bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Hydraulic Fracturing from a Supply Vessel in Russian Caspian Sea
Authors: Stenin V. P. , Delia S. V. , Levchenko V. S. , Vereschagin S. , Butula K. K. , Enkababian P. 
Published: October 2012

Abstract
Rakushechnoe-8 is one of the exploration wells drilled in the Northern Caspian Sea. The understanding of the geometry and performance of the propped fracture completion in the Apt formation was considered critical for the economical development of this offshore oilfield. Because of this, and the potential risk of fracture breaking into the water zone below, no resources were spared and robust engineering methods were applied for the first time in Russian offshore operations to determine the formation productivity without and with a hydraulic fracture completion in place. This case history will detail how a planned joint engineered approach provided critical information for the reservoir and production teams to determine the formations potentials, ensuring at the same time reliable and safe offshore operations.
After a detailed feasibility and engineering study, a local supply vessel was converted into a stimulation vessel to meet the maritime regulation requirements and projected needs of the Russian Federation. As part of the Project Readiness Assessment, the 4000-HHP strong frac equipment was mock-assembled on the dock, tested, and all the hazards evaluated before sailing. The joint engineering team prepared a rigorous plan for multi source data collection before, during, and after treatment operations. The plan included running dipole cased hole acoustic measurements before and after the frac treatment, bottomhole pressure gauges, a complete mini-frac test, multiple post mini-frac temperature logging runs, production logging runs, and well testing and sampling operations before and after the frac. Finally, a novel vertical seismic profile and micro-seismic measurement was employed to further understand the hydraulic fracture behavior in the Apt formation.
The data analyzed before the main fracture treatment enabled safe placement of all 49 tons of 16/20 mesh Intermediate Strength Proppant (ISP) through the drillstem test string obtaining a Cfd = 2.7 deemed optimal for the formation.
Post frac measurements and semi numerical modeling indicated that the mechanical model created before the mini frac required some additional modifications and that the propped fracture remained within the target zone. The acoustic and microseismic post frac measurements and well-test results correlated with the expected fracture effective half-lengths and conductivity, confirming that the preparation and execution involved with attaining accurate measurements provided significant value.
Turbulent Flow Laminarization Under Conditions Of Spatial and Heat Deformations in Pipelines
Authors: Alginov R. A. , Kharlamov S. N. 
Published: October 2012

Abstract
Investigation represented below is devoted to flows in channels with complicated wall configuration, containing cross-section variation along pipes (so-called convergent and divergent pipes) as well as under conditions of intensive heat supply to wall. Investigation was carried out in terms of original two-parametric k-L turbulence model adapted for internal flows on the basis of experimental data [1]. Obtained results are compared with experimental ones. Effects of laminarization are fixed, practical recommendations on use of these effects are given.
Implementation of the Upgraded Shut-Off Valves for Protecting Productive Formations
Authors: Kuznetsov Vasiliy Leontievich , Nurgaliev I. F. , Kutko R. O. 
Published: October 2012

Annotation
The Vankor Field is being developed as network of horizontal production wells, with lateral filter length of not less than 1,000 m. The completion systems options include Equalizer™(Schlumberge), ResFlow (Baker Hughes) systems as well as various designs of slotted and screen filters made by Russian manufacturers.
With the purpose of achieving planned oil production capacities and oil recovery factors, it is critically important to save formation reservoir properties and prevent clogging of bottomhole formation zone.
For this purpose we analyzed the market of technologies used to eliminate contact of killing fluid with bottomhole formation zone during intervention and workover operations, and selected bottomhole shut-off valves for the Vankor Field conditions.
The main challenge of shut-off valves design selection is the functional possibility of conducting geophysical surveys using coiled tubing in lateral hole below packer set interval without prior retrieval of the packer.
By the time of selection, the Halliburton serial shut-off valves completely complied with these conditions but the implementation process was complicated by problems related to setting of shut-off valve in the G-6 packer seat due to complex wellbore profiles and deviation angles up to 90 degrees.
This publication describes the result achieved by joint operations of ZAO Vankorneft Oil and Gas Production Department specialists and Halliburton design engineers, which enabled us to successfully apply shut-off valves in the Vankor field wells.
Integrated Reservoir Fluid Characterization: A Case Study of Multilayered Yuzhno-Tambeyskoe Gas Condensate Field
Authors: Filippova J. , Mezentsev D. 
Published: October 2012

Abstract
Article contains the comparison of traditional and authors suggested methodologies for the composition of fluid modeling of multilayer gascondensate fields. Conditions of practical applications, benefits and constrains were denoted for green low-studied and operated fields.
As prerequisite for application of integrated approach: Basis of experimental determination of reservoir fluids composition's were described, causes and scopes of mistakes were analized.Possibility for integrated fluid model availability were justified.Basis for composition, matching and monitoring were configured for integrated fluid modeling of gascondensate field. Suggested technique could be applyed for reserves calculation, designing of field's development, designing of surface facility of transport and preparations.
Composition and employment of integrated fluid modeling of field can allow to get composition's properties of unstudied layers, to find mistakes data and correct them, to simplify preparation data for calculation gathering and treatment systems.
Increase of certainty of calculation of hydrocarbon reserves on the basis of fuzzy petrophysical compositions method
Authors: Ivanovich Kobrunov Aleksandr , Evgenevich Kuleshov Vladislav 
Published: October 2012

Summary
The problem of parameter assessment characterizing oil-and-gas content, and its adequacy to real data which the geologist interpreter has is considered.
The necessity to appeal to this problem is connected with the existing methods of finding such parameters don't consider: the real character of geological-geophysical data and the specific errors arising at parameter assessment of oil-and-gas content and forecasting of their values;the uncertainty of conclusions concerning all parameters including volumetric data of hydrocarbon reserves on the field.
One of the main tasks of oil-and-gas field geology is calculation of hydrocarbon reserves which is nowadays carried out on the basis of three-dimensional geological-geophysical models. One of the key parameters influencing accuracy of reserve calculation is an authentic definition of factors of porosity and oil content which are calculated by means of field and geophysical methods of research. The last methods don't allow establishing the size of porosity and oil content but they estimate the sizes of geophysical parameters which are connected by correlation dependences with collector properties of breeds. To find the concrete expressions of these dependences and their parameters we use statistical data processing and finally we sometimes use replacement of the real experimental material with the received laws and some integrated assessment of Correlation ratio measure, i.e. the general for all dependence as a whole. According to the accepted technology the found law in the form of the coupling equations between parameters is transferred on the studied object. This way is often the source of erroneous conclusions which can bring: from incorrectly chosen conditions of opening and modes of well operation to mistakes in drill site and the conclusions about reserves and resources of hydrocarbon raw materials in the regions.
Potential to Increase Oil Reserves Due to Non-used "Lost" Deposits Located at Presently Operated Fields of OAO "Samaraneftegas"
Authors: Arkhipov V. S. , Zubova Yu. A. , Krainiy Yu. D. , Manasyan A. E. , Ustinov A. S. 
Published: October 2012

Abstract
Presently the objective to expand the resource basis of the now-operated hydro-carbon reserves remains rather acute. The experience in building-up the oil reserves is given on the basis of revealing previously non-operated reservoirs at the field that are presently operated. The practical efficiency of considered approach is proved. The search and start-up of these now not-operated reservoirs allows to build-up the amount of active reserves and to produce oil using the low-cost measures.
The paper presents the basic results of a system work with the same subject for the last two years. In 2010 they have opened and commissioned 6 new reservoirs at 5 fields that contain 1,364 million of tons of recoverable oil; the growth in oil production rate has made 843 t/d. In 2011 they have opened 14 new reservoirs at 13 fields, of which 11 pools were included into state balance. The build-up in recoverable reserves by industrial category C1 has made 1,681 million tons, the oil production rate growth - 801 t/d.
Integration of Conceptual Considerations in Geological Model of Riphean Carbonate Reservoir in Yurubcheno-Tokhomskoe Field
Authors: Kutukova N. M. , Birun E. M. , Malakhov R. A. , Savichev K. S. , Yatsenko V. M. 
Published: October 2012

Abstract
Carbonate reservoirs usually demonstrate considerable structural complexity and their high heterogeneity makes it difficult to predict their quality. Quite often productivity levels obtained in wells located close to each other and drilled to carbonate reservoirs differ from each other by a factor of ten or much more. Another issue is related to interpretation of log data in carbonate reservoirs: not always logs are sufficient to identify reservoirs and non-reservoirs and determine how much any component of the reservoir (fractures, cavities and matrix) contributes to the reservoir's effective capacity. High variety of poro-perm properties of carbonate reservoirs imply that geology and simulation modeling of hydrocarbon fields and making any forecasts for them bring about considerable difficulties and make it inevitable to use specific approaches to modeling process. Using as a case study one of the least clear fields by their geology in East Siberia, namely the Yurubcheno-Tokhomskoye field, the article describes an integrated approach to determining the reservoir's conceptual model and creating geological and simulation models.
Reservoir Properties of the Bazhenov Formation
Authors: Khamidullin R. A. , Kalmykov G. A. , Korost D. V. , Balushkina N. S. , Bakay A. I. 
Published: October 2012

Abstract
The work is devoted to interpretation of results received from a wide complex of laboratory petrophysical investigations of the Bazhenov formation rocks collected from the core in several fields in Western Siberia. The main goal is comparison and substantiation of evaluation results received from using of different methodologies of petrophysical rock properties measurements. It is necessary for identification of the most adequate and applicable methodology of petrophysical investigations realization for the Bazhenov formation.
The Bazhenov formation draws attention of researchers for many years [2, 3, 4, 6]. It significantly differs from usual sedimentary rocks by both composition and physical properties. Lithological and petrophysical investigations of the Bazhenov formation core from different fields showed that it is represented by clayey-silty porous-fractured and fractured reservoirs characterized primarily by high variability of reservoir properties in the formation's distribution area. The majority of reservoirs have low porosity (1–2%) and permeability of less than 0,1 mD. However in some well columns there are interlayers with porosity reaching 16%.
Standard approaches of traditional in Russian Federation petroleum well logging practically don't allow quantitatively estimate the composition and reservoir properties of natural reservoirs. That's why it is extremely essential, on the one hand, to engage methods providing possibility of quantative definition of rock mineral-component composition and enhancing accuracy of its reservoir properties, effective porosity and permeability, and, from the other hand, to prepare new approaches for interpretation of the proposed complex.
The problem of effective porosity and oil and gas saturation determination is complicated by the fact that these natural reservoirs contain big amount of kerogen while mineral component consists of a silicon dioxide, clayey minerals, pyrite, albite, carbonaceous minerals. Selection of them could be defined by the core but it is essential to estimate its weighting in column of a definite well. Therefore main factors that should be kept in mind while evaluating porosity are complex mineralogical rock composition, shale content and high content of organic matter (reaching 40% by mass).
Existing methodology of reservoir identification and its properties evaluation by well logging don't rely on detailed investigations of the Bazhenov formation composition. This situation is explained by an attempt to average accumulated data of the Bazhenov formation in the whole Western Siberian oil and gas basin not always confirming it by results from a real object core investigation. In the present work there are results of core investigations in some areas allowing adjusting the interpretation of well logging to evaluate reservoir properties of the Bazhenov formation.
Drilling world-class ERD wells in the North Caspian Sea
Authors: Bogdanov Sergey , Deliya Sergej , Latsin Danil , Akhmetov Marat , Gagaev Yury , Udodov Alexander 
Published: October 2012

Abstract
This paper describes some of the major issues around drilling world class ERD wells in the North Sector of the Caspian Sea by a team of industry professionals from Lukoil, Schlumberger, Eurasia Drilling Company (BKE-Shelf) and Rostechnadzor (RTN). The ultimate goal of the well construction organisation is to deliver quality wells with zero environmental impact.
Drilling performance achieved on Korchagina field has considerably improved despite increased complexity of the wells. Key contributing factors to this success are in-depth understanding of well bore stability by 3D geomechanical modeling, comprehensive directional analysis, revised casing design, application of latest drilling technologies and creation of multi-discipline team with common goals.
Auditor Attestation under SOX Section 404 and Earnings Informativeness
Authors: Chen Lucy Huajing , Krishnan Jayanthi , Sami Heibatollah , Zhou Haiyan 
Published: October 2012

SUMMARY
Section 404 of the Sarbanes-Oxley Act requires managers to assess, and their auditors to express an opinion on, the effectiveness of internal controls over financial reporting (ICFR). Policymakers expect the ICFR audits to enhance the credibility of firms' financial statements. Prior research argues that audit characteristics that enhance the credibility of financial reporting are associated with stronger earnings-return associations. We examine whether earnings accompanied by the first-time Section 404 ICFR reports were associated with higher informativeness compared with earnings in the prior year when only financial statement audit reports were available. We conduct our analysis for a test sample of accelerated filers with clean ICFR reports and clean previous Section 302 disclosures. Using a difference-in-differences approach, we compare the change in earnings informativeness for the test sample with that for a control sample of non-accelerated filers. We find that earnings informativeness for companies with clean internal control reports was greater in the Section 404 adoption year than in the previous year, while there was no change in earnings informativeness for the non-accelerated filers. Also, there is no difference in the increase in earnings informativeness across firms with small and large compliance costs (measured by change in audit fees), suggesting that both groups benefited from the Section 404 ICFR audits.
Patient experiences with the Forsus Fatigue Resistant Device
Authors: Bowman Amy C. , Saltaji Humam , Flores-Mir Carlos , Preston Brian , Tabbaa Sawsan 
Published: October 2012

ABSTRACT

Objective:
To investigate patients' experiences with the Forsus Fatigue Resistant Device (FFRD).

Methods:
This was a survey focused on patient's comprehensive experience with FFRD, both initially and after several months of wear, including the patient's overall impression of the appliance. The survey was administered to 70 patients wearing FFRD in both university and private practice settings.

Results:
A high percentage (81.5%) reported a neutral to favorable experience with FFRD; 89.8% reported growing accustomed to the appliance within 4 weeks. The majority of those who had previously worn rubber bands found FFRD to be “easier.” Cheek irritation was the most serious side effect (about 50%). Cheek irritation and other negative effects generally decreased over time.

Conclusions:
The FFRD is relatively well accepted by patients. Most patients experience some discomfort and functional limitations; however, the effect generally diminishes with time, and patients adapt to the appliance. Practitioners should be especially vigilant about problems with cheek irritation.
Neural Correlates of Stress- and Food Cue–Induced Food Craving in Obesity
Authors: Jastreboff Ania M. , Sinha Rajita , Lacadie Cheryl , Small Dana M. , Sherwin Robert S. , Potenza Marc N. 
Published: October 2012

OBJECTIVE
Obesity is associated with alterations in corticolimbic-striatal brain regions involved in food motivation and reward. Stress and the presence of food cues may each motivate eating and engage corticolimibic-striatal neurocircuitry. It is unknown how these factors interact to influence brain responses and whether these interactions are influenced by obesity, insulin levels, and insulin sensitivity. We hypothesized that obese individuals would show greater responses in corticolimbic-striatal neurocircuitry after exposure to stress and food cues and that brain activations would correlate with subjective food craving, insulin levels, and HOMA-IR.

RESEARCH DESIGN AND METHODS
Fasting insulin levels were assessed in obese and lean subjects who were exposed to individualized stress and favorite-food cues during functional MRI.

RESULTS
Obese, but not lean, individuals exhibited increased activation in striatal, insular, and hypothalamic regions during exposure to favorite-food and stress cues. In obese but not lean individuals, food craving, insulin, and HOMA-IR levels correlated positively with neural activity in corticolimbic-striatal brain regions during favorite-food and stress cues. The relationship between insulin resistance and food craving in obese individuals was mediated by activity in motivation-reward regions including the striatum, insula, and thalamus.

CONCLUSIONS
These findings demonstrate that obese, but not lean, individuals exhibit increased corticolimbic-striatal activation in response to favorite-food and stress cues and that these brain responses mediate the relationship between HOMA-IR and food craving. Improving insulin sensitivity and in turn reducing corticolimbic-striatal reactivity to food cues and stress may diminish food craving and affect eating behavior in obesity.
Magnetic resonance study of nanocrystalline 0.10MnO/0.90ZnO
Authors: Żołnierkiewicz Grzegorz , Typek Janusz , Guskos Niko , Narkiewicz Urszula , Sibera Daniel 
Published: October 2012

Abstract
Magnetic properties of nanosize ZnO powders doped with MnO magnetic dopand have been studied. Sample designated as 0.10MnO/0.90ZnO was characterized by XRD that revealed the presence of ZnO and ZnMnO3 phases. An average size of magnetic ZnMnO3 nanocrystallites was 9 nm. Magnetic resonance study has been carried out in the 4-290 K temperature range. The spectrum at each temperature was analyzed in terms of three components. The temperature dependences of resonance field, linewidth and integrated intensity of these components have been determined. Magnetic centers responsible for producing the observed spectra have been proposed.
ADMA and C-reactive protein as mortality predictors in dialysis patients
Authors: Ignjatović Aleksandra , Cvetković Tatjana , Pavlović Radmila , Đorđević Vidojko , Milošević Zoran , Đorđević Vidosava , Pavlović Dušica , Stojanović Ivana , Živanović Slavoljub 
Published: October 2012

Abstract
There is a higher mortality between patients with end-stage renal disease than patients in the general population. These circumstances have led to a search for risk factors as predictors of mortality in dialysis patients. Amongst those, inhibitors of the nitric-oxide (NO) synthesis deserve special attention, since patients with end-stage renal disease are also characterized by accelerated atherosclerosis. Asymmetric-dimethylarginine (ADMA) and symmetric-dimethylarginine (SDMA), as well as C-reactive protein (CRP), have also been recognized as predictors of mortality in patients on dialysis. The aim of our study was to compare the prediction power of ADMA, SDMA and CRP for all-cause mortality in patients with end stage renal disease during the fourteen month follow-up. In total 162 patients on hemodialysis were included. ADMA and SDMA were measured by the high-performance liquid chromatography (HPLC); CRP was measured using immunonephelometric assays. During the 14-month period 28 patients (34.1%) died from all-cause mortality. Using univariate analysis, hazard ratios (HR) of the potential independent predictors of mortality in hemodialysis patients were ADMA (HR 1.39 (1.01–1.91) p=0.043) and CRP (HR 1.024 (1.009–1.1.040) p=0.001). Further, multivariate analysis (MVA), however, showed that ADMA is the only predictor of all-cause mortality (HR 1.76 (1.002–3.11) P=0.049), while SDMA failed to predict death in this population. Therefore, our data shows that ADMA is an independent and better marker of all-cause mortality compared with CRP.
Urine saturation and promoter/inhibitor parameters and ratios in renal stone disease caused by ceftriaxone
Authors: Milošević Danko , Miše Branko , Habuš Ivan , Topalović-Grković Marija , Batinić Danica , Golubić Anja , Turudić Daniel 
Published: October 2012

Abstract
During ceftriaxone treatment of subdural empyema caused by Streptococcus intermedius urinary and biliary stones were noticed. Increased levels of urinary calcium excretion were detected during ongoing treatment in comparison with 2 months check-up. There were no significant changes in the promoter/inhibitor urolithiasis parameters, oxalate, citrate, urate, cistine, glycosaminoglycans or their ratios. Urine saturation was calculated using EQUIL 2 computer programme (calcium oxalate, brushite) and it was normal. Probable trigger for the ceftriaxone/calcium hydroxy carbonate phosphate mixture of stones was a critical boost of solubility products caused by ceftriaxone treatment and phospnate urine content with a subsequent large-scale spontaneous precipitation of crystals.