bluuebunny/crossref_metadata_2025_split huggingface dataset:
Derivation of Candidate Clinical Decision Rules to Identify Infants at Risk for Central Apnea
Authors: Walsh Paul , Cunningham Pádraig , Merchant Sabrina , Walker Nicholas , Heffner Jacquelyn , Shanholtzer Lucas , Rothenberg Stephen J. 
Published: October 2015

BACKGROUND AND OBJECTIVES:Central apnea complicates, and may be the presenting complaint in, bronchiolitis. Our objective was to prospectively derive candidate clinical decision rules (CDRs) to identify infants in the emergency department (ED) who are at risk for central apnea.METHODS:We conducted a prospective observational study over 8 years. The primary outcome was central apnea subsequent to the initial ED visit. Infants were enrolled if they presented with central apnea or bronchiolitis. We excluded infants with obstructive apnea, neonatal jaundice, trauma, or suspected sepsis. We developed 3 candidate CDRs by using 3 techniques: (1) Poisson regression clustered on the individual, (2) classification and regression tree analysis (CART), and (3) a random forest (RF).RESULTS:We analyzed 990 ED visits for 892 infants. Central apnea subsequently occurred in the hospital in 41 (5%) patients. Parental report of apnea, previous history of apnea, congenital heart disease, birth weight ≤2.5 kg, lower weight, and age ≤6 weeks all identified a group at high risk for subsequent central apnea. All CDRs and RFs were 100% sensitive (95% confidence interval [CI] 91%–100%) and had a negative predictive value of 100% (95% CI 99%–100%) for the subsequent apnea. Specificity ranged from 61% to 65% (95% CI 58%–68%) for CDRs based on Poisson models; 65% to 77% (95% CI 62%–90%) for CART; and 81% to 91% (95% CI 78%–92%) for RF models.CONCLUSIONS:All candidate CDRs had a negative predictive value of 100% for subsequent central apnea.
From Petroleum Engineer to CEO: The Success Story of an M&A Market Leader - Mark E. Ellis, Chairman, President, and CEO, Linn Energy
Authors: Cronlund Jenny , Ellis Mark E. 
Published: October 2015

TWA Interview
You started out as a petroleum engineering student and now have been the chief executive officer (CEO) of Linn Energy since 2010. How did you get to where you are today?
My dad was a petroleum engineer from Texas A&M University. I knew I wanted to pursue engineering, and A&M was the obvious choice. I would not say that when I graduated my goal was to be a CEO of a publicly traded company. Somewhere in that first 6–10 years, I realized I liked being in leadership and would like to develop a career to run a publicly traded company. With that in mind, I took a lot of rotational jobs in different functions to give me a breadth of understanding of the whole industry. Not only did I work in engineering, but also in marketing and transactional activities, so I could understand the business aspects of how assets fit within certain companies and strategies.
In how many companies have you worked so far in your career? What lessons did you take from them?
I have worked for five companies. You learn so much by going to different companies and really engaging in their cultures. You pick up on different leadership styles; different things that work in different organizations. At some point in your career, you try to take the best of all of them and create the culture that you think is the best culture for an organization. I realized that people are what make an organization run. You need great assets to be successful, but the assets do not run themselves—they are only as good as the people you have managing them.
To focus a group of people on a common outcome, it is critical to set strategic goals, and make sure the organization is aligned in achieving those goals, ensuring everyone understands how they add value to the organization and feels they are important to the organization. At Linn, we devote the time necessary to make sure that everyone understands where they add value. A lot of our time in leadership is spent doing face time out in the field. I visit every location in the organization at least once a year, and I try to have a personal connection with everyone. It is not easy to do, but I think it is important.
Diversity and Inclusion: A Young Professional’s Tools for Success
Authors: Shanahan Betty , Dalrymple Lori , Caligari Ruben 
Published: October 2015

Soft Skills
From the exploration and production of oil and gas to the ultimate distribution of petroleum-based products to customers, the oil and gas industry is global and multidisciplinary. The global nature of the industry is reflected in the membership of SPE: Professional members of SPE live in 147 countries, and a review of the student membership suggests that the Society will become even more diverse in the years to come.
Given that mergers and acquisitions are the global climate in the industry today, as a young professional, how do you feel about change? Do you feel confident that your job is secure and you have room for growth, or are you worried? It is inevitable that change will be part of your future in this industry, and soft skills hold the key in helping you successfully navigate it.
If you imagine yourself standing in front of a pyramid face (Fig. 1), there is something that you cannot see—the third corner at the back of the pyramid. But without it the pyramid cannot stand. Such is the role that soft skills play in career success.
Take the case of a major professional sports team with highly paid players. They all want to win, but sometimes they let their own importance get in the way of the team’s success. Diversity is having a team of players, each with his or her own unique level of physical capabilities and experiences. Inclusion is all of the team members, including the star players, accepting the talents, strengths, and experiences of others, along with the insight of the coach, to move the team to a higher level of excellence.
Embracing Diversity and Inclusion
Diversity and the ability to accept, adapt, and change with the global climate of the industry is a gift that not every person possesses. To appreciate a gift, you have to understand how valuable it is to you. In a 2014 Ernst & Young series called “The DNA of the COO: Time to claim the spotlight,” a report titled “An oil and gas sector perspective” states that mergers and acquisitions are on the rise as oil and gas companies seek to divest noncore assets.
Three-quarters of the chief operating officers polled for the report said that highly developed leadership qualities and interpersonal skills are the most crucial attributes to success, while 60% emphasized communication and influencing skills. These are professional people in charge of the operations of major oil and gas companies who cited soft skills as a large percentage of the most important attributes they needed to be successful.
How SPE’s Competency Management Tool Can Help Boost Your Career Development
Authors: de Almeida Tiago 
Published: October 2015

SPE 101
If you are a recent graduate trying to find a spot in the sun, or a young professional working hard to establish yourself in the industry, it is essential for you to define and follow an individual development plan that will steer you toward your professional goals.
To help you with that, SPE, in partnership with International Human Resource Development Corp., has recently developed the SPE Competency Management Tool (CMT). The CMT is an online platform that allows each member to not only assess his or her competency levels in detail, but also guides them in addressing any competency gaps.
Since its launch at the 2014 SPE Annual Technical Conference and Exhibition, the number of members using the tool has continued to increase, and as of May 2015, the tool had 1,431 registered users.
To explain how the CMT can help young professionals in their career development, TWA editors interviewed SPE’s assistant director for global training programs, Ken Leonard, who worked with the SPE Global Training Committee to develop and implement the tool.
Who is the CMT built for?
CMT is intended for members interested in assessing their current skills against the SPE competency models for any of the 22 technical jobs covered. Since there are two career levels for each job (entry-level and first supervisory level), we expect many users to be earlier in their career. However, anyone making a job change or wishing to get an idea of how they compare to the rigorous SPE standards can gain value from the tool.
What disciplines does the tool cover? Does SPE plan to expand the number of competency models in the future?
The current competency models cover all the SPE technical disciplines. We took 22 job descriptions and developed 25 to 30 competencies for each job, with four skill levels—awareness, basic application, skillful application, and mastery. We have plans to enhance the tool this year by adding more jobs from operating companies as well as jobs from the service company sector and for graduating engineers.
Reservoir Characterization and Coupled Reservoir-Geomechanical Simulation of CBM Using GSI - Case Studies
Authors: Deisman Nathan , Chalaturnyk Richard J. , Campbell Ryan , Virues Claudio 
Published: October 2015

Abstract
A hydro-geomechanical coalbed methane reservoir characterization workflow is reviewed and applied to three field cases from the same coalseam formation. The workflow begins from core sample characterization and ends at reservoir performance. A core sample and geophysical logging rock mass characterization approach using the newly adopted Geological Strength Index (GSI) is used. GSI was developed for Civil Engineering tunneling projects to characterize fractured rock masses and is adopted here with new functions to related GSI to observed Young's modulus and then included for permeability changes during production.
The GSI characterization is applied to three separate reservoir geomechanical simulation models with separate and distinct production profiles. Reservoir and geomechanical data to populate the models comes from three sources: Nexen, the University of Alberta, and the Alberta Energy Regulator. The significance of this study is to investigate the influence of geomechanics on well productivity for fractured reservoirs using a common geological parameter which relates fracture intensity to mechanical properties.
Draw-Down Management Leads to Better Productivity in Reservoirs with Pressure-Dependent Permeability - or Does It?
Authors: Tabatabaie S. Hamed , Pooladi-Darvish Mehran , Mattar Louis 
Published: October 2015

Abstract
In certain production scenarios of multi-fractured unconventional wells, it appears that there exists the unexpected possibility that increasing the well's flowing pressure (decreasing the drawdown) can result in improved productivity and in larger Estimated Ultimate Recovery (EUR). This has been attributed to the pressure- dependence of permeability. This consideration provided the motivation for this study, namely to understand under what conditions pressure-dependent permeability affects the recovery and production performance.
The effect of pressure-dependent permeability is frequently modelled using the function: k(p)=kieγ(p−pi), where, γ is the pressure-dependent permeability coefficient. Production at constant flowing pressure is studied for linear-flow geometry of systems with pressure-dependent permeability, representing matrix flow into a stimulated-reservoir volume (SRV) and/or a finite conductivity fracture.
It is shown that when the permeability is a function of the pressure in the reservoir, the production rate increases continuously as the drawdown is increased, and no reversal of productivity is observed. However, when the fracture conductivity is a function of the well flowing pressure, there will be an operating point beyond which a reversal of production behavior is observed, and the production rate decreases as the drawdown is increased.
Steady-state and transient models are developed to explore the conditions that lead to such a reversal. A numerical simulator is used to generate the behaviour of a system in which the fracture conductivity varies with respect to the flowing pressure. It demonstrates that the path of the producing pressure can be optimized so that oil recovery is maximized.
Evaluation of Chlorine Dioxide as an Oxidative Biocide for Hydraulic Fracturing in Western Canada
Authors: Malcolm Adam C. , Dempster Steve P. , Chandler Brett , Setiawan Stephanie 
Published: October 2015

Abstract
Effective microbiological control is a vital component of a successful fracturing stimulation. As the development of tight gas, shale and other unconventional resources increased, innovative hydraulic-fracture designs including linear gel, slickwater and hybrid treatments have grown in popularity. These designs often require significant volumes of water that originate from rivers, lakes and ponds as well as produced and flowback water. Frequently, these sources are infested with aerobic and anaerobic bacteria that can lead to degradation of fracturing chemicals, microbially influenced corrosion, hydrogen sulfide generation and other production problems.
Control of bacterial growth may be accomplished through the use of biocides. Glutaraldehyde and quaternary ammonium-based surfactants are two of the most prevalent chemistries used in Canadian fracture fluids. Because of the inherent toxicity of biocide additives, the primary goal is to design a program that minimizes chemical usage while matching the total demand necessary to control and manage bacteria. Controlling bacteria means not only an effective kill at the surface before use, but also maintaining this control long term while the fracturing fluids are in contact with the reservoir. Oxidative biocides are an attractive treatment option because of the rapid kinetics of disinfection, the ability to provide excellent control of bacteria populations and the short residual lifetimes that do not persist in the flowback beyond a few days or hours. In addition, oxidizing biocides enable a concomitant reduction in the quantity of preservative biocides required to achieve long-term control.
This paper reviews the efficacy of a chlorine dioxide-based biocide program used in hydraulic fracturing in central Alberta, Canada. The results of the bacteria enumerated from job site samples are presented, along with application methodologies and program design. It was observed that chlorine dioxide combined with a low concentration of preservative biocide can provide enhanced efficacy and reduce total chemical demand compared to conventional biocide treatments.
Chlorine dioxide is approved for use as a biocide for hydraulic fracturing by the Canadian Pest Management Regulatory Authority (PMRA). Chlorine dioxide provides new opportunities to build more efficient hydraulic fracturing biocide programs.
Achieving Zonal Isolation by Using New-Generation Mud Removal Chemistry and Design Methodology to Displace Non-Aqueous Drilling Fluid
Authors: Taoutaou Salim , Goh Soo Hui , Bermea Jorge Andres , Vinaipanit Manavit , McClure Jason 
Published: October 2015

Abstract
The criteria for success of any primary cementing job is achieving permanent zonal isolation. Incomplete mud removal will affect the zonal isolation in several different ways and may lead to the development of a communication channel in the annulus and subsequently jeopardize the well integrity.
Nonaqueous fluids (NAF) are incompatible with cement slurries; the quality of the cement placement and set properties will be strongly affected by the presence of the NAF residue down hole. Although this problem can be mitigated through the addition of various chemicals providing compatibility, mud-thinning, reduction of the interfacial tension, and water-wetting functions, the current surfactants and solvents on the market have limited application in terms of temperature and type of drilling fluids. In addition, the current API/ISO testing protocols are generic and results are not reproducible. Recently, improved laboratory procedures have been proposed and these improved experimental methods were used on more than 200 surfactants and solvents. A screening process helped in selecting the optimum chemistry as a function of the conditions (type of base oil, salinity, temperature). This enabled developing design guidelines to select an optimized tensioactive package comprising a limited number of chemicals, from which field users would select the ones to combine for their applications.
The new tensioactive package was used successfully in two field trial wells in the 7-in. liner sections in a mature development field offshore Thailand. After a thorough comparison between the currently used package and the new one, the laboratory results using the field mud show superior cleaning results and efficiency with the new chemical package.
The zonal isolation was confirmed using an ultrasonic imager logging tool. After the two successful field trials, the tensioactive package was selected as the spacer of choice for a critical new development field campaign offshore Thailand in which zonal isolation between production zones was critical for selective production from each of the zones separately.
This paper will describe the newly improved laboratory methodology and selection criteria of the new tensioactive products and provide a detailed case history of the application in the development campaign, including the design, execution and evaluation of the job.
Geomechanical Assessment Aids Successful Coiled Tubing Drilling (CTD) of Horizontal Wells Through Depleted Reservoirs Interbedded With Weak Formations in the D18 Field
Authors: Chatterjee Avirup , He Wei , Rahman Khalil , Pozdnyshev Maxim , Wei Ooi Zhon , Hamzah Nurul Ezalina 
Published: October 2015

Abstract
Reservoirs in the D-18 fields, offshore Sarawak, Malaysia, are a combination of structurally and stratigraphically trapped sand bodies. Potential hydrocarbons are accumulated in the stacked sand bodies separated by weaker sealing shale bodies and regional coal seams. The fields have significantly depleted pressure following several years of production from different reservoir levels.
Reservoir pressure depletion results in a lower fracture gradient and a narrower drilling mud window. While a lower mud weight is necessary to drill through heavily depleted sands, the lower mud weight may result in excessive wellbore failure in normally pressured, weak formations. A geomechanical assessment is performed to aid coiled tubing horizontal drilling in the depleted reservoirs, which are interbedded with normal-pressure, weak shaly formations.
A geomechanical model was developed using available data from offset wells. A stress path factor is estimated to model the fracture gradient decrease from production-induced depletion. A safe mud window is optimized using the reduced fracture gradient in depleted sands and the hole collapse pressure in the normal-pressure weak shales. The operational mud window is optimized for hole size and annulus. The wells were drilled successfully using the recommended mud windows, without losses into the depleted sands or hole collapse in weak, normal-pressure formations.
The paper presents the workflow for geomechanical model building incorporating the depletion effect, the safe coiled tubing drilling (CTD) program design assessing various risks and highlights various CTD operational issues and the lessons learned.
Analogy Between the Producing Shale Oil and Gas Plays Formations of Mexico and the USA
Authors: Almarza T. , Garza D. , Romero M. 
Published: October 2015

Abstract
Unconventional reservoirs (UNC) are considered those that do not produce at economic flow rates and cannot be cost-effectively produced without applying stimulation, fracturing, and recovery. They are located in predominantly extensive regional accumulations, which, in most cases, is independent of the stratigraphic and structural traps. This requires using special technology for extraction, either by its oil properties or the characteristics of the rock that contains it.
Today, these reservoirs represent an interesting source of income, because many of them are found in deposits that were considered to be exhausted or non-economic by traditional recovery methods, and it is estimated that they are present in large volumes. The recently exploited shale plays are typically constituted by a matrix of very fine grain rock (size clay, shale or marl might be), with varying proportions of clay, silica, and carbonate, which act as source rock, and reservoir seals at the same time. They have very low permeability and often require massive stimulation to produce hydrocarbon.
Generally, resource shale reservoirs must meet a series of requirements to make them economically viable. These conditions are: Organic richness (&gt; 2% COT for shale gas and shale oil variable)Thermal maturity (&gt; 0.7% Ro)Thickness (&gt; 30 m) and areal extentAdsorption capacity (mainly in shale gas)Fracturability (clay content &lt; 40%)OverpressureDepthSurface facilities
Novel Approach for the Optimal Evaluation and Fracture Design of Shale Oil Horizontal Wells in Mexico
Authors: Garza D. , Almarza T. J. , Medina E. , Romero M. A. 
Published: October 2015

Abstract
As the development of hydrocarbon from shale resources increases exponentially globally, it is essential to have a clear understanding of the key variables for evaluating shale reservoirs and to define the best methods for effectively stimulating wells. However, this is not easy considering that each tool has both advantages and drawbacks with respect to technical, methodological, and economic matters. That is why, for shale projects, it is necessary to know the vital variables to optimize the collection of information, costs, and, of course, the validity of final results and interpretations.
For initial characterization, reference information from previously fractured horizontal wells in the same formation should be considered and a holistic approach using characterization from petro-physical, geomechanical, mineralogy, and geochemical analysis should be considered during the determination of the best zones to be fractured. Analysis and use of diagnostic fracture injection testing (DFIT) and minifrac testing is also to be reviewed for the final calibration of fracture models before execution of the operation. Interpretation of micro-seismic monitoring during fracturing has great importance for obtaining models to optimize completions of wells and the development of a reservoir after an initial approach.
This work analyzes and evaluates different sources of information and studies performed. Several factors and effects during the design stage are presented, such as using regional stress studies to estimate possible interference between the fracture stages and its effect on final fracture space determination.
All in all, using this information is recommended for the initial approach during fracture design for the first wells in a new formation, proving to be a novel methodology to optimize and accelerate the development of a basin that can be applied later to following wells, helping save both time and resources.