bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interplay of Capillarity, Drainage Height, and Aqueous Phase Saturation on Mass Transfer Rate of Solvent Vapor into Heavy Oil
Authors: Ahmadloo F. , Asghari K. , Henni A. , Freitag N. P. 
Published: November 2011

Abstract
Performance of the vapor extraction process is strongly dependent on the efficiency of the mass transfer rate between the solvent and heavy oil or bitumen. Therefore, realistic approximation of diffusion and convective dispersion occurring on the edge of the vapor chamber is required for reliable prediction of production rates in this process. Studies conducted at extremely high permeabilities (&gt;200 D) have reported up to four orders of magnitude increase in the solvent diffusion/dispersion rates between the solvent and heavy oil, such increases could result in unrealistic overestimation of the performance of this process at real reservoir conditions. To address this shortcoming, a comprehensive experimental study was designed and conducted to systematically investigate the interplay of capillarity, drainage height, and aqueous phase saturation on efficiency of mass transfer rate in permeability range similar to western Canadian heavy oil and bitumen reservoirs (i.e. 5.1–6.5D). In order to experimentally simulate the vapor extraction process, a new experimental approach was developed to eliminate the effect of pressure disturbances occurring during the course of experiment (20–45 days) and investigate the interplay between studied parameters in a gravity dominant system. In this study, measured stabilized drainage rates per unit length of porous media (9.17×10-7-3.33×10-5 cm3/s/cm) revealed functionality with drainage height, specific pore surface area of the porous medium, and presence of aqueous phase at higher capillarities. Moreover, analytical modeling was conducted to determine the effective diffusion/dispersion coefficient, which showed convective dispersion is not playing a prominent role in mixing between solvent and heavy oil as it was proposed by studies conducted in high permeabilities. In addition, comparison between the stabilized drainage rates of oil in absence or presence of water saturation confirmed that the presence of water phase enhances the drainage rates at higher capilarities, which is in contradiction with previous studies investigating the effect of aqueous phase saturation on mass transfer rate in higher permeabilities. This paper provides in-depth knowledge of the impact of three major parameters that affect the rate of the mass transfer between heavy oil and solvent, and that are necessary for realistic modeling of the performance of the vapor extraction process.
Geomechanical and Thermal Simulation of ES-SAGD Process
Authors: Deng Hui , Chen Zhangxin , Bao Xia , Wei Yizheng , Liu Hui , Dong Chao 
Published: November 2011

Abstract
Overlying top water and gas thief zones have a detrimental effect on the Steam-Assisted Gravity Drainage (SAGD) recovery process since steam penetrates into these zones which results in great heat loss. Due to the presence of these top thief zones, recovering bitumen by the SAGD process has become challenging for the Athabasca oil sands.
Numerical simulations, laboratory experiments and field production data have demonstrated that oil production tends to decrease as the depletion of top gas occurs; also, heat loss to the overlying thief zone will be more significant when a top water zone is present. Indeed, SAGD is a coupled geomechanical, thermal and fluid flow problem because continuous steam injection changes reservoir pore pressure and temperature, which can alter the effective stress in-situ. Therefore, to represent the physics of thermal flow and soil geomechanics, a coupled geomechanical simulation that solves the flow and stress equation simultaneously in the reservoir is crucial for modeling the SAGD process.
The objective of this paper is to construct a 3D geostatistical model for the Surmont pilot and implement coupled geomechanical modeling for the SAGD process aiming at investigating the impact of dilation and thermal expansion on the surface subsidence and bitumen recovery. Reasonable history match of oil and water rates has been achieved and steam chamber profiles have been conformed to the field data from the observation wells. An Expanding Solvent Steam-Assisted Gravity Drainage (ES-SAGD) process has been investigated on a full field-based heterogeneous simulation model using an optimal solvent mixture. Finally, geomechanical effects on the ES-SAGD process are investigated through an iterative coupling approach.
Production Analysis of Western Canadian Unconventional Light Oil Plays
Authors: Clarkson C. R. , Pedersen P. K. 
Published: November 2011

Abstract
Unconventional low-permeability (tight) light oil reservoirs have emerged as a significant source of oil supply in North America. As with unconventional gas reservoirs, these low-permeability oil plays exhibit a wide variety of reservoir characteristics, and consequently well-performance profiles. Further, different drilling and completion strategies are used to exploit them. In this work, we suggest that a categorization analogous to that used for unconventional gas reservoirs (i.e. based on reservoir/fluid properties) be used for unconventional light oil reservoirs because of the significant difference in reservoir and production characteristics observed to date in Western Canada. We propose the term "Unconventional Light Oil" (ULO) to capture the spectrum of play types and to distinguish them from unconventional heavy (high viscosity) oil plays. We further propose the following categories of ULO, which can be used as a practical guide for exploration and development: "Halo Oil" – light oil plays where the source ≠ the reservoir, and matrix permeability is relatively high (&gt; 0.1 md) compared to the other categories. These plays represent portions of conventional light oil pools that do not meet traditional petrophysical cutoffs and pay criteria, and may be clastics or carbonates."Tight Oil" – light oil plays where the source ≠ the reservoir, and matrix permeability is low (&lt; 0.1 md). These plays are analogous to tight gas plays and may be clastics or carbonates."Shale Oil" – light oil plays where the source = the reservoir, matrix permeability is very low, and organic matter content may be high. These plays are analogous to shale gas plays.
We note that for all three categories, modern completion (ex. horizontal wells) and stimulation methods (hydraulic fracturing) are required to commercially produce oil. We further note that the differences between these play types and their gas counterparts are not strictly related to fluid PVT differences.
In this work, we examine, using modern rate-transient analysis methods, differences in production characteristics of three ULO play types in Western Canada, and infer the primary controls on production performance in each. As expected, there are significant differences related to reservoir type and completion strategy.
Experimental Study of Simultaneous Athabasca Bitumen Recovery and Upgrading Using Ultradispersed Catalysts Injection
Authors: Hashemi R. , Pereira P. 
Published: November 2011

Abstract
The worldwide global demand for oil has grown to 80 million barrels per day, and is estimated to grow by 50% in next 20 years while conventional resources are declining. Unconventional reserve of heavy oil and bitumen has been considered as long term replacement for conventional resources. There are a large number of research projects in order to achieve this goal with technological efficiency. In situ upgrading of heavy oil and bitumen using Ultra Dispersed (UD) submicronic catalysts is a promising idea to improve the quality of produced liquid. In this process, hydrogen and a catalytic suspension are injected to the reservoir to react with heavy oil in the porous media. Nano catalyst particles enhance the recovery of oil by viscosity reduction. Series of experiments have been designed in an elemental model under typical reservoir condition. Tests are performed at a pressure of 500 Psi, residence time of 36 h, and temperatures from 300 to 340 (°C).
This paper presents the results of the in situ upgrading obtained along with the recovery of bitumen evidenced using ultra dispersed catalysts in an experimental rig. These experiments involve the injection of UD catalyst particles and hydrogen into a sand pack which is saturated with Athabasca bitumen. Produced liquids were analyzed with different techniques and results were demonstrated in recovery curves. Also, results of each experiment have been compared with base steam injection case to evaluate recovery performance of the catalyst suspended in a hot fluid. Temperature profile distributions and produced gas analysis are demonstrated to justify the quality of reaction through porous media. Produced liquids from media have higher API gravity and lower viscosity which shows a successful in situ upgrading process.
Examining the Effects of Stress Dependent Reservoir Permeability on Stimulated Horizontal Montney Gas Wells
Authors: Bachman R. C. , Sen V. , Khalmanova D. , M’Angha V. Okouma , Settari A. 
Published: November 2011

Abstract
The Montney gas play in NE British Columbia and NW Alberta is undergoing intense development utilizing multi-stage fracturing of horizontal wells. Problems persist in determining an optimal development strategy for each area within the Montney. For the Groundbirch area, operators are in the early stages of development. As a consequence they have invested significantly in well monitoring including microseismic, pressure build-ups, real time rate and pressure measurements and offsetting pressure observation wells. Conventional core analysis indicates that reservoir rocks have permeability in the micro-Darcy range. Lab experiments indicate permeability is also a function of the changing effective stress. Effective stress increases and permeability decreases as production occurs. A coupled geomechanical/reservoir study was performed after 400 days of production history in order to match behavior and determine the sensitivity of conventional production forecasts to the changing stresses within the reservoir.
This paper focuses on the performance analysis of a single Upper Montney well in the Groundbirch area. The approach is staged, with the analysis proceeding from the simple to the more complex. The first step involved an improved version of production analysis. After the identification of linear flow, the utility of a long neglected plot, dm/q versus superposition linear time is illustrated. The ability of this plot to accurately split production well performance into reservoir properties and skin effects introduced by the fracture treatments is shown. This has wide ranging implications for the industry. Finally a simple practical method has been found to compare performance of various types of horizontal multi-stage fracture treatments where the impact of reservoir properties has been removed.
In the second step of the study various descriptions of the study well were developed for all the processes the well encountered. These reservoir simulation models successfully matched treatment placement, an early build-up test distorted by clean-up effects and long term production behavior. Models types ranged from constant reservoir permeability through stress dependent permeability variation. Techniques were developed that eliminated the need to perform the time consuming geomechanical calculations. This allows the use of conventional reservoir models with pressure dependent permeability functions of a special form, to be used in day to day analysis. Sensitivity of the predicted production response with these models was then quantified.
Integration of Seismic Data and a Triple Porosity Model for Interpretation of Tight Gas Formations in the Western Canada Sedimentary Basin
Authors: Castillo Fernando , Aguilera Roberto , Lawton Don 
Published: November 2011

Abstract
A method is presented that integrates a triple porosity model with sonic, density and resistivity logs for evaluation of tight gas formations. The interpretation takes into account results from petrographic work in the Western Canada Sedimentary Basin (WCSB), which indicates that tight rocks are comprised of different types of pores including (i) intergranular, (ii) slot + microfractures, and (iii) isolated non-effective porosities.
Seismic data are powerful in the exploration and production domains but a method that integrates seismic velocities and the observed triple porosity petrographic characteristics of tight gas formations is not available. This paper provides the theoretical foundation and development of equations for this integration along with examples using real data from tight gas formations in the WCSB.
The proposed method provides estimates of inter-well formation resistivity, porosity and water saturation to obtain estimates of original gas in place. The comparison between resistivity from seismic velocities and resistivity from well logs is good with a strong statistical effectiveness. Under favorable conditions, the partition between effective and non-effective porosity might be estimated.
The proposed methodology has significant potential for application in tight gas formations of the WCSB. The method can probably be extended to other regions around the world, which possess tight gas formations with similar characteristics to the ones described in this work.
The Effect of Past Client Relationship and Strength of the Audit Committee on Auditor Negotiations
Authors: Brown-Liburd Helen L. , Wright Arnold M. 
Published: November 2011

SUMMARY
Auditors and clients are often required to resolve difficult, complex accounting issues in which they have different views. However, we know little about the effect of contextual factors on auditors' negotiation behaviors. This experimental study involving 63 experienced audit managers and partners examines the impact of the strength of the audit committee (strong or weak) and past relationship with the client (contending or compromising) on auditors' judgments in the pre-negotiation planning phase in resolving a difficult, subjective inventory writedown issue. These two important contextual factors are posited to affect auditors' perceived bargaining power and expectations of difficulties with respect to the impending negotiation. Specifically, we hypothesize an interaction where the most contending position (negotiation strategy) is adopted when the audit committee is strong (enhanced auditor bargaining power) and the past relationship is contending (a difficult negotiation). The findings support these expectations. In additional analyses, we obtain parallel results in the negotiation phase. In all, the findings confirm the importance of strength of the audit committee and past client relationship on auditors' negotiation planning judgments, and the concurrent consideration of these two pervasive contextual factors in the audit environment.
Data Availability: Contact the authors.
An Examination of the Effect of Inquiry and Auditor Type on Reporting Intentions for Fraud
Authors: Kaplan Steven E. , Pope Kelly Richmond , Samuels Janet A. 
Published: November 2011

SUMMARY
Employee tips are the most common form of initial fraud detection, suggesting that employees frequently are aware of fraud before others professionally charged to detect fraud, such as internal and external auditors. Given the seriousness of fraud to a range of stakeholders, it is important to increase our understanding of the willingness of employees who learn about fraud to report this information to auditors. We conduct an experimental study describing a hypothetical situation involving an employee's discovery of a fraudulent act by his supervisor. Given the hypothetical situation, participants, assuming they were facing the situation, provide their intentions to report fraud to an auditor. The study examines several issues related to participants' intentions to report fraud to auditors. First, we predict and find that participants' reporting intentions to an inquiring auditor are stronger than their reporting intentions to a noninquiring auditor. Second, we predict and find that participants' reporting intentions to an internal auditor are stronger than their reporting intentions to an external auditor. Third, based on contrast coding results, we predict and find that inquiry and auditor type interact to influence reporting intentions. Fourth, we find that reporting intentions for two different types of fraudulent acts, misappropriation of assets and fraudulent financial reporting, do not significantly differ, nor does the type of fraudulent act interact with whether the auditor engages in inquiry or the report recipient (e.g., internal versus external auditor). Supplemental analysis provides additional information on the extent to which beliefs differ between the two types of fraudulent acts.
Are All Industry Specialist Auditors the Same?
Authors: Cahan Steven F. , Jeter Debra C. , Naiker Vic 
Published: November 2011

SUMMARY
We expand upon the traditional market share-based measure of industry specialization by auditors to address the following question: Are industry specialist auditors who obtain their market share by auditing varying proportions of clients in an industry similar in terms of product (audit) quality and price (audit fees)? Our analyses suggest that the audit market is characterized by a type of segmentation in which some specialists pursue product differentiation strategies, focusing more extensively on the acquisition of requisite expertise, while others pursue cost minimization strategies, producing lower cost, lower quality audits. We find that audit fees and quality are higher (lower) when the specialist gains significant market share by auditing a low (high) proportion of clients in that industry. Our evidence suggests that specialists pursue different strategies in different settings. In some cases, specialist auditors may actually be low-end producers, raising a question of whether the “specialist” label is even appropriate.
Glycemic Control in Pharmacist-Managed Insulin Titration Versus Standard Care in an Indigent Population
Authors: Pitlick Jamie M. , Brooks Amie D. 
Published: November 2011

Abstract
Purpose. To assess the impact of a pharmacist-managed insulin titration program on achieving clinical goals in an underserved population with diabetes.
Methods. The study included 35 subjects followed in a pharmacist-managed insulin titration and 35 matched control subjects. Control subjects were followed under standard procedures within the same clinic and were matched for age, titration time frame, and insulin regimen. The primary outcome was change in A1C between the two groups at 6 months. Secondary outcomes included change in A1C within groups at 3, 6, 9, and 12 months, as well as the proportion of subjects attaining a goal A1C of &lt; 7% and adhering to preventive care recommendations.
Results. Between-group comparison demonstrated a significant absolute difference in mean change in A1C at 6 months favoring pharmacist management (0.9%, 95% CI 0.2–1.6, P = 0.009). Within-group comparisons demonstrated significant A1C reduction from baseline at 6 months (−1.1%, 95% CI −1.7 to −0.4, P = 0.002), 9 months (−1.4%, 95% CI −2.0 to −0.7, P &lt; 0.001), and 12 months (−1.3%, 95% CI −2.0 to −0.5, P = 0.001) in the pharmacist-managed group with no significant changes observed in the control group.
Conclusion. Pharmacist-managed insulin titration resulted in significant improvement in glycemic control compared to standard care in an indigent population.
Predictors of Diabetic Retinopathy in a Community Health Center Population
Authors: Olayiwola J. Nwando , Sobieraj Diana M. , Kulowski Kathryn , St. Hilaire Daniel 
Published: November 2011

Abstract
Objective. To determine the predictors of diabetic retinopathy (DR) in a Federally Qualified Health Center population of patients.
Research design and methods. We retrospectively evaluated 526 patients who were screened for DR in the first year of a newly implemented telemedicine program (July 2009 to June 2010). Through this program, a total of 139 patients were diagnosed with DR, whereas 387 patients were not and then served as the comparator group. Multivariate logistic regression was used to determine the predictors of DR in this cohort of patients.
Results. After multivariate analysis, four positive predictors of DR were found: insulin use (adjusted odds ratio [AOR] 1.94 [1.17–3.22]), years with diabetes (AOR 1.22 [1.16–1.28]), A1C (AOR 1.15 [1.02–1.29]), and kidney disease (AOR 5.11 [2.33–11.20]). No variables were found to decrease the odds of DR.
Conclusion. Among patients with diabetes, use of insulin therapy, longer duration of diabetes, presence of kidney disease, and higher A1C values increase the odds of DR. These preliminary data may suggest patients who are at higher risk of DR to further prioritize screening for DR with a newly implemented telemedicine program.
Usefulness of Cellular Text Messaging for Improving Adherence Among Adolescents and Young Adults with Systemic Lupus Erythematosus
Authors: TING TRACY V. , KUDALKAR DEEPA , NELSON SHANNEN , CORTINA SANDRA , PENDL JOSHUA , BUDHANI SHAAISTA , NEVILLE JENNIFER , TAYLOR JANALEE , HUGGINS JENNIFER , DROTAR DENNIS , BRUNNER HERMINE I. 
Published: November 2011

Objective.In a cohort of 70 patients with childhood-onset systemic lupus erythematosus (cSLE): to determine the baseline adherence to medications and visits; to investigate the effects of cellular text messaging reminders (CTMR) on adherence to clinic visits; and to study the influence of CTMR on adherence to use of hydroxychloroquine (HCQ).Methods.CTMR were sent to 70 patients prior to clinic visits for 14 months. A subgroup of patients were evaluated for medication adherence to HCQ: 19 patients receiving CTMR prior to each scheduled HCQ dose were compared to 22 patients randomized to standard of care education about HCQ. Visit adherence was measured using administrative databases. Pharmacy refill information, self-report of adherence, and HCQ blood levels were utilized to monitor medication adherence to HCQ. Sufficient adherence to visits or HCQ was defined as estimates > 80%. Disease activity was primarily monitored with the Systemic Lupus Erythematosus Disease Activity Index.Results.At baseline, 32% of patients were sufficiently adherent to HCQ, and 81% to clinic visits. Visit adherence improved significantly by > 80% among those who were nonadherent to clinic visits at the baseline CTMR (p = 0.01). CTMR did not influence adherence to HCQ over time.Conclusion.Patients with cSLE were only modestly adherent to HCQ and clinic visits. CTMR may be effective for improving visit adherence among adolescents and young adults with cSLE, but it does not improve adherence to HCQ.