bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microcarriers for Smart Release of Kinetic Hydrate Inhibitors Under Hydrate Formation Condition Inside Flowlines
Authors: Park Juwoon , Lee Sang Seok , Kim Shin-Hyun , Cho Dong-Woo , Kim Jong-Nam , Kim Hyunho , Seo Yutaek 
Published: March 2018

Abstract
Hydrate formation in subsea flowlines is one of the main concerns to safely transport the hydrocarbon fluids in the field of flow assurance. To prevent blockage of hydrate, thermodynamic hydrate inhibitors (THIs) have been injected into the subsea flowlines; however, the high injection amount of THIs may drive up operational expenditure (OPEX) with increasing water depth of oil and gas reservoirs. Kinetic hydrate inhibitors (KHIs) have been investigated as an alternative for few decades. In this study, microcapsules were designed using microfluidics concept for efficient release of KHIs at off-shore transport line of hydrocarbon and gas. Hydrate formation kinetics among four different systems, pure water, microcapsules containing poly vinyl caprolactam (PVCap), microcapsules without PVCap, and PVCap aqueous solution was investigated. The dispersive Raman was applied to understand hydrate formation on microcapsules with temperature change under static condition, and autoclave study also was employed to confirm the shear rate effect on microcapsule stability. From the both experiments, it was confirmed that release of KHI solution from microcapsules delayed the formation of hydrate at the target temperature and showed a similar efficacy comparing to the bulk KHI solution under turbulent condition. These results indicated the release of PVCap solution can be controlled by adjusting the membrane thickness of the microcarriers, which would provide operational flexibility to manage the risk of hydrate plug formation.
Evaluation of Reservoir Compaction and Geomechanical Related Risks Associated with Reservoir Production Using a Two-Way Coupled 4D Geomechanical Model for a Deep-Water Field in South East Asia
Authors: Younessi A. , Gui F. , Guises R. , Ngan A. , Nadzri S. , Zhou C. 
Published: March 2018

Abstract
A two-way coupled 4D geomechanical simulation was conducted for two adjacent deep-water fields, located in South East Asia, to investigate the impact of reservoir compaction over the production profile of the reservoirs. The results of the 4D geomechanical model were also used to calculate the stress path, surface subsidence and evaluate the risks associated with reservoir compaction over the life of the fields.
The 4D geomechanical model is a finite element (FE) model which was prepared from the structural geology model, surface seismic data, offset well geomechanical models and laboratory core tests. A Drucker-Prager/Cap material model was considered for the reservoir layers to calculate the compaction associated with pore collapse in high depletion zones. The 4D geomechanical model was two-way coupled with the reservoir dynamic simulation for predefined simulation steps over the life of the fields.
The impact of the reservoir compaction on the reservoir performance was evaluated by comparing the results of the coupled reservoir dynamic simulation against the uncoupled simulation. The results indicated that the impact of reservoir compaction and pore collapse is negligible for the expected level of depletion. The importance of conducting field-scale 4D geomechanical studies to have a better understanding of the reservoir response over the life of the field is demonstrated in this paper. The obtained results are particularly important for decision making in the field development planning stage.
The Value of Subsea Pipelines to Marine Biodiversity
Authors: Bond T. , Prince J. , Partridge J. C. , White D. , McLean D. L. 
Published: March 2018

Abstract
As offshore oil and gas infrastructure reaches the end of its operational life, owners and regulators will question the best options available to decommission it, with decisions requiring information about the potential ecological value of these structures and the environmental impact of their removal. Using a combination of existing industrial underwater Remotely Operated Vehicle video data and marine scientific remote stereo-video surveys, we describe and compare the fish assemblage on pipelines with those on the adjacent natural seafloor of the North West Shelf of Western Australia. Using these video observations of commercially important fish species on pipelines we were able to summarise the potential monetary value of commercial fish found on pipelines to commercial fisheries. Greater numbers of fish were observed on pipelines, compared with that seen on adjacent seafloor areas, and the monetary value of the fish found on the pipelines was estimated to be ca. six times greater than that of fish in surrounding areas lacking subsea infrastructure. Pipeline spans had high fish abundance, with fish appearing to utilise these spans as refuges. These results, together with allied assessments of marine growth on pipelines, suggest over the course of their operating lives, pipelines gain ecological and fishery value, enhancing the diversity and abundance of fish (including important commercial species) which can be translated to a monetary value for commercial fisheries. With an extensive array of pipeline infrastructure spread across the North West Shelf of Western Australia, knowledge of the ecological and fisheries value of subsea infrastructure is imperative to understanding the environmental and economical consequences of removing infrastructure as part of decommissioning. Where pipelines add value to marine biodiversity and fisheries in Western Australia, engineers and ecologists can work towards quantifying this value and preserving it – and potentially also enhancing it – via novel evidence-based abandonment strategies.
Surfactant Enhanced Waterflood SEW in Medium and Light Crude Oil Reservoirs
Authors: Quintero Lirio , Deighton Michael , Nguyen Henry , Willmott Eric , Kuznetsov Oleksandr V. , Tompkins Rose , Koh Heesong 
Published: March 2018

Abstract
Combinations of surfactant-polymer (SP) and alkali-surfactant-polymer (ASP) have proven, in the laboratory and the field, to be good methods for enhanced oil recovery (EOR). However, field implementation of these methods has not been widely materialized because of economics, especially at the recent crude oil prices.
A more economical EOR alternative is surfactant-enhanced waterflood (SEW), achieved by injecting a small amount of an appropriate surfactant with the injected water. This method could be applied in reservoirs containing medium and light crude oil (less than 5 cP viscosity at reservoir temperature) that are currently under waterflood, and has the economic advantage of minimal additional CAPEX investment for surface facilities.
The main target of this method is to mobilize residual oil trapped at pore throats after an extensive waterflood. Increasing the Ca improves the efficiency of crude oil displacement from injectors to producers.
The workflow of surfactant formulation selection involves a comprehensive sequence of studies that cover: Selection of candidate surfactants based on reservoir fluids properties and reservoir data conditions,Winsor systems phase behavior studies, IFT measurement,Evaluation of surfactant adsorption, andEvaluation of the formulation in porous media (sandpack and coreflood tests).
Parameters involved in the phase behavior studies included a broad range of salinity, hardness, temperature, surfactants ratio in blends, and the equivalent carbon number (EACN) of the evaluated crude oils. After screening and selecting formulations, waterflood simulation with the surfactant formulation is required to estimate the recovery factor, the production profile, and the economics of the project.
Optimal surfactant formulations determined by phase behavior studies using surfactants-brine-crude oil systems were obtained for selected reservoir conditions (temperature, injection water salinity, specific crude oils, and rock properties). These custom-made formulations were Winsor III microemulsions with very high oil solubilization, and an IFT equal to or lower than 10−3 mN/m.
Evaluation of the selected formulations at low surfactant concentrations (around 0.15% in injection water) in sandpack and coreflood tests resulted in approximately 30% additional oil recovery. The results demonstrate that a high percentage of additional oil could be recovered after waterflood by adding a small concentration of a properly selected surfactant formulation to the water injected into cores saturated with light crude oil.
This paper discusses some aspects of the experimental work involved in various phases of the process for selecting surfactant formulations that meet the requirements of ultra-low IFT that result in a high capillary number (Ca) and high recovery of low-viscosity residual medium and/or light crude oil left behind in reservoirs that have been produced by waterflood.
Optimizing Pore Pressure Prediction and Wellbore Stability in Drilling Ultra Deepwater Exploration Well
Authors: Maulana Herry , Ghosh Amitava , Paimin M. Razali , Abitalhah M Abiabhar 
Published: March 2018

Abstract
Optimum mud window prediction is very crucial for drilling any well. Accurate prediction of pore pressure, fracture pressure and other geomechanical parameters such as stresses, rock mechanical properties and finally the collapse pressure are key for designing the optimum mud window and effective well planning. Predrill predictions of pore pressure and wellbore stability become more and more challenging as the industry is moving to more and deeper and ultra-deep water wells. This is primarily becaue of lack of offset calibration together with inherent probrems and challenges associated with deep water environments.
A substantial amount of non-productive time (NPT) was associated during the initial phases of drilling campaigns in the Brunei deepwater. Accurate mud weight window prediction using regional scale pore pressure prediction and geomechanical modeling clearly demonstrated a significant reduction in nonproductive times over the different phases of drilling campaigns till date. This also includes a regular update or refinement of the model as soon as new data or information becomes available.
This paper presents some of the methodologies employed during well planning and construction with refinement along the way, resulting in improvement on pore pressure and geomechanical model. Our intent is to document and share our experiences and lessons learnt in Brunei deepwater well so that design and execution workflow can be continuously improved thus the well can be delivered safely and costeffectively.
Resonant Fluid Motion in the Narrow Gap between FLNG and LNG Carrier
Authors: Wolgamot Hugh , Chua Kie Hian , Feng Xingya , Li Binbin , Zhao Wenhua 
Published: March 2018

Abstract
Resonant fluid motion between an FLNG vessel and LNG carrier may play a critical role in side-by-side offloading operations in open seas. There have been many studies investigating aspects of gap resonance, a number of which have been focused on wider gaps (e.g. 12 m, 30 m) which may be less relevant to side-by-side offloading operations. In this study, we investigate resonant fluid motion in a narrow gap (i.e. 4 m) which is relevant to a typical side-by-side offloading configuration. Both numerical and wave basin tests are reported, and we consider round and square bilge cases. In the experiments, transient wave groups are used which avoids reflections from wave basin walls. Numerical models based on potential flow theory are developed using linear frequency domain, linear time domain and nonlinear time domain approaches. Unlike the majority of existing studies which have focused on reproduction of response amplitude operators, we attempt to reproduce the experimental time histories. This requires accuracy in simulating both amplitude and phase for each wave component, arguably providing a better guide as to whether the relevant physics has been captured in the models. In this study, vessels with identical shapes except for round and square bilges are investigated, and we find that different levels of damping beyond the radiation damping component are necessary to obtain good fits. The comparison between the numerical simulations and the experimental data reveals the difficulty in re-producing the time history of a resonant response with a combination of different resonant modes.
Semiclathrate Hydrate of Methane and Quaternary Ammonium Salts for Natural Gas Storage and Gas Separation
Authors: Gupta Pawan , Sangwai Jitendra S. 
Published: March 2018

Abstract
Methane is the smallest and cleanest burning fuel. It is found in the form of natural gas in which methane present in bulk but contains many impurities such as CO2, H2S which must be removed before being used by the consumer. In addition, it must be stored efficiently and transported economically. Gas hydrate is proposed to be one of the methods for storage, transportation and separation. A subclass of hydrate known as semiclathrate hydrate is capable of acting as a sieve for different sized gas molecules and have the capability to cohost smaller guest gases of specific size. Theses semiclathrate hydrate can be very useful for gas storage and multicomponent gas separation. In this work, a family of quaternary-ammonium salts such as tetra n-methyl/n-ethyl ammonium bromide (TMAB/TEAB) from the clan of tetra-alkyl ammonium bromide are examined at concentrations of 5wt% and 10 wt% for their phase stability along with the TBAB. Additionally, non-isothermal kinetics have been studied. Various experimental data have been obtained at different initial pressures of 8 MPa, 7.5 MPa, and 5.5 MPa to find out the influence of alkyl chain length on methane hydrate formation. It can be observed from experiential results that both TMAB and TEAB have shown thermodynamic inhibition as compared to TBAB. It can also be concluded from the phase stability curves that TBAB has more potential to aid in methane storage and separation than TMAB and TEAB at moderate pressure and temperature. An effect of carbon alkyl chain length is clearly seen on methane gas consumption. It has been witnessed that gas storage in hydrate increases with increase in the alkyl chain length of the salts. From this study, TBAB has found to be a more promising agent for gas processing and methane storage in the form of gas hydrate.
Identifying Shallow Water Flow in Offshore Malaysia Using Multicomponent Data and FWI Approach
Authors: Purnomo Eko Widi , Ghosh Deva Prasad 
Published: March 2018

Abstract
This paper presents the identify of the probably shallow water flow (SWF) conditions in offshore Malaysia by estimating and analyzing the compressional velocity (Vp), shear velocity (Vs), compressional attenuation (1/Qp), shear attenuation (1/Qs), and Density inverted from multicomponent seismic data using full waveform inversion (FWI). Vp, Vs, and Density were estimated through a join inversion of compressional PP and converted PS seismic data. The attenuation parameter is estimated from the quality factor Q which is derived using spectral ratio method. The estimated attenuation was used to build velocity model for inversion, based on the dispersion and attenuation theory. Kennett's full reflectivity inversion approach is used to achieve better velocity estimation especially at shallow (top-hole) zone where SWF typically occurs. Vp/Vs and Poisson's Ratio (rigidity) are then derived from inverted Vp, Vs and Density. The SWF is identified through some anomalies in inverted properties. A 2D multi-components seismic data from offshore Malaysia was used for study. The data is affected by gas clouds which result poor amplitude in some part of study area. The inversion result is considered well, showed by very good correlation between synthetic and real seismic data. Depth image of inverted properties showed good velocity estimation at shallow depth (0-500m). The inversion updated the initial velocity model quite well. Low density and anomalously low Vp and Vs were exhibited, indicated an unconsolidated sediments. Increasing Vp/Vs and Poisson's Ratio indicates that the unconsolidated sediments loss of cohesion due to the increase of pressure which is typical for over-pressured SWF sediment. However, it should be noted that, the seismic data used is an exploration (not a hazardous) data, and anomalous are found at relatively shallow depth (not more than 500 m in depth or about 400 ms in TWT). The inverted property's value may be varied for other data type or location.
Improvement of Field Operations with Automated Shortfall Management Based on Value
Authors: Mukhanov Akhan 
Published: March 2018

Abstract
This paper presents a holistic and repeatable workflow to assess in the economic context the value of decisions aimed at improving operations. This workflow focuses efforts on key root causes by considering the economic value of production volume shortfalls associated with downtimes. Also, the work reviews practical examples where business intelligence can lead to better decision making and project profitability. The workflow covers production engineering and operations, reserves planning, and economics.
The procedure involves capturing actual production; establishing performance targets, for instance, on the basis of a decline curve analysis; and logging nonproductive times according to a company-specific categorization. Next, you calculate an explained deferred production and then shortfall analysis. The detailed economic assessment considers various macro- and microeconomic aspects, in contrast to a basic evaluation with the working interest in the project and the oil price projection. Comparing target cash flows to actual cash flows enables identification of the incremental economic value, and this provides the information needed to create a value-driven action plan.
The suggested process highlights key reasons behind shortfalls, and the incremental economic analysis reveals them in the context of the project value. Consistent implementation of the workflow can aid in generating an effective action plan and tackling key root causes stemming from the variety of areas, including supply chain, design and innovation, and project execution.
When relating shortfall volumes to categorized nonproductive times, you can assess the potential improvement in the project value and profitability by comparing target and actual cash flows and reviewing economic indicators. Consideration of all economic aspects is an accurate approach towards quantifying the value of measures aimed at achieving additional volumes.
Automation of this workflow yields not only volume additions, but also a targeted improvement of business value, profitability, and other aspects important for stakeholders. The work contrasts in detail a full economic simulation to simple economics and classifies economic indicators. In addition to a workflow review, business intelligence is covered to demonstrate examples where this workflow brings value. The paper presents the need for holistic and streamlined decision-making guided with a business mindset.
Design and Evaluation of In-Situ Chemical Regeneration of Foam for Enhanced Oil Recovery EOR, 1D Foam Modelling- Malaysia's Offshore Oilfield
Authors: Sedaralit M Faizal , Saaid Ismail M. , Awang Mariyamni 
Published: March 2018

AbstractEnhanced Oil Recovery (EOR) is one of the focus area for Malaysia's offshore oilfield (Yassin, A. A. M.: 1988, Hamdan M. K. et al: 2005 and Samsudin Y. et al: 2005) to unlock remaining oil inside the reservoir for recovery beyond waterflood, 30% (PE Hanbook, 1992), and as of January 2005, the average oil RF for Malaysia producing oil field is standing at 33% derived from 17.0 Bstb STOIIP, Samsudin, Y. et al (2005). The Malaysia's EOR processes studied were involved chemical, gas flooding and microbial which it has considered having the most practical aspects based on the characteristics of the oil; for light oils, facilities readiness and bundant of produced water and seawater. The most optimum EOR process is proposed for water-alternating-gas (WAG), Wan-Mohamad W.N. et al (2005) and Selamat S. B. et al (2008) and Abu Bakar M. et al (2011). This paper, is to provide an alternative solution for the WAG process by introducing chemicals into both water and gas slugs to further enhance displacement efficiencies. The study requirement was based on, firstly is to further enchance WAG process, secondly, WAG investment protection and thirdly, in overcoming the existing process of foam assisted WAG (FAWAG) limitations such as foam callapse and short propagation distances, Blaker T. et al (1999), Skauge A. et al (2002) and Aarra M.G. et al (2002) from Snorre field pilot experience. This process is called as an in-situ-FAWAG or icFAWAG and discussion focus is on 1D coreflood modelling, which the production matching quality is guided material balance under hybrid condition between alkali, acid and foam flooding. The production is derived from 1-meter coreflood or displacemnet result and meanwhile, the formulation (icFAWAG) properties are obtained from fluid-fluid result, tested in one of Malaysia oil producing field, which the field is undergoing WAG development. The physics and chemistry reactions was modeled using 2016 CMG STAR simulator. Amongst the key finding are, (1) the alternative process of foam flooding, icFAWAG formulation is capable to achieve higher oil recovery, 82.5% than WAG and FAWAG and this contributed by sweep efficiencies improvement, stable foam front, additional &gt;5% RF, (2) reasonable material balance result was achieved based on average historical matching quality index (HMQI) result for oil, water, gas production and pressure, is at 0.5, and (3) Achieved fit-for-purpose icFAWAG modelling workflow and it consisted of 5 steps and the detail sub-workflows were established up-to level 3/4 descriptors. This workflow can be considered a hybrid process to cater 3 chemical reaction modelling; FAWAG (surfactant-gas), straight chemical flooding (A-SP) and acid.