bluuebunny/crossref_metadata_2025_split huggingface dataset:
Translating a Robust Techniques of the EOR-WAG Hysteresis from Laboratory to Field Application
Authors: Sedaralit M Faizal , Hashim Norhayati , Mandal Dipak 
Published: November 2016

Abstract
Malaysia's oilfields production are mostly in a declining trend but the remaining oil left is still significant with an average of oil recovery factor of less than fourty percent, 40%. In arresting this phenomenon, PETRONAS has taken proactive steps to ensure the sustainability and growth of oil production to be inlined with the projected demand and supply outlook for the next five to ten years timeframe. As such, one of major steps taken is looking into Enhanced Oil Recovery (EOR) technique to increase further field recovery factor by improving sweep efficiency of the reservoir for fluids displacement enhancement. Several EOR techniques were put on focused in ensuring target value of sweep efficiency is meeting both macro and micro efficiencies closer to one. Amongst the focus steps are, EOR screening process identification, laboratory work and high order of three dimensional (3D) simulation study. This paper will discuss how displacement test techniques for EOR water alternating gas (WAG) are able to quantity macro and micro sweep parameters at heterogenoues conditions, namely hysteresis; alpha, a, and C. Subsequently, translating it into field 3D simulation study e.g. validation of laboratory result in relationship with relative pemeability modification (imbibition and drainage curves) to quantify the EOR WAG potential. With this, PETRONAS has established a robust techniques for the EOR WAG hysterisis process from laboratory to field application in the context of Malaysia's EOR WAG hysterysis methodology. To-date, the developed processes of WAG hysteresis is proven by first production achieved in year 2014.
Revival of Marginal Oil Field in East Malaysia S-C Field Success Revealed
Authors: Mohsin M Saiful , Rahman Ahmad Ramzi A , Mandal Dipak , Johari Azlan Shah 
Published: November 2016

Abstract
Located offshore East Malaysia, S-C Field is considered a marginal oil field with first development in 2008. While it is a shallow marine with storm and wave influence setting, the reservoir sealing is provided by the unconformity and Major Fault in the west side and further split into three major sub-blocks namely North, Middle and South Block. Middle Block carries two third of total field production as it also carries 80% of total oil volume making it the biggest producing block in S-C field.
The field separation into sub-block came as a surprise during the development drilling which has totally impacted the production strategy and oil recovery as the field is initially expected to be a single buried hill with two separate major oil accumulations. Sand discontinuity and multi-stacked nature of the reservoir proved to be major challenges during development drilling and production phase. Despite the successful drilling and production from most of the development wells, excessive sand production lurks as major threat to oil production and well life. Careful implementation of drawdown limit and sand count monitoring was implemented, nonetheless the oil recovery remained low and the need for additional drainage points was assessed to unleash the full field potential.
This paper captured the case study on this marginal oil field redevelopment which has substantially revived its oil production and successfully overcame the production challenges despite the geological surprises, lesser in-place volume, unoptimised completion and forecasted lower recovery compared to initially prognosed. From the early identification of potential additional infill candidates, project acceleration and economic improvement, the post-production performance has indicated a huge transformation towards realising more oil incremental at reduced cost. Additionally, there were significant lessons learned on subsurface planning and project execution. These were then highlighted for way forwards plan for S-C field and S Cluster in general to further sustain production and extend the field life.
Revitalisation of Upper Assam Mature Fields: Improving Confidence in Reservoir Evaluation by Reservoir Saturation Monitoring
Authors: Khambra Isha , Kumar Ajit , Verma Vibhor , Agrawal Gaurav , Sarma Rajiv , Baruah Neelimoy , Prasad C. B , Bora Pradyut 
Published: November 2016

The Upper Assam Basin is a matured Petroliferous situated in the northeastern part of India . Exploration of Hydrocarbon started way back in 1866, with first commercial oil discovery in 1889. During the exploration, development and hydrocarbon exploitation over the period across various reservoirs of the upper Assam basin, substantial amount of studies were carried out in these brown fields and during the course of these studies, various challenges were learnt. This paper presents an overview of challenges and suggests possible solution to address the complex formation evaluation problems of the mature fields.
The major challenges faced in these reservoirs are high resistivity zones within sands, thereby creating an ambiguity due to very fresh water environment and a complexity in evaluation of the developed prospects between the hydrocarbon bearing and water bearing sand; Low shale density and sand matrix density contrast; Presence of gas across the sands is not effectively evident, especially in the secondary gas cap reservoir scenarios; changing reservoir dynamics due to production from decades, led to an uncertainty in identifying the current fluid contacts and last but not the least identification of mobile oil that could not be produced by existing wells under production from 60-70 years and have been left undrained. Therefore, in order to cater these challenges of old reservoirs and diminishing few unresolved uncertainties involved in redevelopment of the brown fields, reservoir saturation monitoring was carried out successfully in 50 wells in various fields which added immense value both technically and economically.
This paper has the detailed discussion about how this technique proved to be very beneficial and led to the substantial hydrocarbon gain in old wells. The reservoir saturation monitoring was carried out mainly in old wells which helped in taking the informed decision of identifying the sweet spot for hydrocarbon production. It has also helped in overcoming the uncertainty involved in the open-hole data interpretation (especially low resistivity and density contrast). This approach resulted in better understanding of the reservoir characteristics which led to ascertain potential reserves that can be characterized as the "Reserve growth".
The results of this approach also corroborated with the dynamic simulation models of various fields and enhanced the confidence on the predictive field development planning. Last but not the least it also contributed in achieving the annual hydrocarbon production target, considering other economic benefits, it led to reduced rig time spent for workover during the well life with low operational cost.
Application of Coil Tubing in High Density Mud in Deep HPHT Well
Authors: Al-Muhailan Mohannad , Patil Dipak , Aljarki J. , Mahesh V. S. , Shehab A. , Al-Azmi Salah , Alshammari Faisal , Al-Jaber Mohammed , Ababou Mounir 
Published: November 2016

AbstractThis paper highlights the design, planning, challenges, operational complications and successful execution of coil tubing application in active deep well in West Kuwait. The aim of coil tubing job is to clear the pipe from inside to recover the stuck pipe to eliminate the sidetrack in highly pressurized complicated Salt/Anhydrite sequence.In one of the West Kuwait wells, during drilling the well got a kick with high gain rate. During shutting in and at starting of killing the well, it was observed that the pipe & annulus were plugged. Pipe puncture job was carried out & the well was killed off bottom with 19.7 ppg mud. Throughout running in hole with the free point locator tool prior to back off job, the held up was observed at 12,490 ft i.e. 1,300 ft above the bit. It was then selected to clean inside drill pipe to avoid sidetracking.The well conditions presented challenges to the design and operation of coil tubing in this well. Challenging factors included: Use of high weight and yield strength, 15 ksi coil tubing, high mud density of 19.7 ppg, high pumping pressures, deep well, ID restriction 3 ½ in DP with 2 in ID, active well, deviated well of around 57 degrees. The coil tubing job design was critical for success of the operation. It included selection and analysis of coil tubing material, size, wall thickness; managing potential coil tubing burst and collapse pressures, calculation of coil tubing stretch, circulation pressure with high density mud, coil tubing force analysis, and wellbore solids removal with very minimum clearance & minimum pumping rate.Initial simulations with 1.5 in coil tubing showed that circulation pressures would go above the 15 ksi rating. It was then decided to switch to high pressure 1.75 in coil tubing with which simulation showed that pressures at the rotating joint would be at 8,000 psi, using a jetting nozzle. While lowering with jetting nozzle, held up was observed at overshot due to the deviation. After changing jetting nozzle with the 1 11/16 in kick off tool, the coil tubing was able to pass through the gelled mud with circulation. To keep under check, high circulating pressure with aid of hydraulics analysis, related to dynamic circulation rate to 0.2 bpm at 7,500 psi & static rate to 0.35 bpm with 8,500 psi. Resulting in successfully clearing the drill pipe from inside to 12,974 ft, below the observed settling of hard barite.Coil Tubing intervention with the restricted pipe diameter and heavy mud at high inclination well using a kick off tool was done for the first time in Kuwait. It achieved the purpose of cleaning the pipe to definite depth enabling back off operation below the jar & enhanced the chance of pipe recovery.
RESULTS FROM THE 2014 NOVEMBER 15TH MULTI-CHORD STELLAR OCCULTATION BY THE TNO (229762) 2007 UK126
Authors: Benedetti-Rossi G. , Sicardy B. , Buie M. W. , Ortiz J. L. , Vieira-Martins R. , Keller J. M. , Braga-Ribas F. , Camargo J. I. B. , Assafin M. , Morales N. , Duffard R. , Dias-Oliveira A. , Santos-Sanz P. , Desmars J. , Gomes-Júnior A. R. , Leiva R. , Bardecker J. , Bean Jr. J. K. , Olsen A. M. , Ruby D. W. , Sumner R. , Thirouin A. , Gómez-Muñoz M. A. , Gutierrez L. , Wasserman L. , Charbonneau D. , Irwin J. , Levine S. , Skiff B. 
Published: November 2016

ABSTRACT
We present results derived from the first multi-chord stellar occultation by the trans-Neptunian object (229762) 2007 UK126, observed on 2014 November 15. The event was observed by the Research and Education Collaborative Occultation Network project and International Occultation Timing Association collaborators throughout the United States. Use of two different data analysis methods obtain a satisfactory fit to seven chords, yielding an elliptical fit to the chords with an equatorial radius of

km and equivalent radius of

km. A circular fit also gives a radius of

km. Assuming that the object is a Maclaurin spheroid with indeterminate aspect angle, and using two published absolute magnitudes for the body, we derive possible ranges for geometric albedo between

and

, and for the body oblateness between

and

. For a nominal rotational period of 11.05 hr, an upper limit for density of ρ = 1740 kg m−3 is estimated for the body.
ENABLING STAR FORMATION VIA SPONTANEOUS MOLECULAR DIPOLE ORIENTATION IN ICY SOLIDS
Authors: Rosu-Finsen Alexander , Lasne Jérôme , Cassidy Andrew , McCoustra Martin R. S. , Field David 
Published: November 2016

ABSTRACT
It is shown here how new experimental data, for the electrical properties of solid CO, can be used to fill important gaps in our understanding of the evolution of prestellar cores. Dust grains with a mantle of CO lead to a reduction in the degree of ionization in these cores by a factor of between 5 and 6. The lifetimes for expulsion of magnetic fields from cores, a process generally necessary for gravitational collapse, are reduced from current estimates of several megayears, by a similar factor. This removes a major inconsistency, since lifetimes now tally with typical ages of prestellar cores of a few hundred thousand to 106 yr, derived from observations. With the reduced timescales, cores also escape disruption by Galactic supernova remnants. Our results provide a natural mechanism for the generation of so-called magnetically supercritical cores, in which the magnetic field alone cannot prevent gravitational collapse. In addition, we find a minimum value for the density of prestellar cores of ≥(1.1 ± 0.1) × 104 H2 cm−3, in agreement with observations.
Endosonography today: An overview
Authors: Bashir Showkat 
Published: November 2016

AbstractOver the past two decades, the combination of gastrointestinal endoscopy and ultrasonography has shown remarkable progress. This progress has allowed endoscopists to diagnose and treat broad range of not only gastrointestinal disorders but also mediastinal, pancreatic, and perirectal diseases. Endoscopic ultrasound (EUS) offers a vital complementary role to traditional cross-sectional imaging. EUS helps to obtain tissue samples under real-time ultrasonographic guidance using fine-needle aspiration EUS. The ever expanding use of EUS makes it imperative for primary care providers to be familiar with this technology and its application. This progress has made EUS an integral and necessary part of any good endoscopy unit and is here to stay.
Thin energetic O+ layer embedded in the magnetotail reconnection current sheet observed by Cluster
Authors: Wu T. , Fu S. Y. , Zong Q. G. , Sun W. J. , Cui Y. B. , Zhao D. , Guo R. L. , Zhao S. J. , Wang Y. F. 
Published: November 2016

AbstractIn the classical picture of the magnetotail current sheet, the current carriers are mainly ions that undergo nonadiabatic motions. Oxygen ions could contribute a thicker current sheet than the protons due to their large gyroradii. In this paper, however, we report a thin energetic O+ layer embedded in the magnetotail proton current sheet observed by Cluster on 11 October 2001. The thickness of the O+ layer is estimated to be smaller than the half thickness of the local current sheet. And the layer is formed by energetic O+ with energy larger than 20 keV moving along the +Y direction in GSE coordinates. It is inferred that these energetic O+ are probably generated due to the selective acceleration effect of the thin reconnection electric field to the upstreaming ionospheric O+ ions with different initial condition.
Stresses and pressures at the quartz‐to‐coesite phase transformation in shear deformation experiments
Authors: Richter B. , Stünitz H. , Heilbronner R. 
Published: November 2016

AbstractCoesite was found in quartz aggregates, experimentally deformed at confining pressures of 1.0–1.5 GPa and temperatures between 600°C and 900°C. The confining pressure (Pc) and, in most cases, the mean stress (σm) of the experiments were below those of the quartz‐to‐coesite phase transformation. Yet coesite formed when the maximum principal stress (σ1) was within the P‐T range of the coesite stability field. In one sample, the euhedral coesite grains were corroded indicating that coesite started to transform back to quartz. It is inferred that this sample started to deform with σ1 above the quartz‐to‐coesite phase transformation and, with ongoing deformation, σ1 decreased to values in the quartz stability field due to strain weakening. In all cases, σ1 triggered the quartz‐to‐coesite reaction as well as the reverse reaction, suggesting that σ1 is the critical parameter for the quartz‐to‐coesite transformation—not Pc or σm. With progressive deformation, the coesite laths rotated toward the shear plane as more rigid particles with the sense of shear. In case of back reaction, new quartz grains exhibit no systematic crystallographic relationship with respect to old coesite. The experiments cover different degrees of pressure “overstepping,” different temperatures, and different experimental durations at P and T, and deformation always enhances the reaction kinetics. The observation that σ1 is critical for a pressure‐dependent phase transformation (also for reversals) poses questions for the thermodynamic treatment of such phase transformations.
Low‐frequency oscillations of the gravity wave energy density in the lower atmosphere at low latitudes revealed by U.S. radiosonde data
Authors: Li Hai Yan , Huang Chun Ming , Zhang Shao Dong , Huang Kai Ming , Zhang Yehui , Gong Yun , Gan Quan , Jia Yue 
Published: November 2016

AbstractWe adopted 14 year (from 1998 to 2011) radiosonde data from 16 stations at latitudes between 14.33°S to 29.37°N to investigate the low‐frequency oscillations of inertial gravity wave energy densities (including kinetic energy density, potential energy density, and total energy density) in the lower atmosphere from 2 km to 30 km. Apparent signatures of 11 year solar cycle and quasi‐biennial oscillation (QBO) were found in the gravity wave energy densities in the troposphere and lower stratosphere, respectively. Detailed analyses suggested that the 11 year oscillation and QBO of gravity wave activity might be due to the 11 year oscillation of convection activity and zonal wind QBO modulation, respectively. Besides, the gravity wave energy also showed a 35.2 month oscillation in the lower stratosphere, which might be generated by the interaction between the QBO (with the period of 26.7 months), and the 11 year solar cycle, while more possible causes are the direct modulation from the background zonal wind. Our results showed that the QBO signature in gravity wave total energy density could extend northward to over 20°N in the Northern Hemisphere, while the 11 year solar cycle in gravity wave activity could only extend to lower than 7.5°N. The oscillation with the period of 35.2 months may be a prolonged QBO in both gravity wave activity and background zonal wind.
An automatic scaling method for obtaining the trace and parameters from oblique ionogram based on hybrid genetic algorithm
Authors: Song Huan , Hu Yaogai , Jiang Chunhua , Zhou Chen , Zhao Zhengyu , Zou Xianjian 
Published: November 2016

AbstractScaling oblique ionogram plays an important role in obtaining ionospheric structure at the midpoint of oblique sounding path. The paper proposed an automatic scaling method to extract the trace and parameters of oblique ionogram based on hybrid genetic algorithm (HGA). The extracted 10 parameters come from F2 layer and Es layer, such as maximum observation frequency, critical frequency, and virtual height. The method adopts quasi‐parabolic (QP) model to describe F2 layer's electron density profile that is used to synthesize trace. And it utilizes secant theorem, Martyn's equivalent path theorem, image processing technology, and echoes' characteristics to determine seven parameters' best fit values, and three parameter's initial values in QP model to set up their searching spaces which are the needed input data of HGA. Then HGA searches the three parameters' best fit values from their searching spaces based on the fitness between the synthesized trace and the real trace. In order to verify the performance of the method, 240 oblique ionograms are scaled and their results are compared with manual scaling results and the inversion results of the corresponding vertical ionograms. The comparison results show that the scaling results are accurate or at least adequate 60–90% of the time.
Risk of Hypersensitivity to Biologic Agents Among Medicare Patients With Rheumatoid Arthritis
Authors: Yun Huifeng , Xie Fenglong , Beyl Randall N. , Chen Lang , Lewis James D. , Saag Kenneth G. , Curtis Jeffrey R. 
Published: November 2016

BackgroundHypersensitivity reactions (HSRs) can occur with any of the available biologic agents used to treat rheumatoid arthritis (RA). We compared drug‐specific risks for HSRs among RA patients enrolled in the US Medicare program.MethodsUsing Medicare data, we identified new users of infused infliximab, abatacept, rituximab, tocilizumab, golimumab, and injected biologic agents. After identifying HSRs using validated algorithms, for each biologic agent, we calculated the cumulative incidence over 6 months and the incidence rates (IRs) in 0–1, 2–14, and 15–30 days of administration. For each biologic agent administration, followup started on the infusion/injection date and ended at HSR, subsequent biologic agent administration, death, coverage loss, 30‐day followup, or December 31, 2013, whichever occurred first. Adjusted robust Poisson regression was used to compare the HSR risks across biologic agents. A sensitivity analysis was conducted using a nested case‐crossover design.ResultsWe identified 725,591 biologic agent administrations and 248 HSRs among 80,587 new users of biologic agents. Of these, 26.9% occurred in users of intravenous abatacept, 4.6% in rituximab, 5.8% in intravenous tocilizumab, 22.9% in infliximab, and 39.7% in injectable anti–tumor necrosis factor inhibitors (anti‐TNFi). The cumulative incidence of HSRs over 6 months for all biologic agents was low (<1%).The IRs for HSRs ranged from 2.4 (abatacept) to 239.5 (rituximab) per 106 person‐days. After adjustment, and using injectable anti‐TNFi over 0–30 days as the referent, rituximab, infliximab, abatacept, and tocilizumab infusions were associated with a statistically significant higher risk of HSR. The sensitivity analysis yielded similar results.ConclusionAmong RA patients taking biologic agents, rituximab and infliximab were most strongly associated with HSRs. The absolute IRs of HSR events for all biologic agent exposures were low.
Supported Rhodium Nanoparticle‐Catalyzed Intermolecular Regioselective Carbonylative Cyclization of Terminal Alkynes using Oxalic Acid as Sustainable C1 Source
Authors: Guha Nitul Ranjan , Thakur Vandna , Bhattacherjee Dhananjay , Bharti Richa , Das Pralay 
Published: November 2016

AbstractPolystyrene‐supported rhodium(0) (Rh@PS) nanoparticles (NPs) as a heterogeneous catalyst have been used for the synthesis of monocyclic 3,5‐disubstituted cyclopent‐2‐enones from terminal alkynes and oxalic acid as the in situ C1 source following an intermolecular [2+2+1]–reductive carbonylative cyclization (RCC) reaction. Oxalic acid in the presence of Rh@PS catalyst plays a dual role by acting as CO source and reducing agent (H2) which makes the process feasible for the desired product synthesis. The ionic interaction of oxalic acid to the PS surface of Rh@PS helps to maintain the close vicinity and fruitful interaction with substrates and catalyst required for product formation.magnified image
Double Addition of Organometallics to Nitriles: Toward an Access to Tertiary Carbinamines
Authors: Pearson‐Long Morwenna S. M. , Boeda Fabien , Bertus Philippe 
Published: November 2016

AbstractAs depicted in many textbooks, the addition of organometallics to nitriles is generally limited to a single addition, providing ketones after acidic hydrolysis. However, the double addition, leading to tertiary carbinamines is also possible, as demonstrated as early as 1939 by the double addition of allyl Grignard reagents to α‐ethoxyacetonitrile. Since this seminal result, and stimulated by the biological importance of the so‐obtained carbinamines, efforts were devoted to expand the scope of the double addition of organometallics to nitriles. This review presents these different approaches which have led to short accesses to tertiary carbinamine derivatives. Particularly interesting is the double addition of different organometallics, which opens the way towards the straightforward asymmetric synthesis of tertiary carbinamines from nitriles.magnified image