bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advanced Drilling Engineering Methodology Proves Robust in Preventing Mechanical Lock-up While Deploying Sand-Control Completions Through Complex 3D Drains
Authors: Studer R. , Menand S. , Bourgoin S. 
Published: March 2015

Abstract
In Deep Water development wells, the challenge of successfully positioning the drain through the pay zone is key to meet the economics of a project. The industry today provides a wide range of advanced geosteering solutions that are essential to face such challenges. It is indeed possible to drill tortuous 3D horizontal drains to enhance well placement through the sweetest parts of a reservoir sequences along several thousand meters, the directional bottom hole assembly (BHA) being able to trip in and out of hole without too much issues. The question remains whether the Sand Control (SC) completion string will make it to target depth (TD) at all times? This paper shows that the success of running completion to the intended depth depends critically on the well trajectory surveys spacing (standard versus continuous) taken into account in the torque and drag analysis.
This paper illustrates a recent case of failing to reach TD while running in hole (RIH) a SC completion string in a complex 3D well drilled as part of a major deep water development project in West Africa. The reservoir drain was lost with the completion string stuck 170m above TD and a costly sidetrack had to be drilled to recover the well.
A thorough post-mortem analysis of the case was performed, deploying a unique 3rd party approach based on an advanced drilling engineering methodology, to determine the root causes of the incident:
First, the surveyed well trajectory was reconstructed to precisely define the borehole oscillation along the 12 ¼ in. and 8 ½ in. drilled sections, using an advanced rock and bit-BHA coupling model, Second, simultaneous torque, drag and buckling analysis using stiff-string model were conducted in the reconstructed tortuous well trajectory and compared with standard surveys.
This innovative methodology allowed a precise reproduction of lock-up during the incident while using standard friction factors values (0.22 cased hole & 0.35 open hole) with the stiff-string model, instead of unrealistic 0.6 friction factors using the conventional soft-string solution. The analysis showed the mechanical lock-up of the screens through the tortuous open hole as well as lock-up of drill pipe just above the top of the 9 5/8 in. liner.
Combining both advanced solutions processes is proving very robust in preventing reoccurrence of such an incident. The method can be deployed while drilling, and permits the design of “ad hoc” SC completion strings and centralization to overcome the mechanical hole conditions and ultimately managing successful deployment at an intended depth.
Assessing Casing Wear in the Absence of a Baseline Calliper Log
Authors: Sawaryn S.J. , Pattillo P.D. , Brown C. , Schoepf V. 
Published: March 2015

Abstract
Calliper logs provide valuable information on the shape and wear of casing and tubing strings at various times throughout their operational life. In turn, this information is used to determine the remaining design strength. To clearly distinguish deformation and wear from deviations due to manufacturing tolerance, the calliper measurements can be compared with a baseline log run soon after a tubular string has been run, or with surface inspection data. However, a baseline log may not always be available. This paper addresses these situations and provides an assessment of what useful information can be obtained.
A mathematical model, based on the properties of the discrete Fourier transform is presented to determine the calliper offset centre and underlying tubular ovality from 6 or more equi-angularly spaced calliper readings. The series expansion approximation enables these parameters to be determined as a best fit from raw, un-centred data to a numerical accuracy of approximately 0.01% in a single pass. This is consistent with the accuracy and resolution of the currently available callipers. Complete numerical results from test cases based on exact geometric shapes, such as an offset circle and centred ellipse plus field examples are also included along with implementation notes. The same calculations can also be used to determine the underlying elliptic shape and orientation of an open hole calliper.
In the casing specification API 5CT, internal dimensions are indirectly described in relation to the unloaded casing or tubing OD and wall thickness at surface conditions. The manufacturing tolerances and resulting uncertainties may be significant compared to the wear, but in some cases useful information can be obtained with corrections for downhole tension, temperature and pressure effects. Details of these corrections and a discussion of other sensitivities is also provided.
Such algorithms are usually considered by the service provider to be proprietary and little quantitative material has been published on them or their interpretation. Also, data is often presented to the customer in only centre-corrected form, which greatly restricts future reprocessing. This emphasises the importance of acquiring and retaining the raw data.
Novel Mechanistic Modeling of Cased-Hole Fracpack (CHFP) Well Productivity with Non-Darcy Effects and Fracture-Plane Alignment
Authors: Angeles Renzo , Yin Jichao , Hecker Michael T. , Podust Alex V. , Dares Keith M. , Burdette Jason A. , Huang Hao , Spuskanyuk Alexander 
Published: March 2015

Abstract
Cased-hole fracpacks (CHFP) can deliver high-rate, low-skin completions by creating a highly conductive fracture that extends beyond the perforation tunnels, bypassing near wellbore damage and preventing formation sand production. While the industry has a long history of successful CHFP applications, well performance prediction for this type of completions has remained challenged by complex geometrical (fracture geometry and orientation with respect to arbitrarily deviated wellbores) and multi-physics factors (multiphase flow, turbulence). Most fracpack modeling tools are limited to analytical and simplified reservoir simulation models, which can lead to poor accuracy in quantifying near-wellbore effects, such as non-Darcy pressure drop, particularly important for high-rate gas wells.
In this paper, we propose a new mechanistic approach to incorporate the cased-hole fracpack completion with non-Darcy flow through explicitly meshed perforation tunnels, fractures and rock formation in real dimensions. The fracture is modeled by Enriched Finite Element Method (EFEM), which flexibly accounts for arbitrary fracture geometry and orientation while enabling multi-physics effects, impact of perforation/gravel packing damage and perforation-fracture communication uncertainty on deviated well productivities.
The proposed approach is validated using (1) analytical and numerical models, and (2) two Gulf of Mexico (GOM) CHFP wells, one vertical and one deviated; where skins measured from step-rate tests were history-matched to longitudinal and transverse fracture models. We also introduce the concept of fracture neighborhood width to account for perforation performance relative to its alignment with fracture opening and orientation. Finally, the new approach is used to predict the deliverability of a high-rate, high-pressure gas condensate well. Non-Darcy effects, condensate banking effects, perforation gravel packing, and geological model uncertainties are included in predicting the well production.
Modeling Drillstring Magnetic Interference of Wellbore Surveys Using Damagnetizing Factors
Authors: Phillips W. , Aklestad D. 
Published: March 2015

Abstract
Accurate directional borehole guidance requires Bottom Hole Assembly (BHA) non-magnetic spacing of Measurement While Drilling (MWD) systems from surrounding steel components. This is required to limit the magnetic interference and associated azimuth measurement error to acceptable levels.
The current industry method of calculating the Estimated Drillstring Interference (EDI) on MWD magnetometers and the resulting azimuth error produced, are largely based on published material from the late 1970's to early 1980's. The current method models components as magnetic dipoles requiring the knowledge or “guess” of the pole strength of the BHA component and combination of components.
Technological advances in drillstring design and complexity have rendered these methods inadequate. This inadequacy is due to the lack of knowledge of the pole strength information for modern components and/or the unlimited configurations of components, and the limited and simplified BHA configurations normally available in supporting software tools where the EDI calculation is performed.
This paper presents the theory and method of computing the EDI using demagnetizing factors of a prolate spheroid. A worked example of this method is shown to illustrate its implementation with a comparison of the results to published dipole method examples as a reference.
The operational advantages of the demagnetizing factor method are presented showing more consistency in calculation, elimination of BHA complexity limits, ease of computer implementation and system integration, and elimination of subjective and inconsistent selection of component pole strengths used in the dipole method, this providing a means of EDI calculation standardization across the industry.
Integration of Remote Sensing and Crop Modeling for the Early Assessment of Durum Wheat Harvest at the Field Scale
Authors: Orlando Francesca , Marta Anna Dalla , Mancini Marco , Motha Ray , Qu John J. , Orlandini Simone 
Published: March 2015

ABSTRACTIn the Mediterranean, durum wheat is one of the major crops, but a high variability of grain yield and protein concentration (GPC) prevents an adequate agronomic planning at the farm or consortium level. Although there are many studies on monitoring of crop production and early prediction of yields, little has been done at the local scale. The aim of this study was to assess simplified integration algorithms (SIAs) for integrating remote sensing information with a crop model, to forecast the GPC and grain yield at the field scale. To this end, the CERES‐Wheat model was run to simulate the seasonal average of grain yield (AVE) and GPC in Val d’ Orcia (Tuscany Region, Italy) during the 2009–2010 and 2010–2011 growing seasons. The performances of different vegetation indices from MODIS imagery in harvest forecasting were assessed and compared. The SIA formulation was based on the simulated AVE and GPC, and on their spatialization in relation to the intraannual variability between the fields described by vegetation indices. The simulated AVE traced the observed trend. The fraction of absorbed photosynthetically active radiation (fPAR) was the best index in describing grain yield, and the related SIA showed at validation good performance at the field scale (r2 = 0.74). Conversely, the SIA was unable to predict GPC due to the low performance of CERES‐Wheat in capturing the interannual variability and to the failure of the fPAR in describing the GPC interfields variability at intermediate canopy reflectance values.
Internal Control Quality and Credit Default Swap Spreads
Authors: Tang Dragon Yongjun , Tian Feng , Yan Hong 
Published: March 2015

SYNOPSIS
This paper presents the first study on the effects of internal control quality on derivatives pricing. Specifically, we utilize data from the credit default swap (CDS) transactions of well-monitored companies to examine the relationship between the quality of internal control and the cost of debt. CDS data are advantageous for the study of this relationship because CDS contracts are comparatively more homogeneous, standardized, and liquid than either bank loans or public bonds. We find that, all else being equal, companies experiencing internal control material weakness (MW) exhibit higher CDS spreads than companies with effective internal control. Moreover, the MW effect on CDS spreads is more pronounced for company-level MWs than for less severe, account-specific MWs. We also document that CDS spreads increase around the filings of MWs. Furthermore, the deterioration of internal control quality is related to increases in CDS spreads. Finally, short-maturity CDS spreads are more affected by MWs than are long-maturity CDS spreads.
JEL Classifications: M41; G32; K22.
Data Availability: The data are available from public sources.
Accounting as Personal Apology
Authors: Killian Larita J. 
Published: March 2015

ABSTRACT
What is the role of accounting? Typically, accounting is viewed as a technology to inform business decisions, such as allocation of economic resources within the marketplace. In contrast, public interest scholars emphasize the social role of accounting. For example, accounting mediates relationships among various parties, impacts social outcomes, and justifies the distribution of economic rewards. This paper contributes to the public interest perspective by exploring the origin of double-entry accounting (DEA) as a form of personal apologia. To develop the thesis that DEA originated as a form of personal apology, this paper draws from modern and medieval scholars. During the medieval period, profit seeking and markets were deeply suspect and, thus, medieval merchants occupied a precarious social and moral position. The Catholic Church was active in determining the “just price” for goods. Personal morality and just, balanced relationships were primary factors in the development of DEA. Confession and penance, sacraments of the Catholic Church, may have provided the model. The thesis that DEA originated as a form of personal apology is plausible. The contemporary, widespread use personal carbon-offset accounting (PCOA) illustrates that accounting retains the power to help construct the moral self and to mediate the individual's status within the community.
Factors Associated with the Development and Remission of Allergic Diseases in an Epidemiological Survey of High School Students in Japan
Authors: Tokunaga Takahiro , Ninomiya Takahiro , Osawa Yoko , Imoto Yoshimasa , Ito Yumi , Takabayashi Tetsuji , Narita Norihiko , Kijima Akiko , Murota Hiroyuki , Katayama Ichiro , Fujieda Shigeharu 
Published: March 2015

Background Allergic diseases are an important health problem for children and adults. It is important to know how allergic diseases develop and remit from infancy to adolescence. Early intervention is effective in treating allergic diseases. Objective We performed a large-scale questionnaire survey of high school students in Fukui Prefecture, Japan, and analyzed the factors associated with the development and remission of allergic diseases. Methods A total of 21,802 students participated in the epidemiologic survey, and the valid response rate was 89.3% (19,461). We applied an inverse probability weighting method with propensity scores. Results The present prevalence rate of allergic rhinitis (AR) was 19.2%. The remission rate of AR was 15.3%. Only children and firstborns had a significantly higher risk of developing symptoms of allergic diseases [only child: AR, 1.37; bronchial asthma (BA), 1.30; food allergy (FA), 1.33 and firstborn: AR, 1.38; BA, 1.10]. Constipation was an associated factor for development of atopic dermatitis (AD) (1.17) and AR (1.17), regular intake of lactic acid bacteria was not an associated factor for development of allergic diseases but was a factor for remission of AD (1.22). Hypohidrosis was an associated factor for development of AD (1.25). High academic performance was an associated factor for development of AR (1.20) but was a negative factor for development of BA (0.89). The values in parentheses are significant adjusted odds ratios. Conclusion This epidemiologic survey showed that the hygiene hypothesis and intestinal bacterial flora might influence the development of symptoms and remission of allergic diseases.
Maternofetal Transfer of Antibodies and the Influence of Maternal Atopic Status on the Neonate
Authors: Yu Zizhong , Chen Jianjun , Zhang Quanming , Yin Xiaoyan , Wang Yanjun , Fu Junmei , Zou Li , Kong Weijia 
Published: March 2015

Background Epidemiologic evidence has shown that sensitization of allergic diseases develops early in life, even before birth. The gestational environment, including maternal atopic status and transplacentally transferred antibodies to allergens, may be of importance in the sensitization process. Objective To investigate maternofetal transfer of antibodies and the influence of maternal atopic status on the neonatal immune response. Methods Fifty-seven healthy pregnant women who underwent elective cesarean section (ECS) were recruited. Total and specific IgE (Phadiatop) levels in cord blood (CB) and maternal blood (MB) were determined using the ImmunoCAP assay. MB- and CB-specific IgG1 and IgA1 antibodies against ovalbumin and house dust mite were analyzed by enzyme linked immunosorbent assay. The cytokines, interleukin (IL)-13, interferon (IFN)-γ, and IL-10 in the supernatant of cultured CB mononuclear cells were quantified by enzyme linked immunosorbent assay. Two subgroups were defined based on the maternal levels of specific IgE (atopic group, Phadiatop IgE more than or equal to 0.35 kilo international units of allergen-specific antibody (KUA)/L; nonatopic group, Phadiatop IgE less than 0.35 KUA/L). Results Although total IgE was detectable in all MB samples, it could only be detected in 7% (4/57) of the CB samples. Specific IgE was detectable in all MB samples but undetectable in all CB samples. There was no correlation of total IgE between mothers and their neonates. The concentrations of IL-10, IL-13, and allergen-specific IgG1 and IgA1 in the CB samples did not differ significantly between the atopic and nonatopic groups. IFN-γ was undetectable in the CB samples. Conclusions Maternal IgE cannot be transferred to the child in utero. Maternal atopic status has no significant effect on neonatal immune responses.
A Pilot Study of the Self-Administered Computerized Olfactory Testing System
Authors: Jiang Rong-San , Liang Kai-Li 
Published: March 2015

Background The Self-Administered Computerized Olfactory Testing System (SCOTS) was developed recently to perform the olfactory threshold test under computer control. The aim of this study was to evaluate the validity and test-retest reliability of the SCOTS. Methodology A total of 180 subjects were tested for olfactory thresholds using an odor detection threshold test and the SCOTS. There were 60 normosmic volunteers, 60 hyposmic patients, and 60 anosmic patients. Among them, 30 normosmic subjects were retested with the SCOTS at least 1 day after the first test occasion. The olfactory threshold test and retest results from the SCOTS were compared. Results The mean olfactory threshold attained from the SCOTS was -5.48 for normosmic subjects, -3.18 for hyposmic patients, and -2 for anosmic patients. The olfactory thresholds among the normosmic, hyposmic, and anosmic patients were significantly different (p < .001). The correlation coefficient between the olfactory thresholds of an odor detection threshold test and the SCOTS was 0.809 (p < .001). The test-retest correlation for the SCOTS-based olfactory thresholds was strong (r = 0.671; p < .001). Conclusion Our results show that on the basis of its validity and test-retest reliability, the SCOTS was appropriate for self-administered tests of the olfactory threshold.
Temporal trends of intraventricular hemorrhage of prematurity in Nova Scotia from 1993 to 2012
Authors: Radic Julia A. E. , Vincer Michael , McNeely P. Daniel 
Published: March 2015

OBJECT
Intraventicular hemorrhage (IVH) and posthemorrhagic hydrocephalus (PHH) are common in premature newborns. The epidemiology of these conditions has been described, but selection bias remains a significant concern in many studies. The goal of this study was to review temporal trends in the incidence of IVH, PHH, and shunt surgery in a population-based cohort of very preterm infants with no selection bias.

METHODS
All very preterm infants (gestational age ≥ 20 and ≤ 30 weeks) born from 1993 onward to residents of Nova Scotia were evaluated by the IWK Health Centre's Perinatal Follow-Up Program, and were entered in a database. Infants born to residents of Nova Scotia from January 1, 1993, to December 31, 2012, were included in this study. The incidences of IVH, PHH, and shunt surgery were calculated, basic demographic information was described, and chi-square test for trends over time was determined.

RESULTS
Of 1334 successfully resuscitated very preterm infants who survived to their initial screening ultrasound, 407 (31%) had an IVH, and 149 (11%) had an IVH Grade 3 or 4. No patients with IVH Grade 1 or 2 developed PHH. The percentage of very preterm infants with IVH Grade 3 or 4 has significantly increased over time (p = 0.013), as have the incidence of PHH and shunt surgery (p = 0.001 and p = 0.011, respectively) in infants with Grade 3 or 4 IVH. The proportion of patients with PHH receiving a shunt has not changed over time (p = 0.813).

CONCLUSIONS
The increasing incidence of high-grade IVH—and PHH and shunt surgery in infants with high-grade IVH—over time is worrisome. This study identifies a number of associated factors, but further research to identify preventable and treatable causal factors is warranted.
Temperature distribution and thermal anomalies along a flowline of the Greenland ice sheet
Authors: Harrington Joel A. , Humphrey Neil F. , Harper Joel T. 
Published: March 2015

AbstractEnglacial and basal temperature data for the Greenland ice sheet (GrIS) are sparse and mostly limited to deep interior sites and ice streams, providing an incomplete representation of the thermal state of ice within the ablation zone. Here we present 11 temperature profiles at five sites along a 34 km east–west transect of West Greenland. These profiles depict ice temperatures along a flowline and local temperature variations between closely spaced boreholes. A temperate basal layer is present in all profiles, increasing in thickness in the flow direction, where it expands from ∼3% of ice height furthest inland to 100% at the margin. Temperate thickness growth is inconsistent with modeled heat contributions from strain heating, heat conduction, and vertical extension of the temperate layer. We suggest that basal crevassing, facilitated by water pressures at or near ice overburden pressure, is responsible for the large temperate ice thicknesses observed. High-temperature kinks at 51–85 m depth are likely remnants from the thermal influence of partially water-filled crevasses up ice sheet. Steep horizontal temperature gradients between closely grouped boreholes suggest the recent thermal influence of a moulin. These profiles demonstrate the ability of meltwater to rapidly alter ice temperatures at all depths within the ablation zone.