bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Activity in Children Attending Preschools
Authors: Olesen Line Groenholt , Kristensen Peter Lund , Korsholm Lars , Froberg Karsten
Published: October 2013

OBJECTIVE:

To identify correlates of objectively measured moderate and vigorous physical activity (MVPA) in children during preschool attendance.

METHODS:

This cross-sectional study included data from 426 apparently healthy Danish children (49.5% boys), 5 to 6 years of age enrolled in 42 randomly selected preschools. The percentage of time spent in MVPA (≥574 counts/15 second) during preschool attendance was measured using ActiGraph accelerometers over 4.3 preschool days in May and June in 2009. Thirty-seven potential correlates across the child, preschool staff, and preschool environment domains were tested for associations with MVPA.

RESULTS:

The final multivariate model identified 9 significant correlates of MVPA. Preterm birth, vegetation on the playground, and rainy days were negatively associated with MVPA, whereas child motor coordination, location of preschool building on the playground, gender (boys), percentage afternoon hours, and size of indoor area per child were positively associated with MVPA. The direction of the significant association with the parental mean education level was unclear.

CONCLUSIONS:

We identified a number of new modifiable correlates of MVPA during preschool attendance. The positive association with size of indoor area per child and location of the preschool building on the playground seem important correlates to be targeted in future studies.
Off-Label Topical Calcineurin Inhibitor Use in Children
Authors: Manthripragada Angelika D. , Pinheiro Simone P. , MaCurdy Thomas E. , Saneinejad Shahin , Worrall Chris M. , Kelman Jeffrey A. , Graham David J.
Published: October 2013

OBJECTIVE:

To assess off-label use of the topical calcineurin inhibitors (TCIs), tacrolimus and pimecrolimus, in children during periods before and after regulatory action by the US Food and Drug Administration (FDA) in 2005.

METHODS:

We identified new pediatric (age <20 years) users of topical tacrolimus or pimecrolimus in US Medicaid from 2001 to 2009, and examined the annual rate of drug use (pre- and postregulatory action) by age. We assessed medical claims for diagnoses consistent with an indication for a TCI, and assessed prescriptions for evidence of first-line atopic dermatitis therapy use before TCI initiation.

RESULTS:

There were 57 664 eligible pediatric tacrolimus users and 425 242 eligible pediatric pimecrolimus users at baseline. The rate of TCI use decreased substantially after FDA regulatory action. The proportion of new users younger than 2 years of age significantly decreased for both tacrolimus (36.7% to 22.5%, P < .001) and pimecrolimus (47.0% to 33.7%, P < .001) after regulatory actions. Previous use of topical corticosteroids increased by ∼7% for both TCIs from the pre- to postregulatory period. However, after regulatory actions, there was only a small increase in the proportion of tacrolimus or pimecrolimus users with an atopic dermatitis or eczema diagnosis before drug initiation, and high strength use of tacrolimus was unchanged.

CONCLUSIONS:

The rate of TCI use in children younger than 2 years of age fell substantially after FDA regulatory action in 2005. Off-label use of TCI as first-line therapy changed little.
Effect of Palivizumab Prophylaxis on Subsequent Recurrent Wheezing in Preterm Infants
Authors: Yoshihara Shigemi , Kusuda Satoshi , Mochizuki Hiroyuki , Okada Kenji , Nishima Sankei , Simões Eric A.F.
Published: October 2013

BACKGROUND AND OBJECTIVES:

Palivizumab effectively prevents severe respiratory syncytial virus (RSV) disease in preterm infants. Our objective was to test whether palivizumab prophylaxis given to preterm infants during the first RSV season reduces the incidence of subsequent recurrent wheezing up to 3 years of life.

METHODS:

We conducted an observational prospective multicenter (52 registered hospitals in Japan) case-control study in preterm infants with a gestational age between 33 and 35 weeks followed for 3 years. During the 2007–2008 RSV season, the decision to administer palivizumab was made based on standard medical practice. In April 2008, 52 hospitals were recruited. Study participants were prospectively followed to the age of 3 years. Parents of study subjects reported the infants’ physician’s assessment of recurrent wheezing, used a report card and a novel mobile phone-based reporting system by using the Internet. The primary end point was the incidence of physician-diagnosed recurrent wheezing.

RESULTS:

Of 444 preterm infants enrolled, 349 received palivizumab during the first 6 months of life and 95 infants did not. Physician-diagnosed recurrent wheezing was observed in 6.4% and 18.9% of infants in the treated and untreated groups, respectively (P < .001). This difference remained significant after adjustment for known risk factors of recurrent wheezing (P < .001).

CONCLUSIONS:

Palivizumab prophylaxis administered to preterm infants 33 to 35 weeks’ gestational age is associated with a significantly lower incidence of recurrent wheezing during the first 3 years of life.
Reliability of Transcutaneous Bilirubin Devices in Preterm Infants: A Systematic Review
Authors: Nagar Gaurav , Vandermeer Ben , Campbell Sandra , Kumar Manoj
Published: October 2013

BACKGROUND AND OBJECTIVE:

Transcutaneous bilirubin (TcB) devices are widely used for the estimation of serum bilirubin levels in term and near-term infants. Our objective was to review the diagnostic accuracy of TcB devices in preterm infants.

METHODS:

Medline, Embase, Cochrane library, Cumulative Index to Nursing and Allied Health Literature, and Scopus were searched (from database inception date until December 2012). Additional citations were identified by using the bibliographies of selected articles and from conference proceedings. The studies were included if they compared TcB with total serum bilirubin in preterm infants before phototherapy and presented data as correlation coefficients or as Bland-Altman difference plots. Data were extracted by 1 reviewer and checked for accuracy by the second reviewer. An assessment tool (quality assessment of diagnostic accuracy studies) was used for risk of bias assessments.

RESULTS:

Twenty-two studies met the inclusion criteria; 21 studies reported results as correlation coefficients, with pooled estimates of r = 0.83 for each site of measurement. Pooled estimates in infants <32 weeks’ gestation were similar to the overall preterm population (r = 0.89 [95% confidence interval: 0.82–0.93]). For the 2 commonly used TcB devices (ie, JM103 and BiliCheck), the results were comparable at the forehead site, although the JM103 device exhibited better correlation at the sternum. Analysis of the Bland-Altman plots (13 studies) revealed negligible bias in measurement at the forehead or sternum site by using either the JM-103 or BiliCheck device; however, the JM-103 device exhibited better precision than the BiliCheck (SD for TcB – total serum bilirubin differences: 24.3 and 31.98 µmol/L, respectively).

CONCLUSIONS:

The TcB devices reliably estimated bilirubin levels in preterm infants and could be used in clinical practice to reduce blood sampling.
Changes in Bedtime Schedules and Behavioral Difficulties in 7 Year Old Children
Authors: Kelly Yvonne , Kelly John , Sacker Amanda
Published: October 2013

OBJECTIVES:

Causal links between disrupted sleep and behavioral problems in nonclinical populations are far from clear. Research questions were as follows: Are bedtime schedules associated with behavioral difficulties? Do effects of bedtime schedules on behavior build up over early childhood? Are changes in bedtime schedules linked to changes in behavior?

METHODS:

Data from 10 230 7-year-olds from the UK Millennium Cohort Study, with bedtime data collected at 3, 5, and 7 years, and behavioral difficulties scores as rated by mothers and teachers were analyzed.

RESULTS:

Children with nonregular bedtimes had more behavioral difficulties. There was an incremental worsening in behavioral scores as exposure through early childhood to not having regular bedtimes increased: mother rated (nonregular any 1 age, β = 0.53; nonregular any 2 ages, β = 1.04; nonregular all 3 ages, β = 2.10, P < .001) and teacher rated (β = 0.22, β = 0.73, β = 1.85, P < .001). Difference in differences analysis showed that for children who changed from nonregular to regular bedtimes there were clear nontrivial, statistically significant improvements in behavioral scores: A change between age 3 and 7 corresponded to a difference of β = −0.63, and a change between age 5 and 7 corresponded to a difference of β = −1.02). For children who changed from regular to nonregular bedtimes between ages 5 and 7 there was a statistically significant worsening in scores, β = 0.42.

CONCLUSIONS:

Having regular bedtimes during early childhood is an important influence on children’s behavior. There are clear opportunities for interventions aimed at supporting family routines that could have important impacts on health throughout life.
Permeability Upscaling for Carbonates From the Pore Scale by Use of Multiscale X-Ray-CT Images
Authors: Dehghan Khalili A.. , Arns J.-Y.. -Y. , Hussain F.. , Cinar Y.. , Pinczewski W.V.. V. , Arns C.H.. H.
Published: October 2013

High-resolution X-ray-computed-tomography (CT) images are increasingly used to numerically derive petrophysical properties of interest at the pore scale—in particular, effective permeability. Current micro-X-ray-CT facilities typically offer a resolution of a few microns per voxel, resulting in a field of view of approximately 5 mm3 for a 2,0482 charge-coupled device. At this scale, the resolution is normally sufficient to resolve pore-space connectivity and calculate transport properties directly. For samples exhibiting heterogeneity above the field of view of such a single high-resolution tomogram with resolved pore space, a second low-resolution tomogram can provide a larger-scale porosity map. This low-resolution X-ray-CT image provides the correlation structure of porosity at an intermediate scale, for which high-resolution permeability calculations can be carried out, forming the basis for upscaling methods dealing with correlated heterogeneity.

In this study, we characterize spatial heterogeneity by use of overlapping registered X-ray-CT images derived at different resolutions spanning orders of magnitude in length scales. A 38-mm-diameter carbonate core is studied in detail and imaged at low resolution—and at high resolution by taking four 5-mm-diameter subsets, one of which is imaged by use of full-length helical scanning. Fine-scale permeability transforms are derived by use of direct porosity/permeability relationships, random sampling of the porosity/permeability scatter plot as a function of porosity, and structural correlations combined with stochastic simulation. A range of these methods is applied at the coarse scale. We compare various upscaling methods, including renormalization theory, with direct solutions by use of a Laplace solver and report error bounds. Finally, we compare with experimental measurements of permeability at both the small-plug and the full-plug scale.

We find that both numerically and experimentally for the carbonate sample considered, which displays nonconnecting vugs and intrafossil pores, permeability increases with scale. Although numerical and experimental results agree at the larger scale, the digital core-analysis results underestimate experimentally measured permeability at the smaller scale. Upscaling techniques that use basic averaging techniques fail to provide truthful vertical permeability at the fine scale because of large permeability contrasts. At this scale, the most accurate upscaling technique uses Darcy's law. At the coarse scale, an accurate permeability estimate with error bounds is feasible if spatial correlations are considered. All upscaling techniques work satisfactorily at this scale. A key part of the study is the establishment of porosity transforms between high-resolution and low-resolution images to arrive at a calibrated porosity map to constrain permeability estimates for the whole core.
Demonstration of an Efficient Concept-Selection Process for Tight and Unconventional Resources
Authors: Wehunt C.D.. D. , Hrachovy M.J.. J. , Padmakar A.S.. S. , Walker S.C.. C.
Published: October 2013

Making an efficient and wise concept-selection decision—quickly selecting the right project—is often of equal or greater importance than later design and execution tasks for determining project success. An efficient assessment process is one that supports rapid assessment of an appropriately broad range of viable alternatives, leading to an optimized project design, while consuming the minimum necessary assessment resources. Value lost from a suboptimal-concept selection decision or from a needlessly prolonged assessment process is independent of value-generation opportunities during design and execution, and cannot be recovered during later project phases. The objectives of the methods shown in this paper are to improve concept-selection decision quality by allowing simultaneous optimization of interdependent development decisions, and to improve the quality of and reduce the resource requirements for simulation-derived production forecasts. This paper presents a complementary decision framework, productionforecasting process, and economic model that promote an efficient and high-quality concept-selection decision, and are particularly appropriate for early phase development concept selection and optimization for tight or unconventional resources. The method is suitable for both oil and gas resources, and is especially useful for assessing and developing large contiguous tracts.

The decision framework is efficient because it is structured so that some decisions are independent of the simulation model, and those decisions can be optimized within the economic model. Our production-forecasting method is efficient because it uses small, symmetry-element reservoir-simulation models. The symmetry-element sector simulation models run fast and can evaluate many cases, but they still improve forecast quality by explicitly addressing many relevant physical effects that are not addressed by other methods that are attempting to model a much larger volume of the reservoir. The economic model is efficient because it includes an automated optimizer for those decisions that are independent of the simulation-derived forecasts, and it promotes high-quality decisions by incorporating meaningful constraints to ensure that the forecasts are both realistic and achievable. The economic model also includes a fracture efficiency factor that may be important for modeling the diminished performance observed as the number of stages increase in multifractured horizontal wells. This fracture efficiency factor may also be an important discriminator of performance between wells fractured by use of aqueous vs. nonaqueous fracturing fluids.
The Hydrocarbon Potential and Geological Exploration Works In The Arctic Shelf
Authors: Varlamov A.. , Afanasenkov A.. , Peshkova I.. , Lugovaya O..
Published: October 2013

On the basis of the geological and geophysical research in the Russian continental shelf, on the analysis of the resource base and the licensing activities – the regional stage of studying geological structure and oil and gas potential evaluation should be continued in the high-latitude regions of Western and Easten Arctic seas. The licensing process currently covers the entire Arctic. Today, the license areas issued by companies and their applications for licenses cover almost all prospective oil and gas offshore areas.
Transition Zone Seismic Acquisition on the Alaska North Slope, Simpson Lagoon
Authors: Wyman Larry , Ahmad Khaliq
Published: October 2013

The Alaska North Slope, within the Arctic Circle, is a challenging environment to operate seismic crews. The company has operated land and marine seismic programs on the North Slope since 1979. We present a review of the summer 2012 Simpson Lagoon seismic survey, outlining the safety, operational and technical challenges faced in an arctic transition zone environment. Ocean Bottom Seismic (OBS) data on the North Slope is essential for the effective development of the hydrocarbon fields, providing improved and accurate subsurface imaging. The arctic open-water season provides a short window of opportunity to collect OBS data, bounded by the seasonal break-up and freeze-up of the sea ice and subsistence whale hunting. These factors constrain the quantity and influence the quality of the data collected, however sufficient resource allocated to pre-season planning is critical to the success of the seismic project. We demonstrate the planning and decisions made were influenced by the safety of the seismic crew, minimizing impact to the environment, and the collection of quality seamless subsurface seismic data. Key successes of the survey include: 24 hour operations completed within 45 days; completion of the seismic objectives equating to 88 square miles of data; enhanced imaging below the lagoon barrier islands carried out by safe and efficient helicopter operations utilizing autonomous land nodes; and innovative techniques for burying receiver sensors into the surf zone which significantly improved data quality.
In-Situ Real-Time Wireline Formation Testing Unlocks Early Additional Reserves In Kazakhstan: Case Study
Authors: El Battawy A.. , El Khatib K..
Published: October 2013

With today’s economic realities, operators realize the value of attaining information about reservoir potential as soon as possible. The early confirmation of new reservoir potential can translate into time and money savings and can support decisions to optimize the well testing program and plans to drill new wells.

Case studies from appraisal wells in a carbonate gas condensate reservoir located in north Kazakhstan illustrate the importance of real-time information. In these wells, the use of wireline formation tester (WFT) interval pressure transient testing (IPTT) coupled with the latest generation fluid analyzer provided fluid properties and reservoir characteristics and confirmed the presence of additional reserves. When the reservoir was discovered, operational considerations precluded the immediate acquisition of well test data. As a result, the operator had to proceed with significant economic decisions based only on the acquired WFT data. A full year elapsed before the well test results confirmed the initial WFT results.

The IPTT uses two inflatable packers to isolate a borehole interval for testing. A downhole pump is used to clean up invaded filtrate and flow reservoir fluids during fluid cleanup, while composition and gas/oil ratio are measured using a fluid analyzer. After collecting pressure/volume/temperature (PVT) samples, a pressure buildup is performed, and transient pressure data are analyzed for the permeability-thickness product and skin factor.

Two different formations were investigated with WFT IPTT and a full drillstem test (DST). The fluid properties measured in real time matched later PVT laboratory analysis and wellhead production. Reservoir characteristics from both interpretations were in close agreement. The well test, with its deeper depth of investigation, detected a fault boundary that as not seen on the WFT IPTT.

The field examples showed how a judiciously planned and executed WFT acquisition can provide invaluable early information for key investment decisions and complement the design of the well test.
Innovative Seismic Acquisition Technologies in the Far North and Arctic Seas
Authors: Tomashin Denis , Gorbachev Sergey
Published: October 2013

In the extreme conditions of the Far North and Arctic seas any geological prospecting and survey work is highly labour-intensive and expensive. Thus, an enlargement of the resource base and reasonable drilling potential needs a high-quality and comprehensive survey.

The main negative factors for surveying in the Far North are: –the long winters with hard frosts, for which many types of equipment conditions and machinery are not designed;–difficulties with delivery of equipment and personnel in the work areas (absence of roads). The volume and weight of the equipment imposes particular demands.–absence of developed infrastructure in the research regions.–and other factors.

Seismic researches in Northern and Arctic sees also have certain limitations. Amongst others are: –short ice-free period, i.e. depending on the region it can be from 30 to 90 days;–absence of ports and servicing parks and refueling facilities for vessels;–high specialists standards for ice-breaking potential survey boats and support vessels;–reduction of the Russian ice-breaker fleet.–and other factors.

Therefore, the methods and technologies of the field works should be chosen with discretion. Technical and economic conditions should be considered fully in advance, getting maximum information during the survey.

Methods and technologies of geophysical research are very varied.

There are: gravity prospecting, magnetometer measurements and electrical methods, as well as seismic survey. In order to get reliable information about the subsurface resources structure and a map of rock structure during the search for hydrocarbon accumulation it is necessary to make 2D and 3D seismic surveys.

Seismic surveys are an expensive method, so they demand higher quality and more reliable information.

There are many different techniques, technologies and equipment for undertaking a seismic survey. Correctly chosen methodologies, technologies determine the efficiency of geophysical research. They will give comprehensive information about the field explored.

Also, we should not forget about equipment. During recent decades there has been huge progress in the development of electronic systems, their accuracy and autonomy. Therefore, planning the work is essential when using the most modern equipment, which equipment increases the accuracy, reliability and completeness of the data.
Successful Application of Special Log Interpretation Methodology for Estimation of Petrophysical Properties of Thin-Bedded Reservoirs of Vikulovskaya Layers of Krasnoleninskoe Oilfield
Authors: Martinov M E , Kozlov A V , Leskin F Y , Filimonov A Y , Ezersky D M , Egorov S S , Blinov V A , Weinheber P..
Published: October 2013

The Vikulovskaya formation of Western Siberia is characterized by thinly-bedded, sand-shale layers. The vertical thickness of these layers ranges from a few millimeters to a few centimeters. This layered feature presents well known challenges for petrophysical analysis from standard logging suite data. These layers are typically beyond the vertical resolution of the standard tools so net-to-gross cannot be derived directly. The shale layers suppress the resistivity readings in the oil strata and the resulting low resistivity contrast makes it difficult to determine the oil-water contact. Finally, the ability to resolve the individual sand layers makes it impossible to accurately determine their water saturation.

In this paper we discuss how these challenges were surmounted when performing a petrophysical evaluation of a dataset acquired in a recently drilled well in the Krasnoleninskoe field. This dataset consisted of full bore core and traditional ‘triple combo’ data. Additionally, we had NMR data, high resolution micro-imager data and formation tester pressure and fluid analysis data. By combining the measurements from the traditional tools with the resolution of the micro-imager data we were able estimate the desired petrophysical properties of the thinly-bedded layers individually. By using tools with different physics we were able to realize an independent quality control of the interpretation: stationary NMR measurements were used as porosity and irreducible water saturation reference, and formation tester data of direct inflow composition were used as a reference for fluid saturations. As a final check on our method we performed a digital integration of core and micro-imager data to validate our findings. The resultant workflow is concisely explained such that it can be easily applied to similar evaluation environments.
The Borehole Gravity Meter: Development and Results
Authors: Nind Chris J. , MacQueen Jeffrey D. , Wasylechko Roman
Published: October 2013

Borehole Gravity (BHGM) measurements are passive observations of the gravity field beneath the surface. The BHGM responds to the bulk density of a large rock volume surrounding the borehole, which is orders of magnitude larger than the volume sampled by nuclear logs or cores.

A summary of the corrections applied to BHGM measurements during processing as well as simplistic rules-of-thumb for interpreting BHGM data in a uniform host rock are presented. However, processing and interpretation of BHGM data are complicated by changes in the density of formations intersected by the borehole, and modeling and inversion yield more sophisticated solutions.

The first generation borehole gravity instrument was introduced in the 1960s and was suitable for large diameter petroleum wells. A second generation BHGM probe for mining and geotechnical applications was introduced in 2011. Using this recently developed probe several examples of BHGM data acquired in Canada and USA for mining exploration and CO2 sequestration are presented.
Using of Post-Critical Reflections in the Parametric Scanning of Reflections (PSR) Technique—Means of Obtaining Seismic Information in Complex Geological Conditions
Authors: Kondrashkov V.. , Glagolev A..
Published: October 2013

This article is stated that in complex seismic geological conditions where it is hardly possible or even impossible to improve imaging – seismic data acquired at offsets of post-critical reflections zone offer hope of success.

PSR method suits for this purpose and processing system based on it –PROspect – allows to derive Vrms and obtain time and depth sections processing seismic data acquired at far offsets. This is demonstrated by the results of data processing, received in different geological conditions: Amazonian shelf, Kaspian low, zones of trappean complex of the East Siberia. "…additional positive results may be obtained with supercritical reflections. When recording of waves at the offset interval 5–7 H, where H – is the depth of the reflector"Pusyrev N.N.
Technical Considerations for Conducting Marine Seismic, Geotechnical and Site Surveys in Arctic Regions
Authors: Naylor Rob
Published: October 2013

This paper builds on the experience of managing and supervising marine seismic, sites and geotechnical surveys in Arctic regions over several years. Projects are reviewed for the purpose of highlighting technical issues peculiar to operating in extreme latitudes. Data examples are taken from operations offshore Greenland and in the Russian Arctic carried out since 2008.

Technical aspects discussed include: issues with project planning/ ice monitoring; geodesy; the limitations of satellite navigation systems in high latitudes; variation in sound propagation velocity; seismic streamer compass performance and magnetic dip/ field strength issues. The relative impact of these issues in different high latitude operating environments is compared and contrasted via experiences from Greenland and from the Russian Arctic, using data acquired during 2010 to 2012.

It is concluded that although Arctic operations may appear superficially similar independent of location, several technical aspects of the work, such as seismic streamer positioning, have a significant longitude component as well as a latitude component which must be taken into consideration when planning and executing operations. Mitigation proposals for future operations are suggested where feasible.
Oceanic Loading Effect for Gravity Prospecting
Authors: Spiridonov Evgeny
Published: October 2013

At present, high-accuracy gravimetry is one of the efficient methods for prospecting the Earth’s interior. New possibilities were opened by the advent of superconducting gravimeters. However, for interpreting the gravity measurements, it is vital that a number of additional factors are known. Among these factors is the effect of oceanic loading.

In the Russian Arctic, this effect attains 4–6 μGal, which makes up quite a significant fraction of the observed lunar and solar tide.

For calculating this effect, we have developed the ATLANTIDA3.0 program. The distinctive feature of this program is that it allows the geophysicist to take into account the dissipation of tidal energy in the calculation and to apply different models of the Earth’s crust and upper mantle (to date, there are two such models). Due to the fact that all the procedures of interpolation and all decompositions are, in fact, carried out beforehand, the program, as a rule, provides the faster computations than its analogs. This is important in the calculations aimed at obtaining the estimates on a large regional or global grid.

About 77% of the ocean loading effect parameters calculated by the ATLANTIDA 3.0 program turned out to be closer to the observations than the estimates predicted by the known LOAD97 program from ETERNA3.3 package.
Safe and Clean Marine Drilling with Implementation of "Riserless Mud Recovery Technology - RMR"
Authors: Rezk Ramzy
Published: October 2013

Russia has opened up a new era in the development and exploitation of deep-water marine resources. This has meant that the questions of safety, of the ecological impact of similar mega projects and their possible effects on the environment, have become more acute and more current. The worldwide experience of drilling deep-water wells has shown that it is possible to avoid negative consequences with the help of various methods and technologies, including the application of a ‘Riserless Mud Recovery’ or ‘RMR’ system. This paper considers the features of RMR technology, its advantages, its operating principles and its track record in Russia.
Development of Onshore Drilling Complex of XXI Century for Extended Reach Drilling in the Arctic
Authors: Tskhadaya Nikolay D. , Buslaev George V. , Buslaeva Olga N. , Molokanov Denis R.
Published: October 2013

Resume

The article offers scientific solutions regarding drilling of horizontalextended reach wells for the Arctic development. In particular, ground-based drilling complex of XXI century with tipping tower was developed. The article describes constructions of its overland and borehole components. A lot of attention is paid to load transfer from the well head to its bottomhole. The article describes solutions made for addressing problems connected to additional loads on the bottomhole and well head; in particular, even drilling bit feed need. The article also includes calculation of the well profile and load characteristics of the drilling complex for the well of 15 km and horizontal borehole depth of 1.5 km. The author proves perspectives of field’s application and data about testing of downhole drilling thrusting device; offers a horizontal borehole subsea depth estimating method, according to fracturing prevention and sea bed pollution. The article shows a mathematical model of heat and weight transfer in the well for foundation of managerial parameters of formation exposing, drilling and casing in permafrost.
Collaborative Drilling Technical Team, Secures Project Performance
Authors: Kasumov Ruslan , Gallyamova Yulia , Akanaev Rinat , Gavrilov Leonid , Dolgushin Evgeny , Romanov Andrey
Published: October 2013

Advanced drilling technologies were used on two offshore multiwell platforms in the Lunskoye and Piltun-Astokhskoye fields, in the Sea of Okhotsk to deliver wells that required complex drilling to manage well-to-well collision risk, and to perform underreaming operations, extended-reach drilling (ERD), sidetracking, geosteering, and acquisition of thorough logging-whiledrilling (LWD) data.

The project benefited from the successful implementation of a new concept that combined various groups of technical experts within the operating and service companies to address project challenges through proper well planning, 24/7 monitoring, and intervention, when needed, during the execution phase, as well as post-well analysis fed into the planning of subsequent wells.

The effectiveness of the collaborative drilling technical team was proven by the overall results since implementing the new concept. Four wells were drilled "shoe to shoe" 25 days ahead of approved for expenditure (AFE) time for the drilling phase. More than 70 proactive interventions to prevent nonproductive time (NPT) were made and delivered to the drilling teams during trial runs; of these, 60% were considered significant and resulted in the implementation of a drilling and engineering operations planning service on subsequent wells. It was the first time in the Lunskoye field that a well had been delivered 8.9 days ahead of AFE for 53.6 days for the drilling phase. The success established good synergy among the client geoscientists and drilling personnel in town, platform teams, including the drilling supervisor (DSV) and offshore drilling engineer (ODE), and service companies providing mud logging services, drilling fluids, directional drilling and LWD services, and bits and underreamers.

Thanks to the successful results obtained from the collaborative drilling technical team concept, it has been accepted for use in this major offshore project as it brings continuous improvement to drilling operations through a cyclic process of planning-execution-evaluation.
Improvement of Bottom-Hole Cleaning After Hydraulic Fracturing on Urengoy Oil and Gas Condensate Field
Authors: Buriak Ivan
Published: October 2013

Urengoy Oil and Gas Condensate Field as other fields of North of West Siberia is in final stage of development in present time which characterized by depletion of reservoirs and decreasing of reservoir pressure.

Today operating well stock in Urengoy Oil and Gas Condensate Field consists of 174 wells of which 135 wells are in operations and 39 are in off-period. The most reasons of being off period are follows: –low inflow;–technical condition;–water influx after drilling;–water influx after exploitation;–wells in completion after hydraulic fracturing.

Hydraulic fracturing is commonly applies in both operating and off-period wells in Urengoy Oil and Gas Condensate Field for stabilization of hydrocarbons production. Hydraulic fracturing is performed on gas, gas condensate and oil wells of Urengoy Oil and Gas Condensate Field. After hydraulic fracturing one of main problems still remains which is bottom-hole cleaning of proppant plug.

According to design projects of Urengoy Oil and Gas Condensate Field hydraulic fracturing is performed with underflush of proppant in well, in other words proppant is left at perforation intervals and above it.

Preparatory works and post-frac operations in Urengoy Oil and Gas Condensate Field are carried out by different service companies with applying of different technologies of bottom-hole cleaning of proppant. One of such organizations is Urengoy Well Servicing Management of "Gazprom Podzemremont Urengoy" LLC.
Microbial Utilization Of The Oil Wastes In The Conditions Of Arctic Temperature
Authors: Vinogradova E. N. , Abramov S. M. , Sadraddinova E. R. , Fedorenko V. N. , Shestakov A. I.
Published: October 2013

This work is dedicated to the search and analysis of the microbial communities able to perform quick and effective biodestruction of the aqueous oily wastes. We developed a method for estimation of efficiency of existing preparations and for qualitative evaluation of the degree of carbon compounds degradation. This method will be the basis of the technology of oily decontamination of water and forelands in the arctic conditions. The experiments wede done in the conditions very close to the arctic (on the White Sea Biological Station and in a laboratory setting. We have isolated several microbial communities that are able to perform the destruction oil carbohydrates. On the basis of these communities, we plan to create the preparations highly effective in the arctic conditions.

Utilization of oily wastes in the low temperatures conditions is of great actuality when developing oil fields in the far north. In the moderate climate regions, oil residuals (after the physical and/or physic-chemical purification) are utilized by soil microorganisms or using several commercially available microbial preparations that accelerate the process. The active components of such preparations are usually carbohydrate-oxidizing microorganisms that are able to perform oil conversion into the bacterial biomass of organisms that, in turn, transfer the oily wastes into the safe components. These biopreparations are actively used after the physical and/or physic-chemical remediation. Microbial bioremedation allows effective utilization of residual oily wastes, if using of other methods is economically unadvizable, technically complicated and/or ecologically unsafe. At the same time, the end-product of microbial conversion of oily wastes is the biomass of carbohydrate-oxidizing bacteria which serves as a feed for the other organisms of this geobiocoenosis.

The literature search has shown that nowadays many preparations are developed that are aimed to the control of the oily wastes. These preparations are masses of viable microorganisms-biodestructors and differ one from another by strains used for their creation. These strains are characterized by different physiological and biochemical properties, such as thermotolerance, osmophility, optimal pH, ability to utilize different classes of carbohydrates and n-alkanes in their metabolic processes. These properties of the strains- biodestructors determine the efficiency of their using in different climatic zones in order to control chemically different wastes.

Generally, all existing preparations are intended for the destruction of the oily wastes of not only soil, but also fresh-water basins, areas of seas, factory runoffs and contaminated inner surfaces of process reservoirs and tanks.
BOP Performance Post - Macondo - How Are We Doing?
Authors: Sattler Jeffry P
Published: October 2013

Description

The Macondo disaster and other recent environmental incidents have resulted in a new emphasis on the performance and reliability of BOP (Blowout Preventer) equipment and systems, most specifically in the US Gulf of Mexico (GOM), but also in other drilling regions. Due to the environmental sensitivity of offshore Arctic environments, reliable BOP operation is even more important. These combined factors have led to many industry and regulatory changes in BOP systems, their operation and maintenance. This paper will describe the practical effects of these changes from an independent, third-party verifier’s perspective, including perceived benefits and identified but unintended consequences, together with some possible unintended consequences for the future.

Although the materials presented reflect the author’s experience on offshore floating drilling rigs, some of the contents are applicable to other types of offshore rigs as well as land rigs.
A Method and an Apparatus for Killing an Uncontrolled Oil-Gas Fountain at an Offshore Oil Platform Using a Telescopic Rod Assembly
Authors: Tseytlin Simon
Published: October 2013

A method and an apparatus for killing of uncontrolled oil fountains include a series of rods with the first rod having the smallest diameter and successive rods having increasing diameters. Such telescopic assembly of rods is lowered into the well to cause gradual reduction in cross-sectional area available for oil flow discharge. Once sufficiently large rods are lowered into the well, the oil fountain discharge will be greatly diminished. A method of monitoring the conditions of lowering the rods into the well may utilize a weight measuring device mounted at the surface platform. In the case of killing the oil fountain based on the present method, such device will show the difference between the weight of the rods (pushing the entire assembly down) and the combination of various forces acting to push it up, including the reservoir pressure and the drag force from the flow of oil or a multiphase flow of various gases and fluids coming out from the well. Final sealing may be accomplished by pumping cement into a space formed between the well pipe and the rod assembly. A novel system for aligning the rods to the center of the well is also described. The present method is aimed at making killing of the well safe, fast and inexpensive so as to prevent heavy environmental and financial losses typically associated with dealing with offshore well blowouts.
Streamlines for the Target Injection Calculation in Complex Field Conditions
Authors: Gladkov Andrey , Kondakov Danila , Gareev Rustem , Belyanushkina Maria , Lvov Anton , Arsenevsky Ivan
Published: October 2013

The target injection determination is one of the major issues in waterflooding management. The study resulted in a fully automatic approach to the waterflooding management via the block analysis based on continuously updated hydrodynamic models. The authors propose an automated workflow that provides a closed cycle for waterflooding management: from estimation of target voidage replacement ratio (VRR) per blocks, calculation of recommended well injection rates and monitoring of the plan implementation on optimum VRR per blocks.

The paper describes a new approach to key two problems arising from the analysis of waterflooding block performance: the identification of block boundaries with minimum cross-flows between blocks and the correct production / injection allocation (distribution) for wells located on the blocks boundaries.

A real-field example, demonstrating the application of the proposed technique, includes the construction of a three-dimensional hydrodynamic model, automatically updated on a monthly basis using actual production / injection data with the streamline map generation. After that, also automatically, the adjustment of waterflooding block boundaries takes place (with the indication of poor drainage areas), with calculation of well allocation factors. The data derived are used in waterflooding performance analysis and block ranking based on a given set of parameters.
Challenges of Welding in Arctic Areas
Authors: Gens Rouslan , Leconte Sébastien , Graindor Guillaume , Gaffard Vincent , Godinot Henri , Romazzotti Henri
Published: October 2013

The aim of this paper is to review the challenges of onshore and offshore welding operations in Arctic extreme environments in terms of: Health, Safety and Environment,Equipment exposure to cold environment,Logistics,Welding performance requirements: weld quality and productivity.

It lists the key elements to ensure successful onshore and offshore welding operations meeting both project productivity and quality targets in extreme cold areas.

Qualification of equipments either in cold chamber or in extreme cold conditions is a pre-requisite. It must be ensured that batteries, materials (metallic and non metallic), fluids (hydraulic and engine oils …) are suitable for the working conditions. Due to logistics issues, preventive maintenance on all equipments is very important before starting any operation.

Work organization is highly impacted by workers exposure to very low temperature. High performance protective clothes are helpful but harsh external conditions mainly promote the use of automated, reliable and high deposition rate welding processes.

Finally, welding quality is a major concern to avoid pipeline leak or failure in very sensitive environments with difficult access for emergency repairs. It relies on qualified welding procedures, a limited number of manual operations, narrow ranges of welding heat inputs, strictly controlled preheating conditions and real-time monitoring of welding parameters during operations.

The main contributions of this paper are: to list the most important parameters to make welding operations successful in Arctic extreme environments and to reduce logistics issues.to highlight the interest to use fully automated, versatile and compact (limited coating cut backs lengths) welding equipments in terms of welding crew requirements and operation time.to evidence how good low temperature properties (in particular impact properties) can be achieved on QT seamless and TMACC seam welded pipes throughout optimization of welding thermal cycles.
Arctic Offshore Pipeline Design and Installation Challenges
Authors: Paulin Mike
Published: October 2013

With the oil industry’s continued quest for oil and gas in frontier offshore locations, several developments have taken place in regions characterized by seasonal ice cover including the US Beaufort, North Caspian, and Sakhalin Island. In these projects, pipeline transportation systems have been used, which are a cost effective, safe and reliable mode of hydrocarbon transport to shore. Ice gouging is one of the key design issues that affect engineering considerations with respect to strain based design, target burial depth requirements, cost, and safety.

It is generally accepted that offshore pipelines in ice environments will need to be trenched and backfilled for protection. Burial depths can be greater than those that might normally be required for pipelines in temperate climates. Burial depth requirements will be a function of the design ice gouge depth (to prevent interaction between the ice and pipe) and an acceptable level of subgouge deformation beneath a gouging ice keel (which potentially strains the pipeline). There still exists uncertainty on the magnitude and extent of subgouge soil deformations due to ice gouging and the importance of sediment transport mechanisms for biasing gouge statistics.

Other challenges that must be considered include strudel and hydrodrnamic scour, thaw settlement and frost heave, and upheaval buckling. These considerations may also influence burial depth requirements.
Approach to Optimization of Acid Treatment in Oil Reservoirs
Authors: Volnov I. A. , Suchok S. N. , Obsharov P. A.
Published: October 2013

The mathematical model of two-phase displacement of oil by an acid aqueous solution in the neighborhood of a well and a hydraulic fracture [1] was used for investigation processes of optimization acidizing and acid fracturing. It takes into account the kinetics of acid dissolution of a carbonate rock. The proposed model allows us to improve the process of searching and selecting the best design for acidizing and acid fracturing.

The effect of well acidizing and acid fracturing are estimated. It is shown possibility to find the best value of such parameters as the speed of injection, speed of reaction and volume of acid mixture injected into a well during acidizing and acid fracturing. At given process parameters in the real case is shown importance of studying the process of interval treatment including the possibility of optimizing the design of each of the treated intervals.

The control of such parameters as the injection rate, the chemical reaction rate and the volume of injected acid makes possible to reach the maximum treatment effect at the given solution volume. Also calculations showed that in the case of the acid fracturing the significant slowing of the reaction rate may lead to large leakage of unreacted acid into the reservoir, extending the penetration zone, but also reducing the effects near the fracture and thus worsening the result of treatment.

The created model was applied to numerical calculations for real cases. Field and calculated data are in good agreement. Using of this approach allows us to find the ways for new possibilities in improving design of acid treatments and understand the current status of the proposed design.
Performance Evaluation of Gas Condensate Wells Treatment with LNG Rims and Dry Gas Displacement
Authors: Glumov D. N. , Reitblat E. A. , Buchinskiy S. V.
Published: October 2013

The paper reviews the performance evaluation of measures against condensate banks in bottomhole zone. The study is based on compositional simulation. According to the results, optimal parameters for LNG injection and dry gas displacement in the formation are selected; duration of the measures taken and incremental recovery are evaluated.