program focused on renewable energy efforts and low-carbon initiatives. This program is coordinated with oil and gas companies. The approval of the program and budget for low-carbon initiatives provided by SKK Migas provides a positive signal for investment by oil and gas companies, where they receive certainty that the low-carbon initiatives program will be reimbursed by the Indonesian government through a cost recovery mechanism.
Feasibility of Steel Lazy Wave Riser System Configuration in Deepwater Using CRA Clad Steel Pipes
Authors: Enppi T. Eldesouky
Published: November 2024

The application of steel lazy wave risers (SLWRs) is relatively a novel solution in subsea industry. Compared with free hanging steel catenary risers (SCRs), the targeted provision of custom designed buoyant section in SLWR results in decoupling the vertical displacement at hang-off point (HOP) driven by floater production unit (FPU) motion from the rest of the riser, hence limiting fatigue loading at the critical touchdown point (TDP) and reducing top tension and bending stresses. However, due to the highly corrosive nature of some hydrocarbon reservoirs, the wall thickness that must be added to account for corrosion along the design life can increase riser system loading, hence limits the pipe diameter that can be used for the target water depth. Therefore, and as a viable alternative solution, the application of steel pipes internally clad with a limited thickness of corrosion resistant alloy (CRA) was analyzed for deepwater SLWR application. In this work, configuration/shape analysis with basic catenary method was conducted for one of the existing twin 10-inch, grade X65 production SLWRs, as case study in Mediterranean Sea, with spread moored FPSO at 1700 meters water depth. Then after, one of SLWRs planned for project future expansion was designed according to API STD 2RD code, while adopting the analyzed shape. A wide range of commercially available steel grades for CRA Clad pipes, including X70, X65, X60 and X52 were covered in the design. Moreover, different alternatives of pipe diameters including 10, 12 and 14-inch were considered. The static and dynamic analysis for combined loading code check, as well as bending stress range for fatigue life calculations were performed using finite element analysis (FEA) software OrcaFlex version 11.2b. Although the result for design of the new SLWR concluded that all combination of steel grades and pipe sizes are safe for all extreme load cases, when it comes to fatigue, it was found that the 10-inch grade X65 is the only case that can achieve minimum service life of 20 years based on the input design parameters. This result suggests that further detailed analysis for SLWR is needed to optimize the shape parameters and obtain the best configuration that results in minimum payload on the FPSO and stresses on the riser system, sufficient length of the flowline until the anchor point or PLET, and reduced CAPEX by using minimum number of buoys for the buoyant section. All that besides achieving the targeted fatigue and service life. Throughout this study, a comprehensive background about CRA Clad pipes and SLWR is covered. Moreover, the feasibility of their combined application for the first time in the Mediterranean Sea is introduced.
Understanding Talus Formation from Analysis of Wells Data and Conventional Core Descriptions in a Pinnacle Carbonate Reservoir, Central Luconia, Sarawak
Authors: Bakar M. Abu , Ling K. , Leong L. Chee
Published: November 2024

Talus formations hold potential for hydrocarbon reserves, yet drilling and assessment in these areas are not commonly favoured. Central Luconia's carbonate fields have seen limited talus appraisal. The field of study (Field-X) is one of few fields in here drilled and appraised talus as part of its development drilling campaign. Insights derived from this campaign offer valuable data to address and mitigate various uncertainties on depositional concept, and assess future regional potential.

Six wells were drilled during the development campaign in the study area, with two specifically targeting the appraisal of the talus zone. These wells underwent comprehensive logging programs and conventional coring. Pressure data and fluid sampling were conducted to ascertain connectivity between the talus and reef pinnacle, essential for volumetric reserve estimations. Biostratigraphic descriptions of the cores offer valuable evidence for identifying the origin of talus materials, aiding in concluding the depositional concept. Additionally, correlations between field data and regional events, such as sea level variations and wind direction, was studied to strengthen the depositional model.

The conventional core biostratigraphy analysis reinforces the depositional theory of talus formation. Core features provide compelling evidence supporting this theory. Talus zones are primarily characterized by skeletal packstone and skeletal wackestone lithofacies, with prominent allochems such as skeletal fragments dominated by red algae, forams, echinoderms, occasional mollusc fragments, and bryozoans. Bryozoa and coral fragments are exceedingly rare, with occasional presence of dark pyritised grains. Physical structures like solution seams and stylolites indicate chemical compaction, leading to decreased porosity. Solution seams often accompany organic cumulates and occasionally clay lenses. Talus originates from eroded carbonate fragments and reef debris, deposited at flanks in deeper waters. Its composition includes non-skeletal particles (carbonate grains, mud, and clasts) alongside erosional skeletal particles (mollusc, foram, algae, echinoderm, coral fragments). Talus generally exhibits lower reservoir quality due to poor sorting and chemical compaction. Absence of sub-aerial exposure limits diagenesis processes altering porosity.

Through this appraisal campaign, the presence of hydrocarbon potential in talus formations has been proven. With limited wells drilled for talus appraisal in Central Luconia, this paper serves as a valuable reference for other fields where talus occurs. Offering essential insights and lessons learned, this study provides critical information applicable to all carbonate fields featuring talus. Understanding talus formation is crucial for fostering confidence in future appraisal programs, and optimizing development and production strategies effectively.
Oil Recovery Optimisation in High Watercut Heterogeneous Confined Channel Sandstone Reservoirs
Authors: Dzarake B. A. , Essilfie S. , Asigbi G. K. , Adu M. K. , Addae E. Y. A. , Addae-Afoakwa K. , Duodu-Turkson K. M. , Brobbey O.
Published: November 2024

This paper delves into an examination of reservoir management and Enhanced Oil Recovery (EOR) strategies for optimising oil recovery in highly heterogenous confined channel reservoirs characterized by high watercut evolution. It includes the identification of reservoir performance challenges and their root causes while evaluating dynamic reservoir simulation options for selected EOR techniques. The Enyenra Oil field, located offshore Ghana, serves as the case study for this research.

The study focuses on the optimisation of sweep efficiency in such reservoirs, using diagnostic plots to identify root causes of high watercut evolution. Analogue field studies were conducted to benchmark potential techniques for improving oil recovery. Two EOR methods (polymer flooding and surfactant flooding) emerged as the most suitable options from the benchmarking. Subsequently, dynamic reservoir simulation was employed to determine the optimal EOR technique and implementation strategies for mitigating aggressive watercut evolution and enhancing oil recovery.

Results suggest that poor reservoir sweep efficiency and potentially poor recovery factor may be mitigated by avoiding preferential flooding of high permeability streaks by the injected water, thereby improving oil recovery in low permeability streaks. The study demonstrates the effectiveness of these chemical-based EOR techniques over other methods. Simulation outcomes show that cyclic surfactant flooding notably increased the recovery factor by 3% and reduced watercut by 12%. However, cyclic polymer flooding increased the recovery factor by 1.8% and reduced the watercut by 4%. An economic evaluation of the improved profiles revealed a marginal gain in cyclic polymer flooding compared to cyclic surfactant flooding.

Findings from the study offer practical strategies for reservoir management in highly heterogenous sandstone reservoirs and provide valuable guidance for practising Engineers seeking to optimise sweep and production efficiency and sustain operations in similar challenging reservoirs. The workflow employed in this study could be applied to evaluate similar problems in existing fields.
Automated Remote Metering Monitoring
Authors: Caulier Renaud.
Published: November 2024

TotalEnergies was one of the first companies to implement remote metering monitoring technology 15 years ago to assist its affiliates in tracking the performance and accuracy of subsea multiphase flow meters (MPFM). These complex devices are essential for measuring the production rates of oil, water and gas by well and for providing reliable forecasts for future operations.

Since the initial stages, which involved extracting data from a historian into Excel, significant advancements have been made in both the methodology and tools employed to monitor the MPFM. These improvements were driven by the evolution of our knowledge and by the increasing number of MPFM installed in various fields.

Today, the monitoring scope has been extended to include all critical flow meters: the flow meters that are used to report daily production figures to the authorities and stakeholders. In parallel, more and more assets have been added to the monitoring system, which means that today we have 250 MPFMs and 600 other flow meters under our supervision. This global monitoring allows us to perform many comparisons and checks, such as verifying the consistency between the sum of the MPFMs and the total oil, water and gas production. The validated daily production figures are then used for production allocation per well.
20/20 Vision of Your Operations – Creating an Operational Twin of Completions Operations
Authors: Thomas T. , Zhou Y. , Fairley R. , Boyd T. , Segovia A. , Scherer K. , Fatheree K.
Published: November 2024

The industry has seen an increase in the need for digitally connected completions operations, pushing for companies to sensor, aggregate, and stream data to remote operation centers (ROC). While sensoring critical parameters is vital to monitoring operations, the most important element is generally excluded from the ROC – the contextual perspective only provided by personnel. This innovative approach provides clarity to remote operations by integrating human context, engineering, and sensors, aligning operations with engineering and management.

Prioritizing real-time data aggregation and the integration of sensor and contextual data must be a cornerstone of a remote monitoring solution. This approach outlines creating a digital twin by combining and aggregating the three elements into one digital context. The method outlined leverages a tri-directional sync from the operational controls, remote platform, and phone application that allows users to include operational states and human-sensored elements, such as return rate, viscosity, valve position, and rig-up geometry, that are used to align the pre-job modeling and actual operations once the job starts, providing a single source of truth for all users.

Pre-job modeling and procedures provide a roadmap for the operations to follow, but when the human context is excluded once the operation has started, the model becomes invalid. At this point, the variability introduced due to the lack of context can result in undesirable outcomes. When simulated, pre-job modeling uses the best available information, but often, the operation has elements that need to be adjusted once on location.

By including a multi-directional sync, onsite personnel can provide updated information, including rig-up geometry, fluid metrics, and mechanical deviations from models, that are used to update the simulation and keep the operations on track and aligned for the best outcome. Human senses are the best sensors, as these are used to track very difficult-to-sensor elements, such as return rate. These are, in turn, used to derive complex equations such as annular velocity and fluid carrying capacity that are critical to successful completion operations. The incorporation of human context with engineering and sensor data provides an extension of the operation to be viewed remotely, as opposed to an aggregation of sensors that rely on data analytics and engineering deduction. This operational twin enables full engagement in the field and in the office.

Creating a digital, interconnected workspace that aligns sensor data with operational context brings the completions engineer back into the operation. This integration empowers the industry to work toward one goal—completing wells more efficiently and safely and reducing avoidable non-productive time (NPT)—by removing the logistical barrier when developing an ROC.
Navigating the Future: Pioneering Autonomous and Remote Operations with IoT Technologies
Authors: Paraschiv A.
Published: November 2024

The evolution of autonomous and remote operations is significantly impacted by advancements in Internet of Things (IoT) technologies, among which IoT wave radars have emerged as a pivotal tool. By integrating wave radar technologies with IoT frameworks, industries can achieve unprecedented levels of automation and remote monitoring capabilities. This paper explores how the wave radars, equipped with IoT capabilities, offer a unique advantage by transmitting accurate real-time data regarding ocean state conditions which plays a critical role in the dynamic assessment of environmental conditions as well as the potential challenges and solutions in deploying these systems.
Surfactant-Chelating Agent Based Formulations for Enhanced Oil Recovery
Authors: Deng X. , AlOtaibi M. , Fahmi M. , Israr M. , Hussain S. M. Shakil , Patil S. , Mahmoud M. , Kamal M. S.
Published: November 2024

The presence of salts in reservoir brines and seawater can negatively impact surfactant performance. To address this challenge, chelating agents have been investigated as additives to stabilize surfactants. This study evaluates the stability, wettability alteration, and interfacial tension reduction performance of different types of surfactants, combined with chelating agent EDTA, in salt water for carbonate reservoirs. Tested surfactants include anionic, cationic, and nonionic, to cover different situations. A locally synthesized cationic gemini surfactant was also tested. The spinning drop method and sessile drop method were adopted to measure the IFT values. Static contact angle measurements were conducted to assess wettability changes induced by these EOR materials. Stability tests were conducted by monitoring the precipitations in the fluids in glass vials at varying temperatures in the oven.

The application of EDTA requires a moderate pH condition. A low pH (3~5) causes EDTA precipitation while a high pH causes seawater instability. On the other hand, water with high pH can react with oil components to generate surfactants, thus reducing the interfacial tension. While surfactants with other ion types showed a synergic effect with EDTA in changing rock wettability, anionic surfactant (SDS) showed a negative impact that largely inhibited the wettability alteration induced by EDTA. Combinations between EDTA and commercial surfactants such as DTAB and Triton X100 can form stable EOR formulations that are efficient in both IFT reduction and wettability alteration at a proper pH condition. For surfactants largely impacted by salts in stability (SDS) or wettability alteration (GS), a combination with the chelating agent can significantly improve their performance at lifted salinity. In conclusion, this study provides valuable insights into the effectiveness of the combinations between chelating agents and surfactants as EOR materials. The findings highlight the importance of considering reservoir conditions (pH, temperature, salinity) and the synergistic effects of surfactant-chelating agent mixtures for optimizing oil recovery strategies in carbonate reservoirs.
Installing Unsymmetrical Structural Extensions on Jackets: A Case study
Authors: George Charles John , Cherian Litty Dani , Kamal Faris Ragheb
Published: November 2024

The installation of unsymmetrical structural extensions on offshore jackets presents significant engineering challenges that necessitate meticulous planning and innovative solutions. This case study delves into the complexities and unique considerations encountered during the installation process, offering insights into overcoming these challenges.

Offshore jackets serve as foundation structures for oil and gas platforms, providing stability and support in harsh marine environments. When these platforms require modifications or expansions, such as adding unsymmetrical extensions, engineers must carefully assess the implications on structural integrity, stability, and safety.

Key challenges in installing unsymmetrical extensions arise primarily from the asymmetrical loading conditions they introduce. Unlike symmetrical modifications that evenly distribute forces, unsymmetrical extensions create uneven stresses on the jacket structure. This imbalance requires detailed analysis to ensure that the existing structure can withstand increased loads without compromising its integrity.

Moreover, the installation process itself poses logistical and technical challenges. Accessing offshore locations, often in remote and challenging environments, adds complexity to the execution of structural modifications. Engineering teams must devise strategies for transporting materials, managing logistics, while ensuring the safety of personnel throughout the installation phase.

This case study examines a specific project where an offshore jacket required an unsymmetrical extension to accommodate a new Topside (much large than the original due to enhanced facilities). It explores the methodologies used to assess the structural implications, including computational modeling. Special attention is given to the design considerations that influenced the selection of installation methods and equipment.

Furthermore, the study discusses the role of interdisciplinary collaboration between Engineers, Yard, Operations, and Project Managers in overcoming these challenges. Effective communication and coordination were essential in aligning technical requirements with operational constraints, ensuring the successful execution of the project.

Ultimately, this case study provides valuable insights and lessons learned for future projects involving unsymmetrical structural modifications on offshore jackets. By addressing these challenges proactively and leveraging advanced engineering solutions, industry professionals can enhance the efficiency, safety, and sustainability of offshore infrastructure expansions. The critical aspects detailed in this paper can be used as a reference by any EPC Contractor involved in the brownfield modification of jackets.
Integrated Online Monitoring of Piping Loops with Predictive Solutions Applied During Project Execution
Authors: Sahoo Subrat
Published: November 2024

The Integrated ‘Online Monitoring of Piping Loops with Predictive Solutions’ is a new technology that enables digital integration of project piping data with end-to-end tracking of each piping loop, system and unit completion in real time. The system enables transparent visualization of critical piping parameters and provides actionable insights to project engineers in an online interactive dashboard. It thus eliminates the days spent on spreadsheet analysis in conventional mode.

The piping loop calculations and workflow are coded to formulate the predictive algorithms, hosted in a cloud-based platform for implementation. The system assimilates the current data from multiple sources and then the algorithms generate updated reports on work progress, constraints and completion trends. Online material hold-up report acts as a ready reckoner for fast-track decision making on procurement action and prioritizes material allocation. Computation of probabilistic loop-system-unit and overall project completion date provides proactive approach to evaluate the work performance with attributable reasons.

The innovation has resulted in better adherence to the project critical path through extensive monitoring of piping loop data, starting form material availability to readiness of piping systems for unit startup. There has been considerable saving in time for information flow, resources and man-days spent during project execution. As per the case study done, there has been a saving of nearly two-third man-days, exclusively for the monitoring and control of piping works. The results reaped in the implementation of this technology are encouraging and paves its way for implementation in other refinery and petrochemical projects involving piping works.

With implementation of this technology, projects shall be executed with a difference, particularly the critical piping works, at a faster pace that will benefit petroleum industry companies directly. All stakeholders in the project shall be well connected with the work status and garner benefits in terms of superior project performance, improved predictability and project closure within schedule & cost or even better.
Challenges in Accurate Detection of the Main Cause of Blockage: Case Studies
Authors: Vatandoost A. , Tohidi B. , Hoopanah M. , Meybodi M. K. , Mozaffar H. , Joonaki E.
Published: November 2024

Flow blockages in oil and gas pipelines are critical challenges that can lead to severe operational disruptions and significant costs of blockage removal and production loss. These blockages may arise from various sources, including wax deposition, asphaltene precipitation, gas hydrate formation, and ice. Accurately identifying the root cause of a blockage is essential for implementing effective remediation strategies. This paper presents a detailed study of the challenges associated with the accurate detection of blockages in oil and gas production systems, focusing on three real-world case studies.

The first case study examines a subsea pipeline where initial suspicions of hydrate formation were complicated by the presence of ice, requiring advanced thermodynamic modelling to accurately diagnose the issue. The second case study involves a subsea light oil pipeline where wax deposition, rather than the initially suspected hydrate formation, was identified as the root cause of the blockage after comprehensive phase equilibrium analysis. The third case study discusses a chemical process plant where a blockage in a Cold Box, initially attributed to hydrate formation, was later confirmed to be due to ice, as revealed by a combination of phase boundary analysis and methanol injection testing. The findings underscore the importance of precise phase equilibrium modelling and a comprehensive understanding of the system's thermodynamic conditions in diagnosing and resolving flow assurance problems.
B-Factor Variation in the Application of Traditional Decline Curve Analysis in Unconventional Wells
Authors: Alowaid Abdulrahman. M.
Published: November 2024

This paper focuses on investigating the applicability of using the traditional Arps Decline Curve Analysis (DCA) in unconventional resources characterized by rapid decline rates. The study focuses on the variability of the b-factor at different stages of the production life cycle and provides a sensitivity study on the magnitude of change the b-factor has on the Estimated Ultimate Recovery (EUR) of unconventional wells. The methodology adapted in this paper utilizes a reservoir simulator to run multiple DCA scenarios on an application example, providing both a quantitative and a visualized sensitivity analysis of EUR forecasts driven by multiple b-factor values. The production of the application example well was segmented to account for well clean-up post stimulation, and various operational changes throughout the life of the well. Traditional DCA was applied on the segments that most represented the general performance of the well, then benchmarked against an EUR value obtained using Rate Transient Analysis (RTA) utilizing the same reservoir simulator. During the process, the b-factor was varied to achieve the best fit with production data that yielded the lowest error. Two different scenarios were studied. The first scenario applied traditional DCA on all production data without segmentation, while the other scenario was applied on selected intervals where well behavior was considered relatively stable. Both scenarios underwent a sensitivity study estimating EUR at four different b-factor values: 0.82, 1.0, 1.5 and 2.0. It was observed, for the first scenario, that EUR estimates were far from accurate when benchmarked against RTA results, attributed to the initial rapid decline and multiple transitional periods during the production life cycle. On the other hand, for the second scenario, when only the representative segments of the well were accounted for, results were comparable to that of RTA, with a perfect match using a b-factor value of 1.5. The findings from this assessment were indicative in qualifying the traditional DCA for use in an unconventional setting provided that operating conditions are understood, and intervals considered in the forecast are filtered towards a representative well behavior. The novelty of this work lies in studying the application of traditional Arps DCA in unconventional hydrocarbon resources, generally perceived as a challenging approach due to rapid changes in well behavior. The study investigated and confirmed the feasibility of applying the traditional Arps DCA in unconventional wells through introducing an intermediate step, to segment the production life and analyzing the representative portion of the production life cycle.
Strategic Enhancement of Well Integrity in Ultra-Sour HPHT Wells: A Multidimensional Approach to Operational Resilience, Decarbonization, and Sustainable Equipment Efficacy
Authors: Yakoot M. S. , Valecillos D. E.
Published: November 2024

The integrity of downhole completion systems is paramount in high-risk wells characterized by Ultra-Sour conditions, extreme temperatures, and elevated pressures. This study proposes a proactive material testing initiative to fortify well integrity management strategies and mitigate the risk of catastrophic well integrity failures.

A comprehensive review of tubing materials for high-risk wells was conducted, revealing gaps in industry benchmarks and potential failure mechanisms. The proposed environmental material tests, adhering to NACE and ASTM standards, will assess the performance of the selected alloys in simulated operational conditions.

The material testing conducted revealed key findings. For tubing materials, the lab test duration was extended to align with industry standards. This addressed the previously limited duration and incorporated additional tests. The tests also considered higher environmental stress levels and uncertain factors.

The study on Elastomers revealed limitations in chemical compatibilities and temperatures, with recommendations for testing due to limited experience in such environments. The proposed minimum requirements include conducting material tests for an extended duration for both environments.

Rigorous testing and collaboration among specialists are instrumental in safeguarding the operational integrity of high-risk wells. The proposed testing initiative underscores the significance of a systematic approach to well integrity management, with special focus on high-profile wells and the harsh conditions they will encounter.
Hard-To-Abate Decarbonization Strategy Using Waste to Power (WTP) for Clean/Green Hydrogen Generation - Technoeconomic Case Study in Malaysia
Authors: Alias Nur Dalila , Zubir Ahmad Umair , Wazir M Aiman Afif M , Sariman Mior Zaiga , Othman M Hailmi
Published: November 2024

Limitation on reliable clean energy source to power the production of clean hydrogen has led the operator to come out with a business case for an onshore clean hydrogen production, using large-scale deployment of modular Organic Rankine Cycle (ORC) technology in converting industrial waste-heat to power (WTP) the Proton Exchanged Membrane (PEM) electrolyser. The primary objective of this study is to assess technical and commercial viability on large-scale deployment of modular Organic Rankine Cycle (ORC) technology in converting industrial waste-heat to power (WTP) at identified oil and gas plants within Malaysia.

A methodical selection criterion was used to identify suitable plants for assessment. Based on the steam and/or gas turbine heat generated from each plant, the estimation of power generation and its potential hydrogen generation was calculated. The operational parameters and commercial enveloped of the techno-commercial assessment were investigated in this study. These parameters include optimum number of ORC unit installed, tax pricing and Levelized Cost of Electricity (LCOE) as well as cost for hydrogen per kg was established for each scenario to achieve positive NPV. A comprehensive understanding of the commercial approach for this initiative to be implemented can be obtained with insights into the pathway of obtaining the best Levelized Cost of Hydrogen (LCOH) for each site.

The study shows maximum generation of 430mt of clean hydrogen can be generated per year, with maximum net power if 2.74 MW of clean electricity from the modular concept ORC technology. From the commercial analysis, the three (3) critical economic components identified from sensitivity study to make the economic positive are Carbon tax price, WACC % and CAPEX. One of the sites shows the most promising location for immediate implementation is with LCOH of 4USD, which is lower current hydrogen price i.e., 6-8 USD. The estimated payback period is 7 years with 3 mil USD NPV.

This study offers new insight on the best approach to obtain positive economic assessment within the hard-to-abate GHG emission in realizing the NZCE ambition. Setbacks and challenges will be discussed for the technology deployment to be well accepted within the industry, and recommendations on new financial elements and additional policies from various angles will be highlighted to boost large-scale decarbonization deployment within this region.