bluuebunny/crossref_metadata_2025_split huggingface dataset:
Accuracy of Triage for Children With Chronic Illness and Infectious Symptoms
Authors: Seiger Nienke , van Veen Mirjam , Steyerberg Ewout W. , van der Lei Johan , Moll Henriëtte A. 
Published: November 2013

OBJECTIVE:This prospective observational study aimed to assess the validity of the Manchester Triage System (MTS) for children with chronic illnesses who presented to the emergency department (ED) with infectious symptoms.METHODS:Children (&lt;16 years old) presenting to the ED of a university hospital between 2008 and 2011 with dyspnea, diarrhea/vomiting, or fever were included. Chronic illness was classified on the basis of International Classification of Diseases, Ninth Revision, Clinical Modification, codes. The validity of the MTS was assessed by comparing the urgency categories of the MTS with an independent reference standard on the basis of abnormal vital signs, life-threatening working diagnosis, resource utilization, and follow-up. Overtriage, undertriage, and correct triage were calculated for children with and without a chronic illness. The performance was assessed by sensitivity, specificity, and diagnostic odds ratios, which were calculated by dichotomizing the MTS into high and low urgency.RESULTS:Of the 8592 children who presented to the ED with infectious symptoms, 2960 (35%) had a chronic illness. Undertriage occurred in 16% of children with chronic illnesses and in 11% of children without chronic illnesses (P &lt; .001). Sensitivity of the MTS for children with chronic illnesses was 58% (95% confidence interval [CI]: 53%–62%) and was 74% (95% CI: 70%–78%) for children without chronic illnesses. There was no difference in specificity between the 2 groups. The diagnostic odds ratios for children with and without chronic illnesses were 4.8 (95% CI: 3.9–5.9) and 8.7 (95% CI: 7.1–11), respectively.CONCLUSIONS:In children presenting with infectious symptoms, the performance of the MTS was lower for children with chronic illnesses than for children without chronic illnesses. Nurses should be particularly aware of undertriage in children with chronic illnesses.
The Architecture of Provider-Parent Vaccine Discussions at Health Supervision Visits
Authors: Opel Douglas J. , Heritage John , Taylor James A. , Mangione-Smith Rita , Salas Halle Showalter , DeVere Victoria , Zhou Chuan , Robinson Jeffrey D. 
Published: November 2013

OBJECTIVE:
To characterize provider-parent vaccine communication and determine the influence of specific provider communication practices on parent resistance to vaccine recommendations.

METHODS:
We conducted a cross-sectional observational study in which we videotaped provider-parent vaccine discussions during health supervision visits. Parents of children aged 1 to 19 months old were screened by using the Parent Attitudes about Childhood Vaccines survey. We oversampled vaccine-hesitant parents (VHPs), defined as a score ≥50. We developed a coding scheme of 15 communication practices and applied it to all visits. We used multivariate logistic regression to explore the association between provider communication practices and parent resistance to vaccines, controlling for parental hesitancy status and demographic and visit characteristics.

RESULTS:
We analyzed 111 vaccine discussions involving 16 providers from 9 practices; 50% included VHPs. Most providers (74%) initiated vaccine recommendations with presumptive (eg, “Well, we have to do some shots”) rather than participatory (eg, “What do you want to do about shots?”) formats. Among parents who voiced resistance to provider initiation (41%), significantly more were VHPs than non-VHPs. Parents had significantly higher odds of resisting vaccine recommendations if the provider used a participatory rather than a presumptive initiation format (adjusted odds ratio: 17.5; 95% confidence interval: 1.2–253.5). When parents resisted, 50% of providers pursued their original recommendations (eg, “He really needs these shots”), and 47% of initially resistant parents subsequently accepted recommendations when they did.

CONCLUSIONS:
How providers initiate and pursue vaccine recommendations is associated with parental vaccine acceptance.
Management of a Large Schneiderian Membrane Perforation and Repair of the Missing Maxillary Lateral Wall Using a Collagen Barrier Alone in a Patient With Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome
Authors: Vanderburg Nikko J. , Kolhatkar Shilpa , Bhola Monish 
Published: November 2013

Introduction: Sinus floor augmentation (SFA) to aid in implant placement has been shown to be very predictable. A history of membrane perforation or intraoperative Schneiderian membrane perforation (SMP) is one of the most frequent complications of SFA. In this case report, the management of a large preexisting SMP with the aid of a collagen barrier in a patient with human immunodeficiency virus/acquired immunodeficiency syndrome is described.Case Presentation: A 51‐year‐old male presented for retreatment of an endodontically treated maxillary molar (tooth #14). The endodontic consultation recommended extraction, which was performed by the patient's primary dentist. Two months later, a clinical and radiographic examination revealed significant vertical and bucco‐lingual bone loss in that area. Cone‐beam computed tomography (CBCT) indicated insufficient bone volume for implant placement and the absence of cortical bone with a homogeneous fibrous mass in the edentulous region. A lack of Schneiderian membrane continuity, most likely the result of the extraction, was suspected. A treatment plan of guided bone regeneration followed by implant placement was presented. The SMP was repaired using a collagen barrier alone, and postoperative healing was uneventful. One year later, a repeat CBCT scan revealed complete reformation of the buccal cortical plate and sinus floor with ≈6 mm of vertical bone gain. An implant was placed without complications 16 months after SMP repair.Conclusions: This case report describes how a large preexisting SMP was repaired using a collagen barrier alone. Three‐dimensional bone regeneration was achieved without the use of bone grafts primarily because of the stability of the blood clot.
Characterizing Tight Oil Reservoirs Using Dual- and Triple-Porosity Models
Authors: Ezulike D. O. , Dehghanpour H. 
Published: November 2013

Abstract
The response of existing transient triple-porosity models for fractured horizontal wells do not converge to that of linear dual-porosity model (DPM) in the absence of micro-fractures (MF). The reason is the assumption of sequential-depletion from matrix to MF, and from MF to hydraulic-fractures (HF). This can result in unreasonable estimates of MF and/or HF parameters. Hence, the authors proposed a quadrilinear flow model (QFM) in a previous paper which relaxes the sequential-depletion assumption to allow simultaneous matrix–MF and matrix–HF depletion. Also, it is proved that QFM simplifies to both DPM and linear sequential triple-porosity model (STPM).
This work considers the implications of applying QFM, STPM and DPM type-curves and analysis equations on production data from tight reservoirs. QFM, STPM and DPM are applied to two fractured horizontal wells completed in Bakken and Cardium Formations. A comparative study of the reservoir parameters estimated from the application of these models to the same production data set reveals two key results. Firstly, the application of DPM on production data from reservoirs with active MF could result in overestimation of HF half-length. This happens to compensate for the extra fluid depletion pathways/communication-interface provided by MF. Secondly, the application of STPM on production data from reservoirs with active matrix–HF communication could result in underestimation and overestimation of MF spacing and number respectively.
Results from this study are significant when selecting the appropriate model for interpreting production data from fractured horizontal wells completed in formations with or without active MF. DPM is appropriate if analog studies (e.g. outcrop, micro-seismic and image log analyses) reveal high spacing aspect ratio (negligible MF) in the reservoir. Spacing aspect ratio is MF spacing divided by HF spacing. STPM is appropriate if analog studies reveal low spacing aspect ratio (e.g. matrix–HF face damage or high MF density within a given HF spacing). QFM is appropriate for all spacing aspect ratios.
The Critical Role of In-Situ Pressure on Natural Fracture Shear and Hydraulic Fracturing-Induced Microseismicity Generation
Authors: Zhang F. , Nagel N. , Sanchez-Nagel M. , Lee B. , Agharazi A. 
Published: November 2013

Abstract
In this work, the effect of in-situ pressure on natural fracture shear and hydraulic fracturing-induced microseismicity generation was evaluated using a discrete element model. Overall, the initial in-situ pressure was found to play a significant role in the ability to shear natural fractures during a hydraulic fracture stimulation, largely through a reduction in the effective stresses acting on the natural fractures. Simply, the greater the initial in-situ pressure relative to the in-situ principal stresses, the greater the shear on natural fractures for a given stimulation treatment. Shear slip events on natural fractures were divided into "wet" events and "dry" events to help understand the shear failure mechanism and the induced-microseismicity complexity during the hydraulic fracturing process. The results showed that the density and distribution area of the slip events were affected by a combination of multiple factors. Dry events were mainly affected by the total stress change or shear stress change and the initial strength of the natural fractures while the wet events were affected by the total stress change or shear stress change, the initial strength of the natural fractures and the fluid leakoff area. The stimulated reservoir volume (SRV), measured by the scope of the wet events or the shape of the leakoff area, was affected by the trace of the hydraulic fracture and the fracture network connectivity in the matrix. These results provide further understanding and ability to interpret the different microseismicity responses seen in the field, which, ultimately, will allow for improved optimization of stimulation and completion strategies.
Selection of Candidate Horizontal Wells and Determination of the Optimal Time of Refracturing in Barnett Shale (Johnson County)
Authors: Tavassoli Shayan , Yu Wei , Javadpour Farzam , Sepehrnoori Kamy 
Published: November 2013

Abstract
The observed uneconomic production performance in many shale gas horizontal wells suggests refracturing as a restimulation treatment to revive economic gas production. To achieve high-performance re-stimulation, it is critical to select the right well among many other wells in the area and determine the proper time of refracturing. Well selection is challenging in shale gas horizontal wells because of the complexity of natural and induced fracture networks and in many cases due to insufficient reservoir and completion data. Selection of the candidate well and the time of refracturing can be made based on a thorough numerical simulation study developed by precise modeling of hydraulic fractures and refracturing process. Accurate modeling can only be accomplished by considering formation of fracture networks. Induced fracture networks are formed by an altered stress-field as a consequence of the fracturing process and are evidenced by micro-seismic hydraulic fracture monitoring techniques. Tavassoli et al. (2013) modeled gas production of a refractured well in the Barnett formation and validated their simulation methodology with the available field data. The validated model was used to predict gas production after refracturing the well. They then performed systematic sensitivity analyses to specify the characteristics of shale gas horizontal well suitable for refracturing and defined well screening criteria and optimal time of refracturing. In this study we extended their original work to study 188 horizontal wells in Barnett (Johnson County) to identify wells with potentials for refracturing. We found that among these 188 wells only 11 wells are suitable for refracturing and the best time to perform hydraulic fracturing is between 3½ to 5½ years after initial production.
Bottomhole Assembly Result Analysis to Improve Drilling Performance in Pinedale Field, Wyoming, USA
Authors: Han Guangzhi , Lemesany Lane , Azizov Azar A. , DeLeon Frank 
Published: November 2013

Abstract
The giant Pinedale gas field, which is approximately 35 miles long and 6 miles wide, is the largest structural feature in the northern Green River Basin of Wyoming, with conservative estimates of in-place natural gas at 159 Tcf. The Pinedale field ranks as the third-largest gas field in the United States by proved reserves. Gas production is primarily from a 5,500 ft-thick "Lance Pool" on top of the Ericson Sandstone. The pay zone consists of Upper Cretaceous sandstones of the Lance Formation, the Upper Mesaverde Group, and a Paleocene "unnamed" unit. The reservoir is classified as tight gas due to its low porosity and micro-Darcy permeability. The lenticular sands and stratigraphic nature of this area make horizontal drilling impractical, and deviated well drilling is prevalent.
By 2010, the average drilling time was reduced to 15 days by application of automated vertical-seeking tools with limited availability and poor cost effectiveness. Design and reliability improvements to various downhole tools have further reduced the average drilling time to 12.8 days with a conventional adjustable kick-off sub (AKO) mud motor by 2012. However, due to the various downhole tools involved, a bottomhole assembly (BHA) result analysis is a key step to evaluate the effectiveness of each tool, improve BHA design, identify superior drilling strategy, and eventually optimize the overall drilling performance.
Several field cases are presented in this paper to conduct BHA result analysis, and several suggestions are promoted for future operations. These suggestions can reduce bit trip, improve oriented drilling efficiency, increase rotation rate of penetration (ROP) and save substantial financial resources for customers. The valuable information and lessons learned are crucial for Pinedale drilling operations, and they may be readily applied in other tight gas fields with similar characteristics to optimize drilling performance.
Optimizing Well Completions in the Canadian Bakken: Case History of Different Techniques to Achieve Full ID Wellbores
Authors: Alvarez Domingo , Joseph Arun , Gulewicz Dale 
Published: November 2013

Abstract
The development of the Bakken formation has seen a rapid growth in the last ten years thanks to the improvement of horizontal drilling and multistage stimulation techniques. The Canadian Bakken is located in the SE corner of the Province of Saskatchewan. This formation is a Dolomitic Siltstone reservoir that is shallower (1400 to 1700 m TVD) and thinner (4 to 12 m thick) than its counterpart on the US side; adding some challenges to its exploitation. Moreover, it has an overlying water bearing zone (Lodgepole limestone formation) that can dramatically increase the water cut percentage during production if communication occurs during the fracturing process. For this reason, fracture stimulations are typically done at low rates and low sand tonnages and concentrations.
One operator’s focus to date has been to complete the wells using ball drop systems and open hole packers, leaving the balls and ball seats in the wellbore and milling them out later based on well-by-well analysis. This approach does not allow further workover operations or refrac opportunities without removing the restrictions. Production performance dictates the decision of when to mill out the ball seats; however it has several drawbacks like additional cost, loss of production during the operation, longer operation time and excessive fluid losses.
Cost effective and technically sound alternatives to provide full inner diameter (ID) wellbores during initial operations were investigated and a variety of those methods were implemented in the field. The selections included: retrievable frac seat assembly, coiled tubing half straddle frac tool with sliding sleeve ports and milling out conventional frac ports during the initial completions. All of the completions were executed with open hole packers similar to the previous approach. This paper describes and summarizes the observations and lessons from the application of these methods, as well as the modifications to the fracturing fluid systems based on field application. Also, a comparison of all techniques implemented, including time, cost and production, along with this operator’s assessment for future development in the area are presented.
Prior Information Enhances Uncertainty Quantification in Shale Gas Decline Curve Forecasts
Authors: Gonzalez Raul , Gong Xinglai , McVay Duane A. 
Published: November 2013

Abstract
Probabilistic decline curve analysis (PDCA) methods have recently been developed to quantify uncertainty in production forecasts for hydraulically fractured horizontal shale gas wells. The Markov Chain Monte Carlo (MCMC) method has been proposed as a fast and reliable probabilistic method to quantify uncertainty regardless of the decline curve analysis model employed and the amount of production data available for forecasting. In this paper, we integrate other sources of information with PDCA in a Bayesian framework to enhance the reliability of production forecasts for hydraulically fractured horizontal shale gas wells.
Hindcasts using the logistic-growth-curve model coupled to MCMC and two different sources of prior information were performed to assess the reliability of the improved PDCA method. In a hindcast, only a portion of the historical data is matched; predictions are made for the remainder of the historical period and compared to the actual historical production. The logistic-growth-curve model was moderately well calibrated when used with the MCMC probabilistic method and a non-informative prior, regardless of the amount of production data available to match. When EUR distributions from other sources of information were provided as an informative prior, accuracy and calibration of the probabilistic production forecasts were further enhanced. The use of informative prior distributions improves calibration particularly when little production data are available.
The combination of the MCMC method, the logistic-growth DCA model, and use of prior EUR distributions provides an integrated procedure to reliably quantify the uncertainty in production forecasts in shale gas reservoirs. Reliable quantification of uncertainty should yield more reliable expected values of reserves estimates. This can be particularly valuable early in the development of a play, because decisions regarding continued development are based to a large degree on production forecasts for early wells in the play.
A Well Performance Model Based on Multivariate Analysis of Completion and Production Data from Horizontal Wells in the Montney Formation in British Columbia
Authors: Voneiff G. , Sadeghi S. , Bastian P. , Wolters B. , Jochen J. , Chow B. , Chow K. , Gatens M. 
Published: November 2013

Abstract
UGR Blair Creek Ltd. (UGR) developed an empirical equation to predict Montney horizontal well production based on several completion parameters: lateral length, number of fracture stages, perforation clusters per fracture stage and fluid volume. We used multivariate regression analysis to determine how the completion parameters influence observed production rates. Our best model is valid for fracturing treatments using slick-water and all of the wells in this study are located in British Columbia. The Montney is an expansive play and thousands of wells will be drilled in the future, so the results of this analysis and application of this technique to expanded data sets should help with completion optimization and can have a significant impact on well performance and/or completion cost.
We reviewed completion reports on 425 wells to extract several parameters, including lateral length, number of fracture stages, number of perforation clusters per stage, fluid volume, fluid type and sand volume. Public production data were used to obtain monthly production volumes for each well. We performed multivariate linear regression analysis, simultaneously regressing all of the completion variables against the average production during the best year of production.
We found that the number of fracture stages and the number of perforation clusters per stage are the most important completion parameters for predicting well performance. As expected, an increase in either of these variables will increase the production volume of the best year of production. Adding one fracture stage adds roughly 200 Mcf/D (5,600 m3/d) and adding one perforation cluster per stage adds roughly 250 Mcf/D (7,400 m3/d) to the best year of production. The impact of additional fracture stages or perforation clusters was more pronounced on wells using slick-water fracture fluids than treatments using more complex fluid systems. The amount of sand used in the fracture treatments may also have a significant positive impact on production, but there is more uncertainty than with the number of fracture stages and perforation clusters per stage. Lateral length and fluid volume were only marginally important in predicting production volumes. Only by using multivariate regression (all variables are simultaneously combined in a single regression model) were we able to discern the impact of individual variables.
A Numerical Modeling Study for the Impact of Casing Drilling on Wellbore Stability
Authors: Mokhtari Mehdi , Tutuncu Azra N. , Weldu Teklu Tadesse Weldu 
Published: November 2013

Abstract
Smaller annular size in casing drilling impacts both drilling fluid dynamics and wellbore geomechanics. Casing drilling has been the subject of several case studies reporting improvements in wellbore stability in wells traditionally prone to severe breakouts and stuck pipe issues. However, there are only very few publications reporting the theoretical, experimental or numerical results supporting the field observations. In this paper, we will discuss numerical simulations on the wellbore stability studies customized for casing drilling applications.
Compressive failure has been typically prevented in intact shale formations by increasing mud weight since higher mud weight can reduce hoop stresses and raise the radial stress around the wellbore. However, the stress concentration and the formation strength around the wellbore can change with time leading to wellbore instability. Fluid invasion increases the near wellbore pressure which leads to less support to the wellbore. Fluid invasion may also reduce formation mechanical properties due to the physico-chemical interactions between formation and fluid. Casing drilling can help wellbore stability by reducing the shale-fluid interaction time and near wellbore permeability as well as improving near wellbore mechanical properties by plastering effect. We present a numerical study which shows the reduction of potential breakout occurrences using casing drilling compared to conventional drilling scenarios.