bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Drag Anchor Trajectory With Both Shallow and Deep Anchor Behavior
Authors: Wu X , Chow Y. K. , Leung C. F 
Published: March 2016

Abstract
The uncertainty of drag anchor installation behavior is still an issue for drag anchor design. The existing method applying yield envelope for the anchor kinematic analysis ignored the shallow anchor behavior. Finite element analysis is conducted to study the shallow and deep anchor behavior under combined loading, which are characterized by yield envelopes for the kinematic analysis of anchor installation behavior. The impact of yield envelopes and shallow anchor behavior on the anchor kinematic performance is investigated. It is found that the largest difference in the predicted results such as anchor embedment depth using existing yield envelopes based on deep anchor behavior alone is about 43%. When shallow anchor behavior is considered, significant difference is shown. The predicted embedment depth taking account of shallow anchor behavior is shallower than that using only yield envelope for deep anchor behavior. The kinematic parameters are significantly influenced by the shallow anchor behavior. The current research improves the application of the yield envelope approach for drag anchor design and considers the influence of shallow anchor as well as deep anchor behavior on the anchor kinematic performance.
Six Years On: How the Global Industry has Risen to the Oil Spill Response Challenge
Authors: Flynn Steven A 
Published: March 2016

Abstract
The April 2010 Gulf of Mexico oil spill (Macondo), and the earlier Montara incident in Australia, prompted the entire industry to re-examine both the operational aspects of offshore activities, and their preparedness for an oil spill or well blowout.
To meet this challenge, the International Association of Oil and Gas Producers (IOGP) formed the Global Industry Response Group to translate the learning from the incident and subsequent response, into practical recommendations for the future. The oil and gas industry's international environmental association - IPIECA - managed the joint industry project (JIP) to progress the nineteen recommendations on emergency management and oil spill preparedness. Discreet projects were initiated, or other trade associations’ projects supported, to deliver a series of practical guidelines, tools and techniques for the industry.
This paper reviews the products from Phase I of the project and how they are changing the way that organisations plan for, and respond to, incidents. Progress on Phase II, which started in 2015, will also be presented, concentrating on incident management, oiled wildlife response, and satellite remote sensing technology for identifying and tracking spills.
The Joint Industry Project is comprehensively revising the way industry prepares for emergency response and has made several new techniques available. These range from methodologies such a Net Environmental Benefit Analysis (NEBA), through response technologies such as In-Situ Burning and Sub-Sea Dispersant Injection, to comprehensive emergency management tools such as the Common Operating Environment.
Design Considerations for Mitigating the Impact of Contaminants in Rich MEG on Monoethylene Glycol Recovery Unit MRU Performance
Authors: Latta T. M. , Palejwala A. A. , Tipson S. K. , Haigh N. P. 
Published: March 2016

Abstract
Supplying monoethylene glycol (MEG) to the wellhead is critical to gas production since interruption of MEG injection can lead to loss of well production due to the risk of hydrate plug formation in the subsea production infrastructure. Maintaining a high reliability of MEG supply is heavily dependent on good MEG Recovery Unit (MRU) performance.
This paper is applicable to subsea gas-condensate wells using MEG for hydrate inhibition and outlines a holistic approach towards diminishing the impact of contaminants in Rich MEG on MRU operating performance. An overview of the impact of various contaminants on MRU operation and how to deal with them will be discussed. Conceptual design considerations and practical applications as per vendor experience will be presented, as well as, examples of the impact of Rich MEG contaminants on MRU operation.
During the life of the gas reservoir, both short term events (e.g., completions fluid clean up, well start up, flow rate increases) and long term events (e.g., hydrocarbons entrainment, clay, silt, corrosion products, corrosion inhibitors, scale inhibitors, demulsifiers, formation water breakthrough) introduce contaminants into the Rich MEG that need to be considered in terms of impact on operational reliability of the MRU. If the effects of the contaminants result in reducing the reliability of the MRU to less than the desired design target, then they need to be removed or at least reduced in quantity to a level that permits the reliability target to be achieved.
Key groups that need to be involved in conjunction with the Client to ensure successful MRU design are Flow Assurance (wellhead chemistry and pipeline flow), Testing/Simulation facility and/or Vendor facility (study work, bench tests, and/or separation equipment piloting), Hydrocarbons Process Engineering (topsides or onshore processing facilities/MEG Regenerator and MEG Reclaimer design), and the MRU package vendor. Effective communication and collaboration between all parties in the early phases of the project is essential for managing these contaminants and maximizing MRU availability.
Geo-Mechanical Weakening of Limestone Due to Supercritical CO2 Injection
Authors: Zhang Yihuai , Sarmadivaleh Mohammad , Lebedev Maxim , Barifcani Ahmed , Rezaee Reza , Testamantia Nadia , Iglauer Stefan 
Published: March 2016

Abstract
CO2 injection into limestone reservoirs is a typical process in enhanced oil recovery operations, and it is also suggested for carbon geo-storage. However, CO2, together with water, is acidic and creates medium strength acid (pH value 3-4) at HP/HT (High Pressure/High Temperature) conditions. At the same time, it is well known that carbonates react and dissolve when exposed to acid. It can, therefore, be expected that the limestone properties change significantly during CO2 injection.
We thus hypothesized that limestone dissolution results in a substantial reduction of mechanical strength of the rock, with potential subsequent (mechanical) collapse of the rock – which would represent a major geohazard and could lead to land subsidence. We therefore conducted HP/HT core flooding tests on Savonnières limestone plugs; the plugs were thoroughly characterised with various experimental techniques (NMR-T2 response, porosity, dynamic permeability, acoustic response, x-ray computed tomography and rock-mechanical tests) before and after acid injection, i.e. exposure to supercritical CO2.
We indeed measured a significant dissolution of the rock and associated substantial mechanical weakening of the rock. Differently shaped wormholes formed, which strongly influenced the mechanical behaviour. Furthermore, a significant permeability increase was observed (up to 42.3% increase after injection), consistent with wormhole formation. We conclude that CO2 injection may pose a geohazard if the geo-mechanical strength of the reservoir is compromised.
AVO and Spectral Crossplot: A Case Study in the Malay Basin
Authors: Liu C. , Ghosh D. P. 
Published: March 2016

Abstract
Amplitude Varies with Offset (AVO) has been proven to be a useful technique in hydrocarbon exploration in many basins, including Malay Basin. The rocks in this younger Tertiary basin are generally soft, unconsolidated and are sensitive to fluid replacement and response as per Gassmann. Hence, quantitative AVO plays a significant role in hydrocarbon prediction (Ghosh et al., 2014). It was found that the vast majority (70%) of pay zone have Class II AVO types in the Peninsular Malay basin. However, wet sands also can give Class II AVO response in some cases, which causes ambiguous results.
In order to obtain more accurate results, we use spectra cross plot technique which combines AVO and spectral decomposition. This technique is a quick and useful way to discrimination between gas and wet sands (Ren et al. 2007). This study attempts to apply spectral cross plot technique in a field of Malay basin to improve the performance of AVO.
Deep Sea Laser Raman – Past, Present and Future Developments for In Situ Chemical Analysis and Applications
Authors: Kirkwood William J. 
Published: March 2016

Abstract
The Deep Ocean Raman In Situ Spectrometers (DORISS instruments) where developed at the Monterey Bay Aquarium Research Institute (MBARI) for the purposes of identifying compounds and studying in situ chemical reactions in a non-destructive manner while working with solids, liquids and gases. The approach taken began with modification of a standard bench top lab unit for use at sea to demonstrate feasibility. The second generation then solved several impediments to improved performance in the deep sea as well as development of additional tools to enhance capabilities. The third generation is now past the design process and in assembly for bench top testing to bring the fluorescence signal (noise) down to achieve a 19 fold increase in sensitivity. This allows the use of Raman on compounds that have high order organic compounds such as some oils and makes the detection of CO2 much easier. The high power approach in this system will enable faster operations for subsea mining.
The first instrument (DORISS I) was greatly successful and perform science experiments from Canadian waters to the Gulf of California looking at hydrates as well as higher order compounds, gas vents, phase boundaries and the ice cage structures entrapping methane as well as other gases. DORISS I was able to determine thermogenic versus biogenic methane for example. DORISS II increased sensitivity and performance by reducing the pressure effects on the optical system. Precision pointing devices were incorporated to look below the surface of some compounds as well as vertical and horizontal scanning of in situ chemical processes. A pore water probe was developed which allowed for very precise vertical profiling of sediments showing to properly access the methane content in the ocean bottom sediments which in general is greatly underestimated using tube cores and other sampling methods with shipboard analysis. The next generation DORISS, currently in development, promises to give gains in sensitivity as well as the ability to obtain Raman signatures from volatile compounds which would normally be unclassified due to fluorescence.
The application of Raman has revolutionized the medical industry and promises to do the same for oil & gas as well as subsea mining. With the trends in land based Raman spectrometers toward lower costs it can be argued that these techniques enable industry to employ a new tool and manage ocean resources more wisely.
Sensitivity of Smoothed-Particle Hydrodynamic Parameters on Slamming Simulations
Authors: Sasson Marcus , Chai Shuhong , Rafieshahraki Jalal , Jin Yuting 
Published: March 2016

Abstract
The oil and gas industry requires complex subsea infrastructure in order to develop offshore oil and gas fields. Upon installation, these components may encounter high slamming loads, stemming from impact with the water surface. This paper utilises Smoothed Particle Hydrodynamics to quantify these loads on a free-falling object. The investigation is interested in conducting a parameter study and determining the effect of varying simulation parameters on the prediction of slamming event kinematics and forces. The surface impact of a 2D freefalling wedge was simulated, with the results being compared to an experimental investigation. It was found through the parameters that particle resolution and the size of the SPH particle kernel are very important, whilst the diffusion terms do not play an important role. The latter is due to the very transient nature of slamming events, which do not allow sufficient time for diffusion in the domain. The close correlation of numerical and experimental results, along with the robustness and quick set up of SPH slamming simulations, indicate that SPH is a promising method of modelling more complicated slamming problems, which may involve more intricate impacting structures.
Structural Corrosion Modeling for Strength Assessment of Fixed Offshore Platforms for Life Extension Study
Authors: Sari Ali , Ramana Ekkirala , Nguyen Hieu , Arablouei Amir , Azimov Umid 
Published: March 2016

Abstract
The response of a fixed offshore platform subjected to extreme wind and wave loadings (lateral loads) under corrosion conditions is studied. The advanced simulation techniques to model corrosion damage and to perform nonlinear pushover analysis is outlined. The locations of corrosion perforations and thickness reductions can be identified based on an inspection report. A finite element model of the jacket is developed with a focus on these critical locations. The corrosion perforations can be represented as certain analytical shapes, for example, elliptical openings, at different locations, and sizes. The thickness reductions due to corrosion can be approximately modeled as shell elements with varying thickness. The platform capacity under extreme environmental loading is characterized in terms of the platform's Reserve Strength Ratio (RSR). Thus, a non-linear pushover analysis is performed to assess the strength of the corroded structure by quantifying the Reserve Strength Ratio (RSR) value. The nonlinear pushover analysis is carried out using the general finite element package Abaqus.
Remediation of Well Impaired by Complex Organic Deposits Embedded with Naphthenate and Contaminated with Inorganics
Authors: Mohamed Anwarudin Saidu , Alian Sima Sheykh , Singh Jasvinder , Singh Rajindar , Goyal Arvindkumar , Munainni Gurunathan 
Published: March 2016

Abstract
Mature oil wells with high water cut suffer from solids deposition with an agglomeration of species like asphaltenes, wax, resin, metal naphthenates, inorganic scale and formation fines etc. Such solids generally accumulate around the well bore, in the production tubing and surface facilities. These deposits can also change the formation wettability towards oil wet. Solid deposition and wettability change create additional resistance to flow in producing wells leading to decline in rate of oil production. Generally in such cases the production decline can be very steep.
Analysis of some deposit samples from such producing wells in Malaysia shows the presence of macro and micro-crystalline waxes, asphaltenes, resins, metal naphthenates, inorganic scale, sand, silt, clay etc. in varying concentrations. The presence of naphthenate deposits is a new problem in many oil wells. The deposition of naphthenates along with other organic and inorganic components create skin and a restriction to flow. This complex gamut of such deposits, especially naphthenates does not dissolve/disperse completely with solvent followed by conventional acid treatment. This often results in acid induced sludges. Use of solvents, acid blends and other composite fluids is reported to remediate such problems with varying degree of success.
To address the deposit problems induced by naphthenates, an effective micro-emulsion consisting of solvents, surfactants, and inhibited acid etc. has been developed to effectively remove organics. The objective of such treatment is to provide dissolution/dispersion of organics that leads to deeper penetration into near wellbore with no sludge formation.
This paper presents laboratory and field data on a treated well from Sarawak which showed significant enhancement in oil production. The well was completed with a gravel screen and exhibited very low productivity from its initial production due to combined completion skin and formation damage. Significant increase of the production rate (from average of 50 bopd to 900 bopd) was observed after the treatment.
Neural Network Based Adaptive Control for a Thruster Assisted Mooring Vessel in Mooring Line Failure
Authors: Kwon H. , Kim N. 
Published: March 2016

Abstract
Classification society standard requires redundancy in floating vessels with thruster assisted mooring system, but it is not avoidable for floating vessels to drive off in an instant of a mooring line failure such as line breakage or dragging of anchor. Such a failure might cause serious hazard by consequent mooring line breakages. Agile response of assisted thrusters in case of mooring line failure is essential to minimize excursion and prevent consequent hazard. Conventional controller based on the moored vessel's intact dynamics is not proper to handle the configuration and dynamic characteristic changed by a failure and it might cause time delay to be stable and recover the vessel's position. This paper presents a neural network based adaptive control method that guarantees stable control performance even with mooring line failure. Neural network based adaptive control can achieve control objectives in the presence of modeling uncertainty. The advantage of the proposed control method is that the controller does not require dynamical model of failure condition. In the case of mooring line failure, the neural network regards configuration change as added modeling uncertainty. Numerical simulations of a semi-submersible type vessel were performed for the validation. Proposed method has robust control performance in the presence of a failure. The results show that the neural network based adaptive control method enables a vessel to response timely and recover the position effectively.
Data Integration and Reservoir Characterization to Understand Water Movement during Production in a Mature Gas Field, Luconia Province, Malaysia
Authors: Chiew Edwin , Warrlich Georg M. D. , Binda Andrea , Adams Erwin W. 
Published: March 2016

Abstract
Interdisciplinary data integration is key to top-quartile Well Reservoir Field Management (WRFM). In our field case, results from annual well-intervention activities were analyzed and integrated with production data and the regional-to-reservoir scale geological understanding of this carbonate gas field to improve the delineation of the gas-water contact (GWC) development and allow timely water shut off (WSO) at the optimal depths in the reservoir, while at the same time utilizing reservoir heterogeneities (such as horizontal baffles) to delay water breakthrough (WBT).
The carbonate gas field is located in Central Luconia, with over 30 years of production history. Some wells have seen significant WBT and the field experiences an uneven rise of the GWC with production. To improve the GWC prediction, reservoir characterization work was aimed to capture the key heterogeneities that matter for flow: baffles vs. high-permeability conduits to water movement. As such, geological characterization focused on low-porosity zone correlation and platform margin & slope deposit interpretation along the flanks of the field, respectively.
In order to understand the baffling nature of rock facies to fluid flow, low porosity zones were mapped across the field initially on seismic and well logs. In core, two types of low-porosity layers were observed: flooding- and exposure-related low-porosity layers. Both types of low-porosity layers show similar log signatures, but behave very differently during production (Warrlich et al., 2014). Flooding-related low-porosity layers are extensive and composed of fine-grained, argillaceous material. They form baffles that are capable of delaying water rise for several years. Exposure-related low-porosity layers, on the other hand, are composed of cemented, brittle limestones and are often associated with karsts and fractures. Their baffling capacity is limited and can even act as high-permeability conduits speeding up the GWC rise, when connected to karst dissolution.
Platform margin and depositional-slope deposits were observed on seismic in the flanks of the field. These are inclined beds of potentially permeable deposits that have been shed from the carbonate platform during sea-level highstands. Commonly the strongest progradation and best-developed slope deposits are located on the leeward side, i.e. platform-top shedding and transport in the main paleo-current direction. Due to their inclined nature, they dip directly into the water leg and thus can act as conduits for water during production.
Optimum Design of Multi-Body Floating Logistics Terminal
Authors: Wada R. , Mondal R. , Kamizawa K. , Takagi K. 
Published: March 2016

Abstract
In the present study, concept of a floating logistic terminal (FLT) is evolved using three floats. Emphasis is given on the best configuration of the structures and the reduction of motion of the floating terminal. We present the preliminary numerical and experimental studies of response amplitude operator (RAO) for heave, roll and pitch. The analysis is executed for three different configurations of the floating structures. Though, the application area is for shallow water, however the deep water case is also studied. The motion characteristics are studied for head waves as well as oblique waves. The results obtained from two different methods are compared.
Permanent Mooring Anchors for Floating Facilities - A Review and Selection Process for Carbonate Soils
Authors: Kennedy J. , Maconochie A. J 
Published: March 2016

Abstract
The use of conventional catenary moorings provide a viable and cost effective anchoring system for the large FLNG field developments proposed along the deeper water regions offshore the North Western coast of Australia. The design of the catenary mooring systems and the anchors are highly dependent on the water depth and the seabed soil conditions. However, the extreme environmental loads associated with these deep water developments dominate the mooring anchor design with anchors required to sustain significant vertical and horizontal loads. Selection of an appropriate anchor design therefore becomes an intensive exercise involving many disciplines including geotechnical, structural and installation engineering to ensure the appropriate and optimum anchor type is selected.
Due to the size and weight of some conventional anchor designs e.g. driven piles, suction anchors etc., over the last 10 years, a number of new anchor concepts have been proposed and developed including DEPLAs, SEPLAs, VLAs, Torpedo piles etc. to improve anchor installability and reduce costs. However, when considering extreme FLNG mooring loads technical challenges and uncertainties still remain for several of these concepts.
Further considerable complexity is added to the anchor design and selection process given the wide range and nature of the seabed soils encountered in the North Western shelf which typically comprise carbonate soils.
A methodical anchor concept screening process has been developed in this paper to review and rate various mooring anchor concepts for FLNG developments, although the process can also be applied to alternative floating facilities and mooring systems such as FPSO developments. The process considers geotechnical, structural and installation drivers that impact on the design to determine the most practical and technically viable solution for the water depth, design loads and soil conditions. As part of a mooring anchor project the results of the screening process can be presented at an early stage in the mooring anchor design for discussion and can act as a starting point to identify the major risks, help optimize the anchor design and highlight areas that require further analyses and testing.