bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Quest for Productivity Steering
Authors: Haq Shahid A. , Denichou Jean M. , Okoroafor Rita , Zhou Wentao 
Published: November 2016

Abstract
Over the past forty years, steering a horizontal well has evolved from geometric to structural to facies type and now productivity steering. This paper is aimed to summarize the evolution of wellbore steering and the impact of logging-while-drilling on well and reservoir performance.
The quest for productivity drilling began in the late 1980s with the first generation of logging-whiledrilling (LWD) technology that provided directional and formation-evaluation measurements and basic data insurance in vertical and deviated wells. The primary applications were stratigraphic and structural correlation and rudimentary formation evaluation. A shift in LWD technology in the 1990s increased the focus on exploitation of smaller, tighter, and harder-to-reach reservoirs. This second phase saw the introduction of azimuthal measurements, borehole images, instrumented steerable motors, and forwardmodeling programs for well placement through geosteering. Well architectures became more challenging as well construction evolved from geometrical designs to wells steered by geological information. In the 21st century, geosteering entered its third phase; structural steering with deep-reading LWD resistivity measurements and high-resolution imaging. This allowed operators to reposition in real-time horizontal and high-angle wellbore trajectories in anticipation of structural changes ahead of the bit.
Two recent developments since 2010 have taken geosteering to the next phase of productivity steering. The first one is reservoir mapping while drilling. It uses continuous bed boundary logs from deep azimuthal electromagnetic measurements. The second one is fluid mapping while drilling. It incorporates discrete/station measurements of reservoir rock and fluid properties from formation testing while drilling along with advanced mud gas logs. These developments have made it possible to estimate the productivity index (PI) of openhole section, in near real time, during reservoir drilling process.
The productivity index while drilling estimate can therefore be used for drilling decisions as well as completion decisions and to evaluate the effect of trajectory undulations on well productivity while drilling. Real Time Productivity Steering (RTPS) is hence no longer a myth but a reality now.
New Methodology to Quantify Productivity of Vertical Wells in Naturally Fractured Solution Gas Drive Reservoirs with Dual Porosity and Dual Permeability
Authors: Tariq Zeeshan , Alnuaim Sami , Abdulraheem Abdulazeez , Khan Mohammad Rasheed 
Published: November 2016

Abstract
Forecasting the performance of individual wells is of great importance to oil companies for continuous field production optimization and cost per barrel reduction. Well Performance is measured by evaluating the Inflow Performance & Outflow Performance Relationships (IPR & OPR). For that the need to use the correct IPR for subjected reservoir is very essential.
Since many decades, Vogel IPR equation has been used comprehensively for evaluating the productivity of vertical wells in saturated gas drive reservoirs. Vogel's model successfully evaluates IPR for single porosity solution gas drive in homogenous reservoirs. However, the applicability of Vogel's IPR for naturally fractured dual porosity-dual permeability reservoirs is questionable; hence this challenge is addressed by the industry only numerically. Due to composite fluid flow behavior between fracture and matrix system in a dual porosity-dual permeability reservoir, there is a pressing need for a new, practical and simple IPR model that takes into account the consideration of fracture parameters.
This study investigates the effects of reservoir complex fluid flow behavior on IPR curves for vertical wells drilled in naturally fractured oil saturated reservoirs resulting in the development of an IPR curve for such conditions. A base case simulation model is developed with typical reservoir, fluid and rock properties using black oil model. Using a set of points relating oil production rates to flowing bottom-hole pressures, the dimensionless IPR curves are generated. Fluid and reservoir properties were varied between two porous and permeable media such as Inter-porosity flow co-efficient, storativity ratio, oil gravity, reservoir thickness and bubble point pressure. Inter-porosity flow coefficient and fracture storativity ratio were found to have a significant impact on dimensionless IPR curves. Finally, an attempt is made to converge the results into one simple model using non-linear regression technique in order to get a new empirical IPR correlation for vertical well producing from naturally fractured oil reservoirs.
A small and acceptable average absolute error of less than 2% was found with the new proposed empirical IPR model, while comparing the existing published correlations on the same data gives more than 15% error. The developed IPR correlation is accurate enough and can serve as a handy tool for the production engineers to forecast the productivity of wells drilled in a naturally fractured dual porosity-dual permeability saturated oil reservoirs.
Development Strategy for a Low BTU Gas Discovery with Effective Design of Interference Test & Utilization of Limited Pressure & Production Data for GIIP Estimates by Material Balance P/Z Technique - A Case Study
Authors: Anjum Muhammad Ghufran , Khan Muhammad Noman , Rizwan Muhammad , Khan Muhammad Wahjuddin 
Published: November 2016

Abstract
Material balance P/Z method is widely applicable concept in reservoir engineering to estimate GIIP in volumetric dry gas reservoirs. The application of conventional P/Z method is based on constant pore volume assumption and reliable production of GIIP & PVT data. In newly drilled prospects there is always huge uncertainty in dynamic GIIP due to unavailability of significant production & pressure data [1] and uncertainty of drive mechanism. However, production tests (Reservoir Limit Test, Interference Test, etc.) for longer duration are usually designed to acquire reliable production and average reservoir pressure data to have indicative estimates of GIIP and drive mechanism in order to have development & appraisal program with more certainty.
Low BTU gas with more than 50% inert in the gas cannot be allowed to be injected in the buyer's network. Commercial development of such discoveries for power generation needs firm commitments of gas supply which is based on GIIP estimates which usually have uncertainty due to lack of production and pressure data at the time of discovery.
In this paper we will give a brief insight on the techniques to acquire reliable production data with longer production tests & their limitations, Pros & Cons of conventional P/Z approach for GIIP estimation in the newly drilled prospect. The case study will show how the limited pressure & production data may also be utilized with caution to have minimum GIIP estimates using P/Z method especially in case of overpressure reservoir where drive mechanism is most likely volumetric by designing simplified numerical modeling approach without conducting longer production tests. However, this technique has limitations in case of poroelastic nature of reservoir.
Interlaboratory Variability in Plasma Creatinine Measurement and the Relation with Estimated Glomerular Filtration Rate and Chronic Kidney Disease Diagnosis
Authors: Lee Elizabeth , Collier Christine P. , White Christine A. 
Published: November 2016

Background and objectives
The tracing of creatinine (Cr) reference materials to isotope dilution mass spectrometry–assigned values was implemented worldwide to reduce interlaboratory variability and improve assay accuracy. The aims of this study were to examine the current extent of interlaboratory variability and its effect on eGFR.

Design, setting, participants, & measurements
Leftover plasma from 2–3 consecutive days was obtained from 53 intensive care unit patients with a range of kidney functions. Individual patient samples were pooled and split and sent to 12 different laboratories for Cr measurement. For each patient, the mean Cr and Chronic Kidney Disease Epidemiology Collaboration eGFR (eGFR-EPI), assuming a 65-year-old nonblack woman, were determined. Interlaboratory variability was assessed by the range and SD of Cr and eGFR-EPI. This was repeated after stratifying by assay type and by the median Cr of 1.36 mg/dl. For patients whose eGFR-EPI range included 60 ml/min per 1.73 m2, the percentage of laboratories with eGFR-EPI<60 ml/min per 1.73 m2 was determined.

Results
The mean±SD of the Cr and eGFR-EPI ranges were 0.20±0.09 mg/dl and 14±9 ml/min per 1.73 m2 for Cr<1.36 mg/dl. Jaffe Cr results were an average 0.1 mg/dl (Cr≥1.36 mg/dl) and 0.05 mg/dl (Cr<1.36 mg/dl) higher than enzymatic results (P<0.001 for both). Ten patients had an eGFR-EPI range that included 60 ml/min per 1.73 m2. Their median eGFR-EPI range was 15 ml/min per 1.73 m2. There was significant discordance in the diagnosis of CKD (eGFR-EPI<60 ml/min per 1.73 m2), with laboratories using Jaffe Cr methods making the diagnosis more frequently than those using enzymatic Cr methods (60% versus 39%).

Conclusions
Significant interlaboratory variability in Cr measurement still exists. Jaffe assays yield higher Cr values than enzymatic assays, leading to lower eGFR-EPIs and more frequent CKD diagnoses. Further improvements in assay performance are required to standardize patient CKD diagnosis and to facilitate longitudinal Cr monitoring across laboratories.
Long-Term Clinical Outcomes and Factors That Predict Poor Prognosis in Athletes After a Diagnosis of Acute Spondylolysis: A Retrospective Review With Telephone Follow-up
Authors: Selhorst Mitchell , Fischer Anastasia , Graft Kristine , Ravindran Reno , Peters Eric , Rodenberg Richard , MacDonald James 
Published: November 2016

Study Design Retrospective review with telephone follow-up. Background Acute spondylolytic injuries have a dramatic impact on the young athlete. Excellent short-term clinical outcomes have been observed, but not enough is known about long-term clinical outcomes. Objectives (1) To report long-term clinical outcomes for patients diagnosed with acute spondylolysis, and (2) to assess the prognostic ability of retrospective variables for long-term outcomes. Methods Patients from 2010 through 2013 were retrospectively reviewed to identify patients and to obtain demographic, baseline, and short-term outcomes. Long-term follow-up data were collected by telephone from patients diagnosed with acute spondylolysis to assess recurrence rate of low back pain, perceived outcome, pain, and functional ability. Patients were categorized as having a good or poor long-term outcome based on these measures. Logistic regression analysis was performed to assess the prognostic ability of the retrospective variables for long-term outcomes 3.4 years (range, 1.5–5.6 years) after treatment. Results One hundred twenty-one (71.6%) patients completed the follow-up questionnaire (48 female; mean age at baseline, 14.4 years). At follow-up, 81 (66.9%) patients were able to maintain their same or a higher level of sport. Recurrence of significant symptoms was reported by 55 (45.5%) patients, with 41 (33.9%) requiring medical treatment. The final logistic regression model revealed that female sex, adverse reaction during care, and multilevel injury were significant predictors of poor long-term outcome (R2 = 0.22). Conclusion Although excellent short-term outcomes were noted, 42% of patients reported a poor outcome at long-term follow-up. Female sex, multilevel injury, and experiencing an adverse reaction during care were significant predictors of poor long-term clinical outcome for patients diagnosed with acute spondylolysis. Level of Evidence Prognosis, level 4. Registered January 15, 2015 at www.clinicaltrials.gov (NCT02332200). J Orthop Sports Phys Ther 2016;46(12):1029–1036. Epub 8 Nov 2016. doi:10.2519/jospt.2016.7028
Place of Birth and Concepts of Wellbeing
Authors: McCourt Christine , Rayment Juliet , Rance Susanna , Sandall Jane 
Published: November 2016

AbstractThis article is based on analysis of a series of ethnographic case studies of midwifery units in England. Midwifery units1 are spaces that were developed to provide more home-like and less medically oriented care for birth that would support physiological processes of labour, women’s comfort and a positive experience of birth for women and their families. They are run by midwives, either on a hospital site alongside an obstetric unit (Alongside Midwifery Unit – AMU) or a freestanding unit away from an obstetric unit (Freestanding Midwifery Unit – FMU). Midwifery units have been designed and intended specifically as locations of wellbeing and although the meaning of the term is used very loosely in public discourse, this claim is supported by a large epidemiological study, which found that they provide safe care for babies while reducing use of medical interventions and with better health outcomes for the women. Our research indicated that midwifery units function as a protected space, one which uses domestic features as metaphors of home in order to promote a sense of wellbeing and to re-normalise concepts of birth, which had become inhabited by medical models and a preoccupation with risk. However, we argue that this protected space has a function for midwives as well as for birthing women. Midwifery units are intended to support midwives’ wellbeing following decades of professional struggles to maintain autonomy, midwife-led care2 and a professional identity founded on supporting normal, healthy birth. This development, which is focused on place of birth rather than other aspects of maternity care such as continuity, shows potential for restoring wellbeing on individual, professional and community levels, through improving rates of normal physiological birth and improving experiences of providing and receiving care. Nevertheless, this very focus also poses challenges for health service providers attempting to provide a ‘social model of care’ within an institutional context.1The term midwifery unit was adopted by the Birthplace research programme in place of the more popular term ‘birth centre’ to avoid ambiguity. In a midwifery unit care is not only provided by mid-wives but is also managed by midwives and does not normally include use of obstetric instruments or interventions. If a woman planning birth in a mid-wifery unit develops obstetric complications, or decides she wishes to have a medical intervention such as epidural pain relief, she is transferred for care to an obstetric unit. Some units called birth centres are not managed by midwives in this way.2Midwife-led care refers to care where the midwife, rather than an obstetrician or other professional is the lead professional, who takes responsibility for a woman’s maternity care through from pregnancy to postnatal. Following the Changing Childbirth report in 1993, this was re-established as the usual model for women classified as at low risk of pregnancy and birth complications.
Limited linkages of aboveground and belowground phenology: A study in grape
Authors: Radville Laura , Bauerle Taryn L. , Comas Louise H. , Marchetto Katherine A. , Lakso Alan N. , Smart David R. , Dunst Richard M. , Eissenstat David M. 
Published: November 2016

PREMISE OF THE STUDY:Plant phenology influences resource utilization, carbon fluxes, and interspecific interactions. Although controls on aboveground phenology have been studied to some degree, controls on root phenology are exceptionally poorly understood.METHODS:We used minirhizotrons to examine the timing of grape root production over 5 yr in Fredonia, New York, USA, in a humid continental climate; and over 3 yr in Oakville, California, USA, in a Mediterranean climate. We used data from previous experiments to examine the relationship of root phenology with aboveground phenology. We compared interannual variability in root and shoot growth and determined the influence of abiotic factors on the timing of root initiation, peak root standing crop, peak root growth rate, and cessation of root growth.KEY RESULTS:Root phenology was not tightly coupled with aboveground phenological periods. Both sites typically had one yearly root flush and high interannual variability in root growth. Root phenology was more variable in California than in New York. In this and other published studies, interannual variation in root phenology was greater than variation in aboveground phenology. The three phenological phases of root growth—root initiation, peak root growth, and root cessation—were related to different suites of abiotic factors.CONCLUSIONS:Root phenology is highly variable among years. Analysis of potential controlling factors over several years suggest that belowground phenological phases should be analyzed separately from each other. If aboveground grape phenology responds differently than belowground phenology to changes in air temperature, global warming may further uncouple the timing of aboveground and belowground growth.
ON IMPROVING ANALYTICAL MODELS OF COSMIC REIONIZATION FOR MATCHING NUMERICAL SIMULATION
Authors: Kaurov Alexander A. 
Published: November 2016

ABSTRACT
The methods for studying the epoch of cosmic reionization vary from full radiative transfer simulations to purely analytical models. While numerical approaches are computationally expensive and are not suitable for generating many mock catalogs, analytical methods are based on assumptions and approximations. We explore the interconnection between both methods. First, we ask how the analytical framework of excursion set formalism can be used for statistical analysis of numerical simulations and visual representation of the morphology of ionization fronts. Second, we explore the methods of training the analytical model on a given numerical simulation. We present a new code which emerged from this study. Its main application is to match the analytical model with a numerical simulation. Then, it allows one to generate mock reionization catalogs with volumes exceeding the original simulation quickly and computationally inexpensively, meanwhile reproducing large-scale statistical properties. These mock catalogs are particularly useful for cosmic microwave background polarization and 21 cm experiments, where large volumes are required to simulate the observed signal.
SN REFSDAL: CLASSIFICATION AS A LUMINOUS AND BLUE SN 1987A-LIKE TYPE II SUPERNOVA
Authors: Kelly P. L. , Brammer G. , Selsing J. , Foley R. J. , Hjorth J. , Rodney S. A. , Christensen L. , Strolger L.-G. , Filippenko A. V. , Treu T. , Steidel C. C. , Strom A. , Riess A. G. , Zitrin A. , Schmidt K. B. , Bradač M. , Jha S. W. , Graham M. L. , McCully C. , Graur O. , Weiner B. J. , Silverman J. M. , Taddia F. 
Published: November 2016

ABSTRACT
We have acquired Hubble Space Telescope
(HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN 1987A-like SNe, and we find strong evidence for a broad Hα P-Cygni profile and Na I D absorption in the HST grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe IIn, largely powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and strong Hα and Na I D absorption. From the grism spectrum, we measure an Hα expansion velocity consistent with those of SN 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the Hα emission of the WFC3 and X-shooter spectra, separated by ∼2.5 months in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, photometry of SN Refsdal favors bluer B − V and V − R colors and one of the largest luminosities for the assumed range of potential magnifications. The evolution of the light curve at late times will provide additional evidence about the potential existence of any substantial circumstellar material. Using MOSFIRE and X-shooter spectra, we estimate a subsolar host-galaxy metallicity (8.3 ± 0.1 dex and <8.4 dex, respectively) near the explosion site.
SURVEYING THE BRIGHT STARS BY OPTICAL INTERFEROMETRY. I. A SEARCH FOR MULTIPLICITY AMONG STARS OF SPECTRAL TYPES F-K
Authors: Hutter D. J. , Zavala R. T. , Tycner C. , Benson J. A. , Hummel C. A. , Sanborn J. , Franz O. G. , Johnston K. J. 
Published: November 2016

ABSTRACT
We present the first results from an ongoing survey for multiplicity among the bright stars using the Navy Precision Optical Interferometer (NPOI). We first present a summary of NPOI observations of known multiple systems, including the first detection of the companion of β Scuti with precise relative astrometry, to illustrate the instrument’s detection sensitivity for binaries at magnitude differences Δm ⪅ 3 over the range of angular separation 3–860 milliarcseconds (mas). A limiting Δm
700 ∼ 3.5 is likely for binaries where the component spectral types differ by less than two. Model fits to these data show good agreement with published orbits, and we additionally present a new orbit solution for one of these stars, σ Her. We then discuss early results of the survey of bright stars at δ

−20°. This survey, which complements previous surveys of the bright stars using speckle interferometry, initially emphasizes bright stars of spectral types F0 through K2. We report observations of 41 stars of apparent visual magnitude m

V

, all having been observed on multiple nights. Analysis of these data produces fitted angular separations, position angles, and component magnitude differences for six previously known visual binaries. Three additional systems were examined as possible binaries, but no conclusive detection could be made. No evidence of close stellar companions within our detection limit of Δm ≈3 was found for the remaining 32 stars observed; however, uniform-disk angular diameters are reported for 11 of the resolved stars in this last group.