bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applying the Underbalanced-for-Life Philosophy to Well Construction
Authors: Bowling J. , Riyami M. , Somat E. , Vieira P. 
Published: January 2008

Abstract
Three years ago Petroleum Development Oman (PDO) implemented an "Underbalanced for Life" philosophy as a means to improve well and reservoir productivity. This philosophy requires not only drilling the well underbalanced but completing the well underbalanced so that only produced fluids are exposed to the reservoir.
From 2002 to 2004, the UBD campaign focused on wells and fields that had a reservoir pressure low enough to not flow to surface. This meant BHA trips and well completion operations were conducted conventionally and no special procedures and operations were required. At the end of 2004, PDO began drilling underbalanced in fields that had sufficient reservoir pressure to flow to surface.
Until recently, the only way for a drilling rig to trip pipe into and out of the well was to kill the well so that there was no surface pressure or to snub the pipe under pressure. A new alternative was identified where a down hole valve is used to lubricate pipe into and out of the well without surface pressure. To meet the philosophy of "underbalanced for life" the down hole valve was selected and new equipment, procedures and methods developed.
Early trials with the retrievable down hole valve provided sufficient success to continue drilling wells with natural flow to surface. More than 20 flowing wells have been completed underbalanced with a high rate of success.
This paper explains the well design, procedures and equipment used to implement the "Underbalanced for Life" philosophy.
Systematic Evaluation of Kuwaiti Reservoirs to Determine Optimum Candidates for Underbalanced Drilling
Authors: Al-Matar Bader , Al-Atroshi Kamal , Chetri Hom , El-Aziz Sabry Abd , Kabir Mir Md Rezaul , Shayegi Sara , Ibrahim Emad Bakri 
Published: January 2008

Abstract
Underbalanced drilling technology (UBD) has increased production potential from many oil and gas reservoirs worldwide. Kuwait Oil Company (KOC) decided to pilot this technology in Kuwaiti reservoirs to assess the viability of this technique and its capability to optimize production and development of their reservoirs. To maximize the potential for successful implementation, a scientifically rigorous process was implemented to evaluate the reservoir candidates.
The reservoirs include Upper Burgan, Mauddud, Tayarat, and Radhuma. Since there is a high degree of variation in reservoir quality, hydrocarbon properties, formation pressures and other properties depending on location, candidates from different locations were examined. In the first phase, a high order qualitative ranking of the candidates was performed. The basis of comparison included an examination of the reservoir and fluid properties, production data, review of the core, log and geological/geophysical data, drilling and operational information.
The ranking of the candidates was based on production potential, drilling benefits, potential for instability, early water break through, and other operational, reservoir and drilling considerations. The top-ranked candidates were examined determining the range of potential reservoir behavior during UBD and the corresponding wellbore hydraulics (drilling the well on paper) was performed.
It was concluded that UBD technology was suited for several of the reservoirs but that some of the candidates might not realize as much improvement as others to justify implementation in the first implementation stage. If UBD proves successful on the candidates chosen for the pilot study, the candidates showing a lesser degree of potential will again be considered.
This paper describes the screening methodology used and discusses the results from the candidate evaluation process.
Underbalanced Drilling of Oil Wells in Saudi Arabia: Case History and Lessons Learned
Authors: Muqeem Muhammad A. , Jarrett Clark M. , Abdul Hassan J. 
Published: January 2008

Abstract
Saudi Aramco started a campaign in the fall of 2004 to drill Power Water Injection (PWI) Wells underbalanced. After drilling several PWI wells, it was envisaged that adequate experience and learning curve has been established to implement the next phase of this campaign. In the 4th quarter of 2005, a three well pilot program was undertaken to plan and execute this enabling technology safely and in an environmentally safe manner in oil wells.
The primary objective of drilling these oil wells underbalanced was to demonstrate that a closed/semi-closed system can be utilized properly and safely to undertake underbalanced drilling (UBD) operations in the Ghawar field. Furthermore, the aim was also to verify whether it is possible to ship the produced sour crude to the nearby facilities without any environmental or operational concerns.
This paper summarizes Saudi Aramco's experience gained during the drilling of these three oil wells. Mechanical and hydraulic down-hole valves were utilized for tripping and stripping into and out of these wells in an underbalanced mode. It further highlights the operational complexity and the challenges faced during the implementation of this technology in a hydrocarbon bearing zone for the first time. It also elaborates on the interdisciplinary team that was instrumental behind the safe and successful implementation of underbalanced drilling.
The paper also elaborates on the lessons learned and how they were implemented continuously with regards to Health, Safety and Environmental (HSE) during the drilling operations. The long term goal was to evaluate whether the application of UBD can be extended to other asset teams/areas effectively to reap its potential benefit.
Sometimes Neglected Hydraulic Parameters of Underbalanced and Managed Pressure Drilling
Authors: Stone Charles R. "Rick" , Tian Shifeng 
Published: January 2008

Abstract
Successful drilling, especially in very deep wells, may be driven by hydraulic limiting parameters. Two new technologies, UnderBalanced Drilling (UBD) and Managed Pressure Drilling (MPD) have emerged as solutions to specific hydraulic issues during drilling. A hydraulic parameter can be defined as any factor, mechanical, structural or fluid that impacts the exertion of hydrostatic head on the open hole. Hydraulic parameters, as a group, must be planned for and managed during all drilling operations to prevent unwanted or unsafe conditions.
Many hydraulic parameters are documented thoroughly and therefore well-known in the upstream oil and gas industry. They include; Pump Rate; Drillstring and Hole Geometry; Mud Rheology (including surge effect, swab effect, standpipe pressure and hole cleaning); Surface Backpressure; and Rate of Penetration (ROP). These factors are commonplace and routinely addressed as part of a complete drilling program. Other hydraulic limiting parameters are lesser known and sometimes not addressed in the basis of design for unconventional drilling prospects.
It is paramount that drillers consider all hydraulic parameters that influence UBD or MPD operations or the project can end in failure or with unsuccessful consequences. This paper discusses in general some of the lesser-known hydraulic issues that might be encountered when drilling vertical wells using UBD or MPD techniques, especially to deeper horizons.
Disparities in A1C Levels Between Hispanic and Non-Hispanic White Adults With Diabetes
Authors: Kirk Julienne K. , Passmore Leah V. , Bell Ronny A. , Narayan K.M. Venkat , D'Agostino Ralph B. , Arcury Thomas A. , Quandt Sara A. 
Published: January 2008

OBJECTIVE—Hispanics have higher rates of diabetes and diabetes-related complications than do non-Hispanic whites. A meta-analysis was conducted to estimate the difference between the mean values of A1C for these two groups.
RESEARCH DESIGN AND METHODS—We executed a PubMed search of articles published from 1993 through July 2007. Data sources included PubMed, Web of Science, Cumulative Index to Nursing and Allied Health, the Cochrane Library, Combined Health Information Database, and Education Resources Information Center. Data on sample size, age, sex, A1C, geographical location, and study design were extracted. Cross-sectional data and baseline data from clinical trials and cohort studies for Hispanics and non-Hispanic whites with diabetes were included. Studies were excluded if they included individuals &lt;18 years of age or patients with pre-diabetes or gestational diabetes.
RESULTS—A total of 495 studies were reviewed, of which 73 contained data on A1C for Hispanics and non-Hispanic whites, and 11 met the inclusion criteria. Meta-analysis revealed a statistically significant mean difference (P &lt; 0.0001) of −0.46 (95% CI −0.63 to −0.33), correlating to an ∼0.5% higher A1C for Hispanics. Grouping studies by design (cross-sectional or cohort), method of data collection for A1C (chart review or blood sampling), and care type (managed or nonmanaged) yielded similar results.
CONCLUSIONS—In this meta-analysis, A1C was ∼0.5% higher in Hispanic patients with diabetes than in non-Hispanic patients. Understanding the reasons for this disparity should be a focus for future research.
Effects of Age, Time Period, and Birth Cohort on the Prevalence of Diabetes and Obesity in Korean Men
Authors: Kwon Jin-Won , Song Yun-mi , Park Hye soon , Sung Joohon , Kim Ho , Cho Sung-il 
Published: January 2008

OBJECTIVE—We examined changes in the prevalence of diabetes, obesity, and overweight in 412,881 Korean men in birth cohorts from 1933 to 1972 over 8 years from 1992 to 2000 and separately analyzed the effects of age, time period, and birth cohort.
RESEARCH DESIGN AND METHODS—The study included male employees of Korean government organizations and schools who were between 20 and 59 years of age in 1992. Diabetes was diagnosed on the basis of self-reports in 1992 or fasting blood glucose levels (≥126 mg/ml, 7.0 mmol/l). The age-period-cohort model was used to estimate the effects of age, time period, and birth cohort.
RESULTS—In Korean male birth cohorts from 1933 to 1972, the age-specific prevalence of diabetes, obesity, and overweight in men aged 28–59 years increased annually by 0.41% (3.03 to 6.29%), 0.18% (0.70 to 2.16%), and 1.49% (23.48 to 35.41%), respectively, from 1992 to 2000. The relative change in diabetes was largest among the younger cohorts (&gt;400% increase over 8 years) and corresponded to the change in obesity. Apart from the contribution of age, clear cohort and period effects were evident for diabetes, although the magnitude of the effect was slightly less than that for obesity.
CONCLUSIONS—Prevention of diabetes through the control of obesity, particularly in young men, clearly needs to be emphasized.
Glucose Indices, Health Behaviors, and Incidence of Diabetes in Australia
Authors: Magliano Dianna J. , Barr Elizabeth L.M. , Zimmet Paul Z. , Cameron Adrian J. , Dunstan David W. , Colagiuri Stephen , Jolley Damien , Owen Neville , Phillips Patrick , Tapp Robyn J. , Welborn Tim A. , Shaw Jonathan E. 
Published: January 2008

OBJECTIVE—This national, population-based study reports diabetes incidence based on oral glucose tolerance tests (OGTTs) and identifies risk factors for diabetes in Australians.
RESEARCH DESIGN AND METHODS—The Australian Diabetes, Obesity and Lifestyle Study followed-up 5,842 participants over 5 years. Normal glycemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes were defined using World Health Organization criteria.
RESULTS—Age-standardized annual incidence of diabetes for men and women was 0.8% (95% CI 0.6–0.9) and 0.7% (0.5–0.8), respectively. The annual incidence was 0.2% (0.2–0.3), 2.6% (1.8–3.4), and 3.5% (2.9–4.2) among those with normal glycemia, IFG, and IGT, respectively, at baseline. Among those with IFG, the incidence was significantly higher in women (4.0 vs. 2.0%), while among those with IGT, it was significantly higher in men (4.4 vs. 2.9%). Using multivariate logistic regression, hypertension (odds ratio 1.64 [95% CI 1.17–2.28]), hypertriglyceridemia (1.46 [1.05–2.02]), log fasting plasma glucose (odds ratio per 1 SD 5.25 [95% CI 3.98–6.92]), waist circumference (1.26 [1.08–1.48]), smoking (1.70 [96% CI 1.11–2.63]), physical inactivity (1.56 [1.12–2.16]), family history of diabetes (1.82 [1.30–2.52]), and low education level (1.85 [1.04–3.31]) were associated with incident diabetes. In age- and sex-adjusted models, A1C was a predictor of diabetes in the whole population, in those with normal glycemia, and in those with IGT or IFG.
CONCLUSIONS—Diabetes incidence is 10–20 times greater in those with IGT or IFG than those with normal glycemia. Measures of glycemia, A1C, metabolic syndrome components, education level, smoking, and physical inactivity are risk factors for diabetes.
Body Iron Stores and Dietary Iron Intake in Relation to Diabetes in Adults in North China
Authors: Luan De Chun , Li Hui , Li Sui Jing , Zhao Zhuo , Li Xin , Liu Zhong Mei 
Published: January 2008

OBJECTIVE—To evaluate the association between body iron stores, dietary iron intake, and risk of diabetes in northern China.
RESEARCH DESIGN AND METHODS—The data of a cross-sectional household survey in 2002 in Liaoning Province in northern China was used. The final sample in our study contained 2,997 subjects aged ≥18 years. Fasting plasma glucose and serum ferritin were measured. Dietary information was collected by 3-day food records.
RESULTS—Serum ferritin was associated with elevated risk of diabetes even adjusted for age, sex, nondietary factors, and dietary factors. No association among total iron intake, nonheme iron intake, and diabetes risk was found. However, higher heme iron intake was significantly associated with elevated risk of diabetes after adjusting for known factors.
CONCLUSIONS—In Chinese, associations among higher serum ferritin level, higher heme iron intake, and elevated risk of diabetes were found.
Perception of Neighborhood Problems, Health Behaviors, and Diabetes Outcomes Among Adults With Diabetes in Managed Care
Authors: Gary Tiffany L. , Safford Monika M. , Gerzoff Robert B. , Ettner Susan L. , Karter Andrew J. , Beckles Gloria L. , Brown Arleen F. 
Published: January 2008

OBJECTIVE—Recent data suggest that residential environment may influence health behaviors and outcomes. We assessed whether perception of neighborhood problems was associated with diabetes behaviors and outcomes.
RESEARCH DESIGN AND METHODS—This cross-sectional analysis included 7,830 diabetic adults enrolled in Translating Research Into Action for Diabetes, a study of diabetes care and outcomes in managed care settings. Perception of neighborhood problems was measured using a summary score of participants’ ratings of crime, trash, litter, lighting at night, and access to exercise facilities, transportation, and supermarkets. Outcomes included health behaviors and clinical outcomes. Hierarchical regression models were used to account for clustering of patients within neighborhoods and to adjust for objective neighborhood socioeconomic status (percentage living in poverty) and potential individual-level confounders (age, sex, race/ethnicity, education, income, comorbidity index, and duration of diabetes).
RESULTS—After adjustment, residents of neighborhoods in the lowest tertile (most perceived problems) reported higher rates of current smoking (15 vs. 11%) than those in the highest tertile and had slightly lower participation in any weekly physical activity (95 vs. 96%). In addition, their blood pressure control was worse (25 vs. 31% &lt;130/80 mmHg), and their Short Form 12 scores were slightly lower (44 vs. 46 units for emotional well-being and 43 vs. 44 units for physical well-being); all P &lt; 0.01.
CONCLUSIONS—Neighborhood problems were most strongly associated with more smoking and higher blood pressure, both of which have significant implications for cardiovascular risk. Potential mechanisms that explain these associations should be further explored in longitudinal studies.
High Serum Uric Acid as a Novel Risk Factor for Type 2 Diabetes
Authors: Dehghan Abbas , van Hoek Mandy , Sijbrands Eric J.G. , Hofman Albert , Witteman Jacqueline C.M. 
Published: January 2008

OBJECTIVE—To investigate the association between serum uric acid level and risk of type 2 diabetes.
RESEARCH DESIGN AND METHODS—The population for analysis consisted of 4,536 subjects free from diabetes at baseline. During a mean of 10.1 years of follow-up, 462 subjects developed diabetes.
RESULTS—The age- and sex-adjusted hazard ratios (HRs) (95% CIs) for diabetes were 1.30 (0.96–1.76) for the second, 1.63 (1.21–2.19) for the third, and 2.83 (2.13–3.76) for the fourth quartile of serum uric acid, in comparison with the first quartile. After adjustment for BMI, waist circumference, systolic and diastolic blood pressure, and HDL cholesterol, the HRs decreased to 1.08 (0.78–1.49), 1.12 (0.81–1.53), and 1.68 (1.22–2.30), respectively.
CONCLUSIONS—The results of this population-based study suggest that serum uric acid is a strong and independent risk factor for diabetes.
Detection of a Meal Using Continuous Glucose Monitoring
Authors: Dassau Eyal , Bequette B. Wayne , Buckingham Bruce A. , Doyle Francis J. 
Published: January 2008

OBJECTIVE—The purpose of this study was to introduce a novel meal detection algorithm (MDA) to be used as part of an artificial β-cell that uses a continuous glucose monitor (CGM).
RESEARCH DESIGN AND METHODS—We developed our MDA on a dataset of 26 meal events using records from 19 children aged 1–6 years who used the MiniMed CGMS Gold. We then applied this algorithm to CGM records from a DirecNet pilot study of the FreeStyle Navigator continuous glucose sensor. During a research center admission, breakfast insulin was withheld for 1 h, and discrete glucose levels were obtained every 10 min after the meal.
RESULTS—Based on the Navigator readings, the MDA detected a meal at a mean time of 30 min from the onset of eating, at which time the mean serum glucose was 21 mg/dl above baseline (range 2–36 mg/dl), and &gt;90% of meals were detected before the glucose had risen 40 mg/dl from baseline.
CONCLUSIONS—The MDA will enable automated insulin dosing in response to meals, facilitating the development of an artificial pancreas.
Evaluation of a System for Automatic Detection of Diabetic Retinopathy From Color Fundus Photographs in a Large Population of Patients With Diabetes
Authors: Abràmoff Michael D. , Niemeijer Meindert , Suttorp-Schulten Maria S.A. , Viergever Max A. , Russell Stephen R. , van Ginneken Bram 
Published: January 2008

OBJECTIVE—To evaluate the performance of a system for automated detection of diabetic retinopathy in digital retinal photographs, built from published algorithms, in a large, representative, screening population.
RESEARCH DESIGN AND METHODS—We conducted a retrospective analysis of 10,000 consecutive patient visits, specifically exams (four retinal photographs, two left and two right) from 5,692 unique patients from the EyeCheck diabetic retinopathy screening project imaged with three types of cameras at 10 centers. Inclusion criteria included no previous diagnosis of diabetic retinopathy, no previous visit to ophthalmologist for dilated eye exam, and both eyes photographed. One of three retinal specialists evaluated each exam as unacceptable quality, no referable retinopathy, or referable retinopathy. We then selected exams with sufficient image quality and determined presence or absence of referable retinopathy. Outcome measures included area under the receiver operating characteristic curve (number needed to miss one case [NNM]) and type of false negative.
RESULTS—Total area under the receiver operating characteristic curve was 0.84, and NNM was 80 at a sensitivity of 0.84 and a specificity of 0.64. At this point, 7,689 of 10,000 exams had sufficient image quality, 4,648 of 7,689 (60%) were true negatives, 59 of 7,689 (0.8%) were false negatives, 319 of 7,689 (4%) were true positives, and 2,581 of 7,689 (33%) were false positives. Twenty-seven percent of false negatives contained large hemorrhages and/or neovascularizations.
CONCLUSIONS—Automated detection of diabetic retinopathy using published algorithms cannot yet be recommended for clinical practice. However, performance is such that evaluation on validated, publicly available datasets should be pursued. If algorithms can be improved, such a system may in the future lead to improved prevention of blindness and vision loss in patients with diabetes.
Soluble CD36 and Risk Markers of Insulin Resistance and Atherosclerosis Are Elevated in Polycystic Ovary Syndrome and Significantly Reduced During Pioglitazone Treatment
Authors: Glintborg Dorte , Højlund Kurt , Andersen Marianne , Henriksen Jan Erik , Beck-Nielsen Henning , Handberg Aase 
Published: January 2008

OBJECTIVE—We investigated the relation between soluble CD36 (sCD36), risk markers of atherosclerosis and body composition, and glucose and lipid metabolism in polycystic ovary syndrome (PCOS).
RESEARCH DESIGN AND METHODS—Thirty PCOS patients were randomized to 30 mg/day pioglitazone or placebo for 16 weeks. Fourteen weight-matched healthy female subjects were included as control subjects. sCD36, oxidized LDL (oxLDL), high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, euglycemic-hyperinsulinemic clamps, and whole-body dual-energy X-ray absorptiometry scans were performed.
RESULTS—sCD36 (2.87 relative units [0.88–9.36] vs. 1.67 relative units [0.72–3.89]), oxLDL (44.9 units/l [26.9–75.1] vs. 36.1 units/l [23.4–55.5]), and hsCRP (0.26 mg/dl [0.03–2.41] vs. 0.12 mg/dl [0.02–0.81]) were significantly increased in PCOS patients versus control subjects (geometric mean ± 2 SD). In PCOS, positive correlations were found between central fat mass and sCD36 (r = 0.43), hsCRP (r = 0.43), and IL-6 (r = 0.42) (all P &lt; 0.05). After adjusting for fat mass, sCD36 and oxLDL correlated inversely with measures of insulin-stimulated glucose metabolism and positively with lipid oxidation during insulin stimulation in PCOS patients and control subjects (n = 44). sCD36 and oxLDL were significant independent predictors of glucose and lipid metabolism, whereas hsCRP and IL-6 showed no significant contribution. Following pioglitazone treatment, insulin sensitivity increased, whereas sCD36 (3.21 relative units [0.76–13.6] vs. 2.33 relative units [0.84–6.46]) and hsCRP decreased (P &lt; 0.05). No significant changes were measured in body composition.
CONCLUSIONS—sCD36 and oxLDL correlated with measures of insulin sensitivity independent of central fat mass. Pioglitazone treatment reduced sCD36 while improving insulin-stimulated glucose metabolism, further supporting the association between sCD36 and insulin resistance in PCOS.