bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperglycemia Potentiates the Slowing of Gastric Emptying Induced by Exogenous GLP-1
Authors: Plummer Mark P. , Jones Karen L. , Cousins Caroline E. , Trahair Laurence G. , Meier Juris J. , Chapman Marianne J. , Horowitz Michael , Deane Adam M. 
Published: March 2015

OBJECTIVE
Acute hyperglycemia markedly slows gastric emptying. Exogenous GLP-1 also slows gastric emptying, leading to diminished glycemic excursions. The primary objective was to determine whether hyperglycemia potentiates the slowing of gastric emptying induced by GLP-1 administration.

RESEARCH DESIGN AND METHODS
Ten healthy participants were studied on 4 separate days. Blood glucose was clamped at hyperglycemia using an intravenous infusion of 25% dextrose (∼12 mmol/L; hyper) on 2 days, or maintained at euglycemia (∼6 mmol/L; eu) on 2 days, between t = −15 and 240 min. During hyperglycemic and euglycemic days, participants received intravenous GLP-1 (1.2 pmol/kg/min) and placebo in a randomized double-blind fashion. At t = 0 min, subjects ingested 100 g beef mince labeled with 20 MBq technetium-99m–sulfur colloid and 3 g 3-O-methyl-glucose (3-OMG), a marker of glucose absorption. Gastric emptying was measured scintigraphically from t = 0 to 240 min and serum 3-OMG taken at regular intervals from t = 15 to 240 min. The areas under the curve for gastric emptying and 3-OMG were analyzed using one-way repeated-measures ANOVA with Bonferroni-Holm adjusted post hoc tests.

RESULTS
Hyperglycemia slowed gastric emptying (eu/placebo vs. hyper/placebo; P &lt; 0.001) as did GLP-1 (eu/placebo vs. eu/GLP-1; P &lt; 0.001). There was an additive effect of GLP-1 and hyperglycemia, such that gastric emptying was markedly slower compared with GLP-1 administration during euglycemia (eu/GLP-1 vs. hyper/GLP-1; P &lt; 0.01).

CONCLUSIONS
Acute administration of exogenous GLP-1 profoundly slows gastric emptying during hyperglycemia in excess of the slowing induced by GLP-1 during euglycemia. Studies are required to determine the effects of hyperglycemia on gastric emptying with the subcutaneously administered commercially available GLP-1 agonists in patients with type 2 diabetes.
Effects of Administrator’s Role in Training Programmes and Trainees’ Motivation on Training MaIntenance
Authors: Ismail Azman , Foboy Nurul Afiqah , Abdullah Nur Atiqah , Mat Norazila , Makhbul Zafir Khan Mohamed 
Published: March 2015

Abstract
The purpose of this study is to examine the relationship between the administrator’s role (i.e., communication and delivery mode) in training programmes, trainees’ motivation, and training maintenance. Data were collected from 123 employees of various military health centres in Malaysia. The results of SmartPLS path model analysis revealed two important findings: firstly, communication and trainees’ motivation are positively and significantly related to training maintenance. Secondly, delivery mode and trainees’ motivation are positively and significantly related to training maintenance. As a whole, these findings posit that trainees’ motivation does act as an effective mediating variable in the relationship between the administrator’s role in training programmes and training maintenance in the studied organizations. Further discussions, implications and conclusion are presented in the succeeding sections.
Nasal Mucosa Narrow Band Imaging in Granulomatosis with Polyangiitis (Wegener Granulomatosis): A Preliminary Study
Authors: Trimarchi Matteo , Bozzolo Enrica , Pilolli Francesco , Bertazzoni Giacomo , Campochiaro Corrado , Sabbadini Maria Grazia , Bussi Mario 
Published: March 2015

Background Narrow band imaging (NBI) endoscopy is a technique that allows for real-time visualization of mucosal and submucosal vascular patterns. Objective Because granulomatosis with polyangiitis (GPA) (Wegener granulomatosis) is an autoimmune disease defined by vascular inflammation, we examined patients with GPA and with NBI to evaluate whether disease-specific mucosal vascular patterns were present. To the best of our knowledge, the use of NBI endoscopy for assessment of an immune system disease such as GPA has never been previously attempted. Methods We conducted a prospective observational study by performing an endoscopic evaluation of upper airways with NBI on patients diagnosed with GPA; on patients with symptoms and signs suggestive for GPA, who were scheduled to undergo nasal biopsy to confirm diagnosis; on patients affected by chronic rhinosinusitis with nasal polyps; and on healthy controls. Results We enrolled 69 patients. NBI vascular patterns in patients with GPA were consistently and recognizably different from healthy mucosal patterns in 53% of our cases. In patients with GPA, biopsy and NBI results were for the most part comparable, except for three cases. Conclusion Nasal mucosa NBI endoscopy can be considered a promising rapid and noninvasive live imaging technique for nasal mucosa GPA that, based on further study, could become a supplementary diagnostic tool in the complex workup of GPA and vasculitis.
A Rigorous Correlation for Quantification of Skin in Pre-analysis of Hydraulic Fracturing
Authors: Khan Rizwan Ahmed , Alnuaim Sami , Rammay Muzammil Hussain 
Published: March 2015

Abstract
Hydraulic fracturing is practiced to stimulate unconventional and tight oil and gas reservoirs. This technique increases the deliverability of reservoir by inducing reduction in pressure drawdown and exposing more reservoir contact; hence, improving the well productivity index. Fracturing can also help to break through and pass near well-bore severe formation damage and can make low permeability and tight reservoirs economically viable.
Prior to execution of fracturing job, the feasibility of the operation can be accessed through analyzing the effect of skin on overall deliverability of the system. Valuable extent of research has already been done to analytically model or numerical simulate the whole scheme for evaluating this effect. While the orthodox analytical approach to address this problem incorporates simple assumptions, an attempt has been made to build a semi analytical correlation.
This paper proposes a mathematical correlation to determine equivalent skin in hydraulic fractured system for pre-analysis of hydraulic fracturing obtained through numerical simulation modeling. The paper describes two 3D simulation models scenarios; Scenario 1 is without hydraulic fracture and Scenario 2 is with hydraulic fractures. Both scenarios consider the anisotropy (different Kx and Kv) in the system. Scenario 1 has been run for the whole range of matrix permeabilitity values from 0.001 to 1 md. Scenario 2 has been run with different sets of varying fracture's lengths, fracture widths and fracture permeability as well as matrix permeabilities. The two scenarios with corresponding matrix permeability are comparatively analyzed and skin has been determined by calculating fold of increase. Total number of 29040 Data points are obtained by the 29040 number of simulation runs by coupling the commercial reservoir simulator with Matlab. Multivariate regression technique is used to obtain generalized correlation for skin as a function of hydraulic fracture and matrix permeabilities properties. 20000 data points are used to develop proposed correlation and remaining 9040 data points are used to validate and test the proposed correlation.
The newly derived correlation was compared with prevailing analytical approach for skin estimation. It has been found that the degree of absolute percentage error, average percentage error and standard deviation by using of this new correlation has reduced to 3.21%, 3%, and 6.4 respectively.
A Comparison of North American and International Risks in Unconventional Resource Plays
Authors: Meehan D  Nathan 
Published: March 2015

Abstract
Unconventional resources are defined to include coal-bed methane (CBM), tight gas and source rock- (often shale) based reservoirs. Tight gas and CBM have not been "unconventional" in the United States and Canada for more than a decade and are being developed in many countries as more or less conventional plays. Source rock-based plays (shale oil, shale gas) in North America have become widely commercialized and contribute substantially to both gas and hydrocarbon liquid production. Vast quantities of shale resources outside of the United States and Canada have been identified but generally remain at early stages of development. Although large numbers of horizontal, multi-stage hydraulically fractured shale wells have been drilled commercially, such plays remain unconventional for a variety of reasons.
Shale plays differ from tight gas, CBM and historically conventional plays for the same reasons. Unlike the other plays whose characteristics that result in success are well known, shale plays only have indicators pointing to success. The reasons for variability in individual well performance for shale plays are poorly known. Methodologies to "derisk" potential plays vary. Mathematical models to predict performance for shale plays are less rigorous and operators often rely on overly simplified approaches.
Highly competitive North American markets with scores of well-funded competitors and relatively easy access to land and technology have resulted in rapid evaluation of many shale plays at the cost of a substantial number of underperforming wells. In the study, several plays are presented, showing how quickly derisking occurs, what factors contribute to them and how they impact long-term efficiency.
A consistent method for gathering data (seismic, test wells, cores, logs, geomechanical information) is proposed to minimize excess costs and maximize NPV. The approaches to optimize development are applied to shale plays with synthetic properties established on observed heterogeneities but reservoir characteristics for some international shale prospects. The economics are tested with various strategies to illustrate the differences in value obtained.
First Successful Proppant Fracture for Unconventional Carbonate Source Rock in Saudi Arabia
Authors: Al-Mulhim Nayef Ibrahim , Al-Saihati Ali Hussein , Hakami Ahmed M. , Al-Harbi Moataz , Asiri Khalid Saeed 
Published: March 2015

Abstract
Widely recognized as the world leader in crude oil production, Saudi Aramco has only recently begun to explore for unconventional gas resources. Saudi Aramco started evaluating its unconventional reservoirs to meet the anticipated future demands for natural gas. One of the subject plays that is currently being evaluated is a carbonate source rock with nanodarcy permeability and very low porosity. The target formation has few, if any, analogs that can be used for comparison. Knowledge of the formation characteristics, geomechanics, stimulation response and production potential has been nonexistent until recently. Historically, all attempts to hydraulically fracture stimulate carbonate formations in Kingdom have resulted in premature screen-outs. This paper will discuss the hydraulic fracturing stimulation design, execution and evaluation of the first successful proppant fracturing treatment in an unconventional carbonate source rock in Saudi Arabia. The successful two-stage treatment proved that proppant fracturing techniques could be utilized to stimulate carbonate formations after modifying the stimulation design, specifically the perforation strategy, fracturing fluids and proppant type. The Tuwaiq Mountain and Jubailah formations were treated with 104,000 lbs and 114,956 lbs of proppant respectively.

INTRODUCTION
Saudi Aramco's unconventional gas exploration efforts were influenced by the growing local gas demand and the economic success of shale exploration in the United States, Canada, Europe and Australia. Saudi Aramco started evaluating its unconventional reservoirs and their potential to reduce oil consumption in the electricity sector and to fuel the anticipated future demands for natural gas.
"The multi-stage fracturing technique has facilitated the development of shale gas and light tight oil production in the United States and is believed to do so in the other countries with unconventional hydrocarbon resources" (1).
Saudi Aramco has embarked on an unconventional exploration and appraisal project to assess its unconventional resources potential in three geographic areas, Northwest, South Ghawar and East Ghawar. Hydraulic fracturing techniques will be utilized to enhance production by connecting natural fissures and creating high connectivity pathways for gas to flow into the well.
Comparison of Recursive RMS vs. Monte Carlo Errors for Saturation Height Function and Its Implications in Oil Field Activities
Authors: Altunbay Michael Mehmet , Bonnye Yoel , Poit Raymond Elug 
Published: March 2015

Abstract
Uncertainties in hydrocarbon saturation calculations have to be quantified and managed prior to STOIP/GIP estimations for economics evaluation of reserves. There are numerous statistical tools to do the quantification of variances. This study compares the root-mean-squared (RMS) error in the results of saturation-height-function (SHF) as functions of input variances against Markov Chain Monte Carlo (MCMC) treatment of the same. Deterministic aggregation of errors in SHF (or variances of results -Sw-) via RMS against the simulations of solutions of SHF with randomly selected inputs of a given range (MCMC) are compared to evaluate the error margins in deterministic against probabilistic treatments of the same data and equations.
RMS-driven error estimations are more sensitive than Monte Carlo (MC) simulations of errors when a large error in one of the inputs may produce disproportionate weight on the formulations originating from partial derivatives of the equation. However, Monte Carlo approach has also theoretically questionable treatment of data due to conceptual violation of independency of the individual variables in subject equation because of inter-dependencies of permeability to porosity in our models. However, these potential issues are circumvented by the proper range for the systematic errors (due to measurement and treatments) in RMS and by using Markov Chain method in MC, respectively.
The comparison of variances (error margins) from RMS versus MCMC methods are presented for different forms of SHF (e.g., Leverett-J and modified forms). This study presents the ranges of Sw determined from two different approaches as avenues of selecting the more appropriate methodology for a specific case. The width of the confidence intervals from RMS is proportional to the RMS-driven error margins while Monte Carlo simulation of the Sw by SHF also yielding the boundaries where the outcome of a specific J-function would lie.

Introduction
Estimations of in-place hydrocarbon volume and reservoir modeling require calculations of uncertainties in petrophysical properties together with other relevant data. Based on outcome of uncertainty computations, field development and required data acquisition need to be managed by putting either tighter constrains on data acquisition and interpretation methods or changing the course of actions and directions of field progress. The impact of uncertainties on net present value or anticipated return on total investments is large enough to demand the quantification of uncertainties at every stage of the field activities and development.
Well Integrity Evaluation for Methane Hydrate Production in the Deepwater Nankai Trough
Authors: Qiu Kaibin , Yamamoto Koji , Birchwood Richard Anthony , Chen Ying Ru 
Published: March 2015

Abstract
Large accumulations of methane hydrates are known to exist in the deepwater Nankai Trough located off the southern coast of Japan. Due to its enormous potential as an energy source, there is growing interest in the production of methane gas from these deposits. An offshore production test was scheduled to test the technological viability to produce the methane hydrate by using a depressurization method. However, methane hydrate production may cause large amounts of compaction and subsidence, which can damage well integrity and cause loss of zonal isolation in the overburden. This condition could provide potential leakage pathways for methane gas to the surface and endanger offshore operations.
The paper presents a study in which well integrity was evaluated for a methane hydrate production test well in the Nankai Trough. In this study, a new workflow was proposed and applied to honor both fieldwide formation heterogeneity and near-wellbore geometry. The geomechanics properties were determined through integration of seismic inversion data, log data, and core data from the Nankai Trough. Interface elements were installed between the casing and cement and the cement and formation to evaluate the impact of cement bond quality on the well integrity. The numerical simulation was conducted through coupling of the simulation results produced by a methane hydrate production simulator from a third party with a 3D finite-element (FE) geomechanics simulator.
The study predicted the occurrence of 2-cm of subsidence on the seafloor generated by approximately 1.5% of reservoir compaction for a production test of 20 days. Over this period, casing would yield with a plastic strain of about 1%. Most findings indicated a low risk in the loss of zonal isolation which is consistent with the results of the production test conducted in March 2013.
This simulation evaluated potential risks related to well integrity, and provided critical information for the preparation and execution of the pioneering offshore methane hydrate production test in the Nankai Trough.
Surface Modification of Proppant to Improve Transport and Placement
Authors: Maley Darren , Boyer Jeff , O'Neil Bill , Zhang Kewei 
Published: March 2015

Slick water hydraulic fracturing treatments are the preferred method for stimulation of tight hydrocarbon plays as these treatments enhance the complexity of fracture networks, increase fracture lengths, reduce formation damage and decrease treatment costs. These characteristics of a slick water treatment are critical to produce economic wells in unconventional formations. Even though these treatments are effective, they also have disadvantages that can limit production and increase treatment costs. With slight modifications to the treatment design of traditional slick waters - the addition of a novel chemical and 5% nitrogen - the limitations can be reduced.The performance of the slick water treatment is improved by modifying the proppant's surface properties. A novel surfactant preferentially adsorbs onto the surface of the proppant (for both quartz and ceramic), hydrophobically modifying the surface of the solids. The enhanced surface properties create an attraction between the proppant surface and nitrogen gas, in effect, surrounding the particle with a thin layer of gas and thus increasing the buoyancy of the proppant in water. These enhanced properties allow for improved proppant distribution, deeper proppant penetration within the complex fracture network, increased proppant pack volume, and increased maximum proppant concentration that can be placed. Improving proppant placement and increasing the volume that the proppant occupies within the fracture enhances the conductivity of the fracture network, therefore improving the productivity of the well.Laboratory studies of polymer adsorption, sand pack column flow analysis, crush resistance and brine compatibility testing will be presented to complement laboratory analyses previously published. Case studies of field treatments will also be provided. The first case study uses pad wells and compares the new system to traditional fracturing fluids. It will show that, without changing any other variables in the treatment design, production is enhanced significantly. The other two case studies will illustrate how production has been increased in two formations in the Western Canadian Sedimentary Basin.
Workflow for Modelling an Arbitrary Number of Fluid Slugs in a Wellbore Using a Commercial Reservoir Simulator
Authors: Mogensen Kristian 
Published: March 2015

Abstract
Fluid slugs pumped into a wellbore as part of a near-wellbore treatment may exhibit complicated flow characteristics, which are not always captured with sufficient accuracy with commercial simulators. Two such examples include pumping slugs of gelling agents for conformance control and flow of acid with varying concentrations of additives such as drag-reducing agents (DRA).
This paper details a workflow implemented in the commercial simulator Eclipse, which can be applied to describe the transient effects that occur during any fluid-fluid displacement in any wellbore geometry. An important feature of the proposed workflow involves generation of a large number of VFP tables, each of which can be invoked in individual wellbore segments using ACTIONX logic.
The workflow has been tested against field measurements acquired during acid stimulation of a very long horizontal well from a low-permeability North Sea reservoir. The selected well has been completed with around 300 pre-drilled holes in the liner according to the Controlled Acid Jet (CAJ) concept originally described in SPE 78318 and SPE 110135. The pumping schedule involved slugs of brine and acid with varying concentrations of DRA. The rheology of the DRA solution was modelled based on a formalism proposed by Virk, which enabled successful matching of the friction pressure in the wellbore. The wellbore is modelled with a number of segments with known volume. At any given injection rate, it is therefore possible to minimise numerical dispersion in the wellbore by adjusting the time step so that the fluid front advances one segment at a time. In essence, the workflow allows modelling of any fluid-fluid displacement in a wellbore of arbitrary complexity.

Introduction
The Controlled Acid Jet (CAJ) technique was originally developed in 1998 to stimulate very long horizontal well sections in a single operation (Hansen, 2001). The CAJ concept is based on a non-cemented liner with a limited number of unevenly spaced holes of different size to ensure efficient acid stimulation of the complete reservoir section provided the acid is pumped at sufficiently high rates to enable complete displacement of the mud phase. The CAJ liner can be installed incombination with traditional cemented liners or cover the entire reservoir interval, as described by Hansen and Nederveen(2002) in greater detail.
The CAJ technique has, in several ways, set new standards for the completion and stimulation of long horizontal wells; its most significant achievement is the remarkably effective acid coverage resulting from stimulation of long reservoir sections in a single operation.