bluuebunny/crossref_metadata_2025_split huggingface dataset:
Applications of Material Balance for Determining the Dynamic Performance of Fractures in a Dual-Porosity System in HP-HT Reservoirs
Authors: Alcantara R. , Ham J. M. , Paredes J. E. 
Published: October 2017

Abstract
Fractured systems are paramount to the productivity of carbonated formations; this is the main reason why the on-time appraisal of fractures behavior in High Pressure-High Temperature (HP-HT) Naturally Fractured Reservoirs (NFR) is decisive for the optimum selection of the exploitation strategy of the field. Considering the classifications for NFR proposed by R. Nelson and R. Aguilera, it is prone to apply the dual-porosity material balance to know the fractured network performance in different types of NFR during its exploitation, and to match the production history based on the discretization of the acting drive indices and its impact on the fractured system, resulting in one recovery factor for the matrix, and another for fractures.
Several HP-HT Naturally Fractured Reservoirs (NFR) were analyzed and the material balance models were adjusted to the values of compressibility obtained from real saturation data observed in cores and petrophysical evaluations based on rock quality, rock typing and computed through correlations in order to obtain the performance of the fractured system, indicating the corresponding contribution of both to the total reservoir production; therefore it is possible to calculate a single recovery factor for fractures and other for the matrix only, and consequently, determine the type of NFR whose behavior is representative of the pressure-production history matching, agreeing with the numerical simulation model.
Moreover, Pressure Transient Analysis (PTA) was considered as a good source of information to determine some critical data that are useful for the calibration of dual-porosity material balance models and the resultant description of fracture behavior for the optimum characterization of NFR, despite of the fact that well tests are not always available for every single well and the adverse wellbore effects involved that could cause interpretation problems. Additionally, it was possible to determine the matrix block size with applied material balance and well testing, achieving a better understanding of NFR.
In this paper we present some cases of study of NFR hydrocarbon producers from Mesozoic age in the Southeast of Mexico with the applied methodology in order to reevaluate them, achieving important conclusions with the results obtained.
Coiled Tubing Boosts Efficiency of Multistage Hydraulic Fracturing Technique in Novoportovskoe Field
Authors: Belov A. V. , Shestakov S. A. , Trifonov A. V. , Korepanov A. A. , Simakov S. M. , Garenskikh D. A. , Tishkevich S. V. , Kichigin A. S. , Burdin K. V. , Vdovyak V. V. , Murzakhmetov R. A. 
Published: October 2017

Abstract
Today, when most reservoirs have low productivity, the question of whether hydraulic fracturing can be applied to the oil rims becomes very important. In such environment, the challenge of this widespread method of production intensification is significantly increased risk of gas breakthrough. Another challenge that is faced primarily during development of oil-rim (sub-gas) reservoirs is the selection of the most suitable completion designs. An outstanding example of oil rim stimulation was a project in Novoportovskoye field where an operator faced with a complex geological model of the reservoir characterized by an absence of strong clay bridges and minor contrasts in stress between interlayers associated with high risks of breakthrough into the gas zone.
In 2016, the Novoportovskoe field operator successfully performed a 20-stage fracturing job. An innovative optimized multistage fracturing (MSF) solution was used that employed shifted closable fullbore sliding sleeves operated by coiled tubing (CT) intermittently with fracturing operations. This method was used for the first time in the development of the hydrocarbon deposits of the Yamal Peninsula and is based on the use of sliding sleeves that allow opening and closing of separate hydraulic fracturing ports. Such a design allows, in the course of further operation of the well, to cutting off or separating ports to prevent the inflow of water and gas, or, at the same time, to conduct refracturing of certain parts of the formation if required. This technology, which optimizes the fracturing process by utilizing shifted closable fullbore sliding sleeves/ports consists of the following: Reclosable CT fracturing sleeve (fullbore cemented sleeve that could be opened/closed an unlimited number of times)Openhole hydraulic packers to isolate zones in case of uncemented completionCT shifting tool (CT/tubing conveyed)Multistage mechanical packer (optional, could be used in case of inability to close one of ports). The resettable packer could be activated in any part of liner with axial CT movements; 10 000-psi rated.
The main risk for hydraulic fracturing, in the absence of barriers is the proximity of the gas and water layers. Breakthrough of a hydraulic fracture into a gas- or water-bearing zone leads to a significant reduction in oil production rates. Stimulation operations in such difficult geographic and geological conditions have shown opportunities for the oil industry in the Arctic.
Multistage Fracturing at Top Gear
Authors: Demkovich M. , Ablaev A. , Vereschagin S. , Nizamova N. , Gromovenko A. , Burdin K. , Novikov M. , Starodubtseva K. , Karpov V. , Parshin N. , Ryazanov A. , Moiseenko A. , AyupovOAO R. , OOO A. Aleroev 
Published: October 2017

Abstract
The objective of this study was to identify efficiencies and prospects for future implementation of an advanced fracturing system for horizontal wells in which fracturing operations are combined with coiled tubing (CT) operations and are run together with CT inside the well. This results in decreased operation time for multistage fracturing (MSF) jobs.
Nowadays, in Western Siberia extensively used following workflow at wells: preoperational work (which include casing drifting, bottom-hole cleaning with sludge trap, coiled tubing slack off for opening a frac-port, pulling the coil out of the hole and following fracturing operation). The method of pumping fracturing operations through the annulus of a CT had been given especially for elimination of extra operationsat wells during jobs at Vinogradova field. The method implemented with a modern completion system that includes special four-way union and protector for coiled tubing and coiled tubing 50.8 mm. The paper contains the analysis of executed MSF jobs with coil tubing inside the well and special equipment which were used in order to implement all the operations during fracturing.
The innovative approach to cooperative work between the hydraulic fracturing and CT fleets enabled to reduce the operational timeline by 40% at the first well. As this technology comes into greater use in Russia and abroad, there will need to be sophisticated study and correct implementation. For future success, it will be necessary to perform an in-depth analysis to achieve further reduction in the operating timeline reduction and to eliminate complications in the process.
Well Completion Technology Evaluation for Oil Rim Field Development Using Permanent Tracers: A Case Study from North-Komsomolskoye Field
Authors: Gashimov R. R. , Salyaev V. V. , Nuykin A. M. , Arzamastsev G. G. , Safin A. F. , Mukhametshin I. R. , Nukhaev M. T. , Prusakov A. V. 
Published: October 2017

Summary
Excessive sand production, uneven recovery of reserves throughout the length of a horizontal well and early water and gas breakthrough are deemed to be the main problems while developing poorly consolidated terrigenous fields with contact reserves. Assessment of feseability of possible completion systems (gravel packing and autonomous inflow control devices were chosen for implementation) is necessary at the pilot stage of the project. Pilot wells shall be monitored at each stage including development, recovery, observation over the dynamics of water and gas breakthrough processes. The use of traditional PLT methods is not always technologically feasible and cost-effective. This article describes the experience of using stationary of intelligent inflow markers for permanent monitoring for the purposes mentioned above.
Improving Quality and Efficiency in Exploration Well Testing on Perspective Fields of Uvat Project
Authors: Kulyatin Oleg , Sosnovskikh Andrey 
Published: October 2017

Abstract
Confidence and certainty in evaluation of formation properties based on performed hydrodynamic well testing at exploration well is one of key factor for oil & gas company not only for purpose of proving reserves, but as well in taking decisions on perspective well design, planning surface infrastructure and defining general strategy of field development. The present article covers various aspects on perfuming hydrodynamic well testing on field in Western Siberia, which ensure obtaining high quality well test data for confident and accurate evaluation of formation properties at exploration phase.
It is quite common in Western Siberia that well test materials, obtained through well testing exploration wells are of low quality and lead to high uncertainty evaluation of formation properties. It happens due to gathered material being inaccurate, incomplete and ambiguous, and can be questionable on fluid type saturating formation. To avoid such situation, good quality and descriptive well testing operations shall be planned to test the well in efficient manner. Steady practical depression shall be exerted on testing interval, with depression propagating in formation quite far and subsequent informative pressure build-up shall be registered, which will eliminate uncertainty in evaluation of formation properties and will ensure defining true well productivity [1,2]. In present article authors describe cycle of planning and onsite operations on hydrodynamic well testing with employing customized "welltest assembly" with jet pump.
Thanks to well-detailed planning, rational application of modern technical equipment and fit-for-purpose technological solution, along with strict and accurate adherence to hydrodynamic well testing program there can be achieved successful operational results, quality and representative well test materials and high efficiency in well testing operations at exploration well.
Adaptive System for Analysis and Interpretation of Combined Well Test Data
Authors: Sergeev Viktor Leonidovich , Hoai Phuong Nguyen Thac , Krainov Aleksandr Igorevich , Gorlach Aleksandr Yurevich 
Published: October 2017

Abstract
The objective of this work is to develop a system of models and an adaptive algorithm to analyze combined well test data with resulting inflow performance relationship (IPR) curve and pressure buildup (PBU) curves, which allows defining the reservoir parameters, the required number of test stages, and the test completion time while testing.
The adaptive system for data analysis of combined well test is based on an integrated system of interacting IPR and PBU curve models with time variable parameters and considering additional a priori information. The process of adaptive identification and interpretation of well test data implies consecutive interpretation of IPR and PBU curves at different test stages. The solution on test completion is taken on the basis of quality indicator by means of comparing current estimates with approximations obtained at the previous test stages.
The proposed system allows defining filtration parameters and the initial reservoir pressure as well as the required number of test stages and the test completion time, since input data are registered in real time. The case study of well test data analysis for gas wells equipped with Permanent Downhole Gauges (PDG) shows that the adaptive interpretation method provides robust estimates of reservoir parameters, which starting from the second test stage are almost as adequate as those obtained at the following stages.
This novel integrated system of IPR and PBU models takes into account additional a priori information with time variable parameters presented as unknown unambiguous functions of time. Adaptive algorithms of identification and interpretation allows obtaining robust estimates of reservoir parameters, required number of test stages and completion time of the test within data input process in real time.
The proposed adaptive system is a new resource-efficient technology to automate data analysis for intelligent well tests conducted with PDG in oil and gas fields.
PI Evaluation by Well Tests in Case of Low Permeability Formations Exposed by Complex Geometry Fracs
Authors: Kremenetskiy Mikhail , Kokurina Valentina , Morozovskiy Nikita , Grishina Ekaterina 
Published: October 2017

Abstract
This paper deals with the assessment of the well tests information value for the diagnosis and examination of various fracs in low-permeability reservoirs. The main identifying features of fracs are their complex configuration (manifested in the plurality and nonlinearity of fracs planes) and change in the fracs geometry in time. Informative features of well tests for the diagnosis and estimation of complex fracs parameters and their predicted influence on well performance have been justified
Well Performance Wireless Monitoring with Stationary Intelligent Tracer Systems on the Prirazlomnoye Oilfield
Authors: Morozov O. N. , Andriyanov M. A. , Koloda A. V. , Shpakov A. A. , Simakov A. E. , Mukhametshin I. R. , Nukhaev M. T. , Prusakov A. V. 
Published: October 2017

Summary
This work describes the technology for inflow profiling based on the data from intelligent inflow tracers installed on production well completion elements at the Prirazlomnoye oilfield. Specially designed polymer matrices with tracers are installed at certain borehole sections depending on the well trajectory and the distribution of reservoir porosity and permeability. Individual sampling methodology and physical and mathematical model for tracing substance flushout and transportation are selected individually for each borehole and provide for not only qualitative but also quantitative inflow profile in the multizone horizontal well. The innovative technology described in this article helps solving tasks usually addressed by traditional well logging.
This study discusses the experience of Gazprom Neft Shelf LLC in implementing stationary tracing monitoring technology for horizontal wells in the Prirazlomnoye field.
A Comprehensive Approach to Basement Fractured Reservoir Development in the Pannonian Basin: Case Study
Authors: Polivakho Artem , Dragosavac Mile , Ezhov Kirill , Kharyba Elena , Bogatyrev Ilya , Stulov Leonid , Olneva Tatjana 
Published: October 2017

Abstract
The complex approach for analysis is especially actual for unconventional reservoirs of Pannonian basin related to fractured metamorphised rocks.
Oilfield T respresents complex fractured reservoirs presented by metamorphised schists of Paleozoic age. They composed of tectonic breccias, eroded rocks, sericite and crystalline schists.
At the beginning the field was producing by natural drive mechanism. At this period around 3% of geological reserves were extracted and it was resulted in formation pressure decreasing by 50-60%. After 5 years of such production there was a try to organize the system of peripheral waterflooding, but due to the geological complexity it failed. It was observed that wells productivity is very heretogeneous and the success of the conducted workovers is much variable.
The complex analysis of this field is of a great interest because it could be used as a reference object for further exploration and production in the region. Also, it could be a site for new techniques and approaches verifications, especially working with complex fractured reservoirs.
Therefore, the main goals of this work are deeper understanding of geology, estimation of heterogeneity with localization of the most productive intervals for further infill drilling and completion, and evaluation of oil recovery factor.
To achieve these goals all available information was analysed: geological and geophysical data, production history, and numerous special methods, which are explained further.
New Approach to Estimate Reservoir Complexity Index for West Siberian Fields
Authors: Naugolnov Mikhail Valerevich , Bolshakov Maxim Sergeevich , Mijnarends Runo 
Published: October 2017

Abstract
The main purpose of this project became a creation of the reservoir complexity index calculation method. This index should integrate the whole complex of geological characteristics which work on the reservoir engineering complexity in one value. The article describes the approach to calculation the reservoir complexity index based on the Gaspromneft Company's assets using simplified simulation. This index allows you to conduct an express assessment of the field potential and is useful in the process of benchmarking the fields of the Company or the region.
We analyzed widespread available approaches of figuring the complexity index (RCI) in which RCI acts as a function of a number of parameters affecting the Recovery Factor (RF). Then based on results of analysis a new advanced approach was submitted that takes into account, in addition to the main geological characteristics of the formation, the indices of layered and lateral inhomogeneity expressed in numerical form
During the next stage was realized the multivariate statistical modelling with 2D-simulator on the stream-line that is necessary for obtaining real function connection RF=f(RCI). For the simulation, statistical data of the fields of Western Siberia (Gazprom Neft Company) were used. Then with use of gradient method were matched weighing coefficients of equation linear regression expressing RCI as a function of its parameters.
As a result, a set of equations (linear regressions) with a different number of variables and different weight coefficients was obtained. These equations make it possible to calculate the field complexity factor for different sets of input data, as well as for different methods and development systems, operating conditions for the deposit, well completion types, field development periods, etc.
RCI for the company's fields was evaluated and noted the high convergence of project RF data with theoretical dependence found out earlier. At the same time, it was noted that for a number of Company's fields with a high index of complexity, the values of project RF could be unjustly uprate.
This approach was used for the benchmarking of the Company's fields and proved to be a good express method for assessing the field potential.
The aspects considered in the article are related to the new and quite unknown area in Russian speaking segment of OnePetro library. The novelty of the approach is to use a set of simplified simulation models to obtain the linear regression equation, and also to take into account in this equation the indices of reservoir heterogeneity in numerical form. It is also a point of interest to apply this approach in conditions of deposits in Western Siberia.
Control of Displacement Front Uniformity by Fractal Dimensions
Authors: Suleimanov Baghir A. , Guseynova Naida I. , Veliyev Elchin F. 
Published: October 2017

Abstract
This paper presents a study of the impact of fractal dimensions on water flood front propagation based on the analysis of well production profiles. The following parameters describing the water flood front dynamics have been calculated: flow and potential functions, fractal dimensions for time series of oil production, produced and injected water flow rate and the minimum distance from the displacement front to producing wells.
The Hausdorff – Besicovitch monofractal dimension was obtained using a box-counting method and the generalized Renyi Fractal Dimension based on multifractal fluctuation analysis. The proposed methodology allows management of the uniformity of displacement front propagation and control of viscous fingering.
Search and Argumentation of Decisions Aimed at Increasing the Efficiency of Bottom-Hole Zone Stimulation in Oil Accumulations with Challenged Reserves
Authors: Mukhametshin V. , Andreev V. 
Published: October 2017

Abstract
The main goal of the work was the algorithms of search creation and solutions justifications aimed at of Jurassic age hard to recover terrigenous deposits of the West Siberian oil and gas province bottom-hole formation zone treatment efficiency increasing with the use of the acidic compounds composition on the basis of the results analysis and in field conditions treatment experience generalization.
A total of about 300 impacts on the bottom-hole zone of wells with the use of acid compositions have been carried out. The methods of mathematical statistics and probability theory have been used. The influence of parameters characterizing objects’ geological features, technological features of wells and deposits performance, impact technology on success and impact effectiveness indices were studied. The impact effectiveness was reflected with the help of a complex of seven parameters characterizing the process from different perspectives. When analyzing and generalizing the results, the methods of nonparametric criteria, discriminant and stepwise regression analyses were used, which made it possible to formalize the impact process on the basis of the models obtained.
On the basis of the research, a set of algorithms is proposed allowing search and justification of solutions reducing costs significantly and risks when bottom-hole formation zone treatment is being performed. This set of algorithms allows: –to increase the treatments success basing on the established geological and technological conditions for the most successful treatment; scientifically-based wells selection, and treatment parameters regulation;–to predict the technological effect values by absolute and relative incremental oil rate and water cut production decrease, by oil production increase during the impact time; by the comprehensive efficiency parameter;–to justify the wells selection basing on any effectiveness criterion depending on company's tactics and strategy in the market economy environment;–to justify the impact parameters taking into account the deposits’ geological characteristics and objects’ development technologies.
The algorithms and techniques involve different volumes of geological information use, depending on its availability, the objects’ development stage and are offered for implementation within the analyzed objects and of the analogous range of objects.
Possibilities of Microseismic Monitoring Technology for Control and Optimization of Hydrocarbon Reservoir Development the Case of Eastern Kazakhstan Oilfields
Authors: Anokhina E. , Zhegalina L. , Erokhin G. , Demidova E. , Strokov V. , Kozlov M. 
Published: October 2017

Abstract
The work purpose - application of microseismic monitoring in the process of technological actions. They are directed to intensification of hydrocarbon production, by identifying fracturing zones to control the fracturing, identifying zones of emission activity in the reservoir when injecting liquid in injection wells.
A feature of this technology is the possibility of determining fracture zones using surface observation antennas, without observation wells. This distinguishes it from traditional well monitoring technologies. Also, this significantly reduces the cost of work, since there is no need to stop the wells at the time of monitoring and additionally bear the costs of lowering special equipment. This technology, in addition, has a high resolution mapping.