bluuebunny/crossref_metadata_2025_split huggingface dataset:
MTHFR C677T and postmenopausal breast cancer risk by intakes of one-carbon metabolism nutrients: a nested case-control study
Authors: Maruti Sonia S , Ulrich Cornelia M , Jupe Eldon R , White Emily 
Published: December 2009

Abstract
Introduction
The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene has been hypothesized to increase breast cancer risk. However, results have been inconsistent, and few studies have reported the association by menopausal status or by intakes of nutrients participating in one-carbon metabolism. Our aims were to investigate whether MTHFR C677T was associated with postmenopausal breast cancer risk and whether this relation was modified by intakes of folate, methionine, vitamins B2, B6, and B12, and alcohol.

Methods
We studied 318 incident breast cancer cases and 647 age- and race-matched controls participating in a nested case-control study of postmenopausal women within the VITamins And Lifestyle (VITAL) cohort. Genotyping was conducted for MTHFR C677T and dietary and supplemental intakes were ascertained from a validated questionnaire. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression.

Results
We observed a 62% increased risk of breast cancer among postmenopausal women with the TT genotype (OR = 1.62; 95% CI: 1.05 to 2.48). Women with a higher number of variant T alleles had higher risk of breast cancer (P for trend = 0.04). Evidence of effect-modification by intakes of some B vitamins was observed. The most pronounced MTHFR-breast cancer risks were observed among women with the lowest intakes of dietary folate (P for interaction = 0.02) and total (diet plus supplemental) vitamin B6 (P for interaction = 0.01), with no significant increased risks among women with higher intakes.

Conclusions
This study provides support that the MTHFR 677TT genotype is associated with a moderate increase in risk of postmenopausal breast cancer and that this risk may be attenuated with high intakes of some one-carbon associated nutrients.
Dimensionless flow equations for dynamic simulation of turbomachine components and fluid systems
Authors: Puddu P 
Published: December 2009

In this work, a dimensionless form of the equations of motion used for dynamic simulation of turbomachine components is presented. The dimensionless equations are obtained from the governing equations of unsteady compressible viscous one-dimensional flow by defining three variables of state that have a direct link with the variables measured in the experimental investigations: total pressure, total temperature, and the Mach number. The new dimensionless form of equations presents the characteristics of generality that makes it easy to apply to many fluid dynamic problems. The application of dimensionless equations to more complex systems can be simplified and made easier by using the lumped parameter discretization method. Another important feature of the dimensionless system of equations is that it can be solved explicitly without any iterative process within each step of integration, thus making it easier and faster during dynamic simulations. The equations can be further simplified in the case of stationary flows for which some examples of application are given in order to highlight the generality of the method and its ease of application.
Characterizing Hospitalizations of End-Stage Renal Disease Patients on Dialysis and Inpatient Utilization of Erythropoiesis-Stimulating Agent Therapy
Authors: Brophy Donald F , Daniel Gregory , Gitlin Matthew , Mayne Tracy J 
Published: December 2009

BACKGROUND In 2006, there were over 350,000 patients with end-stage renal disease (ESRD) receiving dialysis therapy. Studies have found that hemoglobin concentrations are often low among dialysis patients after hospital discharge, yet little is known about inpatient anemia treatment. OBJECTIVE To characterize hospitalizations among patients with ESRD on dialysis, specifically, inpatient utilization of erythropoiesis-stimulating agent (ESA) therapy. METHODS A cross-sectional, retrospective study of claims data from 5 commercial health plans for the years 2004–2006 was conducted. Inclusion criteria included 1 or more ESRD-specific International Classification of Diseases Ninth Edition (ICD-9) codes, 3 or more ESRD-specific Current Procedural Terminology/Healthcare Common Procedure Coding System (CPT/HCPCS) procedures on different days, or 3 or more dialysis ICD-9 codes or CPT/HCPCS dialysis procedures on separate days. ESRD patient and hospital characteristics were outlined. RESULTS ESRD patients were hospitalized an average of 1.8 times in both 2004–2005 and 2005–2006. The mean ± SD hospital length of stay (LOS) was 13.3 ± 20.5 and 12.8 ± 19.0 days for 2004–2005 and 2005–2006, respectively. For each year, LOS greater than 7 days occurred in 44% of hospitalizations. Many of these patients were admitted for kidney-related comorbidities and ultimately received procedures and services relevant to dialysis care. For each year, ESA utilization was 13% in year 1 and 11% in year 2 across any LOS. For ESRD patients with a 4- to 7-day LOS (the most common LOS), less than 20% received ESA treatment. ESA utilization increased correspondingly with longer hospital LOS (p < 0.001). CONCLUSIONS Although ESRD patients are commonly hospitalized and claims recognize that kidney-related conditions exist, the utilization of ESAs is low.
Laboratory Investigation of Asphaltene Precipitation Problems During CO2/Hydrocarbon Injection Project for EOR Application in Kuwaiti Reservoirs
Authors: Oskui G. P. , Jumaa M. A. , Abuhained Waleed A. 
Published: December 2009

AbstractAsphaltene precipitation and deposition from oil reservoir fluids during production are serious problems for the oil industry, as it can cause plugging of reservoir formation, wellbore, tubing and production facilities. Kuwait Oil Company (KOC) is facing asphaltene deposition problems in the wellbore of some of the Marrat Jurassic reservoirs in West Kuwait (WK), South East Kuwait (SEK) and North Kuwait (NK). This has caused a reduction in production and shutting of some of the wells and a severe detrimental effect on the economics of oil recovery.As part of a major strategic program for development of the master plan for Improved and Enhanced Oil Recovery (IOR/EOR) techniques for Kuwaiti reservoirs, two projects have been conducted by a joint team in Kuwait Institute for Scientific Research (KISR) and KOC to screen all the reservoirs with the available techniques by assessing incremental recovery, miscible gas injection such as CO2 and Hydrocarbon techniques were recommended for more than 80% of the light oil reservoir in Kuwait. Currently the Field development (FD) teams in KOC are planning further investigation and are conducting lab tests and simulation studies to design the first pilot tests for CO2/HC injection for several of the selected reservoirs in NK, WK. Comprehensive laboratory testing, modeling tuning and simulation preparation is required for this design study.Any Oil production processes and the application of IOR & EOR can modify the flow and phase behavior of the reservoir fluids, and rock properties. These modifications could lead to asphaltene precipitation. Asphaltene deposition on formation is a serious problem, and it might occur during CO2/gas injection, and can cause porosity and permeability reduction in the reservoir, and plugging wellbore and piping in production facilities. In the planning of any gas injection IOR projects, the flocculation and deposition of asphaltene in porous media and their interaction with rock and fluid represent complex phenomena which need to be investigated under dynamic flowing conditions.In this paper, a systematic approach for the investigation of Asphaltene problems in reservoirs during primary production, pressure depletion and IOR/EOR processes under gas injection processed will be presented. Some of the results of the initial laboratory studies on the characterization and phase behavior studies of typical crude oil samples from Kuwaiti reservoirs will be presented.
A Novel Method to Construct Capillary Pressure Curves by Using NMR Log Data and Its Application in Reservoir Evaluation
Authors: Zhang Chong , Xiao Liang , Mao Zhi-qiang , Sun Zhong-chun , Luo Xing-ping 
Published: December 2009

Abstract
In view of the problem that there is a good agreement with big porosity while a bifurcation with small porosity in practical applications of the method that a linear function of the conversion scale is used to construct NMR capillary pressure curves, it is proved by profound analysis of the morphologic characteristics of mercury intrusion capillary pressure curves that capillary pressure curves can be constructed continuously only if the mercury saturation corresponding to different mercury pressures is calculated. Based on the theory of J function and the classical SDR model, by analyzing 50 core samples, the mercury injection experiment and NMR measurement of which are taken simultaneously, a NMR capillary pressure curve constructing method is put forward and a model of NMR capillary pressure curve construction is established. Accuracy of the new method is verified by analysis of morphologic characteristics of the mercury injection capillary pressure curves comparing with the real ones. Processing analysis of the well A01 of an oilfield is carried out with the method to evaluate the reservoir pore structure and calculate the original reservoir water saturation. The result shows that the method is effective and its deployment can be carried out in the oilfields.
Meeting The Challenges Of Planning A Thermal Pilot For Ratqa Lower Fars Heavy Oil Field
Authors: Sanyal T. 
Published: December 2009

AbstractKuwait is keen in developing the shallow Miocene Heavy Oil resources of Ratqa Lower Fars. EOR screening studies indicate thermal methods of Cyclic Steam Stimulation (CSS) and Steamflood as most promising technologies for developing this resource and meeting KOC goals. Thermal development was tried earlier in this field. In 1980's two CSS pilots were carried out that are considered successful. Steam Flood was also planned at that time but the project got stalled due to the Gulf War. Facilities got destroyed during that war. The present paper describes how thermal simulation techniques were used to design a new and improved thermal pilot, by matching the old CSS pilot performance, learning from history matching process and carrying out multiple prediction scenario analysis.The pilot plan is currently at the early phase of implementation in this field and is considered very important risk mitigation step, towards commercialization of the project. The paper summarized the objectives of the pilot, so that a firm understanding is generated of the expectations and relevance of the pilot in the larger development scheme of the project.Thermal simulation study results for arriving at the pilot plan would be presented in the paper. How history matching of old CSS pilots and the cold flow data obtained from recent CHOPS pilot wells help in arriving at an improved design of the Steam Flood pilot would be documented.The contents of the paper can help generating ideas in designing pilots in similar Heavy Oil fields. The document can also serve as a score card for the Lower Fars thermal pilot post implementation, to understand the original objectives of the pilot.
Studies Of Effluent Water Quality For The Enhancement Of Oil Recovery In North Kuwait
Authors: El-Mohemeed Emad , Carew John , Falah M. , Al-Azmi Rasheed , Uthaman Kuppusamy 
Published: December 2009

Abstract
The future plan for North Kuwait oil fields is to produce 900,000 bpd by the year 2013/2014. To meet this target, it is necessary to inject up to 1.5 million barrels of water per day (bwpd). The future plan is to inject 500,000 bwpd of treated sea water with the balance from produced water re-injection. However, if water flooding is not implemented, significant amounts of oil would be left in-place, and the current plan could not be achieved.
Dispersed oil in produced water is detrimental for several reasons. First, bacteria utilize certain components in the crude oil as food. Second, oil is strongly adsorbed on iron sulfides and other scale deposits, which makes it difficult to remove these deposits with acid treatments. Third, oil reduces the relative permeability to water in the injection well. As relative permeability to water decreases, it requires more pressure to inject the same amount of oil free water. Dispersed oil in the injected water can be reduced by proper selection of water treatment equipment, this equipment selection dependant on this study results.
One of the main objectives of this study is to perform a system audit of effluent water specifications from gathering centers (GCs) in one of the Kuwait oil field. This would involve the collecting and analysing the effluent water samples from various points in each gathering center (GC) and evaluate the water quality and its suitability for re-injection to enhance the recovery of oil.
Deterministic versus Stochastic Discrete Fracture Network (DFN) Modeling, Application in a Heterogeneous Naturally Fractured Reservoir
Authors: Tavakkoli Meyssam , Mohammadsadeghi Mehdi , Shahrabadi Abbas , Khajoee Saeed , Malakooti Reza , Beidokhti Mohsen Safari 
Published: December 2009

AbstractFracture Modeling is a multi-step process involving several disciplines within reservoir characterization and simulation. This note applies Discrete Fracture Network (DFN) concept in a unique and comprehensive study of fracture modeling in one of the naturally fractured carbonate reservoir in Iran.A Discrete fracture network is a group of planes representing fractures. Fractures of the same type that are generated at the same time are grouped into a fracture set. Each fracture network containing fractures has at least one fracture set but may have many.The simplest fracture sets are defined deterministically as a group of previously defined fractures, either as a result of fault plane interpretation extraction from a seismic cube, or as previously defined fractures.Fractures modeled stochastically can be described statistically either using numerical input or properties in the grid. These properties can vary in 3D and can easily be modeled using seismic attributes from seismic data. Seven seismic attributes are used in this study. The final results of both deterministic and stochastic DFN modeling upscaled to a simple model and used as base grid in dynamic simulation.
Application of Differential Evolution as a New Method for Automatic History Matching
Authors: Hajizadeh Yasin , Christie Mike , Demyanov Vasily 
Published: December 2009

Abstract
This paper presents a novel approach in automatic history matching using a differential evolution algorithm. Differential evolution is becoming a popular global optimization method and has been widely applied in many challenging engineering problems outside the oil industry. Some advantages of differential evolution are its simplicity in structure which leads to ease of coding and straightforward parallelisation, and its few control parameters making it easy to use in an operational context. These advantages make it important to evaluate differential evolution for use in automatic history matching frameworks where reservoir engineers require a powerful, yet easy to work tool with little effort to find optimum algorithm parameters.
We have applied differential evolution approach to obtain history matched models of a reservoir simulation case in Gulf of Mexico. The effect of different tuning parameters on the performance of differential evolution has been studied and the algorithms sensitivity to initial starting conditions investigated. Results confirm that differential evolution is a good optimization tool in obtaining multiple good history matched models. We have also compared the match quality of models obtained using differential evolution with the Neighbourhood Algorithm (NA). This comparison shows that differential evolution obtains comparable or better models in terms of matching misfit.
Finally, we studied the effect of the number of observation data points used in history matching with differential evolution algorithm. We show how additional information helps the algorithm in finding the promising regions of the search space and narrowing down the uncertainty intervals of the predictions.
Planning Miscibility Tests and Gas Injection Projects for Four Major Kuwaiti Reservoirs
Authors: Al-Ajmi Moudi , Alomair Osamah , Elsharkawy Adel 
Published: December 2009

AbstractThe escalating oil demand and maturity of most of the giant oil fields in the world, especially in the Middle East, the techniques for improving oil recovery have became more feasible and essential. Kuwait long term strategy is to increase oil production to meet marked demand. Currently, miscible gas injection is considered for enhancing oil production from Kuwaiti oil reservoirs. A key parameter for assessing the applicability of gas injection for a given reservoir is the minimum miscibility pressure (MMP). In this paper various miscibility experiments for planning gas injection projects in major producing fields in Kuwait are discussed. These experiments include swelling tests, slim-tube tests, and core flooding studies. These tests are useful tool for screening of the potential reservoirs for improving their future oil production and for developing suitable EOS for planning gas injection projects of the chosen fields.
Temperature Logging in Russia: Development History of Theory, Technology of Measurements and Interpretation Techniques
Authors: Valiullin R. A. , Ramazanov A. Sh. , Sharafutdinov R. F. 
Published: December 2009

Abstract
The history of development and the state of the art of well temperature logging in Russia is described in the paper.
As it is known, the first logging in oil wells were temperature ones. In 1906 D. Golubyatnikov made the first measurement of temperature distribution along the well bore using the maximal thermometer. In 1932 it was developed the first electronic well thermometer. From 1970 in practice of field reserarches the high sensitive thermometers with resolution of 0.01K are used: it is registered and analyzed the temperature changes of hundreds and tens parts of degree, caused by Joule-Thomson effect and adiabatic effect.
The development of theoretical and methodical basis of well thermometry was made by several groups of Moscow oil institute (now it is RGUNG), VNIINeft (Moscow), Kazan state university (Kazan) and Bashkir state university (Ufa). In Bashkir SU the model of the first industrial small-size well thermometer STL-28, theoretical basis of thermometry of transient processes in the well and formations were developed and the wide practical experience of solution of different problems in oil wells by thermometry was accumulated.
At present time the most volume of production log is accounted to thermometry. In the paper it is given the examples of field cases from Bashkiria, Tataria and Western Siberia by means of well thermometry in production (flowing, rod pumping and ESP ones) and injection wells, and also during the development by the gas (air) compressor, swab and jet pump. The results of practical testing of new methods of well thermometry as "active thermometry", which is based on local inductive heating of casing on different depths and observation of the transient temperature behavior, and "infrared thermometry" for survey of "dry intervals" of the well above the liquid level.
Also it is discussed the mathematical models, used at interpretation of temperature log. The most recent results are connected with quantitative interpretation of pressure and temperature transients with the purpose of determination of flow rates and individual parameters (for example radius and permeability of damaged zone) of formation in multilayer wells.
3D Geological Modeling of a Tight Naturally Fractured Carbonate Reservoir as an input to Reservoir Simulation – A Case Study from North Kuwait Jurassic fields
Authors: Chakraborty Subrata K. , Rao Narhari Srinivasa , Al-Awadi Mishari , Kidambi Vijaya Kumar , Al-Houli Mariam , Al-Ateeqi Khalid , Perrin Christian , Ghorayeb Kassem 
Published: December 2009

Abstract
Dedicated exploration efforts targeted on the Jurassic reservoirs in North Kuwait culminated in the discovery of six separate fields, encompassing an area of approximately 1,772 km2. These reservoirs are known to hold commercial accumulation of gas, gas condensate and volatile oil and are currently in an early phase of development. The producing Jurassic reservoirs belong to the Marrat, Sargelu and Najmah Formations of Toarcian to Tithonian ages. These reservoirs consist of tight carbonates with several other complex lithologies and are naturally fractured with fractures acting as a driver to production in the Najmah and Sargelu formations and fractures acting as production assist in the Marrat Formation.
A 3D geological model was developed for these reservoirs. The static geological model consists of a matrix model capturing the facies, and other matrix reservoir properties like porosity, permeability and water saturation; and the fracture model captures the fracture properties like fracture porosity, permeability and matrix to fracture coupling parameters. The model framework was guided by seismic horizon interpretation from 3D seismic data while the model vertical resolution was optimized to adequately capture the log defined reservoir properties. Electro facies were interpreted at wells with extensive core calibration and were used to develop a 3D facies model capturing the worked out depositional environment. This facies model was used to develop the porosity, permeability and water saturation models using the processed wireline log data, core plug based measurements. The 3D fracture model was developed capturing the areal distribution of fractures using the calibrated 3D seismic volume curvature attribute as soft data and constrained vertically by hard data from image log and cores from wells, thus bringing robustness and reliability for planning the development wells. This 3D geological model was optimally upscaled depending on the aerial well density for use of flow simulation studies.