bluuebunny/crossref_metadata_2025 huggingface dataset:
Ergogenic effects of phosphatidylserine alone and combined with branched-chain amino acids in trained rats
Authors: Guimarães J. Costa , Cordeiro A.L. , Borbely K.S. Cruz , de Oliveira Barreto E. , Scariot P.P. Menezes , Spineli H. , Gobatto C.A. , de Araujo G.G.
Published: March 2022

Acute phosphatidylserine (PS) or branched-chain amino acids (BCAA) supplements alone may have an adrenocorticotropic hormone, cortisol suppressive effect and increase the testosterone/cortisol ratio, but the associated effect of these supplements during a period of high-intensity physical stress is not yet known. The study investigated the effects of chronic PS supplementation alone and combined with BCAA during high-intensity interval training (HIIT) on training volume tolerance, anabolic-catabolic balance and stress biomarkers in rats. Thirty-three rats were separated into: placebo (PLA, n=11), PS alone (n=11) and combined with BCAA (PSBCAA, n=11). Groups performed swimming sessions of HIIT (5 series × 1 min × 1 min recovery; external load equivalent to 13% of body mass) and nine recovery sessions of moderate-intensity training (30 min at 5% of body mass) alternately. One-way ANOVA was used to compare biochemical variables and two-way ANOVA was calculated to compare training volume. Training volume performed (TVP) was higher in first, fourth, fifth, sixth, and eighth HIIT sessions in the PS group in comparison to PLA (P<0.05). TVP was higher in the fourth session in PSBCAA compared to PLA. There were no differences in TVP during the sessions between PS and BCAA groups. Creatine kinase (CK) was lower in PSBCAA in comparison to PS alone (P=0.03) and PLA (P=0.04) after the experimental period. Testosterone concentration was enhanced in PSBCAA group compared to PLA (P=0.01); testosterone/corticosterone ratio was higher in PSBCAA compared to PS (P=0.05) and PLA (P=0.004) after protocol. PS combined with BCAA increases testosterone concentration and testosterone/corticosterone ratio, demonstrating an enhancement of anabolic state in trained rats.
Effect of subjective tool based aerobic exercise on pulmonary functions in patients with type 2 diabetes mellitus – a feasibility RCT
Authors: Saini M. , Kaur J.
Published: March 2022

Literature has proved the benefit of exercise on pulmonary functions among the patients with type 2 diabetes mellitus (T2DM). However, objective tools of exercise intensity prescription have been used in previous trials. The trials to explore the effectiveness of subjective tools-based exercise on pulmonary functions among these patients are scarce. The purpose of this study was to explore the feasibility of subjective tools-based exercise among patients with T2DM. Another objective was to see the effectiveness of this kind of exercise on pulmonary functions among patients with T2DM. 49 patients were randomly allotted to three groups, talk test group (TTG, n=16); rating of perceived exertion group (RPEG, n=16); and control group (CG, n=17). Subjects were evaluated for five progression criteria. The intervention period for the groups was 8 weeks. Recruitment and retention rate was 62.82 and 75.5%, respectively. Adherence rate was 67.34% and 58.91% for supervised and unsupervised sessions, respectively. 78.38% of the patients were available for post-intervention outcome evaluation. A significant increase in pulmonary functions in both the experimental groups (P=0.00) was found after 8 weeks of training. This study provides evidence that a trial of this nature is feasible with a few amendments in methodology. Additionally, the study also concluded that the subjective tool based aerobic exercise may be effective in improving pulmonary functions among patients with T2DM. Trial registration at Clinical Trial Registry-India: CTRI/2019/02/017531.
On a time-space fractional diffusion equation with a semilinear source of exponential type
Authors: Nguyen Anh Tuan , Yang Chao
Published: March 2022

In the current paper, we are concerned with the existence and uniqueness of mild solutions to a Cauchy problem involving a time-space fractional diffusion equation with an exponential semilinear source. By using the iteration method and some $ L^p-L^q $-type estimates of fundamental solutions associated with the Mittag-Leffler function, we study the well-posedness of the problem in two different cases corresponding to two assumptions on the Cauchy data. On the one hand, when considering initial data in $ L^p({\mathbb{R}}^N)\cap L^\infty({\mathbb{R}}^N) $, the problem possesses a local-in-time solution. On the other hand, we obtain a global existence result for a mild solution with small data in an Orlicz space.
Eternal universe in dynamic equilibrium
Authors: Šorli Amrit , Čelan Štefan , Jafari Saeid , Fiscaletti Davide , Brzo Aram Bahroz
Published: March 2022

Big Bang cosmology is problematic because of the hypothetical beginning that is not in accord with the conservation of energy. Furthermore, it is based on the interpretation of astronomical data that is questionable. Cosmic microwave background radiation (CMB) is not direct proof of
the existence of the recombination period in some remote physical past. Cosmological redshift can be seen as the “tired light effect” proposed by Zwicky [Proc. Natl. Acad. Sci. U. S. A. 15, 773 (1929)]. Based on direct reading of astronomical data, here we introduce a model
of the universe, which predicts that in Active Galactic Nuclei (AGN) in the centers of galaxies, matter is transforming back into the elementary particles in the form of huge jets that are throwing elementary particles into the intergalactic space and so creating “fresh material”
for new stars formation. This process occurring in AGNs, invoked by our model, has no beginning, and it is in permanent dynamic equilibrium, non-created, which means the universe is eternal. The entropy of the universe as a whole is constant.
Coordinates in general relativity: Frequency shift
Authors: Lin Wenbin
Published: March 2022

It is easily shown that the theoretical calculations for the frequency shift in the Schwarzschild spacetime under the standard, isotropic, and harmonic coordinates are different. Since the relations between these coordinates and the observer's reference frame are not clear, it remains
an unsolved problem to make the coordinate-independent prediction for the frequency shift when the light comes from the extremely strong gravitational fields, for example, the light emitter is near to the horizon of black holes or the surface of neutron stars.
Newtonian gravitation derived by the elastic energy in the Earth’s interior
Authors: Kohiyama Noboru
Published: March 2022

The pressure distribution in the Earth’s interior is expressed using the Adams‐Williamson equation. The elastic energy is stored inside the Earth by the pressure. The Newtonian gravitation is expressed by this energy.
A Phenetic Approach to Selected Variants of Arabic and Aramaic Scripts
Authors: Salman Osama A. , Hosszú Gábor
Published: March 2022

This paper aims to introduce the phenetic method for processing paleographical datasets and evaluating their similarity relationships. The presented numerical taxonomic method was applied for selected varieties of the Arabic and Aramaic scripts. The phenetic model was evaluated by hierarchical clustering and—after applying multidimensional scaling—a centroid-based clustering method. The hierarchical clustering results were presented as dendrograms (phenograms), while the centroid-based results were given in 2- and 3-dimensional Cartesian coordinate systems. The obtained results demonstrate that the numerical taxonomy's phenetic approach is useful in describing the distances between different writing systems. The long-term goal of the research is to apply machine learning tools to clarify the relationships between the large number of Aramaic and Arabic script variants. This study belongs to the field of pattern evolution, in which machine learning methods of biological evolution are used to model evolving patterns (such as writing systems) over time.
Convolutional Locality-Sensitive Dictionary Learning for Facial Expressions Detection
Authors: Ghansah Benjamin
Published: March 2022

Facial Expression (FE) detection is a popular research area, particularly in the field of Image Classification, Pattern Recognition and Computer Vision. Sparse Representation (SR) and Dictionary Learning (DL) have significantly enhanced the classification performance of image recognition and also resolved the problem of the nonlinear distribution of face images and its implementation with DL. However, the locality structure of face image data containing more discriminative information, which is very critical for classification has not been fully explored by state-of-the-art existing SR-based approaches. Furthermore, similar coding results between test samples and neighboring training data, contained in the feature space are not being fully realized from the image features with similar image categorizations, to effectively capture the embedded discriminative information. In an attempt to resolve the forgoing issues, we propose a novel DL method, Convolutional locality-sensitive Dictionary Learning (CLSDL) for Facial Expression detection.
Attention-Based Convolution Bidirectional Recurrent Neural Network for Sentiment Analysis
Authors: Sivakumar Soubraylu , Haritha D.  , Sree Ram N.  , Kumar Naveen , Rama Krishna G.  , Dinesh Kumar A.
Published: March 2022

Customer conveys their opinion in natural language about an entity. Applying sentiment analysis to those reviews is a very complex task. The significance terms that are influencing the polarity of a review are not examined. The terms that are having contextual meaning are not recognized which are present across multiple sentences in a review. To address the above two issues, we have proposed an Attention-based Convolution Bi-directional Recurrent Neural Network (ACBRNN). In this model, two convolution layer captures phrase-level feature, while Self-Attention in the middle assigns high weight to the significant terms and Bi-directional GRU performs a conceptual scanning of review through forward and backward direction. We have conducted four different experiments viz., Unidirectional, Bidirectional, Hybrid and Proposed model on IMDB dataset to show the significance of the proposed model. The proposed model has obtained an F1 score of 87.94% on IMDB dataset which is 5.41% higher than CNN. Thus the proposed architecture performs well while comparing with all other baseline models.
Novel Hybrid Algorithms for a Single Machine Scheduling Problem With an Overtime Constraint
Authors: Latthawanichphan Jakkrit , Sukkerd Watcharapan , Songserm Watchara , Wuttipornpun Teeradej
Published: March 2022

In this paper, a single machine scheduling problem with an overtime constraint is studied. The objective is to minimise the total penalty cost defined as the sum of tardy, early, and overtime costs. Three novel hybrid algorithms that hybridise a new heuristic with genetic algorithm, tabu search, and simulated annealing, referred to as GAH, TSH, and SAH, are proposed to solve the problem. In each iteration of the proposed hybrid algorithms, a given metaheuristic is used to determine a sequence of jobs, whereas a new heuristic is used to minimise the total penalty cost of the sequence using a backward-forward scheduling technique and a penalty cost trade-off process. Exhaustive experiments are conducted to evaluate the effectiveness of the proposed hybrid algorithms. For medium-scale and large-scale problems, TSH with its best common parameter setting referred to as TSH2, clearly outperforms the exact algorithm, whereas both algorithms can obtain the optimal solution for small-scale problems. In addition, the computational time of TSH2 is in an acceptable range for the planner.
The Role of Information Systems and Organizational Communication Culture in Transforming a Business Function
Authors: Lee Joonghee
Published: March 2022

This research explores the transformational consequence of information systems (IS), and the moderating impact of organizational communication culture in human resource management (HRM). This study used panel data from 2011 to 2015 in South Korea for this investigation. This study found that using IS for HRM is positively associated with the shift of HRM’s position from administrative workers to strategic partners. Also, the positive moderation effect of the open communication culture was demonstrated.
Synthesis and Characterization of Rice Straw Derived Nanoscale Biochar-Based Fertilizer Infused with Nutrients
Authors: Ramos Nerissa C. , Abon John Eric O. , Pascual Kristine S. , Bulatao Rodel M. , Monserate Juvy J. , Diaz Jose Mario A.
Published: March 2022

Biochar research has been gaining recent interest in agricultural applications because of its use as a soil amendment. Biochar is a porous carbonaceous solid produced from heat in the absence of any introduced oxygen (pyrolysis). It has relatively high surface area and slow-release properties that makes it suitable for fertilizer formulation. In this study, rice straw is used for biochar production using modified carbonizer at 600-650°C temperature range. After synthesis in the nanoscale level, the biochar produced was infused with nutrients such as nitrogen, phosphorus, potassium and zinc. The morphological characteristics were studied using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and energy dispersive Xray spectrometry (EDS). Nutrients were incorporated in the biochar and analysis revealed concentrations of 4.96% N, 3.46% P, 2.25% K, and 10.90% OM. The nanoscale biochar-based fertilizer was then applied into rice production. Rice grown in soil amended with nanoscale biochar-based fertilizer showed higher yield than control treatments but with comparable result from the inorganic fertilizer treatments. This implies that biochar can be used as an alternative to chemical based fertilizer when infused with the essential nutrients needed by plants. Furthermore, the soil amended with the nanoscale biochar-based fertilizer was also found to have a higher nutrient and organic matter content after harvest. Therefore, it could preserve the soil fertility which is beneficial in the long term.
Inkjet Printing of UHF RFID Antennas Using Silver and Gold Inks
Authors: Hamoy Fatimah Nasra P. , Romero Diana G. , Macaraig Lea Cristina D. , Enriquez Erwin P.
Published: March 2022

Compared with current methods, additive manufacturing processes could offer a more environment-friendly and cost-effective solution in producing long lasting RFID tags for identification and sensing applications. In this work we report the fabrication of UHF RFID antennas by inkjet printing on a flexible substrate. Silver and gold were chosen as ink materials since they are more resistant to weathering than other metals, particularly for applications that require long-term reusability. We compared the print performance of a commercial silver ink and our lab-developed gold nanoparticle (AuNP) ink on polyethylene naphthalate. The printing process for each ink is described using an adopted loop antenna design optimized for 866-868 MHz frequency range. Assembled passive and battery-assisted RFID tags using single-and double-layer sintered, printed antennas coupled with a readable UHF RFID chip showed tolerable detection distances using a commercial compact reader (with short read range specifications). Additionally, we observed a more consistent print behavior and quality, and consequently longer read ranges for the gold antennas (up to 40 cm with battery). Furthermore, the silver antennas oxidized over time resulting in decreased read ranges. Overall, our results show the viability of a printable gold RFID antenna with a tag working range that may be fit for close range non-contact reading.
Detection of Nitrogen in Layer-by-Layer Polymeric Films by Energy Dispersive X-Ray Spectroscopy
Authors: Castillo Virgil Christian G. , Limpoco Ted , Enriquez Erwin P.
Published: March 2022

Scanning electron microscopy - energy dispersive X-ray spectrometry (SEM-EDS) is an elemental analysis technique widely used in various fields to identify any element in the periodic table except H, He and Li. It can be a quick way to assess the response of sensing films before deposition on sensing devices. Sensing films are usually organic thin films, but quantitative analysis of light elements and thin films is not recommended for SEM-EDS due to its limitations. In this study, SEM-EDS analysis of nitrogen in layer-by-layer polymeric thin film was optimized. The films were analyzed containing nitrogen in the form of nitrate counterions or as part of the repeat unit of the polymer. The build-up of the layer was verified by thickness measurement using atomic force microscopy. The results show that the limit for nitrogen concentration detection using nitrates was 2% by mass. Below this concentration, nitrogen content had no quantifiable response in either calculated nitrogen concentration by standardless correction methods or intensity of N Kα X-ray line. However, by adding nitrate ions to a film that already contains nitrogen in its structure the concentration was raised to 13.75%. In the range of 9.63 to 13.75%, a nonlinear response was observed using calculated nitrogen concentration while the response was linear with intensity of N Kα.
Facile Synthesis and Characterization of Sea Urchin ZnO Nanostructures via Sol-Gel Method
Authors: Arevalo Benyl John A. , Doronio Jocelyn P. , Pondoc Dionesio C. , Monserate Juvy J.
Published: March 2022

Sea urchin zinc oxide (SU-ZnO) nanostructures were successfully synthesized using the sol-gel method and characterized by various analytical techniques. The present work reports a facile and straightforward route for synthesizing sea urchin ZnO nanostructures consisted of self-assembled ZnO nanorods with sharp tips yielding the sea urchin-like shape. The SU-ZnO nanostructures were characterized using Scanning electron microscopy and Energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared (FTIR) spectroscopy, particle size analysis (dynamic light scattering technique), and ultraviolet-visible (UV-vis) spectroscopy. The result of energy dispersive X-ray spectroscopy shows that the SU-ZnO nanostructure contains 77.30% zinc and 22.70% oxygen content. Scanning electron microscopy shows that the synthesized ZnO exhibits a sea urchin-like structure with a homogeneous and consistent size. FTIR spectroscopy confirmed the structural features and functional groups that are present in ZnO nanostructures. The particle size analysis shows that the synthesized SU-ZnO nanostructures have an average particle size of 812.62 ± 55.92 nm. The growth of SU-ZnO nanostructure was also investigated by recording the UV-Vis absorption spectra at different reaction times.
Microstructural and Nanostructural Characteristics of MSe2 (M= Nb, Mo, Ta and W) Single Crystals
Authors: Vaidya Rajiv D. , Dave Mehul S. , Patel Kaushik R.
Published: March 2022

The single crystals of MSe2 (M = Nb, Mo, Ta and W) were grown through vapour phase by screw dislocation mechanism. The development of stresses by variation in high temperature of the dual zones involved, resulting into slip lines and vapour inclusion, might possibly lead to generation of favourable screw dislocation sites. The morphology of as grown crystals has been studied by TEM. From this analysis, the general rule that nanoparticles of compounds, crystallizing in layered structures tend to form closed shapes. The formation of closed shapes reduces the number of dangling bonds on the periphery of the layers.
Overcoming Geohazard Challenges During Installation of Shallow Water Dynamic Risers
Authors: Mearns Paul , Hafidz Shuhaimi Mohd , Yen Kienmin
Published: March 2022

A typical brown field will undergo several development, repair or maintenance campaigns over its life cycle to either increase or de-risk existing productivity. This includes replacement of faulty existing assets, which pose a risk to continued production. Several challenges typically exist when working within brown field environments, chiefly of which can be the requirement to work within the constraints of existing live assets. In this paper, the challenges faced during replacement of dynamic umbilicals tied back to a Floating Production Unit (FPU) at shallow water depths alongside live risers, coupled with a coral outcrop (otherwise known as a geohazard) are discussed.

Rigorous engineering was carried out during the initial riser replacement concept development stage. Evaluating the most appropriate recovery and lay method, optimizing the vessel deck layout and performing analysis checks were among the key tasks performed in the effort to avoid clashes with existing assets and the geohazard. Further, reflecting the final as-analysed installation methodology in a dimensionally accurate animation, enabling visualization of the operations from start to finish, maximized stakeholder engagement in the planning and execution of the work, reducing the risk of unforeseen circumstances. This shall be discussed in detail within this technical paper.

Following development of the methodology and subsequent careful offshore planning, the existing dynamic riser umbilicals were successfully replaced with the new products. No contact was observed during the process between the products being replaced and existing live assets, nor the geohazard obstacle. Remotely Operated Vehicle (ROV) footage, Dynamic Positioning (DP) and crane instrument read-outs were used to verify the as-installed approach matched the methodology developed during the engineering stages. Ultimately this resulted in successful completion of the operations within the client's targeted shutdown period.

This paper aims to highlight prudent additional engineering with the goal of risk reduction for project delivery. Valuable experience gained from this study shall be shared effectively across other projects and organizational functions.
Pioneer Design of Unmanned Utility Buoy to Unlock Challenging Subsea Tiebacks in Asia
Authors: Clark Cecilie , Emran Fikri Anwar , Steed David
Published: March 2022

A floating Normally Unmanned/Unattended Installation (NUI) or "utility buoy" can provide key services to overcome flow assurance and control constraints directly at the well site. The objective of this paper is to explore how implementing an NUI can enable development of a typical Southeast Asian subsea tieback that could otherwise be considered uneconomical.

The approach is based on using Buoyant Production Technologies Ltd. (BPT) floating NUI solution to provide power, chemicals, and control to subsea developments. This removes the need for a long umbilical and potentially costly host modification to accommodate a subsea tieback.

A case study is presented to explore the benefits of the NUI. A low power utility buoy is sized to cater for well control and chemical injection. This simple subsea tieback is compared to a conventional approach with an umbilical to a host facility. An assessment of procurement, fabrication, installation, and operation phases is performed to identify the advantages of the utility buoy.

The floating NUI design is such that fabrication location is flexible allowing for local fabrication near to the field. In addition, the transportation and installation can be performed by small locally available vessels, resulting in a cost-effective solution, and reduced environmental emissions.

Material and equipment selection are focussed on high reliability and low maintenance requirements. This allows for less frequent inspection and maintenance visits, which reduces personnel risk and results in low lifecycle cost.

A low power utility buoy shows significant benefits compared to a long umbilical. Combined with the flexibility and re-deployment capabilities, the buoy solution can benefit long tiebacks, as well as early production schemes.

An NUI is seen as an enabler for mature regions dominated by subsea tiebacks to feed existing hubs. The improved economics, local fabrication opportunity and reusable profile all adds to the flexibility which will be needed as tiebacks become longer and developments more technically challenging and complex.
Abandonment of Wells Under the New Norm – Sacrificial Tubing Approach
Authors: Abitalhah M Abiabhar , Abu Bakar Nurul Nadia Ezzatty , Hod M Aizat Haidi , Kumar Avinash Kishore , Lau Chee Hen , Thuzar Myat
Published: March 2022

This paper presents the success story of an exploration well in Malaysia evaluating the conventional approach of stacked cement plugs against the use of sacrificial tubing with a hydraulic disconnect sub system.

Plug and Abandonment (P&A) is the process where the well is sealed permanently, and permanent well barrier must extend across the full cross section prior rig move. It is vital to ensure that plugged wells do not leak after abandonment, as there could be several potential leak paths or channeling from microannulus. Thus, well integrity shall be the utmost priority in designing the P&A strategy.

Conventional P&A requires multiple cement plugs of a given length to be set and pressure tested, which could however be quite time-consuming and thus costly. The number of cement plugs will be based on the length of the open hole section, hydrocarbon zones presence or caprock to meet the P&A guidelines. The guidelines require that cement plugs be placed and tested across any open hydrocarbon-bearing formations, across all casing shoes, across freshwater aquifers, and perhaps several other areas near the surface.

The thought process, design requirement both for the hardware and cement slurry, and execution follow through of a P&A approach with a sacrificial tubing method, driving for cost savings and operational efficiency will be elaborated.

Some of the key points for replication based on lessons learnt are P&A with sacrificial tubing is economical justified for well scenario. As for the design, tubing centralizers or rotation is required in deviated hole for proper cement placement. Rotation of tubing during cementing is recommended for effective mud removal and cement placement for the case of no centralizer placement.

This paper provides the novelty of the extensive planning, execution and improvement methods that will aid the project team to save cost and time in plug and abandonment (P&A) the well.
Delivering a Dependable Zonal Isolation Barrier for an Extreme HPHT Well in Offshore Vietnam - Lessons Learned from Cementing High Pressure High Temperature Well
Authors: Nguyen Tam Chanh , Bhaisora Devesh , Ninh Nga Thi , Nguyen Tai Trong
Published: March 2022

With recent discoveries, offshore Vietnam continues to provide promising prospects for hydrocarbon production, especially with rapid exploration and deployment in the offshore HPHT fields in the last decade. However, Vietnam has some of the most complex and hottest wells in the region. An operator was planning to break the barrier of the hottest well in offshore Vietnam. Bottom hole pressure and temperatures for this well were predicted to be around 12,000 psi and 200 deg C, respectively. Designing and delivering a dependable zonal isolation barrier was paramount to the success of the well.

The well architecture included the primary cementing job for six casing strings - 30-in. conductor casing, 20-in. surface casing, 16-in. casing, 13 5/8-in. casing, 9 7/8-in. casing, and 7-in. production liner. The well was for exploration purposes and was to be abandoned by seven (7) cement plugs in cased hole across various depths. A total of 4,200 bbls of cement slurry with a wide density range from 12.0 lbm/gal for the surface casing to 18.0 lbm/gal for the production liner, were tailored and pumped in the well. Rigorous slurry testing was conducted up to 198 deg C and 13,000 psi downhole pressure for the production section slurries. To provide for proper hole cleaning a tailored spacer was designed and tested for stability under the same downhole pressure and temperatures. A total of ~1,000 bbl of spacer were pumped in the well, having a density range from 10 lbm/gal to 17.2 lbm/gal. To maintain the robustness of the slurry design in order to handle any changes in well parameters various sensitivity tests were performed at different temperatures, retarder concentrations and with mud contamination levels (predicted by computational fluid dynamic modelling). For the production section, an aggressive slurry with less than a 15 min transition time was designed to avoid any gas migration in the setting cement.

This case study, techniques and lessons learned can be applied to similar wells around the globe especially in the challenging environments of extreme HPHT.
Effective Mono Ethylene Glycol Meg Injection Optimisation at Offshore Gas Platform Facility: A Novel Case Study for Hydrate Control During Summer and Winter Operation
Authors: Samusideen Salu A. , Alwani Mohammed Abdo , Kurdi Abdullah A.
Published: March 2022

The objective of this paper is to show five innovative options of operating the hydrate inhibition system which aims to eliminate future wet natural gas production limitations and optimize capital and operation expenses during a 25-year life cycle period.

Mono-Ethylene Glycol (MEG) is injected in wet natural gas trunk lines from an offshore gas field, as a means of hydrate inhibition during the winter season. The used MEG is supposed to be recovered in MEG Regeneration Unit (MRU) at onshore gas plant, where the wet natural gas is further processed. The MRU often faces challenges in producing to achieve specified MEG purity, which consequently results in injecting a diluted solution of MEG into the offshore systems, and thereby lowering the maximum allowable production capacity of wet natural gas.

This paper describes the study in five different options. Option 1 represents the current operating scenario of maintaining the existing system with MRU in service, while option 2 explores shutting down MRU at onshore gas plant, and pumping fresh MEG during winter days from the gas plant to the offshore platforms. Option 3 explores shutting down MRU at the gas plant and pumping fresh MEG during winter days, but from a Beach Valve Station (BVS) at an onshore location. Option 4 explores maintaining the existing system with MRU in service and upgrade the storage tanks to address the unsteady state nature of rich MEG flow. Option 5 explores pumping lean MEG during winter days from the gas plant, storing rich MEG in tanks for MEG regeneration and reclaiming MEG through the existing system during the summer including storing lean MEG in tanks for winter usage.

The evaluation has shown that options 2 and 3 can easily meet the required hydrate depression specification during winter period, at far lower MEG injection rates and at a substantially lower life cycle cost (LCC) compared to option 1. The evaluation also showed that options 4 and 5 will ensure MRU operation not interrupted due to low-low levels in MEG storage tanks and will maintain high purity MEG in the trunk lines, which is different from option 1. In conclusion, option 5 has the lowest LCC which is the most economically attractive option.
Noise Logging Application for Well Integrity Evaluation: A Case Study in Peninsular Malaysia
Authors: Saw Li Juan , Linda Hanalim , William Tolioe Amelio
Published: March 2022

Objectives/Scope

Field-X was first discovered in 1979, comprising of saturated oil reservoirs with several shallower non-associated gas reservoirs. Field-X is currently producing from several oil producers. X8 well was recently drilled, completed, and produce from A and B reservoirs. However, 5 months later, the oil rate has been reduced by half with gas oil ratio (GOR) increased up to 5 times. Consequently, the well had to be shut-in due to reservoir management plan (RMP) violation. X9 well was drilled and completed, but 5 years later the well started experiencing the sustained production casing pressure (PCP) and was forced to shut-in in the following year with the locked-in potential of both A and B reservoirs.

To diagnose the root cause of high GOR (HGOR) in X8 well and sustained PCP in X9 well, the Spectral Noise Log (SNL) was deployed. The main advantage of utilizing SNL is its capability of detecting fluid movement behind tubing and casing. High differential pressure creates lots of fluid movement, which generates higher noise amplitude. Meanwhile, smaller pores or leaks generate higher frequency noise that can be easily picked up by SNL.

SNL tool was run in flowing condition for X8 well and the results indicated the HGOR zones were mainly contributed by the shallower B05 sand which was flowing through the leaked 4-1/2″ liner packer. Temperature deflections also indicated that the liner packer seal was leaking and B05 reservoir was contributing to the production. The liner packer leak and B05 reservoir flow would not have been detected by conventional production logging tools as the flow was happening beyond the tubing and casing. For X9 well, SNL was run in the wellbore whilst pumping water via annulus, through the leaks and flowing back up the tubing. Three tubing leaks were successfully detected from the SNL run, whereas previous conventional noise log only managed to detect 2 leaks. It is possible that the third small leak was very small, hence the conventional tool was unable to detect it.

X8 well successfully back online with 8.4% rate increase than last production with GOR reduced back to initial GOR and X9 well successfully back online as per last production rate. The liner packers which are not permanent barriers for reservoir isolation and allocation can be validated, moreover, verifying that tubing leakage is mainly contributed by tubing joints, which can be used as the main input in tubing materials selection in the future.

Well integrity issues can cause significant loss of production, oil spill or worst case, even loss of lives. Proper selection in data acquisition tools helps to accurately diagnose well integrity issues that can be swiftly addressed. In the low oil price environment, skimming down on data acquisition costs may not uncover the true underlying well issues or reservoir issues, but might jeopardize future projects to be undertaken in years to come.
Mitigating Downhole Hazards and Improving Operational Performance using Advanced Human Performance Techniques and High-Fidelity Simulations
Authors: Pathy Kuhanesapathy Thavaras , Khazali Khairul Amir B , Wallace Grant , Christie Bruce , Battisby Clive
Published: March 2022

In August 2020 the Operator deployed a fully immersive On The Rig (OTR) Simulator for the execution of a Drill the Well On Simulator (DWOS) project on the semi-submersible Maersk Developer to prepare the crew to drill the 1st Petronas Deepwater exploration well (name redacted to Well X) offshore Suriname. The offset well data showed numerous downhole troubled time events, such as well control and stuck pipe in addition to other risks that required to be actively managed.

With many of the crew being new to the rig, competence was identified as a key risk. The Operator engaged a DWOS program to ensure the rig crew competence was accelerated and project risks were understood and mitigated. This was achieved through realistic simulations, well/rig specific training and advanced human factors training, specifically designed to ensure the successful delivery of the well.
A New Way to Extend the Life of Pipe
Authors: Wells Austin J.
Published: March 2022

It is well known that formations can be very abrasive, and can quickly and severely wear drill pipe tube bodies. Once the body wall of the tube no longer meets requirements for used pipe, the entire joint must be scrapped. A new method of applying sacrificial wear pads to drill pipe tube bodies is presented, by using a proprietary low heat input welding process to apply hardbanding directly to drill pipe tubes.

Using a proprietary low heat input welding process, hardbanding was safely applied to drill pipe tube bodies. This created new, raised contact areas for the tubes with the abrasive formation. Two wear bands consisting of this hardbanding create a wear pad for the tube body, improving its overall wear-resistance by up to 15 times and casing-friendliness up to 3 times. The application itself was validated through metallurgical testing, including advanced hardness mapping, tensile testing, and non-destructive inspection methods. Following this testing, multiple field trials were performed, which provided case studies for the effectiveness of the wear pads.

Three separate oil and gas Exploration & Production (E&P) companies were having issues with tube body wear of drill pipe in various formations in the USA. To address this, wear pads were applied to a sample set of drill pipe for each E&P company using a proprietary low heat input welding process. Measurements were taken from the drill pipe before and after drilling activities to determine if the wear pads protected the pipe as planned. In addition, non-destructive testing was performed on the wear pads to determine if any cracks existed. For all three case studies, the wear pads effectively protected the tube bodies of the drill pipe, preventing them from wearing. This proved that the wear pads were a cost-effective solution for protecting pipe from abrasive conditions downhole.

The novelty of this improved welding method is that it allows for the economical protection of drill pipe that would otherwise be scrapped due to tube body wear. This extends the life of the drill pipe itself, which is of great value to owners of drill pipe and E&P companies that rent or own strings. Furthermore, the hardbanding used for the wear pad is far more casing-friendly than the unprotected tube, which is also very important to E&P companies.
Polymer Lining – A Solution for Water Injection Corrosion Challenges in Asia
Authors: Suhaimi Radzlan Ahmad , Feeney Allan , Roux Arnaud
Published: March 2022

Deterioration of carbon steel water injection subsea pipelines caused by internal corrosion is a common problem in oil fields around the world. Addressing this issue requires costly and complex water management solutions or could lead to reduced performance and total replacement of corroded pipelines.

This paper shall present the Polymer Lined Pipe (PLP) technology, a field proven solution to the water injection corrosion challenges, extensively used in the North Sea. A description of the key building blocks and the recent technology qualifications shall highlight the latest product development. Eventually, the main fabrication and installation steps shall be presented in view of a regional PLP application. A regional business case comparing the three water injection corrosion approaches shall highlight the typical economic metrics that could be achieved thanks to the use of PLP technology.

Today, this technology is accessible to operators in the Asia Pacific region with the recent opening of the Bintan Spoolbase in Indonesia enabling the deployment polymer lined water injection pipelines using the reel-lay method of installation. The strategic location of the spoolbase eliminates the significant intercontinental transit costs and the reel-lay method reduces offshore vessel days normally associated with conventional pipe-lay methods (S-lay and J-lay).
Predictive Analytics for Gas Turbine Driven Trains to Achieve Optimum Performance, Economics and Greenhouse Gas Emissions
Authors: Chidambram Siva Kumaran , Tan Jin An , Yusoff Mohd Amaluddin , Roy Jihok June Janesby
Published: March 2022

The current gas turbine performance monitoring infrastructure in Shell Malaysia yields inaccuracies of ±15% with no links towards emissions and fuel economics. This has resulted in severe limitations towards the ability to improve greenhouse gas (GHG) performance and generate value. This paper describes a novel, data centric approach to derive meaningful insights and economics/carbon savings from existing data on Plant Information (PI) and SMART CONNECT, a Shell in house performance management IT tool.

This project applies advanced analytics techniques based on historical data, supplemented by engineering performance models to derive robust outcomes. First, gas turbine and compressor modelling principles are programmed in Python and validated with engineering software such as UNISIM based on available operating data via PI. This yields a multivariate dataset tabulating the historical efficiency, power and fuel gas consumption of the fleet. The model is then utilized in a mathematical optimization algorithm and the optimized data used for training and validation of a Random Forest Regressor model.

The performance model in Python is able to achieve accuracies of <1% absolute error when validated with UMSFM on the key performance parameters. Through parametric optimization, the Mean Squared Error (MSE) of the gas turbine and compressor powers is reduced to 0.55MW2 from its original 4.94MW2. The Heat Rate, Shaft Power, and gas generator exit pressures are also identified as the variables most correlated with efficiency. Lastly, the trained machine learning model demonstrated agreement with the dataset during testing, with a R2 value of 0.86 reflecting a strong correlation.

With a predictive digital model in place, production programmers can accurately identify the key levers to optimize the machine operating point for optimum fuel gas consumption. Optimizing Gumusut Kakap's high pressure compressors can yield 62,400 USD in savings per annum from increased sales gas and and 880 tCO2e per annum of reduction in GHG emissions, for every 1% increase in efficiency. This approach is a novel concept, leveraging on expertise from both engineering and data science to enhance equipment performance, and can be replicated towards other types of equipment to achieve efficiency, economic and emissions improvements at scale.
Deployment of Small Area Exposure Radiography S.A.R Technology to Maximise Multiple Work Fronts in Operating Offshore Facility
Authors: Sivarajah Jothi , Hassan Emran , Toh Jason , Lim Tee Bin
Published: March 2022

Malikai Phase 2 project is a brownfield infill drilling project consisting of 5 new infill wells with 1 sidetrack scope. These new wells are tied into existing Malikai Tension Leg Platform (TLP) production facilities for offshore processing prior to export. Offshore execution activities were heavily congested with multiple works fronts from Drilling, Mooring, Hook-up Commissioning alongside existing production and maintenance operations of the Malikai facility requiring prioritization via simultaneous operations (SIMOPS) activities.

The paper highlights the challenges of conventional radiography for inspection activities post pipework welding, which is usually scheduled within windows of low activities i.e. in the night with lower risk of personnel exposure to possible radiation. Since drilling operations runs 24 hours continuously, it renders almost impossible for conventional radiography inspection activities to take place as required.

This paper also describes the benefits with the introduction of SAR technology, the radiation exclusion zone can be set to less than 5 meters, thus allowing the topsides facilities pipework welding to take place concurrent with drilling and operation activities, achieving project success factors of optimized manning requirement and earlier than plan First Oil Date (FOD).

Advanced NDT technologies in the market like small area radiography and phased-array ultrasound were evaluated. Considering the piping diameter/wall thickness & material being Stainless Steel/Duplex SS (coarse grain welds – requires more extensive PAUT qualification), the final decision was to use SAR. A demo was conducted onshore with representation from various internal stakeholders. Necessary approvals from local regulatory bodies were obtained to facilitate the use of this technology for offshore assets.

The team further evaluated the implementation in our offshore facilities in a HAZID workshop, collaborating with several contractors and asset counterpart to assess the hazards and risks associated with SAR. Results were then compared and used by the execution team to develop procedures suitable for offshore use.

The paper compares past experiences of hook-up and commissioning activities using conventional radiography methods. By using SafeRad technology, the project can continue with the topside's fabrication work simultaneously during drilling instead of conducting the pipework fabrication activities in series after drilling is completed. This allowed project team to be able to continue the fabrication works and subsequent pre-commissioning and commissioning activities whilst drilling in progress. As a result, project is able to liquidate the critical path in hook-up and commissioning activities and ultimately contributed to the project delivering early project ahead (circa 6 months) of the first oil milestone.
Marginal Field Development: Evaluation of Offshore Developments
Authors: Arora Eka
Published: March 2022

Offshore marginal fields historically have been discoveries that have not been pursued due to factors such as size of field, lack of infrastructures, product incompatibility with the nearest host or uneconomic assets. However, according to Energy Information Administration Report (2021), Malaysia’s total liquid field production have been declining since reaching peak of 762,000 b/d in 20161. To offset the decline, marginal fields are being considered. This trend is also being echoed in other Asian oil and gas producing nations.

Through the advancement of technology, standardization and focus on cost control during the last oil downturn; marginal fields are now seen as economically viable and are being sanctioned to keep up with the falling production demand. These fields are typically developed via the use of minimum often unmanned wellhead platform or through Jack up Shallow water Subsea systems. It is a vital consideration for the operator to make in selecting either of the methodologies or a combination of the two. The offshore marginal fields being classified here are usually based in shallower water depth (<100m) and have 7-12 years production lifespan.

The aim of this paper is to highlight key technical considerations that will assist the operator in making informed decision to develop the marginal fields using Integrated offshore solutions (IOS). Case study scenario is presented in which the operator was able to optimize their field layout, perform equipment selection by leveraging standardization and engineering and focus on minimizing installation and completion timelines.
A Hybrid Wind and Solar Energy Supply System for Offshore Platform in Gulf of Thailand
Authors: Tangpuk Sirichat , Thubthimsang Warawath
Published: March 2022

For offshore unmanned platforms, reliable and continuous power is critical in the remote wellhead platform operation of the oil and gas company. Thermoelectric generators (TEG) and solar panels are being examined as sources of power to meet the energy needs. Because of high expenses of TEG installation and upkeep, a study was initiated to explore the renewable energy source with better reliability while minimizing costs. A combination of solar and wind turbine system was fully met these requirements.

TEG was replaced by a wind turbine during the experimental phase. The wind turbine can be easily connected to an existing system, making it incredibly versatile and cost-effective for upgrading to a hybrid wind and solar system.

The wind speed profile was used to figure out how big a wind turbine and battery should be. The study suggested that by combining solar and wind power, the cost of consistent power generation can be reduced. There is a huge potential for capital cost savings when compared to TEG.

As a result, a Hybrid Wind and Solar Energy Supply System could be a viable option for remote power supply for offshore platforms, lowering capital, operating, and maintenance costs while also environmental friendly.