bluuebunny/crossref_metadata_2025_split huggingface dataset:
Image Processing and Machine Learning Approaches for Petrographic Thin Section Analysis
Authors: Budennyy Semen , Pachezhertsev Alexey , Bukharev Alexander , Erofeev Artem , Mitrushkin Dmitry , Belozerov Boris 
Published: October 2017

Abstract
The article presents the methodology of petrographic thin section analysis, combining the algorithms of image processing and statistical learning. The methodology includes the structural description of thin sections and rock classification based on images obtained from polarized optical microscope. To evaluate the properties of structural objects in thin section (grain, cement, voids, cleavage), first they are segmented by watershed method with advanced noise reduction, preserving the boundaries of grains.
Analysis of segmentation for test thin sections showed a fairly accurate contouring of mineral grains which makes possible automatically carry out the calculation of their key features (size, perimeter, contour features, elongation, orientation, etc.). The paper presents an example of particle size analysis – definition of grains size class. The roundness and rugosity coefficients of grains are estimated also. Statistical analysis of templates for manual determination of roundness and rugosity coefficients revealed drawback of examined templates in terms statistical accuracy (high dispersion of coefficient for all grain within one template, outliers presence).
In the frame of classification problem the feature importance analysis and clustering of non-correctly segmented grains are handled. The classifier for rock type definition (sandstone, limestone, dolomite) is trained with decision tree method, while the classifier of mineral composition of sandstones (greywackes, arkose) is learnt with "random forest" method. Both classifiers are learnt in the feature space generated from segmented grains and their evaluated properties.
As a result, we proved the possibility to conduct automatic quantitative and qualitative analysis of thin sections applying image processing and statistical learning methods.
Estimation of Abilities of Surface Microseismic Monitoring during Hydraulic Fracturing
Authors: Dyagilev R. A. , Shumilov A. V. 
Published: October 2017

Abstract
This paper deals with methodical aspects of the microseismic monitoring as used to localize cracking which accompanies hydraulic fracturing (HF), and with the issue of recording useful signals from the surface where reception conditions are highly adverse due to strong attenuation of waves. Surface based seismic observation systems are shown to be usually able to record only a low-frequency component of microseismic radiation within the first hundred of Hertz. The comparative characteristic of resolution of methods of absolute and relative microfracture location in relation to the considered situation is provided. It is shown that only relative location is capable to provide acceptable accuracy at layer intersection area. The conclusion shows the major technical, methodical and natural factors which either facilitate increase in informational content of surface microseismic monitoring of hydraulic fracturing, or interfere with unbiased fracturing patterning.
Numerical Modeling of Microseismic Events on the Surface
Authors: Butorin A. V. , Krasnov F. V. 
Published: October 2017

Abstract
The urgency of conducting microseismic studies in the process of hydraulic fracturing is considered in the article.
The increased interest in this area in domestic geophysics is a reflection of the current challenges of the oil industry: an increase in the share of non-traditional and hard-to-recover reserves in the structure of the assets being developed. Increased interest of researchers in the issue of microseismic monitoring makes it necessary to develop methodological recommendations for the most effective positioning of field observation systems, as well as for choosing the most correct method for solving the inverse problem. Achieving this goal is impossible without digital modeling, which will allow, in conditions of a priori known solution, to develop recommendations for optimizing each of the MSM.
Within the framework of the article, the first stage of this large-scale work is considered, which consists in setting up a digital experiment - obtaining synthetic seismograms of MSM.
A Quantitative Assessment Method of the Productive Formation Wettability Indicator According to the Data of Geophysical Surveys
Authors: Akhmetov R. , Mukhametshin V. , Andreev A. 
Published: October 2017

Abstract
The reservoir wettability nature should be taken into account while well logging conducting, reservoir engineering, methods of oil recovery enhancement and intensification selecting with the aim of residual oil reserves involvement into the development.
In this respect, the development of a methodology for reservoirs’ wettability quantitative assessment on the basis of well logging data is very urgent and relevant.
In this article, basing on the analysis of laboratory data on the wettability index and reservoir characteristics, a methodology for quantifying the wettability index from field geophysical data assesment has been developed, and the results of the method application in carbonate reservoirs of the Ural-Volga region are presented.
For the first time, the analytical expressions between wettability and reservoir characteristics are obtained. It is shown that the formation wettability at its microlevel is determined by the average thickness of the residual water film on the filtration channels surface, and at the macrolevel – by the residual water saturation volume of the effective part of the productive strata void space.
A methodology for wettability index by the residual reservoir water saturation volume quantitative assessment was worked out, and the necessary analytical expressions were obtained.
The proposed methodology is as follows: –on the reservoir core samples collection in the laboratory environment, the following parameters are determined: wettability index, porosity, residual water saturation;–using the laboratory core studies data, the dependence diagram of the wettability index on the residual water saturation volume (volumetric moisture content) is plotted;–basing on the reservoir resistivity, determined by the prior to development geophysical studies, the residual water saturation volume of the formation is estimated and, using the graph, the wettability index is determined.
The worked out wettability index quantitative assessment methodology has been successfully proven in the Ural-Volga region carbonate reservoirs. The method allows the wettability degree according to the geophysical data in every layer intersection assessment both in the cross-section and in the deposit area. The information about the reservoir nature and wettability degree will make it possible to proceed more rationally to the development analyzing, controlling, regulating and enhanced oil recovery methods engineering and, as a consequence, to reduce the risks of their practical implementation.
Identification of Inflow Zones in Low-Rate Horizontal Wells by Spectral Noise Loggin
Authors: Aslanyan I. Y. , Minakhmetova R. N. , Pimatyev V. G. , Kozlov A. A. , Kuznetsova A. G. 
Published: October 2017

Abstract
The modern petroleum industry in Russian Federation has been lately focusing on developing fields with complex flow properties typical, for example, to low-permeability reservoirs. Therefore, it is important to identify flow zones in wells, mostly horizontal ones, when producing from such low-permeability reservoirs. This task is complicated not only by the effect of complex well completion components but also by the small specific rates of inflows into the wellbore. The conventional logging techniques do not always yield sufficient information under such conditions.
This paper presents the results of a conventional downhole logging suite supplemented with High-Definition Spectral Noise Logging (SNL-HD) and targeted at determining flow profiles in low-rate horizontal producers. A separate objective was to evaluate the SNL-HD efficiency in identifying flow zones in low-permeability carbonate reservoirs. Upon SNL-HD data analysis, depth-specific broadband noises typical to turbulent flows from naturally fractured carbonate reservoirs into the wellbore were identified.
The proposed technique is illustrated with four case studies performed in an oilfield situated in Krasnoyarsk Region in the south of the Evenk Municipal District. These cases studied dealing with the survey, results of which that application of SNL-HD in combination with the conventional downhole logging techniques helps to identify flow zones and thereby monitor horizontal well production and work out recommendations on well performance enhancement.
Novel Approach for Evaluation of Petrophysical Parameters from Time-Lapse Induction Logging-While-Drilling Measurements in Deviated and Horizontal Wells
Authors: Podberezhny Maxim , Polushkin Sergey , Makarov Alexander 
Published: October 2017

Abstract
Selection of the chemical composition of the mud, as well as an appropriate strategy for the future development of the well, requires knowledge of properties of the invaded zone and reservoir quality. The main objective of this study was to determine the evolution stages and properties of the invaded zone using induction logging while drilling (LWD propagation resistivity) and repeated measurements. For this purpose, numerical modeling of the invasion zone evolution, modeling of the induction logging signals, evaluation of mud/mudcake properties (measured in the lab) and analysis of drilling data were performed.
As input data to simulate invasion zone evolution, the following parameters were used: formation fluid and drilling mud filtrate viscosities; Corey-Brooks constants in phase-permeability functions; formation brine and mud-filtrate resistivity; Waxman-Smits equation constants; mudcake filtration properties and drilling data. All these parameters are measured at the surface level both while drilling and while performing petrophysical measurements.
The invasion simulation enables water saturation and salinity distribution to be obtained in the near-wellbore area at different moments in time. These characteristics are used to calculate resistivity distribution using the Waxman-Smits equation. The obtained distributions are utilized to calculate synthetic induction log signals. Joint analysis of the synthetic and measured signals make it possible to correct the formation evaluation. After the formation properties are corrected, the invasion simulation and induction log modeling is iterated again until the formation properties are found providing the best match between synthetic and measured signals. In other words, the induction time-lapse measurements were inverted to obtain the porosity, permeability and water saturation of the formation at given mudcake parameters. The obtained formation properties were compared against the reservoir properties determined for the neighboring wells with full logging suite and showed good correlation.
The main advantage of the method is the use of additional available measurements such as drilling data and mudcake tests that are usually available on the rig site, but are not applied for formation evaluation. Extra core filtration tests with mudcake growth are used for fine model adjustment. In addition, the method can be recommended to estimate reservoir properties in sidetrack wells that are usually drilled with a limited set of LWD tools (gamma ray and induction logging). The main condition for successful application of the method is a presence of repeated time-lapse LWD induction logs.
New Approach to Interpretation of Hydrodynamic Study of Horizontal Wells Located in Under-Gas-Cap Zones
Authors: Fedorov Aleksei E. 
Published: October 2017

Abstract
One of the main tasks of oil and gas production companies is increasing the efficiency of wells operation while gas-cap oil reservoirs development. In particular, a successful solution of this task can contribute to a significant increasing of production rates of wells located in under-gas-cap (UGC) zones or near the gas-oil contact (GOC) zones with a small thickness of the gas cap, which is in direct interaction with an oil-saturated part of a reservoir.
In such conditions, the task of estimating the thickness of the gas cap, which directly affects the value of the gas-oil ratio (GOR) and the regulation of the well operation mode acquires special importance. In particular, this ensures the growth of well productivity with a low GOR, which allows a substantial increase in oil production and net present value (NPV).
In this paper the new approach to interpretation of hydrodynamic study of horizontal wells by numerical methods in the Saphir software and an analytical method for GOR evaluation are proposed. The proposed solutions allow: To correctly interpret the hydrodynamic studies of horizontal wells located in UGC or near the GOC;To determine the thickness of the gas cap above the horizontal well, to evaluate "expansion" of the gas cap and to correct the map of the GOC distribution;To regulate an operating mode of production wells.
Design of 5 Liner Drilling System for Directional Drilling
Authors: Agishev A. R. , Gelfgat M. Ya. 
Published: October 2017

Abstract
The application of classical field development systems in the modern world is becoming more and more complicated. The global portfolio of oil and gas fields virtually ran short of reservoirs located in favorable conditions for geologists and drilling & completion engineers. New fields are either located in adverse climatic conditions (e.g., Arctic projects) or are faced with various problems related to unconventional reservoirs, complex geological structure, high pressures and temperatures.
One of those problems, which has become a particularly pressing issue in recent years, is the problem of incompatibility of borehole pressures, which causes complications in the well construction: borehole wall collapses, fluid losses and sticking of drilling tools. For the well construction process this means an increased non-productive time (NPT) and extra costs. One of the solutions to such challenges is a liner drilling technology, which is actively used as a means to lower NPT and operational risks.
Liner drilling systems, including those for directional drilling, are available, but for strings 178 mm (7″) and more in diameter. Smaller diameter liner drilling is carried out using directionally-uncontrollable systems, which restricts the application of the technology. In this regard the authors are offering the technology of directional drilling with a 127 mm (5″) liner, which would reduce the rig time and address the above technical problems.
The task is completed by the use of a disposable bottom-hole directional assembly - a drilling bit and a bent-housing positive displacement motor (PDM with adjustable bent sub) and a retrievable telemetry system. The coil tubing (CT) can be used to extract the retrievable telemetry system. All the system elements are available on the market, the article describes the calculation results that demonstrate the possibility of the use of such a system in drilling of deep directional and horizontal wells.
Opportunity in Adversity: A Paradigm Shift in Chemical Stimulation
Authors: Rylance M. , Hoq A. 
Published: October 2017

Abstract
Chemical stimulation has a strong track record of production improvement, and has always adapted to suit ever new environments, regulations and scenarios. From early arsenic based chemical techniques, the approaches have moved on and matured to HF and HCl solutions, and more recently with environmentally friendly additives. However, the pendulum continues to move and due to an increasing impact of conventional acid systems on ageing production infrastructure, facilities and pipelines as well as an inability to commercially support independent intervention and/or flow-back, even these systems are sometimes considered unacceptable.
Fortunately, the industry is now in the privileged position of being able to address these issues, it simply does not yet appear to have fully appreciated this widely. All too often stimulation interventions are reasonably justified on the basis of poor well performance; only to be disregarded when it becomes clear that simplistic deployment and flow-back are not considered available options, due to corrosive stimulation fluid behaviour. However, more recently synthetic acid formulations have removed the majority of these concerns; with neutral pH, inert corrosion behaviour and environmentally acceptable chemistry, they are the ideal answer to the range of issues that have mounted over recent years.
This paper will demonstrate that the oilfield has recently developed the necessary solutions, that when combined together provide for a low cost, environmentally friendly, low impact, integrity aligned approach to well stimulation operations under the majority of conditions. Certainly requiring a multi-disciplinary deployment approach, these new chemistries and methodologies offer the very tantalising prospect of a reinvigorated chemical stimulation business, particularly in mature/high-cost/remote basins. With case histories, process considerations and holistic intervention considerations; the paper will demonstrate the extensive opportunity that is currently simply waiting to be accessed by these techniques throughout the brownfield environment. No longer referred to as "acid treatments", these twenty-first century approaches to stimulation, offer the industry the unique potential to redefine and reclassify the delivery from these operations.
Maximising recovery from existing assets is heavily relied upon in annual wellwork; particularly in challenging commercial environments. While wellbore stimulation can deliver this, historically, the percentage of delivery from intervention has reduced, due to increasing issues related to environmental, integrity and commercial challenges. The deployment of synthetic acids as environmentally, integrity and commercially attractive solutions; offers an opportunity for a complete revitalization of chemical stimulation in mature and commercially challenged basins.
A Case Study of the Verkhnechonskoye Field: Theory and Practice of Eastern Siberia Complex Reservoirs Development
Authors: Chirgun A. , Levanov A. , Gordeev Y. , Lazeev A. , Timchuk A. 
Published: October 2017

Abstract
A number of large greenfields has lately been brought into development in Eastern Siberia, Russia, one of which being the Verkhnechonskoye oil and gas condensate field. There, for the first time in the history of domestic oil and gas production at regional scale, geologists faced a high-mineralized section, where the pore space of productive horizons is partially or fully filled with salt, which defines differential characteristics when developing new assets.
This study highlights the field development in the context of uncertainties, and the risk control strategy. It describes solutions for well operation in low temperature formations and for maintaining the oil-rate plateau using new approaches to development of sections of low formation reservoir properties (FRP) and under-gas-cap zones with the contact reserves of oil.
DIABEO App Software and Telemedicine Versus Usual Follow-Up in the Treatment of Diabetic Patients: Protocol for the TELESAGE Randomized Controlled Trial (Preprint)
Authors: Jeandidier Nathalie , Chaillous Lucy , Franc Sylvia , Benhamou Pierre-Yves , Schaepelynck Pauline , Hanaire Hélène , Catargi Bogdan , Farret Anne , Fontaine Pierre , Guerci Bruno , Reznik Yves , Penfornis Alfred , Borot Sophie , Serusclat Pierre , Kherbachi Yacine , D'Orsay Geneviève , Detournay Bruno , Simon Pierre , Charpentier Guillaume 
Published: October 2017

BACKGROUND

Self-management of diabetes minimizes the risk of macrovascular and microvascular complications, but understanding and/or adherence to self-management recommendations is often suboptimal. DIABEO is a smartphone app (downloaded via the internet) used to calculate bolus insulin doses. A previous study (TELEDIAB 1) showed that the use of DIABEO was associated with a significant improvement in glycemic control in patients with poorly controlled type 1 diabetes mellitus, particularly when combined with teleconsultations with physicians.

OBJECTIVE

Here, we present the protocol for a new study (Suivi A Grande Echelle d’une cohorte de diabétiques de type 1 et de type 2 sous schéma insulinique basal bolus par la TELEmédecine; abbreviated TELESAGE), conducted in a larger population of diabetic patients with poorly controlled basal-bolus insulin levels.

METHODS

TELESAGE is a multicenter, double-randomized, open-label, three parallel–arms study, conducted in approximately 100 centers in France. The study will compare a control group (arm 1: usual follow-up) with two DIABEO telemedicine systems: (1) physician-assisted telemedicine (arm 2), and (2) nurse-assisted telemonitoring and teleconsultations by a diabetologist’s task delegation (arm 3). Initial randomization will allocate the study arms in 12 French regions. A second randomization will assign patients in the groups allocated to each studied region. The primary objective of TELESAGE will be to investigate the effect of the DIABEO telemedicine system versus usual follow-up, with respect to improvements in the glycated hemoglobin levels of approximately 696 diabetic patients with poorly controlled basal-bolus insulin levels.

RESULTS

The TELESAGE study is sponsored by Sanofi (Gentilly, France). A primary completion date is expected in June 2018, and publication of results is expected within 6 months of work completion.

CONCLUSIONS

The TELESAGE study is expected to confirm the previous results of the TELEDIAB 1 study using a larger sample of diabetic patients. It is also expected to evaluate a nurse-assisted telemonitoring system. We will assess the potential of the DIABEO telemedicine service in terms of its utility and explore whether it can become an integral part of diabetes care for patients.

CLINICALTRIAL

ClinicalTrials.gov NCT02287532; https://clinicaltrials.gov/ct2/show/NCT02287532 (Archived by WebCite at http://www.webcitation.org/6ykajhJKd)