bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risks Management In Russian Offshore Geotechnical Prospecting
Authors: Kornishin Konstantin , Efimov Yaroslav 
Published: December 2011

Abstract
This paper presents a new approcah to risk essesment in offshore geotechnical surveys. A traditional deterministic method of time estimation needed for the survey can not be found satisfactory due to influence of uncertainties of different types, for example weather uncertainty and management uncertainty of the specific contractor. The proposed method of risk estimation is based on fuzzy logic and presents all uncertain values as fuzzy membership functions with high level of certainty.
The described methodology allows the client to choose a contractor in a situation when the client doesn’t have a long term joint experience with the contractor. It also allows the client to obtain a quantitative estimation of the work of contractor and to choose the most favorable start date for the survey.
The Oil Based Mud Formulation Improvement To Reduce ERD Drilling Risks In The Arctic Conditions
Authors: Voronin R.. , Valuev D.. , Korolev A.. 
Published: December 2011

Abstract
One of the features of the drilling in YaNAO area is the long section of permafrost. This feature impacts on different technological processes of well constructing. Drilling fluid cools in the annular opposite permafrost without circulation in particular. This feature should be considered in the development of the mud program with oil based muds.
Non-aqueous based fluid is the drilling fluid of choice to drill ERD wells. They make it possible to drill long sections even with the unstable formations. But they have some features, such as quite high rheology and its temperature dependence. The oil-based mud formulation which allows to decrease temperature dependence of rheology was applied in April – July of 2011 on Yurkharovskoye field.
Lab research, extensive computer modeling and hydraulic simulations were performed to take into account temperature and pressure conditions of the north of YaNAO. Main features and results of the new OBM formulation field application are described. Comparative data of the rheology-temperature profiles of formulations used in other regions of Russia are presented in the paper.
The experience of new OBM formulation application in ERD drilling on Yurkharovskoe field provided in the paper can assist with planning and project execution of OBM implementation in Arctic areas.
Piltun Field PLT Results in Commingled-Reservoir Wells Drive Smart-Well Implementation & Field Redevelopment
Authors: De Wit Andre , Yakovlev Alexey , Sumrow Mike , Urazovskaya Oxana , Belonogov Andrey 
Published: December 2011

Abstract
The subsurface development and well intervention teams recently completed a campaign of five production logs (PLTs) in the extended reach and highly deviated production wells of the Piltun field. The challenges of running the PLT logs were considerable: 4,000 to 7,000 m long deviated wells, complex well trajectories, long tractoring intervals, risk of tool lift due to high oil and gas rates, high wellhead pressures of ~2000 psi, harsh winter conditions, the problem of hydrate formation on the wire and in the pressure control equipment when pulling out of hole. Despite these challenges, the logs were completed safely and revealed a number of surprises about production from these multi-reservoir commingled wells.
The logs revealed that major reservoir intervals, with excellent porosity and permeability development, were not flowing. Some lower completion intervals in these good quality reservoirs remained covered with completion brine and debris, while selective zones with high GOR development had dominated production from the wells. Prior to this learning, the team assumed production from the wells had followed a rate distribution profile matching permeability thickness (kh) distribution. The logs also revealed off-depth perforations in some cases, which may have contributed to productivity issues for those reservoirs.
The learning from the PLT logs has affected dynamic modeling history matching effort, influenced further field development plans, and has driven the need for workovers to install smart-well equipment in essentially all of the production wells drilled to date. Learning from the logs has also led the team to apply greater quality control and assurance to perforation operations, investigate the use of less damaging completion methods or perforation pills, and use smart-well equipment for newly planned development well completions.
This paper discusses the issues and challenges to further field development and how learning from the recent PLTs has affected this effort.
Key Lessons in Social Engagement and Impact Assessment in the Arctic
Authors: Southam Anne L. , Swanzey Kim R. 
Published: December 2011

Abstract
This paper presents lessons learned from recent case studies in Alaska and Greenland, and examines the steps for a successful social engagement and impact assessment strategy. These steps can be used to conduct impact assessment in Arctic conditions. The integrated approach presented herein complies with national and international guidelines, and addresses public expectation. Changing climate, improved technology and the demand for energy have ignited interest in Arctic oil and gas resources. Industry is challenged to address ecological risks, climate change, cumulative effects, impacts on subsistence, and community concerns through a successful impact assessment process. As a key requirement of national regulators, international finance institutions and other socially responsible investors, impact assessment sets the foundation for effective management of environmental and social performance. What defines successful impact assessment and social engagement in Arctic communities where there may be many uncertainties? An integrated approach recognizing the interdependence of society and the environment is paramount for facilitating an effective stakeholder engagement and impact assessment process.
Significant Production Improvement Through Effective Well and Reservoir Management On Sakhalin Energy's Astokh Area
Authors: Yambayev Marat F. , Foreste Kenny , Jones Malcolm Kevin , Brown David Archibald , Kovalevich Alexander Sergeevich 
Published: December 2011

Abstract
When improving field production, the traditional focus on drilling activity means that the benefits from effective Well and Reservoir Management (WRM) are often overlooked. Within Sakhalin Energy’s Astokh area, an integrated field management approach has realized significant oil gains with minimal well interventions.
When phase 1 of the Astokh development was completed in 2001, only seasonal production via an FSO was available. Associated gas was re-injected into the crest of the reservoir, leading to a secondary gas cap. When this caused gas coning in updip wells, oil production declined because the gas handling equipment limits were exceeded. Pressure maintenance wells in 2004 helped to minimise associated gas levels, but it was not until the Sakhalin Energy Phase 2 project came on stream in 2009 that year round export was available, allowing gas injection to cease. With the drilling rig not available until Q4 2011, the application of effective well and reservoir management was the only way to address the declining field production.
The primary focus was the depletion of the secondary gas cap. The first decision was to open high GOR updip wells whilst managing others through downhole shut-off / choking of zones. Secondly, water injection well volumes were optimized depending on levels of gas cap depletion in various areas of the reservoir. Thirdly, the reservoir model was regularly updated, reflecting gas cap behaviour seen through GOR levels in updip wells. Executing this approach required the gas compression facilities to operate at &gt; 100% efficiency and put strain on the equipment, so a significant effort to maintain the reliability of the surface facilities was pursued.
Within a year of implementing this multi disciplinary approach, three wells more than doubled their oil production rates.
Differentially-normalized Method of Electroinvestigation (DNME) - An Efficient Instrument for HC Exploration Off- and Onshore
Authors: Legeydo P. Y , Ageenkov E. V. 
Published: December 2011

Abstract
Considerable costs of onshore and offshore wells drilling require effective geophysical methods of HC deposits exploration and study. One of such methods is DNME dealing with conductive and polarization medium properties.
In some cases electrical resistivity can indicate HC presence in reservoir that have increased resistivity or water having reduced resistivity. Polarizable medium properties alter in presence of HC. Such alterations are observed to the first regional confining layer, which typically occurs at depth to 1000m. Hence studying medium polarization properties HC occurrence can be detected even at relatively small depth.
DNME exploration is conducted both off and onshore. Horizontal electric lines are used as the source and the receiver of the electromagnetic signal. At marine exploration electric field potential differences of the first and second order are registered at several spans. Offshore measurements are carried out on the move of a vessel.
At that inductive sounding based on skin-effect is combined with induced polarization (IP) based on the geometric principle. Combined inversion of measurements on several spans allows studying distribution along with conductivity depth and polarization properties of geological environment.
In order to obtain quality electromagnetic data the series of measuring techniques was developed. Digital filtration also significantly increases S/N ratio.
Onshore and offshore DNME explorations are carried out all over the world: shelves of Sea of Okhotsk and Barents Sea, Caspian Sea, Sea of Azov, Baltic and Caribbean Seas, Gulf of Ob and Tar Bay, Volga-Ural Timan-Pechora, West Siberian, East Siberian, Peri-Caspian, Baltic, North-Caucasian oil-and-gas provinces, China, Cuba, Peru.
One of the examples of successful DNME usage offshore is the exploration in Barents Sea (Severo-Gulyaevskoye field). Technique of induction (EM) and IP fields' separation in the whole measuring range allowed to map deposit’s contour occurring in IP field. Geoelectric modeling showed polarizability coefficient increase in deposit's contour at depth complying to regional confining layer. According to well testing data this depth interval (500-600 m) contains high concentration of epigenetic pyrite. The same is observed directly above the oil-saturated reservoir at depth around 2500.
Basic Principles Underlying Permanent Scientific Support of Complex Field Development
Authors: Timchuk A. S. , Sokolov S. V. , Sunagatullin A. F. 
Published: December 2011

Summary
Scientific and technical support of fields in the complex environment requires a unique approach for each field. Most of the new projects of TNK-BP, one way or another, are associated with extreme conditions, complex geological structure, lack of infrastructure and, therefore, higher investment risks. In recent years, TNK-BP has successfully brought a number of Uvat Project and Eastern Siberia fields into development (Urna, Ust-Tegus, Verkhnechonskoye). Besides, active work on future Yamal projects (Russkoye, SuzunϬ and other assets) is in progress.
The article describes the main methods used for scientific support for the development of the Company’s new projects. The main challenges of Uvat project, i.e. the remoteness from infrastructure, marshland, and poor predictability of net pay thicknesses, have been successfully solved by drilling of super-pads with big step-outs, up to 3 kilometers, and continuous support of drilling using geological and hydrodynamic models. The uniqueness of Verkhnechonskoye field is in very low temperatures, salinization, and high heterogeneity of reservoirs. The geological conditions are complicated by geography, i.e. Eastern Siberia is a new development area. The field is drilled out by horizontal wells using geosteering and detailed geological and hydrodynamic models. Russkoye and Suzun fields are, in fact, in arctic conditions, reservoir evaluation is made using a unique approach to modeling. The experience received in the process of development of such fields can be used in more extreme conditions of the Arctic Region, Yamal, and East Siberia.
Approach for Full Field Scale Smart Well Modeling and Optimization
Authors: Khrulenko Alexey , Zolotukhin Anatoly B. 
Published: December 2011

Abstract
Smart (or intelligent) well is a well equipped with downhole sensors and downhole valves to control fluid inflow from the separated perforated intervals towards well, in real-time mode and without well interventions, to optimize production.
The advantages of smart wells can be briefly comprised in the following four points: reduction of operational expenses;increased oil production;improved oil recovery;mitigation of the geological uncertainty impact on the project performance.
But disadvantages of smart well technology, that derive from its technical complexity, restrict a scale of its deployment. These disadvantages can be summarized as follows: High cost;Risk of the valves and sensors failures;
Thus, three questions must be addressed while screening possible smart well deployment: How to estimate the value added by smart completion?How to control smart well completions in order to gain the maximal effect?How to estimate possible losses in production due to ICV failures?
A lot of publications were addressed to these problems in recent years. Majority of researchers used reservoir simulation as the main tool. Within the frameworks of such a concept a reservoir model impersonated both a real field and its reservoir model and was used for optimization. This work, on the one hand, partly adopts these approaches and, on the other hand, suggests the optimization strategy in full field scale based on subdivision of the initial big task into several ones with smaller dimension that require less time for the evaluation. Optimization routine is based on using commercial reservoir simulator coupled with Matlab-based program controller that optimizes downhole valve settings by using Direct Search optimization routine and imitates valves failures. The introduced optimization routine has been tested on multiple realizations of generic reservoir model always showing good performance and the added value.
New Approaches to Improve Economical Efficiency of Development of Gas-Condensate Reservoirs with Thin Oil Rims
Authors: Yushkov A. Y. , Romanov A. S. , Mukminov I. R. , Ignatiev A. E. , Romashkin S. V. , Buchinsky S. V. , Glumov D. N. , Magdieva L. K. 
Published: December 2011

Abstract
Using BU161-4 formation of the Urengoy oil and condensate field deposit as an example the authors have demonstrated that today in the absence of developed transport infrastructure high CAPEX and OPEX investments are inevitable. It will result in negative economic results in developing oil banks in gas and condensate deposits located in the Northern and Polar regions of the Russian Federation. This factor decreases attraction of such assets for investors significantly and actually oil reserves in oil banks and gas reserves in gas caps are not developed and it is uncertain when these reserves might be developed. As a result the state will get less revenue from developing hydrocarbon reserves.
Design and Field Practice of Arctic Cement Systems Applied for Well Construction in Permafrost Zones
Authors: Korostelev A. S. 
Published: December 2011

Abstract
The requirements to improve the quality of well cementing in permafrost zones stipulate the application of unconventional multicomponent cement systems with proper technological characteristics (freeze-thaw durability, zonal isolation, short set times), which do not lose their properties during long-term storage periods in cold open-air conditions.
The new cementing systems are being introduced in the given article; they are plug-and-play non-gypsum blends of base cement and lightweight, stabilizer, expanding additives.
The results of laboratory researches and field application practices of such cementing systems in Yamal fields of Russia are being described in this paper.
The Vibration of Fixed Offshore Structures under Ice Action
Authors: Shkhinek Karl , Zhilenkov Alexander , Thomas Graham , Gebson Richard 
Published: December 2011

Abstract
Ice induced vibration of fixed offshore structures has been observed in different seas, for example: Beaufort Sea, Cook Inlet, Gulf of Bothnia, Bohai Bay, Sea of Okhotsk. It can have a significant impact, as it may lead to failure due to structural fatigue (Bohai Bay) or softening of foundations, or cause problems with the serviceability of platforms. Possible future arctic developments will be in deeper water, where the phenomenon of ice induced vibration may be one factor limiting the maximum water depths for the economic use of fixed (bottom-founded) structures. Therefore it is important to be able to predict the responses of structures of different shapes and sizes to the ice conditions specific to the region of interest, in order to optimize development options.
A 2D solution for the numerical study of ice induced vibration of vertical-sided fixed offshore structures based upon common assumptions and mathematical models of ice properties has been developed by St. Petersburg State Polytechnical University and BP. The solution considers the whole process of vibration as it develops in time: successive ice failure, structural response and mutual ice/structure interaction. The model has been applied in order to understand the environmental conditions and structural characteristics that are important to the incidence of ice induced vibrations.
Ice induced vibration of fixed offshore structures has been observed in different seas, for example: Beaufort Sea, Cook Inlet, Gulf of Bothnia, Bohai Bay, Sea of Okhotsk. It can have a significant impact, as it may lead to failure due to structural fatigue (Bohai Bay) or softening of foundations, or cause problems with the serviceability of platforms. Possible future arctic developments will be in deeper water, where the phenomenon of ice induced vibration may be one factor limiting the maximum water depths for the economic use of fixed (bottom-founded) structures. Therefore it is important to be able to predict the responses of structures of different shapes and sizes to the ice conditions specific to the region of interest, in order to optimize development options.
A 2D solution for the numerical study of ice induced vibration of vertical-sided fixed offshore structures based upon common assumptions and mathematical models of ice properties has been developed by St. Petersburg State Polytechnical University and BP. The solution considers the whole process of vibration as it develops in time: successive ice failure, structural response and mutual ice/structure interaction. The model has been applied in order to understand the environmental conditions and structural characteristics that are important to the incidence of ice induced vibrations.
Control of Gathering and Transport System for Multiphase Product on Russian Arctic Continental Shelf
Authors: Papusha A. N. , Nankin A. A. 
Published: December 2011

Abstract
Flow assurance is an engineering analysis process to assure hydrocarbon fluids are transmitted economically from the reservoir to the end user over the life of a project in any environment.
The term "Flow Assurance" was first used by Petrobras in the early 1990s, it originally only covered the thermal hydraulics and production chemistry issues encountered during oil and gas production. While the term is relatively new, the problems related with flow assurance have been a critical issue in the oil/gas industry from very early days. Hydrates were observed causing blockages in gas pipelines as early as the 1930s.
Another problem is slugging and liquid handling. The occurrence of slug flow in a transportation pipeline and a gathering system can cause many problems in design and operation processes, which include kinetic force on fittings and vessels, pressure cycling, control instability and inadequate phase separation. Slugging affects greatly the design of receiving facilities. In gas condensate systems, larger lines result in more liquid being retained in the pipeline at low rates. When the flow rate is increased, much of the liquid can be swept out, potentially overwhelming the liquid handling capability of the receiving facilities. The facilities can be flooded and damaged if the slugs larger than the slug catcher capacity. Therefore, quantifying the slug size, frequency and velocity is necessary prior to equipment design.
Toll-Like Receptor 2 Gene Polymorphisms Associated with Aggressive Periodontitis in Japanese
Authors: Takahashi Marika , Chen Zhiyong , Watanabe Kaoru , Kobayashi Hiroaki , Nakajima Toshiaki , Kimura Akinori , Izumi Yuichi 
Published: December 2011

Background and Objective:
Aggressive periodontitis is a rare and very severe periodontal disease of early onset, which is closely associated with Porphyromonas.gingivalis (P.g.) infection in the Japanese population. TLR2 encodes Toll-like receptor 2, which plays an important role in the protective response to P.g. infection. We investigated a possible association between TLR2 and aggressive periodontitis.

Material and Methods:
Of 2,460 Japanese patients with periodontitis, 38 patients with aggressive periodontitis were enrolled in this study. These 38 aggressive periodontitis patients and 190 Japanese healthy controls were examined for an insertion/deletion (Ins/Del) polymorphism in exon 1, a polymorphism in intron 1 (rs7696323), and a synonymous polymorphism in exon 3 (rs3804100) in TLR2.

Results:
We found significant associations of resistance to aggressive periodontitis with the Ins allele (allele frequency in the patients versus controls, 0.540 vs. 0.676, OR=0.56, 95% confidence interval (CI); 0.34-0.92, p=0.022) and the T allele of rs3804100 (0.579 vs. 0.716, OR=0.55, 95% CI; 0.33-0.91, p=0.018), although the C allele of rs7696323 showed no significant association (0.733 vs. 0.829, OR=0.58). A permutation test of Ins/Del-rs7696323-rs3804100 haplotype revealed a significant association between Ins-C-T haplotype (0.252 vs. 0.479, p=0.0003) and resistance to aggressive periodontitis.

Conclusions:
The TLR2 polymorphisms were suggested to confer protection against aggressive periodontitis in a Japanese population. The association should be replicated in other cohorts to further identify the responsible TLR polymorphism(s) involved in the pathogenesis of aggressive periodontitis.
Uniqueness results for the Minkowski problem extended to hedgehogs
Authors: Martinez-Maure Yves 
Published: December 2011

Abstract
The classical Minkowski problem has a natural extension to hedgehogs, that is to Minkowski differences of closed convex hypersurfaces. This extended Minkowski problem is much more difficult since it essentially boils down to the question of solutions of certain Monge-Ampère equations of mixed type on the unit sphere
$\mathbb{S}^n $
of ℝn+1. In this paper, we mainly consider the uniqueness question and give first results.