bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of Reservoir Pressure from the Sensor Data Before and After Injection Tests in Low-Permeability Formations
Authors: Bobreneva Yu. O , Davletbaev A. Y. , Makhota N. A. , Kamalova Z. K.
Published: October 2017

One of the most promising and less costly methods to determine formation pressure is pressure curve analysis after injection tests (displacement, minifracturing, DFIT) during hydraulic fracturing. When pressure performance is interpreted after the fracture closure (ACA), for instance, by Nolte method, it is not always possible to diagnose a flow mode (pseudo-linear, pseudo-radial) and to determine formation pressure and reservoir parameters. The paper discusses one the methods of obtaining a "rough" estimate of the formation pressure value in cases with "undertracked" pressure builup curves after frac injection tests.

When ACA methods are used to diagnose flow modes after the fracture closure, and when pressure drawdown test is not long enough, it is impossible to determine formation pressure for certain. The paper analyzes bottomhole pressure performance for the time periods before, during and after hydraulic fracturing. The offered approach is an addition to Nolte's (analysis after fracture closure) and Horner's methods. The main advantage of this approach to formation pressure evaluation is that it does not require a complex interpretation or analyzing of bottomhole pressure performance using special software - a visual analysis of the pressure chart received from downhole pressure gauges is enough.
Complex Distributed Permanent Monitoring System for Horizontal Wells. Noviy-Port Field Case Study
Authors: Ipatov A I , Kaeshkov I S , Krementskiy M I , Bazhenov D U , Buyanov A V , Panarina E P , Figura E V , Klishin I A , Nukhaev M T
Published: October 2017

This paper presents the results of long-term monitoring based on distributed fiber-optic sensing in producing horizontal well. The reported data illustrates high informative value of non-stationary temperature logging used to control well operation, inflow profiling and formation depletion.
Evolution of Approaches to Oil Rims Development in Terrigenous Formations of Eastern Siberia
Authors: Levanov A. , Kobyashev A. , Chuprov A. , Yashchenko S. , Musin R. , Chirgun A. , Svyashchenko A. , Grinchenko V. , Ovchinnikov A. , Burdakov D. , Zimin S.
Published: October 2017

Evolution of approaches to the development of oil rims is presented, based on the results of full-scale development of large oil and gas fields of East Siberia (Verkhnechonskoye, Srednebotuobinskoye, and Yaraktinskoye) put into production, in which a significant share of oil reserves (29% to 69%) is concentrated in the areas having a gas cap on top (figure 1).

Production from these fields is confined to clastic reservoirs which in a number of key parameters are geologically similar, and at the same time in other key parameters are substantially different.

A distinctive feature of the publication is the description of the process of change of solutions for the development of oil rims, where simulation models were used as the main tool of investigation.

All available technologies and the efficiency of their combined application were assessed for each reservoir, taking into account their unique geological structure (areal and crosssectional heterogeneity, reservoir permeability, presence of an aquifer).

The value of this work lies in systematization of practical experience of designing the development of, and operating the oil rims of the three large oil and gas fields in East Siberia, which forms a knowledge base for the development of the second stage oil and gas fields of the region. The accumulated pool of technological solutions adopted for implementation covers a range of various geological conditions of the productive clastic reservoirs.
Information Support of Field Development Control and Analysis in LUKOIL Research and Development Complex
Authors: Chertenkov MIkhail V. , Zolova Irina V. , Pryanichnikova Elena V. , Vidyakin Vasiliy V.
Published: October 2017

This article presents new functional capabilities and prospects of development of the corporate analytical system used in the LUKOIL PJSC research and development complex for solving the problems of operational monitoring of the process of development of oil and gas fields. The system provides users with unified access mechanisms and toolkit for analysis of field information on the level of affiliated oil and gas companies, regional production divisions, fields, development targets and elements, wells. The system provides performing of comprehensive assessment of the status of site development based on analysis of oil production capabilities, production and reserves indicator behavior, condition of well stock, realization of the set rates of oil production. The article contains the brief description of the basic principles of system building and new functions of the development target status monitoring subsystems, analysis of well data, map documents and results of geological and reservoir simulation modeling.
Active Technologies of Production-Logging and Well-Testing in Injection Wells with Induced Fractures
Authors: Musaleev Kharis
Published: October 2017

This work is dedicated to the creation of complex methods of determining reservoir properties in injection wells with injection-induced fractures by production logging tests (PLT) and well testing.

During exploitation, injection wells are known to create uncontrolled fractures so called injection-induced fractures. They appear when the injection pressure exceeds formation tensile strength. They can spread both in height and length, depending on the injection rate.

The risks of fractures inducing during work are especially great in tight formations. They influence oil field development negatively because their growth in height can connect additional layers that change the distribution of water injection in layers.

Complex analysis of PLT and well testing during step-rate injection tests and shut in provides the opportunity not only to determine fracture properties, but also to estimate parameters of layers connected by injection-induced fracture. Series of different injection pressure tests and a fall-off are suggested to perform this task. Suggested interpretation method is based on the fact, that the size of fracture changes with different injection pressure, connecting more or less layers. Joint analysis of well tests and PLTs helps to diagnose and estimate the number of these changes.
Application of Special Well Logging Techniques for Geomechanical Model Imporvement in Naturally Fractured Reservoirs
Authors: Ezhov K. , Arsibekov A. , Dubinya N.
Published: October 2017

Geophysical Well Logging (GWL) is an important source of information about stress-strain state of the upper Earth's crust. Nowadays there are many methods of mechanical and stress properties estimation around the wellbore are developed and implemented. However, quantitative estimation of maximum horizontal stress (SH) is still quite problematic. This paper is dedicated to reduction of uncertainty on the stage of SH estimation by means of additional information of rock structure from special GWL: full-waveform logging (FWAL) and wellbore imagers (WBI). Straight consequence of this specification is geomechanical model reliability increasing and clearer understanding of naturally fractured reservoirs.

This paper was done for oilfield located on the south of Pannonian basin. Productive intervals are associated with crystalline schists of Paleozoic age. These rocks are very dense, have relatively high britlleness and many natural fractures, which are the main drivers for oil production. In this case, geomechanical parameters are closely related with petrophysical properties.

The work is based on complex interpretation of conventional and special GWL, which resulted in natural fractures identification and characterization. As one of the possible approaches of qualitative fracture permeability prediction Rock Physics was used. After classification of all fractures on induced and natural, permeable and impermeable it is possible to specify 2 important geomechanical parameters: azimuth of SH and its magnitude. The last parameter is one of the most complicated for quantitative analysis and there is still no direct or general method of estimation. At the same time, by minimization of error around this value, we can achieve several applied benefits: reduction of costs due to optimal well trajectory, mitigation of risks related to wellbore failure, increasing of hydraulic fracturing efficiency etc.

Analysis of relationship between stress state of the fracture and its flow properties allowed to estimate the possible range of SH values. Together with calibrated magnitude of minimum horizontal stress (Sh) this approach was used to prepare the complete analysis of main stresses on the examined field.
Prediction of Physical-Mechanical Properties and In-Situ Stress State of Hydrocarbon Reservoirs from Experimental Data and Theoretical Modeling
Authors: Dubinya N. , Tikhotsky S. , Bayuk I. , Beloborodov D. , Krasnova M. , Makarova A. , Rusina O. , Fokin I.
Published: October 2017

The study is devoted to preparing data for three- and four-dimensional geomechanical modeling. The main focus remains on the problem of predicting the physical and mechanical properties of the medium at the scale of the reservoir based on the logging data and laboratory studies. The predicted properties are further used to prepare a three-dimensional geomechanical model of the reservoir. The model is complemented by the boundary conditions for solving the poroelastisity problem formulated in terms of stresses. The question of obtaining these boundary conditions remains a distinctive point of investigation. The main approaches of estimating in-situ stress state from logging data are considered with further choice of the method of reconstructing stresses from special well-logging techniques’ data. The stress profiles are reconstructed for the wells added to the geomechanical model.
Practical Application of Geomechanics for Critical Depression Estimation in Sand Control Problem. Case Study for Kikinda Oilfield
Authors: Konstantin Lezhnev , Tatyana Timofeeva , Biluta Maksim
Published: October 2017

Unconsolidated reservoirs on Kikinda oil field cause sanding issues, which complicate exploiting of the wells. As a result, predicting critical depression above which intensive sand production commences becomes substantial problem to solve.

1D-geomechanical wellbore stability models were used as a tool to evaluate critical depressions on production wells. The fundamental complicacy in modeling was the poorly preserved core, so that it was impossible to conduct rock strength tests. Therefore, the approach to solve inverse problem approach was investigated. It allows determining formation strength from completions, historical production data and production initiating tests.

Input data for modeling included standard set of logs (resistivity, gamma, neutron, acoustic (compressional wave velocity)); shear wave velocity recovered by means of a neural network, mini-fracturing data was used in matching the value of minimum horizontal stress. The correlation between the strength of uniaxial compression and elastic modulus was derived from matching the modelled profile of cavities with caliper log in conjunction with historical data.

There were two ways to confirm the models. The first was by production initiation tests on pre-targeted depressions for new intervals along with sand production monitoring. The second was by calculating depression and comparing with predicted value for previously perforated intervals (where data was available), that is retrospective analysis.

According to historical data, the wells equipped with filters and gravel pack systems have 1000 days less mean time before failure (MTBF) than the wells that flow freely on subcritical depressions. Moreover, filters, presenting supplementary obstacle for fluid, often result in high skin values up to 40-80. At the same time, to reduce risks of needing the next workover gravel packs are being installed on the vast majority of the wells. It is possible to indentify relatively firm intervals with high critical depressions and design their completions excluding the installation of filtering equipment. As a result, well performance could be improved.

Conducted evaluations juxtaposed with production tests showed that solving the inverse problem approach allows utilizing geomechanical models in critical depression estimation for pay intervals. The main uncertainty of the technique is associated with low accuracy of forecasts for intensively flushed intervals. Supplementary studies on how high watercut influences rock strength was beyond the scope of the project.

To sum up, the approach of solving the inverse problem was introduced to predict sand production problems for the complex F on Kikinda oil field. The methodology incorporates rock strength determination based on caliper log and production history data. The advantage of the technique is the possibility to carry out evaluations even in the absence of core geomechanical tests data.
Methodology for Calibration of Geomechanical Field Model for Assymetric Hydraulic Fracture Design Based on Actual Data
Authors: Solovyev T. , Vishnivetskiy A. , Naumov Y. , Martynov D. , Kiselev V. , Naymushin A. , Frolov A. , Leontev I. , Abdrakhimov A. , Korovaychuk Y. , Bezikov A.
Published: October 2017

This paper discusses an approach to the static Young's modulus calibration on the basis of fracturing statistics from one of the West Siberian fields. The relevance of this work is due to the fact that there are many fields in the region where multi-stage fracturing is en masse carried out in horizontal wells, but laboratory tests of mechanical and strength properties are lacking. The procedure is based on reiterated matching of estimated fracture closure time to the actual values obtained during interpretation of data-frac test (or calibration or minifrac test) results in the course of the sequential search over the pairs of Young's modulus and leakage factor values. Then simulation of main fracturing is carried out, and simulation result is compared to the actual results of the works (whether fracture was successful or finished with emergency shutdown of pumps). From the entire set of experiments, the multiplier that satisfies all accidents and describes successful operations is chosen. Calibration of mechanical properties and stress model was successfully carried out in this field using the field data of more than hundred fracturing operations, which is evidenced by the similar values obtained in fracturing simulation and half-lengths of hydraulic fractures matched with field development data in one of the hydrodynamic model implementations.

This work is a continuation of research [1, 2] and includes comparison of field development parameters in both calibration methods, which led to the final decision on the repeated laboratory studies, because none of the calibration methods used allowed creating a single universal model of mechanical properties. One of the models more reliably describes the situation of fracture development within the rock mass, the other relates to fracture development along the fault. In addition, the geomechanical model analysis also revealed that in most cases where fracture intersects the fault it would develop along it.
Creation of the Strength Envelope for Rock Samples by the Multi-Cycle Loading Method
Authors: Skripkin A. G. , Polyakov D. A. , Toropetsky K. V.
Published: October 2017

The paper presents the results of a comparative analysis of strength envelopes plotted by two methods — in accordance with GOST 21153.8 and by the multi-stage loading method (ISRM [1]). The importance of this study is associated with a number of issues that arise during selection of core samples for analyzing elastic deformation, as well as during laboratory rock mechanics tests. The comparative analysis of the results shows that a curve that describes an elastic zone of rocks (the so called "strength envelope") can be generated promptly and with greater accuracy if samples are tested by the multi-stage loading method. This method can be recommended for situations where there is no sufficient number of conforming samples for laboratory deformation tests. The paper illustrates correlations for various parameters of the strength envelope plotted by the multi-stage loading method and demonstrates a wellbore stability log based on these correlations.
EOR by Smart Water Flooding in Sandstone Reservoirs - Effect of Sandstone Mineralogy on Initial Wetting and Oil Recovery
Authors: Mamonov Aleksandr , Puntervold Tina , Strand Skule
Published: October 2017

"Smart Water" is a modified injection brine specially designed for inducing wettability alteration to improve the oil recovery, and it can be injected in both secondary and tertiary (EOR) production phases. It is a low cost and environmentally friendly EOR technique, easily implementable in most oil reservoirs, both carbonates and sandstones. For an optimized Smart Water design, both initial reservoir wettability and the wettability alteration need to be understood. It includes surface mineralogy, brine composition and surface-active components in the crude oil. In sandstone reservoirs, the Smart Water EOR understanding is complex, involving several chemical liquid-solid interactions. The scope of this paper is to investigate how different sandstone minerals could affect initial rock wetting and wettability alteration during Smart Water injection.

A set of experiments was performed to study the influence of sandstone mineralogy on the Smart Water EOR processes. The chemical interactions between brine and rock minerals in sandstone cores were tested by evaluating the produced water chemistry. Crude oil-brine-rock interactions were also tested by static adsorption tests and core floods. Oil recovery tests were performed to compare the ability of the different injection brines to enhance oil recovery from sandstone core material.

Clay minerals contribute with most of the pore surface in sandstones. The experimental results have shown that adsorption of polar organic components onto the clay minerals are mostly dependent on brine pH, but also on brine composition/salinity, temperature, and type of clay minerals. For a wettability alteration to take place, initially adsorbed polar crude oil components must be desorbed from the mineral surface. Presence of feldspar minerals may affect the brine pH, and thereby affect the desorption of the polar organic components, and the reservoir wettability. Other minerals, such as evaporites, may also affect the wettability alteration process by Smart Water.

As a result, detailed knowledge of the rock mineralogy is needed to be able to predict the initial rock wettability, and to evaluate the Smart Water EOR potential in a sandstone reservoir.
Effective Use of Data-Driven Methods in Brown Fields
Authors: Temizel Cenk , Putra Dike , Anggraini Henny , Moreno Raul , Drozdov Oleg , Skiba Andrey
Published: October 2017

Several facets and uncretainties are present in petroleum oilfield operations, due to which decision making is a crucial process that ensures operational viability. For the purpose of decreasing risk and providing better insight, uncertainties must be reduced through a well-organized historical database. This is critical especially in the development of new fields.

An understanding of the cause-effect relationship between attributes and outcome of field operations can be gained through statistics. Through the use of statistical methods there is an opportunity to turn large amounts of data into knowledge for efficient decision making. Unfortunately, the lack of a well organized historical database limits the use of these data for improved results.

Reservoirs, being physically complex systems or having comple relations between the causes (attributes) and effects (outcomes), could use a multi-attribute based statistical model that will allow for improved results of future actions through better decision making. The first step in building a data driven model collection of relevant historical data pertaining to the phenomena to be modelled. Significance of each attribute of the historical data to the outcome is mapped through a multi-variate regression. From this analysis optimum range for each attribute that will give best results and maximize returns can be identified. It must be noted that relevant attributes must be those events and key parameters that largely influence the outcome.

In this study, performance of vertical and horizontal wells in tight reservoirs was selected as the outcome with the factors affecting it to be modeled. A numerical simulation model has been used for validating the data-driven model by determining the significance of each parameter and the optimum operating intervals.
Integrated Approach to Determination of Optimal Capacity and Configuration of Booster Compressor Station at Different Realization Stages
Authors: Poushev A. V. , Nerodenko D. G. , Kudrin P. A. , Yazkov A. V.
Published: October 2017

Development of a natural gas field by depletion drive is characterized by a decrease of average formation pressure, bottom hole and wellhead pressures of production wells over time. As a rule, during the initial field development period available formation pressure is sufficient for gas transportation from wellheads to a treatment facility and then to a tie-in to the trunk gas pipeline without using the compressor equipment. However, the formation pressure is decreasing gradually during the whole field life and this in turn leads to a decrease in the entire system "Reservoir - Well - Infield Gas Collection Networks - Gas Treatment Plant". There comes a point of time when the pressure of gas at the gas treatment plant (GTP) inlet becomes insufficient for its treatment and further supply into the trunk gas pipeline under the required pressure and flow rate.

Thus, from the point of view of infrastructure development and production technology the process of development of gas and gas condensate fields is divided into two periods: natural pressure and artificial lift production. The difference between these two periods lies in usage of a compressor unit designed for increase of the produced gas pressure to values required both at inlet of the treatment plant (in order to ensure the working parameters of the gas treatment process) and for further supply into the trunk gas pipeline. This unit is called a booster compressor station (BCS). As a rule, it is located at the site adjacent to the GTP site (Figure 1) and is used for the following purposes: Compression of gas for its downstream transportation;Maintaining of the required gas pressure at the GTP inlet.

Thus, BCSs are used for extension of the stable gas production period at gas and gas condensate fields where formation pressure is decreased to the point at which pressure in the field gathering main pipeline, at GTP and in trunk gas pipeline restricts flow rates of the wells. In other words, BCS allows to maintain the GTP capacity at the designed level and to increase gas recovery factors as decreased pressure at the BCS inlet may be used for wellhead pressures decrease and increase of flow rates.
Influence of Permeability Distribution on Gas Recovery from Massive Reservoir with Bottom Water
Authors: Indrupskiy I. M. , Arkhipov Yu. A. , Anikeyev D. P. , Zakirov E. S. , Mamedov E. A. , Zakirov S. N. , Mikhaylov V. N. , Volkov Yu. A. , Tsagan-Mandzhiyev T. N. , Klimov D. S. , Varyagova E. P.
Published: October 2017

A significant contribution to the natural gas production is delivered from massive reservoirs with bottom water of several unique fields of Western Siberia, confined to highly productive Cenomanian formation. Most of them are brownfields at low reservoir pressures.

Despite the high permeability of the reservoirs, a strong heterogeneity in the distribution of reservoir pressure and elevation of the gas-water contact (GWC) is observed, which is not reproduced by full-scale flow simulation models.

The purpose of this study was a comprehensive analysis of permeability data from various sources for one of such objects to explain the observed features of field development. The analysis of areal and vertical permeability distribution includes the results of well log interpretation (WLIR) by three methods in 81 wells over more than 250 m of reservoir thickness, and several tens of pressure build-up curves (PBU). The analysis made it possible to identify the main causes of the uneven distribution of pressure, GWC elevation, drainage of gas volumes associated with a multi-fold difference in the average permeability between the drilled central (dome) part of the site and on its periphery.

As the gas is produced and the GWC shifts upward, the contrast in permeability of the drilled and un-drilled zones increases, and the most permeable intervals pass to the area below the GWC. It is for the first time for the long-developed highly productive gas reservoirs with bottom water in the Cenomanian formation that complex analysis of well logging data, field development control data, and 3D reservoir models has been used to justify interrelation between the inhomogeneity of gas drainage, reservoir pressure distribution and GWC advance and the distribution of permeability within the reservoir. The need for detailed geological analysis is shown for constructing a model of the reservoir properties distribution in the inter-well space to help localizing and activating the remaining gas volumes, which are greater than 440 billion m3 for the Medvezhye field alone.
Perspective View on Gas Well Stimulations in Case of Complex Carbonate Reservoir
Authors: Zhukov A. , Volnov I. , Ermilov A. , Sidikhodzhaev R.
Published: October 2017

Most modern challenges of gas field development are caused by an increase in complexity of geological structure, mainly associated with carbonate reservoirs. The studied field is characterized by the reservoir complexity, heterogeneity of reservoir properties both laterally and in section, the high impact of stratification factor and variability of rocks at micro scale. It significantly affects reliability of well productivity and field gas production prediction.

For such fields, in order to reduce risks, it is necessary to identify the best technology for well stimulation, which allows achieving high gas recovery and economic efficiency. In this article, the five main criteria for the efficiency of such well operations are formulated.

The authors present the results of application of basic well stimulation technology for carbonate reservoirs. It is acid treatment (acidizing) with various chemical compositions. The results of work on selective acidizing, both with the use of packer systems and with the use of chemical deviators, are described.

On the next step a review of existing methods of well stimulation and selection of a new perspective technology, alternative to acid treatment, is performed. As an untested technology, the acid fracturing with flow deflectors is considered. Polymer spheres or complex polymer systems based on glass fibers and resins may be used as the deflectors.

The purpose of acid fracturing is production enhancement by increasing of reservoir conductivity in the bottom-hole area, activation of non-flowing reservoir zones and reducing skin factor and D-factor values. An important task is to involve low permeable zones containing significant volume of gas in the production and preserve high productivity of high permeable zones.

The selectivity effect is provided by flow deflectors. This technology is advisable to conduct on reservoirs that have several separated productive layers, when it is necessary to treat each layer.

The authors identified main criteria for application of acid frac and selected appropriate wells. The design of acid fracturing was made with the use of a specialized software package. The impact of the reservoir features on fracture geometric parameters was studied. The final forecast of gas production increased. Economic efficiency was estimated with a use of the full-scale reservoir simulation model.

The practical significance of the work is to generalize the experience of pilot projects carried out at the field, and to select a perspective technology for well stimulation in conditions of complex low permeable carbonates.
Impact of Drain Length on Well Performance in Karachaganak Field
Authors: Naurzgaliyev Timur , Mutaliyev Galymzhan
Published: October 2017

Karachaganak is a giant gas-condensate field located in north-western Kazakhstan. In 1997 a production sharing agreement was signed between the partner companies and the Republic of Kazakhstan. Karachaganak Petroleum Operating b.v. (KPO b.v.) joint venture is operated by Shell (previously BG-Group) and Eni S.p.A. Chevron, LUKoil and KazMunayGas are the rest shareholders in this project. Karachaganak was discovered in 1979 and the production began in 1984.

The field comprises Permian and Carboniferous reservoirs with complex geological and fluid properties. The reservoir fluids are gas-condensate with the underlying oil leg.

Since 1997 the focus of the field development has been on the oil leg with the objective of producing low gas-oil ratio (GOR) oil. This is being achieved by drilling sub-horizontal wells. The design of these wells is aimed at maximising the reservoir contact to overcome the challenges of significant heterogeneity present in the field. It also allows accessing partially or fully isolated compartments associated both with reservoir heterogeneity and with the presence of clinoforms formed during the prograding phase of the Carboniferous platform evolution. Initially a drain length of sub-horizontal wells was limited to 700 metres by the available drilling technology. Today, modern rigs are capable of drilling a single 2000 metre long sub-horizontal drain to a total well length of more than 6600 metres. Simulation studies indicate that long drains optimise the field development by reducing the number of wells required to maximise the oil recovery. This paper focuses on the impact that drilling long sub-horizontal wells has had on well performance in the Karachaganak field. The paper also discusses the evolution of the well completions from open-hole drains to multistage stimulation completions that allow selective stimulation of a drain interval.
Unique Technologies for Seismic Data Interpretation: Sedimentation and Paleotectonic Analysis, Pseudo 3D
Authors: Avdeev P. , Efremov I. , Gogonenkov G. , Elmanovich S. , Plakhov A.
Published: October 2017

The main purpose of the work is to get the petroleum industry acquainted with a number of unique tools for seismic data interpretation, namely, sedimentation and paleotectonic analysis modules, as well as with technology of 3D interpretation of 2D survey data - "pseudo 3D.

The sedimentation analysis technology is based on rather simple and intuitive algorithm: a set of quasigeoisochronic surfaces in entire volume of seismic cube is calculated with the use of frame of key reflections between adjacent horizons. It makes possible, while moving in the cube continuously in time/depth (in "animated seismics" mode), to perform analysis by a number of parameters (optionally, by cube amplitude, by acoustic impedance, by dip, by coherence, etc.) both along key reflectors, and in intervals between them.

The sedimentation analysis module was used as the basis for creation of work algorithm of the paleotectonic analysis program and "pseudo 3D" technology, what makes these tools unique compared to various analogs.

The multi-year application experience proves that such technological developments promote qualitative and effective solution for interpretation of seismic data of various complexity.

In particular, the sedimentation analysis allows for significant extension of features of seismic methods in study of detailed structure of reservoir intervals holding hydrocarbon deposits, as well as for the most complete extraction of wavefield history changes from the seismic cube related to paleochannels, sedimentation bodies, various anomalies of geological cross-section, as well as faults.

The paleotectonic analysis module makes it possible to assess the geological history of study area.

The technology of creation of a "pseudo 3D" cube by 2D survey data is extensively applied to get an idea of spatial location of local sedimentation bodies, clinoform complexes and prospective objects.
New Production Logging Tool for Inflow Profiling of Low-Rate Oil and Water Horizontal Wells: Case Studies of Field Testing an Experimental Prototype
Authors: Miklashevskiy D. , Shako V. , Borodin I. , Mukhin V. , Skochelyas R. , Shalamov V. , Valiullin R. , Iarullin R.
Published: October 2017

The current results of development of a new production logging (PL) tool based on an azimuthally distributed array of thermal anemometers and aimed at determination of inflow profiles beyond the limits of common mechanical sensors in horizontal wells producing oil and water at low rates are described in this paper.

Theoretical background, implementation technique, and experimental prototype (EXP) were developed for the PL tool using azimuthally distributed thermo-anemometer (TA) sensors to obtain a dataset characterizing the production regime in low-rate (below 150 m3/d) oil and water horizontal wells.

The new PL tool's TA sensors record overheating profiles along a well that depend on the local velocity of the fluid and its phase composition. The periodic heating regime of the TA sensors enabled measuring the undisturbed fluid temperature for determination of overheating and acquiring high-resolution temperature profiles, thus providing a valuable additional dataset of diagnostic attributes for characterization of the inflow.

Laboratory testing allowed determination of calibration dependencies of TA signals versus velocities of single-phase water and oil flows. The calibrations were used for interpretation of data obtained with the PL tool and evaluation of the distribution of fluid phases for cross sections along a well and profiles of phase velocities. These results indicated the new tool's potential for implementation with a standard PL toolstring in low-rate oil and water horizontal wells.

Interpretation of the EXP data together with that from standard PL tools enhanced the reliability of the determination of inflow zone intervals, phase composition of an inflowing fluid, and phase distribution of producing fluid along a well.

Analysis of the field data established that effective resolution of temperature measurements by the new PL tool is approximately 0.015 K to enable registration of the effective fluid velocity in range of 0.5 to 15 m/min with corresponding resolution of 0.01 to 0.3 m/min to result in a spatial resolution of 1 to 20 m of the recorded parameters for uniform inflow along a horizontal wellbore. The evaluated values of spatial resolution are based on optimized logging speed, taking into account TA measurement specifics, well construction design, and total production rate.

In this first field test of the innovative EXP in two horizontal wells producing water and oil at low rates, the tool was conveyed on coiled tubing and tractor. Joint interpretation of data recorded with the EXP and standard PL tools confirmed that the inflow profiles for each well along with profiles of phase velocities and water inflow zones were reliably established.
A New Technology Based on Two-Phase Flow Models for Rapid Selection of Wells for Cyclic Waterflooding
Authors: Rodionov S. P. , Pichugin O. N. , Kosyakov V. P. , Shirshov Y. V. , Pyatkov A. A.
Published: October 2017

The method of cyclic waterflooding is one of the most cost-effective methods of enhanced oil recovery.

Simulation of cyclic waterflooding will take much more time than conventional waterflooding. This is due to the time step limitation which should be much less than the half-period of fluctuations and the characteristictime of pressures equalization in neighboring interlayers.

This paper proposes the flow equations averaged over the cycle period in the case of a periodic law of variation in production rates or bottomhole pressures in wells that are free from the specified time step limitation and allow to simulate cyclic waterflooding in a time comparable to the time of simulating a conventional waterflooding.

The simulations based on the averaged and conventional (used in flow simulators) equations of a two-phase flow are compared using a synthetic example and actual field areas in Western Siberia and Kazakhstan.

A complete solution to the cyclic waterflooding problem involves the selection of the promising areas, well locations, as well as the period and duration of stimulation. As a rule, this requires running multiple simulations. Therefore, in order to reduce the number of simulation runs, in this paper we propose an efficient technology for 3D modeling of cyclic waterflooding in oil fields. This technology allows to select, in real time, the promising areas and to assess the effect on incremental oil recovery of such factors as locations of wells, the frequency of cycles, etc. Also, it allows to predict incremental oil production in a time much shorter than using a conventional simulator, without accuracy losses. The successful results of technology application in some fields of Western Siberia and Kazakhstan are given below.
The Role of Import Replacement in the Development of the Russian Oil and Gas Machine Engineering
Authors: Zhdaneev O.
Published: October 2017

Detailed analysis and the role of import-replacement for oil and gas machinery building in Russian Federation has been done in the paper. Definition of the import-replacement term has been clarified for oil and gas machinery building. Comprehensive review is presented for one of the import-replacement mechanism – localization. A set of recommendation is listed to ensure success of the import-replacement program in Russia.

For the industries of the fuel and energy complex amid the modernization and innovational development the import replacement program is viewed as the main mechanism for implementation of the Energy Strategy of Russia till 2030 [Minutes of the meeting of the Government Commission on High Technology and Innovations dated August 3, 2010 No.4; Energy Strategy of Russia till the period of 2030].

Currently it is possible to define to main systematic existing risks for the economic security of the Russia oil and gas machine engineering. Firstly, inability to provide the customers in the Russian Federation with the basic range of modern products with full production cycle organized within our country (immediate threat). Secondly, low level of innovations and technologies used for development and production of devices.

One of the methods of facilitation of the economic growth and industrial development in the oil and gas machine engineering is import replacement focused on the replacement of the foreign equipment by similar domestic one.

There are many definitions of "import replacement" [Baranov E.F., 2013; Berezinskaya O.B., Vedev A.L., 2015; Volkodavova E.V., 2009; Zaitsev D.N., 2002; Kadochnikov P.A., 2005; Marketing: Dictionary. Moscow: Economy, 2000; Nazarchuk E.N., 2007; Raizberg B.A., Lozovsky L. Sh., Starodubtseva E.B., 1999; Smirnov D.A., 2012; Starovoitova O.V., 2011; Suchkova N.A., 2009; Kalashnikova T.M., 1990; Faltsman V.K., 2015]:
Selection of a Suitable Pollinizer for ‘Summer Fantasia’ Plum
Authors: Kwon Jung Hyun , Jun Ji Hae , Nam Eun Young , Chung Kyeong Ho , Yoon Ik Koo , Yun Seok Kyu , Kim Sung Jong
Published: October 2017

Being self-incompatible, most Asian plums should be planted with a compatible pollinizer to produce fruits. Therefore, the selection of an adequate pollinizer is essential when new plum cultivars are released. To select a suitable pollinizer for ‘Summer Fantasia’ plum, the S genotype, cross-compatibility, pollen viability, and flowering time of five candidate cultivars were evaluated. Using polymerase chain reaction (PCR) analysis, the S genotype of ‘Summer Fantasia’ was determined as SaSc, which was expected to be compatible with other S genotypes. To test cross-compatibility, the trees were covered with caging net to prevent unintended pollination, and pistils were hand pollinated without emasculation. Fruit set percentage was calculated 10 weeks after pollination. The fruit set percentage resulting from the cross between ‘Summer Fantasia’ and ‘Taiyo’ (SbSc) was 13.8%, whereas that resulting from other combinations was less than 5.0%. Pollen germination percentage was investigated to monitor pollen viability; it varied yearly among cultivars, although ‘Formosa’ (10.6%) and ‘Taiyo’ (13.8%) showed the highest pollen germination percentages among the cultivars. When averaged over three years and two locations, ‘Summer Fantasia’ bloomed 2–3 days after ‘Akihime’, ‘Formosa’, ‘Oishiwase’, and ‘Purple Queen’. Blooming period of ‘Summer Fantasia’ and ‘Taiyo’ overlapped almost entirely. Overall, the results indicated that ‘Taiyo’ was the most suitable pollinizer for ‘Summer Fantasia’.
The Role of Spur Leaves, Bourse Leaves, and Fruit on Local Flower Formation in Apple: An Approach to Understanding Biennial Bearing
Authors: Elsysy Mokhles A. , Hirst Peter M.
Published: October 2017

Lack of consistent flower formation is the underlying cause of biennial bearing. Flower formation in apple (Malus ×domestica Borkh.) has been associated with different factors, such as leaf area, shoot growth, bourse length, crop load, and seed number. However, it is unclear how these different factors interact to promote or inhibit flower formation. The effect of spur defoliation, fruit removal, and their interaction were evaluated on spur flower formation and bourse length in annual-bearing ‘Gala’ and the biennial-bearing ‘Honeycrisp’. Eight different combinations of spur defoliation and fruiting treatments were applied in three consecutive springs, 2013–15. Bourse shoot defoliation and fruiting treatments inhibited spur flower formation in both cultivars, but in different patterns from year to year. In addition, spur leaf defoliation did not affect flower formation in either cultivar. Furthermore, local defoliation and fruiting treatments did not affect bourse length. We propose that bourse leaves play a major role in both producing and transporting flower formation signals, but the effect depends on cultivar.
Effects of Low Oxygen and 1-Methylcyclopropene on Storage Disorders of ‘Empire’ Apples
Authors: DeEll Jennifer R. , Lum Geoffrey B.
Published: October 2017

The objective of this study was to investigate the effects of low-oxygen storage and 1-methylcyclopropene (1-MCP) on disorders and quality of ‘Empire’ apples. For 2 years, ‘Empire’ apples were obtained from commercial orchards during their harvesting period. After cooling overnight at 3 °C, the apples were treated with or without 1-MCP (1 µL·L−1) for 24 hours and subsequently stored in controlled atmosphere (CA) with 2.5 kPa O2 (+2 kPa CO2) or 1.5 kPa O2 (+1.2 kPa CO2) for 8 months at 1.5 and 3 °C for the first and second year, respectively. In the second year, a third group of the ‘Empire’ apples was also held in respiratory quotient (RQ)-based dynamic CA storage (SafePod) that reached 0.6 kPa O2 (+0.5 kPa CO2), and half of these apples were treated with 1-MCP (1 µL·L−1) for 24 hours at 3 °C upon removal after 8 months. All apples were then evaluated for disorders and quality after 1, 7, or 14 days at room temperature (RT, 23 to 24 °C). Substantial external CO2 injury, flesh browning, and core browning (up to 38% incidence) developed in ‘Empire’ stored in 2.5 and 1.5 kPa O2 during both years of study. Storage in 1.5 kPa O2 reduced flesh browning in the first year and core browning during the second year in apples without 1-MCP, as compared to storage in 2.5 kPa O2. 1-MCP-treated apples stored in 2.5 or 1.5 kPa O2 had higher overall incidence of disorders than similar fruit without 1-MCP. In contrast, there was negligible incidence (0% to 1%) of these disorders in ‘Empire’ apples held in 0.6 kPa O2, regardless of 1-MCP treatment upon removal. Storage in 0.6 kPa O2 also resulted in the greatest fruit firmness retention while at RT for 14 days. This regime can provide flexibility to postpone 1-MCP treatment until after storage, to prevent increased susceptibility to disorders during storage, without compromising fruit quality. However, results from the RQ-based dynamic CA with 0.6 kPa O2 were from a single season, and further research is needed to confirm these observations.
PondR: a process-oriented model to simulate the hydrology of drainage ponds
Authors: Willkommen Sandra , Pfannerstill Matthias , Guse Björn , Ulrich Uta , Fohrer Nicola
Published: October 2017

Drainage ponds are a useful measure to manage water resources. However, these small water bodies are characterized by highly dynamic internal processes. This article discusses a simple process-oriented model developed to simulate temporal dynamics of internal processes within drainage ponds. The PondR model is able to simulate the relevant hydrological processes of the pond by using commonly available input data. For model development, data from a 3-year monitoring campaign of the investigated drainage pond served to validate the newly developed model for the autumn and winter time periods. A temporal parameter sensitivity analysis (TEDPAS) revealed that groundwater parameters are predominant during the whole year. The model performed well in simulating outflow together with simulated pond volume and improved the understanding of the hydrological regime for drainage ponds. Regarding the practical benefit, the developed PondR model could be useful in future studies for more precise planning of pond dimensions and water resource management in the field of research and engineering services.
Surrogate-based pumping optimization of coastal aquifers under limited computational budgets
Authors: Christelis Vasileios , Regis Rommel G. , Mantoglou Aristotelis
Published: October 2017

The computationally expensive variable density and salt transport numerical models hinder the implementation of simulation-optimization routines for coastal aquifer management. To reduce the computational cost, surrogate models have been utilized in pumping optimization of coastal aquifers. However, it has not been previously addressed whether surrogate modelling is effective given a limited number of numerical simulations with the seawater intrusion model. To that end, two surrogate-based optimization (SBO) frameworks are employed and compared against the direct optimization approach, under restricted computational budgets. The first, a surrogate-assisted algorithm, employs a strategy which aims at a fast local improvement of the surrogate model around optimal values. The other, balances global and local improvement of the surrogate model and is applied for the first time in coastal aquifer management. The performance of the algorithms is investigated for optimization problems of moderate and large dimensionalities. The statistical analysis indicates that for the specified computational budgets, the sample means of the SBO methods are statistically significantly better than those of the direct optimization. Additionally, the selection of cubic radial basis functions as surrogate models, enables the construction of very fast approximations for problems with up to 40 decision variables and 40 constraint functions.