bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrity and Life Extension Assessment of Fixed Offshore Platforms
Authors: Shanker Vivek 
Published: November 2018

Abstract
A considerable number of fixed offshore platforms around the world have either already surpassed their design life or are approaching it. In the Middle East, more than 70% of the platforms are operating for more than 25 years; some of the assets are even operating for more than 40 years. High oil price and advancement in technology planned to increase the productivity of reservoirs have led to significant investment in terms of cost and resource to manage these assets. There is still a lot of recoverable oil and gas in the reservoirs hence, there is an increased need to extend the life of these facilities while managing the associated risk. This technical paper details a methodology for assessment of remaining life and details some of the degradation/ life extension issues for fixed offshore assets. As it is extremely difficult to cite all the degradation issues, some of the critical degradation issues based on experience and knowledge has been covered in this paper.
Use of Distance Protection in EHV Submarine Cable Network in Oil and Gas Industry
Authors: Mandal Prabuddha , Paul Raju , R. Kamal Faris , Takeiddine Oussama 
Published: November 2018

Abstract

Objective
Present trend around the world is to power up the Offshore Oil and Gas facilities by power from shore. The popular choice is to use Extra High Voltage submarine cables for handing these large quantities of power. The objective of this presentation is to focus and explain how the EHV cables and offshore facilities can be protected by Distance Protection.

Application of Distance Protection in Oil and Gas Industries
The efficient protection of the costly submarine cables and the offshore facilities from the electrical fault is extremely important. One of the most efficient ways to protect these types of electrical network is by using Distance Protection. EHV Interconnected grid network often involves bidirectional flow of power. If a fault in one interconnecting cable is not identified and isolated fast, it can cause substantial damage to the equipment and system. Also it is necessary to identify the faulty section correctly and ensuring the continuity of the service for the healthy section.

Benefits of Distance Protection in EHV Submarine Cable Network

Novelty focused on this paper
This paper provides comprehensive ideas about effective use of Distance Protection in EHV submarinecable network. This is utmost important because offshore oil and gas facilities are increasingly powered up from shore power using EHV submarine cable. Effective use of the Electrical System will both reduce downtime of the plant and save cost of operation.
Reactive Flow in Unconsolidated Sandstone: Application to Carbon Geosequestration
Authors: Yu Hongyan , Zhang Yihuai , Lebedev Maxim , Wang Zhenliang , Verrall Michael , Iglauer Stefan 
Published: November 2018

Abstract
Carbon dioxide (CO2) inject to the saline aquifers are general considered as the best candidates for large-scale storage and CO2 enhance oil recovery. The pore structure and permeability are changed by the fines release, migration in the initial stage of CO2 injection, which is of great importance for reservoir screening and injection design requires adequate understanding. We thus imaged an unconsolidated sandstone at reservoir condition before and after live brine injection in situ with micro-CT core flooding apparatus. We conclude that the pore structure of the unsolid high pores media rock can be significantly changed after live brine injection, although the porosity just have a small increased. Meanwhile, many fractures are generated in the quartz after live brine flush away. Specific surface area are quantified from micro CT scan image analysis to calculate the absolute permeability. The permeability is significantly improved due to the pore structure change which can improve CO2 infectivity, especially low-permeability reservoirs. The results of this study present a broad characterization of the mechanical properties in lacustrine shale and can therefore help optimize hydraulic fractured fundamental and enhanced gas recovery.
Enhancing Rock Mechanical Properties Estimation for Thin Beds Using Microresistivity Borehole Imaging Tool
Authors: Abbas Ahmed K. , Al-Hamad Nasser , Alsaba Mortadha 
Published: November 2018

Abstract
The knowledge of rock mechanical properties of the Zubair Formation is required to assure the success of future exploration and development of this reserves. Hence, high consistency and quality of these parameters could expressively increase the economic revenues derivable from the reservoir. The main objective of the current work is to generate a high-resolution continuous profile of the rock mechanical properties using microresistivity image log across the thin-bed intervals along with rock mechanical properties laboratory tests.
Retrieved core samples from the Zubair sandstone formation were run through extensive laboratory testing. The rock strength parameters were determined using consolidated drained (CD) multistage triaxial tests, while static elastic parameters were measured using consolidated drained (CD) triaxial tests. A petrophysical log enhancement technique was applied to achieve enhanced resolution neutron porosity log (with a vertical resolution of 0.2 in.). The critical components of this process were achieved high-resolution neutron porosity log from microresistivity image log. This log was directly utilized to calculate high-resolution rock mechanical property logs through porosity empirical correlations.
The resulting downscaled rock mechanical logs exhibited a reasonable degree of positive agreement between the estimated rock mechanical property logs (i.e., unconfined compressive strength (UCS), internal friction angle (φ), Young's modulus (E), Poisson's ratio (v), bulk modulus (K), and shear modulus (G)) and those acquired from the lab measurements, with 1.42%, 2.21%, 2.44%, 1.86%, 2.33%, and 1.92% absolute relative average difference (ARAD), respectively.
A Robust Surveillance and Optimization System for Unstable Flows in Offshore Gas Lifted Wells
Authors: Xiao Feng , Long Ted A. , Velamur Asokan Badri , El-Bakry Amr , Dani Neeraj R. , Holub Curtis , Poole Stephanie 
Published: November 2018

Abstract
In [1] and [2], an automated surveillance and optimization system has been developed and deployed to multiple offshore gas lifted assets. In this paper, we will present key enhancements to the system that improve the detection and management of unstable flows in offshore gas lifted wells. The enhanced system provides engineers and operators with a comprehensive solution for well flow surveillance and optimization.
Examples will be presented to show the successful implementation of quantitative slug scanning, gas lift multi-pointing diagnostics, and production surveillance for unstable flows. The slug scanning module supplements the pattern recognition and machine learning features in GLOWTM [1]. It scans the historical high-frequency pressure data, quantifies the amplitude and frequency of the cyclic oscillations, and then aggregates the data into bins of varying severity levels and a simple slugging index that can be used by operations for effective communication. To better understand gas lift multi-pointing that damages gas lift valves and harms production, transient flow models were developed with accurate modeling of gas lift valves, and then calibrated to historical well tests. Models accurately replicated the amplitude and frequency of pressures that may appear like hydrodynamic slugging, and revealed the open-and-close behaviors among multiple gas lift valves. Finally, the calibrated models were used to generate operational maps with different flow regimes, and such maps aid either asset staff or the GLOW™ system to optimize asset production while managing various types of unstable flows.
The developed system combines data-driven and physics-based approaches for online advisories, and utilizes a novel history matching procedure to enhance the model's predictive capability for complex well behaviors. In summary, the system provides a comprehensive, robust, and integrated set of tools that meets the surveillance and optimization needs of asset staff.
Study on Chemical Combination Formulations for High Temperature and High Salinity Carbonate Reservoirs
Authors: Zhang Fan , Yang Siyu , Ma Desheng , Lv Jianrong , Zhang Qun , Luo Wenli , Zhou Zhaohui , Tian Maozhang , Cai Hongyan 
Published: November 2018

Abstract
Chemical flooding technique is one of effective EOR (Enhanced Oil Recovery) ways to improve the oil recovery for mature oilfield in China. It is usually applied successfully in low temperature and low salinity sandstone reservoirs, such as Daqing oilfield (45°C, 5,100 mg/L) and in Changqing oilfield (50°C, 4,700 mg/L). However, it is great challenges to develop chemical EOR formulations for the high temperature and high salinity carbonate reservoir. On the one hand, the high temperature and high salinity condition may cause decomposition of the conventional chemical agents with poor long-term stability. On the other hand, the oil types and compositions, rock surface property and pore structure are all different for sandstone and carbonate reservoirs. Therefore, it is necessary and important to development low cost and high efficiency chemical formulations for high temperature and high salinity carbonate reservoirs.
In this paper, the betaine surfactant has been synthesized with cheap raw material of fatty acid, and its functional group of hydroxyl propyl sulfo hydrophilic group can improve the heat resistant and salt tolerant abilities; the star-polymer has been developed and the introduction of multi-functional monomer can inhibit the hydrolysis at high temperature and high salinity conditions. The new SP and ASP chemical formulations have been developed, and show good properties for high temperature and high salinity carbonate reservoir. The SP chemical formulations of the betaine and star-polymer show good heat resistant and salt tolerant capability. It could achieve ultra-low interfacial tension (less than 1.0×10-2mN/m) with temperature range from 30°C to 95°C, or salinity range from 5,000 mg/L to 220,000 mg/L.The effect of alkalis on interfacial tensions were studied, including Na2CO3, Na2SiO3, Na3PO4 and Na2B4O7. The ASP combination formulas with Na2B4O7 showed the best interfacial properties.The SP and ASP chemical formulations had good long term stability, and could maintain ultra-low IFT within 180 days, and the viscosity retention rates were greater than 90%.The dynamic adsorptions of this betaine were less than 1.0 mg/g rock, which can meet the requirement of field applications.After water flooding, the oil recoveries of the SP and ASP formulations increased about 22% (OOIP, Original Oil In Place) and the oil displacement efficiencies of chemical combination flooding reached to 75%.
Excellent properties of chemical formulations with the sulfobetaine and star-polymer indicate that this EOR technology can be applied in high temperature and high salinity carbonate reservoir with or without alkaline.
Verification of Shore Pull Anchor Pile Designed Using Simplified Method
Authors: Chen Zongrui , Tan Joshua , Huang Zhiwei , Ng Eng Bin 
Published: November 2018

Abstract
Shore pull anchor piles, which have been proven to be effective during pipeline installation, are designed using simplified method and basic structural analysis software in accordance with API RP-2GEO. This method simplifies the interaction between soil and pile using a series of non-linear soil springs along the pile shaft. In this paper, this simplified method is validated by using a refined finite element model and software which captures the soil and structural member interaction behaviours more accurately. The actual project site soil data is used in this paper for the validation. It is proven that the simplified method is capable of considering both geotechnical and structural capacities of the anchor pile and yields a design that is slightly conservative. Additionally, the simplified method is cost effective with regard to the analysis time and software cost. Parametric study such as soil stiffness and pile group effect are carried out to evaluate this simplified method and provide a guidance for the future design.
Verticalization of Sonic Logs Acquired in a Highly Deviated Well from Offshore Abu Dhabi
Authors: Van Kleef Franciscus , Verma Ravi , Brindle Frank , Dasgupta Suvodip , Donald Adam , Waqas Muhammad , Jocker Jeroen 
Published: November 2018

Abstract
Analysis of single-well sonic measurements to determine formation TI elastic parameters has traditionally been done using deterministic models with multiple, simplistic assumptions using only vertical or horizontal wells with flat structural dip. Here a probabilistic Bayesian-type inversion method is shown, which provides a flexible solution for any wellbore orientation solving for all five TI (transversely isotropic) parameters. This inversion is guided by prior information, which may be; core tests, borehole seismic survey results, offset well data or a public database.
The approach demonstrated here uses prior information of TI elastic properties to determine a consistent model at each depth. The inversion uses all sonic slownesses, compressional, fast and slow shear, as well as Stoneley shear and density to provide a continuous output of Thomsen's parameters and anisotropic mechanical properties at each depth. The results are consistent with offset well data as well as walk-above VSP velocities obtained in the same well. This technique was applied on a prominent and thick shale formation, which is present throughout UAE. Most of the wells drilled in UAE penetrate through this shale formation which is locally unstable for drilling, and is a prominent seismic reflector which directly overlies the reservoir. Accurate geomechanical characterization of this shale formation is critical as more wells are drilled at high angles with the application of full 3D finite-element modeling. Similarily the velocity models used for pre-stack depth migration (PSDM) and seismic well tie require accurate anisotropic TI parameters.
This workflow is new and applicable to any well orientation or structural dip and yields results that are consistent with offset sonic and borehole seismic measurements. Application of this method will have a profound impact on geophysical velocity and geomechanical model building methods and results.
Increased Reliability Using Asymmetrical Six Phase Induction Motor with Double Isolated Neutral
Authors: Mahmoud Elhussien 
Published: November 2018

Abstract
This work suggested the use of asymmetrical six phase induction motors instead of the conventional three phase motors for safety critical equipment to improve the overall system reliability. The rule of thumb is that a single fault should not be able to draw safety critical equipment out of service. Multi-phase machine in general and six phase machine in particular are able to continue running with one phase or more open circuit. The ability of multi-phase machines even to start under fault is another useful feature. Statistically, the main reason for losing one of the motor phases is the single open gate transistor fault. The defected phase is entirely disregarded, and then the current in the rest of phases which still functioning is optimized. Consequently, if minimum copper loss criterion is applied, the paid penalty is 50% additional losses that leads to motor derating, if not pre-designed with proper safety factor. This paper introduces an alternative post fault control strategy, which allows the usage of the entire healthy power electronic switches. An achievement of reducing the post fault increase in stator copper losses to 25% is realized.
A Thorough Investigation of PVT Data and Fluid Model for Giant Onshore Field, Hidden Lateral Trends Identified
Authors: Meziani Said , Tahir Sofiane , Al Hashemi Tayba 
Published: November 2018

Abstract
A best practice for PVT modeling and reliability analysis had been developed in order to characterize complex giant oil reservoir fluid model, oil in place assessment and to optimize full field development and management plan for EOR studies. This study builds on previous studies done by various parties but includes recent data and revised objectives. The primary objectives are: (1) to develop understanding of fluid properties across the reservoir and the influence of separator conditions on formation volume factor. (2) to generate PVT models for the reservoir’s units, accounting for lateral and vertical variations in properties and including the ability to predict the performance of gas injection schemes 3) to estimate the potential for asphaltene precipitation and recommend further work to improve the reliability of the reservoir simulation model. The study is divided into three phases: (1) Review of previous work and conduct Data QC of PVT data. (2) Establish lateral and areal PVT property trends and EoS fluid model. (3) Historical separator conditions issues, reserves and oil in place volumes.
The undertaken review of the previous EOS modeling studies had resulted in very different fluid models, each tailored slightly to focus on the specific priorities of the different studies.
In this study, the understanding of the fluid properties and their distribution within the reservoir has been achieved by: Using a thorough QC process which rejected unsuitable sample dataIdentifying C6+ mass content as the reliable indicator of the fluid compositionGenerating lateral and cross-section fluid property plots to identify regional differencesGenerating C6+ mass content versus depth plots to define compositional gradients and property trends.
Besides, analysis of the later MDT samples did not appear to have been used in identifying fluid property trends in any of the previous reviews. However, after Data QC, 18 PVT samples and reports were chosen to determine the compositional trends, 16 to determine property trends and 2 were identified for development of the EoS fluid model.
Therefore, vertical and lateral fluid property gradients have been identified consistent with the reservoir structural and stratigraphy model. The initial GORs in the layer-cake South/Central regions fall between Rsi= 816 scf/bbl at the top (7551 ft TVDss) down to Rsi=582 scf/bbl near the OWC (8245 ft TVDss). A similar trend is observed in the northern clinoform region, but 106.6 ft deeper. None of the earlier PVT studies had identified lateral trends within this complex reservoir. The main uncertainty in the fluid description is a lack of data below 7950 ft TVDss.
Design and Implementation Challenges for Extra High Voltage Gas Insulated Switchgear, Transformers and Subsea Cables at Offshore Platforms
Authors: Singh Kamaljit , Paul Raju , Kamal Faris , Takeiddine Ousama 
Published: November 2018

Abstract
Use of GIS to handle bulk power distribution has now become popular in offshore facilities due to the inherent advantage of a compact design. This paper highlights the challenges faced during GIS (and associated items) design based on experience on recent offshore projects and recommendations are proposed for methodical approach.
Handling of bulk power at Extra High Voltages poses numerous risks to both personnel as well as assets. This paper discusses the key design parameters, industry standards, interface requirements with transformers/subsea cables/platform structure and installation challenges.
Design engineer must be familiar with industry codes so that all design requirements, including proper selection of GIS configuration, are considered from early stages of the project. Omissions or oversight in this regard can impact the whole project.
Duration for design, procurement, installation and commissioning phases must be adequately accounted for. Specialist studies such as insulation coordination, very fast transient and touch potentials shall be carried out in addition to usual power system and arc flash studies.
Special consideration must be given in case of ring configuration with regard to logic diagrams and differential protection based on multiple CT locations and interconnections. Requirement of voltage selection scheme requires extensive wiring for synchronization function. Relay & CT selection shall be made considering required protection functions, interface with remote location and communication interface with Electrical Control & Monitoring System.
Interfaces with transformers and subsea cables shall be in strict compliance with industry standards such as IEC 62271-209 & 211. Requirement of additional surge arrestors shall be verified.
GIS exerts large static and dynamic forces on platform steel structure. These are also sensitive to forces during platform lifting and transportation. Support structure suitably shall be designed to mitigate the same.
This paper addresses concerns and interface requirements to be considered during design of GIS which will benefit the design engineers, Client personnel and Structural designers along with Project Management Team for safe and smooth execution.
Note: Data / details used in this paper are typical for the GIS handled by our Company that may vary based on the makes, models and ratings of GIS.
Commissioning Advanced Hoist Technologies to Mitigate Challenges Associated with Selective Workover Wells - A Revolutionary Approach
Authors: Shehhi Abdul Naser , Draz Alauddin Mohamed , Mahboob Tayyab Aziz , Agnihotri Praveen 
Published: November 2018

Abstract
Since 2014, ADNOC Onshore has utilized the potential of hoists and commissioned its operational significance, which allowed saving in rig time (4 – 6 rig years per year over 5 years business plan period) and generating a cost saving opportunity.
During this period we have faced many challenges and complications mainly during fishing operations which result in unsuccessful retrieval of the completion. Other factors and challenges that are commonly faced which require hoist intervention include: Old wells melted or corroded fish (Tubing + Casing)Reservoir Thammama Zone B wells (High water cut)Pushing the corroded fishComplete plug & abandonPartial plug & abandon required for future side trackWait on conventional rig arrival for intervention
Main challenge we faced during our business development phase is losing number of oil producing wells due to fishing complications, therefore the hoist rig is not capable to drill or sidetrack such wells. This will result in delaying requirements to restore production and meet the field quota objective since the wells should be scheduled to conventional Rig intervention. In order to optimize the hoists capability and performance to overcome this issue, we have to optimize based on priority and cost-effective selection criteria which will support to save the rig time & cost.
Various advantages of hoists applications experienced in the last 2 years in ADCO include: Running scraperCorrosion and Cement Bond LogsFaster rig move.Work-over well repairs for single completion (well-kill, pulling old completion and running new completion)Well preparation for re-entry and sidetrack plug back to top of 7'’ linerESP work-over. Pulled old ESP pumpsFishing and milling operationsRun 7 "tie back liners.Plug and abandon wells partially or fully Abandonment (inactive string).Spotting and squeezing cement plugs and squeeze off old perforations, changing THS and X-mass tree.Cure Sustainable Annulus Pressure (SAP)Pressure test casingRun completion & special completion such as gas lift mandrels
This paper presents methods of optimizing application of hoist in Abu Dhabi onshore fields by modifying enhanced well selection criteria based on the operation experiment and avoid production loss to sustain our field development plan. This implemented strategy benefit the optimization of number of workover wells which will increase in next five years scenarios, which in turn is expected to utilize rig cost savings. In addition, the new selection criteria will create "fit for purpose" solution to overcome these challenges of existing workover wells with less time and complication