bluuebunny/crossref_metadata_2025 huggingface dataset:
New Methodology to Quantify the Productivity of Hydraulically Fractured Multilateral Wells in Tight Oil Reservoirs with Gas-Drive
Authors: Eliebid Mohammed , Ahmed M. Elmuzafar , Al-Nuaim Sami
Published: October 2018

The main objective of this paper is predicting the inflow performance relationship (IPR) for hydraulically fractured multilateral wells in tight formations to measure the flow rate corresponding to the bottom hole flowing pressure distribution along the horizontal laterals and the fractures. Due to the unavailability of analytical solutions for two-phase and three-phase flow problems in vertical, horizontal and multilateral wells because of the complex variable phases distributions in the reservoir. To predict the performance of two and three-phase several empirical models pioneered by Vogel's equation are used to forecast the IPR of two-phase for vertical wells and his method has been modified for multilateral and horizontal wells. Furthermore, there is no model to predict the performance of hydraulically fractured oil wells. In this work, we present a two-phase hydraulically fractured well model utilizing modifications to the present IPR models for two-phase planner horizontal laterals wells.
The Method of Localization of Residual Oil on the Basis of Complex Multi-Well Diagnostics and Calibration of the Hydrodynamic Model
Authors: Zhdanov Ivan , Kotezhekov Victor , Margarit Andrei
Published: October 2018

Currently, many fields in Russia are at the final development stage known not only for a decreasing percentage of active recoverable reserves, but also for a growing share of hard-to-recover reserves, confined, for example, to complex reservoirs featuring primarily highly zonal and layered heterogeneity. In this context, the priority issue is to spot areas containing remaining reserves with a view to subsequently recovering them. Obviously, this issue cannot be tackled without the aid of advanced technologies of crosswell formation evaluation.

This publication presents the remaining reserves detection technology involving integrated multi-well diagnostics and reservoir flow model (RFM) [1] calibration techniques focused on refining development targets and shaping an appropriate RFM to come up with an action plan to tap reserves and ramp up production at the Company's current assets.
Digitization of Petrographic Data for Standardization and Genetic Interpretation
Authors: Bukharev Aleksandr , Zhukovskaia Elena , Budennyy Semen , Lokhanova Olga
Published: October 2018

Resume

The article describes the methodology of digital analysis of terrigenous rocks from petrographic images obtained with the help of an optical microscope. The developed methodology is aimed primarily for automatic analysis of the structure, composition of rock-forming components and pore space, but also allows evaluating the type and composition of cement, autigenic minerals.

The result of proposed analysis is a standardized set of quantitative characteristics, which includes the linear dimensions of each grain and distribution parameters (kurtosis, asymmetry, dispersion, sorting, modal, median and maximum values), shape characteristics (area, roundness), grain - texture packing parameters of the sample (linear and area density, contact, morphology of contacts, orientation of minerals, uniformity of packaging, uniformity of distribution). The set of characteristics also includes information about the pore space: the total pore area, hydraulic coefficient, average pore size and connectivity, the shares of intra-and intergranular pore space are additionally calculated. In addition, the set of quantitative characteristics is supplemented by the result of classification of individual rock-forming minerals by composition and secondary changes, and the classification by mineral composition is carried out for autigenic minerals.

The methodology and the result of calculation of these characteristics in this work are demonstrated by the example of a test sample (from the reservoir rock). Petrographic analysis was carried out for this sample in advance and digital pictures were taken with the help of an optical microscope.

Automation and digitalization of such analysis became possible only in conditions when the following problems are solved: computer vision problem (segmentation of individual minerals, classification of their composition and secondary changes based on images taken under an optical microscope), computational geometry problem (calculation of numerical characteristics given above, based on binarized images of “masks" of individual pores and minerals).
Application of Machine Learning Technologies for Rapid 3D Modelling of Inflow to the Well in the Development System
Authors: Simonov Maksim , Akhmetov Alexey , Temirchev Pavel , Koroteev Dmitry , Kostoev Ruslan , Burnaev Evgeny , Oseledets Ivan
Published: October 2018

The most convenient and physically justified tool for optimization of oil field development system is 3D hydrodynamical modeling. The high resource consumption of the method, however, does not allow carrying out fast multivariate calculations. In this paper, we propose an approach to 3D modeling in a development unit, based on the machine learning algorithms. According to available data of the reservoir properties and using high-performance computing systems, we've created a training set and a metamodel of the development unit. Forecasting in the latent variables space makes it possible to perform the necessary calculations many times faster than for the classical approach. We also offer a method for improving the quality of calculations on coarsened grids, that allows to greatly increase the size of training set and to reduce the complexity of setting up a metamodel.
Experience with Using Data Analysis Technologies in Identification of Lost Production Zones
Authors: Nadezhdin Oleg Vladimirovich , Efimov Dmitrii Vital'evich , Minikeeva Lyaysyan Rishatovna , Markov Alexandr Vadimovich
Published: October 2018

Recent reserves depletion and increasing complexity of methods of development efficiency improvement and production stimulation requires solving the problem of "lost sections" of oil-saturated reservoirs. One of the approaches of lost production section search is based on comprehensive analysis of well logging and core data and automation of multi-well analysis of this data. In this case the process of search of lost sections includes both stages of well logging and core data interpretation (including initial work) and analysis of data interpretation results and rating of candidate wells for geological and engineering operations. During initial work and well logging interpretation, specialist has to perform routine tasks that take significant time. For example, such tasks include: initial unification of well logging and core data, depth matching of well logs (single- an multi-type), calibration and splicing of well logs, depth matching of well logging and core data, self-consistent with well logging and core data adaptation of parameters of petrophysical functions and interpretation models, determination of stable correlation "core-log" relationship for complex reservoirs, etc. Most of the tasks listed above involve data analysis. This paper reviews how to automate performance of routine tasks arising during lost section search.

Widely used technologies of data analysis (Data Mining), that are first of all related to tasks of optimization, relationship determination, pattern identification and classification, are to some extent applied during geological modelling. For instance, artificial neural networks, decision trees, Bayesian networks, genetic algorithms, etc. can be used for analysis of geological and geophysical information. Statistical methods such as correlation and regression analysis are often referred to data analysis methods and are applied as well to geological and geophysical information analysis. However, specific research area set its own limits and requirements on the use of tools related to Data Mining.

These are the examples of problems causing unsatisfactory outcome when direct using of Data Mining tool and technologies: –the data does not correlate with each other (in terms of depth), i.e. it is necessary to perform depth matching before data analysis;–training set is inconsistent;–inverse or optimization problem does not have unique solution.

The article discusses the problem of application of data analysis methods and tools to geological and geophysical tasks under presence of uncertainties. Methods of preparing and pre-processing of well data at various stages are presented.

There are introduced the results of using algorithms of data processing and methods of data analysis developed and adapted for particular application tasks.
The Results of Deming Cycle Concept Implementation into Oil Production Processes
Authors: Frolov Sergey , Ermolovich Igor
Published: October 2018

The work analyzes the results of the implementation of the Production Management System (hereinafter System), based on the concept of the Deming Cycle. The system allows automatic selection of Well Interventions, integrated planning of production activities, as well as calculate the production forecast using an integrated field model.

The system uses Big Data technologies, optimization algorithms for various target functions, machine learning methods. The system implements automation of typical tasks, solved by such specialists as geologist, production technologist, reservoir engineers, economist, risk manager. This allows to issue effective recommendations for various production activities on the asset. These recommendations pass the stage of approval by real experts of the Company, after which, based on optimization algorithms, an integrated plan of operational activities is formed. Based on the received integrated plan, the production profile is calculated taking into account interference effects from each of the activities. Then the fact of the planned activities is monitored, on the basis of which the expert system is self-learning in order to improve the accuracy of planning in future.

A significant number and not always satisfactory quality of the data required for the operation of the System, available at the Company, led to the need to develop additional algorithms that are able to work in the case of a limited amount of data. The results of the work in this case require a deeper analysis by field specialists before making a decision. To understand the reliability of the results obtained, the Risk parameter was introduced into the System, which clearly demonstrates which of the recommendations are based on less reliable data and use less accurate methods for evaluating the effects from the activity.

Thanks to the implementation of the Production Management System, significant results have been achieved in terms of reducing bottlenecks and optimizing operating costs. In particular, due to better integrated planning with regard to the selection of measures, taking into account their compatibility, the shortfalls were reduced by more than 10%. By improving the quality of monitoring the effectiveness of planned activities and the corresponding automatic System self-learning, it was possible to achieve a reduction in operating costs by more than 2%.
Applications of Artificial Neural Networks in Gas Injection
Authors: Chu Hongyang , Liao Xinwei , Zhang Wenlong , Li Jinlong , Zou Jiandong , Dong Peng , Liu Wenyuan , Zhao Chaojie
Published: October 2018

Because the ANN model has the ability to fit the data of the complex nonlinear, a large number of field data about gas flooding are collected to train the ANN. Using the formulas, we translate the weighting matrix of ANN which possesses good fitting precision to the weight of single factors for fuzzy mathematic. Then, the fuzzy mathematic method is used to implement comprehensive evaluation to quantized indicators.

The new screening methodology could determine exactly the potential of gas flooding in candidate reservoirs. To overcome the slow convergence of ANN and easy trapping in the local minimum, a large number of field data about gas flooding are collected to train the ANN. Results indicate that the ANN is reliable, and it's mean-square error(MSE) is smaller than 0.01. The weight coefficients of those indicators for fuzzy mathematic are calculated with ANN. The results are as follows: the oil viscosity is the highest score (its weight coefficient is 0.3), followed by the reservoir thickness, reservoir pressure, and reservoir permeability. Moreover, others indicators play a relatively small role. By using the above screening methodology, seven field cases from Ordos Basin are used to evaluate the potential of gas flooding. Results from the field application, indicate that the recovery factors of gas flooding in the field cases are sequential consistency with those from our methodology.
Reservoir Properties Distribution Based on Petroelastic Modeling PEM
Authors: Churanova Nina Yurevna , Chorniy Aleksei Vadimovich , Baranov Timofei Sergeevich , Solovyev Alexey Vitalevich , Sadreev Ernest Anvarovich , Kurelenkov Sergey Khalimovich , Yudin Evgenii Viktorovich , Danko Dmitry Anatolievich
Published: October 2018

The main uncertainty for building 3D geologic and process models is distribution of properties in the inter-well space. The fields comprised of carbonate reservoirs are characterized by the complex porous space structure: availability of secondary porosity, cavern or fracture components. The objective of this paper is to increase the accuracy of the prediction of lithology and permeability and porosity of complex carbonate reservoirs applying the method of petroelastic modelling using the example of one of the Central Khoreyver Uplift (CKU) fields. Obtaining 3D geological and process models capable of quality implementation of representation of the fields’ geological peculiarities is necessary for the purpose of the development tasks: decreasing the uncertainties and reducing the development drilling risks.

The paper proposes a method for predicting reservoir properties of carbonate deposits of Famennian strata of Timano-Pechora petroleum province on the basis of petroelastic modelling. The basis of the method is the principle of complexing different scale geological and geophysical surveys. The lithological division of rocks and identification of reservoir types were performed for the reviewed carbonate deposits. The detailed volumetric lithological and petrophysical models with subsequent tying the obtained results with the core material lithological survey data were developed under results of the complex well logging survey interpretations. An efficient environment model was selected for the reviewed carbonate deposits and petroelastic modelling was carried out. The criteria for predicting the reservoir properties using the seismic data with application of the amplitude inversion method were formulated under results of the petroelastic connections analysis.
Multivariate Asset Assessment: Fast and Reasonable Decision on Oil Rims Development on the Example of a Unique Field in the Arctic Onshore.
Authors: Komin Maxim , Magdeyev Igor , Schulze-Riegert Ralf , Mukminov Iskander
Published: October 2018

The key economic drivers for the development of several oil fields in the North Yamal-Nenets region were the commissioning of the main oil pipeline "Zapolyarye-Purpe-Samotlor", as well as a regional tax exemption regulation applicable to the mineral extraction tax, valid until the end of 2021.

At the same time, the economic decline in 2008 and 2014 forced many oil companies to reconsider their production programs in the region. As a result, geological assessments and operational drilling programs in many fields were postponed, especially studies on complex development sites such as oil rims.

As economic conditions for the oil and gas industry improved, the production activity began to increase. However, a continuation of proven work processes revealed disadvantages to meet short term economic targets. A quick assessment showed that a traditional approach to studying geological structures and assessing the current state of oil fringes would be too time consuming. Long study periods will lead to the fact that the main volume of oil will be extracted beyond the horizon of the tax exemptions, which would make projects uneconomical and jeopardizes the implementation plans for filling the new main oil pipeline.
Ways to Improve the Ensemble Smoothing Method, Taking Into Account the Specifics of the Oil and Gas Fields Production Prediction
Authors: Olenchikov Dmitry
Published: October 2018

Last years, the methods for prediction of probabilistic distributions of oil and gas reservoir development characteristics are actively researched. It is important for solving of risk management tasks. The key problem here is the need to perform the history matching for a large numbers of flow models. The Ensemble Smoothing method is the one of promising approaches to solving this issue. However, sometimes its results are not good enough for real practical cases. In this article the analysis of advantages and disadvantages of Ensemble Smoother method is made and the ways of method improvement are proposed.
Assessment of Reactivated Natural Fractures Influence on Overall SRV During Multi-Stage Hydraulic Fracturing
Authors: Gula Alexey , Bochkarev Alexander , Vishnivetskiy Alexey , Nikitin Ruslan , Ovcharenko Yuri , Alchibaev Daniil
Published: October 2018

This work is devoted to the development of methods for determining the stimulated reservoir volume (SRV) taking into account the contribution of natural fractures hydrodynamically not connected with technogenic one with the example of Western Siberia reservoir. At present, more and more fields with a complex geological structure, including low-permeability reservoirs, require effective technologies for exploitation, which in turn has led to the massive applying of horizontal wellbores and technologies of multistage fracturing. Modeling of multistage fracturing is a complex process that requires an understanding of the mechanical behavior of the formation, cracks and faults. The cracks formed during the hydraulic fracturing change the stress field around it, this effect is called the shadow stress effect. Natural fracturing can have a significant effect on production rates, in particular, on the hydrodynamic connection of the reservoir and the migration path of fluids. If stress shadow effect of the technogenic fracturing is taken into account, then can be additionally taken into account the reactivated natural fractures with induced stresses as well.

In the process of the work, mechanisms of formation of natural fracturing were determined on the basis of seismic attributes and reconstruction of paleostresses, a natural fracture network model was constructed using geomechanical information. The results obtained during the construction of a NFN play one of the key roles for the modeling of the multistage fracturing in fractured reservoirs allows to take into account information on the intensity and direction of development of natural fracturing in addition to mechanical properties: elastic and strength characteristics of rocks.

In this paper, we demonstrate the results of a numerical evaluation of multistage fracturing influence in the change of the stress field. The stress field, modified during the stimulation, was used to assess the critical stress fractures, which allows increasing the stimulated reservoir volume due to reactivated natural fractures. Such cracks do not need to be fixed, since they are formed by sliding along the plane of failure with small changes in the stress field and give an additional contribution to the total area induced fractures.

The demonstrated technique allows to maximize the area of induced fractures and increase the stimulated reservoir volume by taking into account the critically-stressed one.
Fully Coupled Geomechanics Approach to Determine Critical Wellbore Intervals
Authors: Shelkov Vasilii , Bogachev Kirill , Piskovskiy Evgeny , Piatsky George
Published: October 2018

A method to locate critical wellbore intervals during oilfield development is proposed in this article. A variant of fully coupled geomechanics approach is used. Geomechanical 3D modeling is performed on the same mesh that is used for reservoir simulation. The proposed algorithm uses Mohr-Coulomb criterion to locate critical wellbore intervals.
Forecast of Well Drilling Events in Salt Bodies Based on Geomechanical Modeling for Eastern Part of the Orenburg Oil and Gas-Condensate Field
Authors: Galliamova Dilia , Kalinin Oleg , Lukyanov Pavel
Published: October 2018

The paper is dedicated to problem of forecast of well events drilling through nonproductive reservoirs at shallow depths: mud losses, wellbore instability due to salt tectonics, mud and reservoir temperatures difference and drilling time. Problem of forecast in those zones is complicated because of insufficient amount or complete lack of core tests, well loggings and noisy of seismic data.

There is three-dimensional geomechanical modeling was showed with taking into account thermal stresses and time factor in the clay and salt zones on the example of the Eastern part of the Orenburg oil and gas condensate field. Also geological features were analyzed for prediction of mud losses zones.

As a result of modeling, a relationship was found between the drilling mud losses and the wells location with respect to the sides of the salt folds and domes, which are accompanied by the development of natural fracturing. While well is drilling in overbalanced conditions in these zones, fractures and faults become critical stressed, which leads to their reactivation and mud infiltration. The trajectory can not be significantly corrected in the 300-800m depths so well schematic recommendations are reduced to a warning about the zones of possible losses.

Wellbore stability calculation with taking into account the temperature effect shows an increase or decrease (depending on the drilling season) of the stresses, acting on the wall of the borehole up to 10 MPa; the influence in salts is greater than in clays. Taking into account time factor showed that long-term drilling with high mud density can lead to numerous stuck pipes and tight pulles.

The obtained results make it possible to clarify wellbore stability calculations and, accordingly, the intervals of borehole failures. The prediction of critical stressed zones allows to warn the intervals of drilling mud losses. Thus, due to the combination of these approaches, it is possible to reduce the nonproductive time of well drilling and choose candidate wells for an optimized well design.
Organization of New Projects Search and Assessment Process
Authors: Kudryashov Sergei , Ismagilov Azamat , Khamitov Ilyus , Smyslov Vitaliy , Kozhemyakin Anatoly , Sedykh Kira
Published: October 2018

The paper considers the process of searching and evaluating new projects of the Oil Companies. Three main components are distinguished: structure, organization of the process and tool set. The experience of the world's leading oil companies in the organization of this process is considered. The concept of Zarubezhneft JSC is described in the context of selected components. Practical examples from the Company's experience are given.
Perspective Oil Production Planning Based on Static and Dynamic Modelling Fields of PJSC Tatneft
Authors: Loscheva Zoya , Kolsanov Eugenii , Muryzhnikov Anton
Published: October 2018

Article describes main stages and results of oil production perspective business planning of Company implementation based on digigal technologies like static, dynamic and economic modelling. This was inspired by building and integration of key parts like design and analysis system of assets development based on static and dynamic modelling toolkit, which allows to take in accout all existing information; economic model of assets effectiveness evaluation and proposed oil production planning analysis; scheme of investment allocation to assets with oil production growth and advance in economic effectiveness with taking in account ranking of company's risks and constraints. Replication of practical results allows increasing Company stocks growth speed and operating activities effectiveness due to oil production potentisal increase and investment minimization.
Application of Integrated Design Technology to Manage Existing Assets and Evaluate New Projects
Authors: Afanasiev Igor , Ismagilov Azamat , Fedorchenko Gennady , Kozhemyakin Anatoly , Smyslov Vitaliy , Zokhan Grigory
Published: October 2018

The trends of the last decades show that the leading Russian and international oil & gas companies come to a concept of integrated design technology when forming the prospective development programs. Such approach, contrary to the conventional one, allows efficient planning of the asset development with account of its components interference (reservoir, well, surface facilities, economics, license obligations etc.).

The main purpose of integrated design is to ensure comprehensive smart and efficient asset management. The expected results from the application of such approach are: Comprehensive representation of production, gathering, transportation and treatment systems;Making of optimal asset development strategy (short-, medium- and long-term programs);Production and operation processes optimization;Efficient engineering solutions;Minimization of CAPEX and OPEX;Multi-level economic evaluation (from well to asset levels);Minimization of risks and uncertainties.

In 2014 JSC Zarubezhneft initiated the development of integrated design technology with the multiple strategic interests of the company with own efforts to achieve the abovementioned results. As a result, a concept of integrated design technology was formed and a software tool for making integrated models was developed. The concept and softwaretool are the basis for solution of production and investment tasks. The peculiarity of the approach is its universal nature, applicability to the projects at various development stages (exploration, greenfield, brownfield) and with various detailed specification degree depending on the available information.
First Successful Proppant Fracturing Treatment in Cretaceous Carbonate formation in Kuwait
Authors: Nagarkoti Malvika , Pooniwala Shahvir , Alam Anwar , Anthony Elred , Al-Othman Mohammad , Aloun Samir , Buhamad Ali , Ashkanani Meshari
Published: October 2018

Proppant fracturing treatments in sandstone formations are routinely executed in Kuwait, however when carbonate formations are the target, acid fracturing is the preferred treatment method. It has been observed that acid fracturing delivers a high initial production however maintaining a sustainable production rate is a challenge in the tight cretaceous carbonate formations in Kuwait. A production enhancement technique needed to be identified in order to deliver more sustainable production and maximize recovery from these carbonate formations.

Based on global experience it was proposed that proppant fracturing can deliver more sustainable production rate as compared to acid fracturing.

Proppant fracturing had been previously attempted on two occasions in Kuwait, however both the attempts were evaluated as not being operationally successful. Hence prior to executing the first successful proppant fracturing treatment in carbonates in Kuwait a thorough study was undertaken to identify and mitigate the possible risks.

The cretaceous carbonate formations in North Kuwait are relatively shallow and are known to be tight and highly ductile. Due to the ductility of these formations, proppant placement and reduction of the fracture conductivity due proppant embedment were thought to be significant risks. During the course of the project, detailed core analysis and testing was conducted using formation core samples to ascertain the severity of this risk.

Successful execution of this hydraulic fracturing treatment was pivotal in order to plan the future production strategies from these formations. A cautious approach needed to be followed as proppant placement was of paramount importance. Different strategies were incorporated in the fracturing workflow to ensure the success of the treatment and to maximize data collection in order to optimize future treatments and well placement. Multiple mini-fracs, temperature logs and pumping of novel non-radioactive tracer proppant were some of the techniques utilized.

During execution various decisions were taken real-time to ensure success of the treatment. It was observed that all parameters were consistent with the results of the core and laboratory testing conducted during the initial phase of the project which lead to optimizing the proppant placement.

The success of this treatment has been a game changer resulting in more wells being identified as candidates for proppant fracturing in this field.

Now that proppant placement has been established the objective of future treatments is to optimize fracture designs, fluids and treatment schedules which will help the future production enhancement strategy for this field.

Lessons learnt from this first successful well will be applied to future wells planned in carbonate reservoirs in Kuwait, in order to maximize recovery.
Comprehensive Production Evaluation for Gas Condensate at Early Exploration Stage by Using Downhole Fluid Analysis DFA and Numerical Simulation: Case Study from China Bohai Bay
Authors: Zhang Guoqiang , Tan Zhongjian , Hao Zhongtian , Fan Zhao Ya , Chen Ji Chao , Gao Bei , Shelomikhina Irina , Zhang Tao
Published: October 2018

The new gas condensate has been discovered recently in Bohai Bay China, and due to the complex of the fluid behaviour in nature, appropriate characterization of the in-situ fluids and relevant flow testing can provide valuable insight into gas condensate reservoir forecasting. This paper discussed a comprehensive methodology for reliable productivity evaluation with the aid of in-situ fluid characterization and interval pressure testing, and its results as a key factor not only fed into DST design and equipment optimization for better production evaluation design but also can be optimal production prediction for reserve booking. Based on the efficient and reliable productivity evaluation, we can make the real-time decision on whether to carry on DST and which DST equipment should be chosen and where to test it. However, we has been dealing with heavy oil for very long time, and the common DST equipment in Bohai Bay is not designed for condensate reservoir, but heavy oil, plus there were no published case studies in China about DST modification from heavy oil to gas condensate, and what can be done for production forecasting in gas condensate reservoir. In this paper, a new solution was proposed base on the problem elaborated above.

An integrated approach was conducted to overcome challenges by using all available data from Wireline Formation Tester (WFT) and conventional log data. An accurate permeability is always the foundation of a good prediction, a single well model was built by taking full advantage of all permeability information; Compositional model is the best way to simulate the condensate phase change, in this paper, a calibrated composition was deduced by combining with semi-quantitative DFA composition and PVT analysis software (PVTi) via calibrating downhole measured GOR and density; Black oil model is the most common and popular method to evaluated single well productivity, but the uncertainty of condensate viscosity usually leads huge error, based on the calibrated composition results, evaluated the downhole fluid viscosity, after downhole fluid viscosity correctly evaluated, black oil model can also be applied in condensate productivity evaluation.

DST results were used to validate the results from this approach, the error percentage range is around 10% compare with DST results. This new solution has following values: an accurate gas condensate production forecast become possible even without PVT lab results. A quick gas condensate production workflow has been set up for this field; and the methodology applied is not limited to this specific field but applicable to other fields with condensate fluid type.
Prediction Flooding of Well Stock on the Large Gas Fields with Stratified Heterogeneity
Authors: Ponomarev Aleksandr , Shayakhmetov Airat
Published: October 2018

Practically all large gas deposits of Russia are developed on the elastic water-pressure mode. At initial stages of their development owing to a lack of data on a productive layers structure there are considerable uncertainty at creation of 3D geological and hydrodynamic models of a deposit. At the same time relevant regulations on drawing up design and technological documentation provide calculation of indicators for the entire period of development of an object before the fullest extraction of reserves of gas. As practice shows, 3D digital models of large gas deposits are exposed to periodic specification on a measure of replenishment of geological field information what leads to essential change of initial estimates of technological indicators and efficiency of investments. In these conditions gain development and application of proxy models of the bedded systems using the steadiest characteristics of heterogeneity of collectors and geometry of deposits. It is also relevant to use such models for the developed fields at expert assessment of results of 3D hydrodynamic modeling. Simultaneous using of several approaches and tools when calculating process of development will allow to reduce risks and to narrow area of change of probable values of technological and technical and economic indicators of gas production.

Considered methodology assumes creation of zone and layered and non-uniform model of a gas deposit with use of the probabilistic determined approach to distribution of filtrational parameters on deposit model volume. Intake of reservoir water in a deposit happens to plantar water both on bedding, and in the vertical direction taking into account anisotropy of layers. When forecasting flood of a well stock mechanisms of accounting of a variability of wells on gas and water due to selective flood of productive thickness on interlayer, distributions of reservoir pressure in a zone of placement of wells and the differentiated opening of the allocated interlayer of productive thickness in wells are put. Groups of wells on a state are allocated for each timepoint: not flooded, flooded – capable to take out the water arriving from layer and waters, flooded – incapable of full and continuous carrying out. The moment of a spontaneous stop of the flooded wells is defined on the basis of hydrodynamic calculations of a gas-liquid stream in lift columns of wells.

The algorithm is developed and the computer program of calculation of selective flood of productive thickness of a gas deposit and fund of production wells is created. The technique is approved on Cenomanian deposits of the Yamburg, Urengoy and Medveghiy fields. The received results on indicators of stock of flood well satisfactory are coordinated with historical data.
Image-Based Evaluation of Retained Proppant Pack Permeability
Authors: Beletskaya Anna , Chertova Anastasia , Abashkin Vladimir , Willberg Dean , Korobkov Dmitry , Yakimchuk Ivan , Dovgilovich Leonid
Published: October 2018

Design of hydraulic fracturing and flowback jobs involves application of fluid flow modeling. Most of the existing research and commercial flow modeling software utilizes experimentally determined permeability of a proppant pack as an input parameter. These experiments are time- and resource-consuming and have some limitations. To overcome these issues, we propose a new image-based approach for determination of transport properties of a proppant pack.

This approach involves scanning of the proppant pack under reservoir pressure using X-ray microcomputed tomography, construction of a digital model of a proppant pack, numerical simulation of the fluid flow through the proppant pack, and determination of the pack permeability. Based on analysis of streamlines, the impact of damaging material on the transport properties of a proppant pack can be evaluated. This approach is demonstrated and experimentally validated on the two types of sand with different particle size distribution. A suspension of SiO2 microspheres (50 μm) has been used as damaging material.

To validate the suggested approach, the 3D structure of the tested proppant pack is required. This is not possible to achieve using the standard API cell. Hence, a special high-pressure minicell with walls transparent to X-rays is designed and applied in this study for flooding experiments. Experimentally determined permeability reduction due to suspension filtration agrees well with the permeability reduction estimated in the framework of the image-based approach.
Non-Seismic Methods Development at Gazprom Neft
Authors: Grigoriev Gleb , Zakharova Oksana , Liubimov Evgenii , Morozov Nikita , Kasyanenko Anton
Published: October 2018

Field non-seismic methods are one of the strategic directions of geological exploration that can improve the scientific and technical assessment quality of oil and gas prospects of the studied areas. The main advantage of non-seismic methods in comparison with seismic works is the high mobility and low cost.

This article describes various technological solutions in the field of non-seismic methods. Within the framework of the work, perspective directions of development were evaluated and identified, with perimeter of geophysical, geochemical and geomorphological studies.
Seismic and Electromagnetic Methods Integration to Increase a Quality of Reservoir Properties and Saturation Prediction in East Siberia Region
Authors: Mostovoy Pavel , Oshmarin Roman , Ostankov Andrey , Tokareva Olga , Orlova Daria
Published: October 2018

This paper describes a case study of the Chonskaya group of fields to demonstrate an approach to the integration of TDEM electrical and seismic data when building a geological model for improving a reservoir properties and saturation prediction quality.
Analysis of Results Confirmation of Simultaneous Inversion for East Siberian Terrigenous Reservoirs
Authors: Emelyanov Pavel , Ostankov Andrei
Published: October 2018

New exploration projects with a scarcity of drilling data give much consideration to advanced high-density 3D seismic studies. Updated high-density seismic data is presumed to be utilized to build detailed geological reservoir models and substantially enhance further exploration drilling.

The latest developments in seismic data interpretation stem from inverse transformations of seismic data. Seismic data can be reviewed and interpreted by themselves, without inversion, however, this does not allow us to obtain the most detailed understanding of the structure of the formation, and under certain conditions can lead to an unreliable result. Benefiting from the efficiency and quality of seismic inversion, most oil and gas companies currently employ inversion technologies to enhance seismic data resolution and improve the prediction reliability and reservoir rock properties assessment accuracy, including with regard to porosity and net pay thickness. There are a host of various inversion technologies with some of them to be selected for the quantity and quality of prior geological and geophysical data, as well as for the specific needs to be addressed and the rock properties of of the section under study.

The key objective of this publication is to assess the potential of inversion transformations in predicting sweet-spots in terrigenous reservoirs forming part of a challenging seismogeological environment in Eastern Siberia. The simultaneous inversion validity analysis is based on the data obtained from two pilot boreholes of a newly drilled well.
Hydrocarbon Detection Method and Application Based on Two-Wide and One-High Seismic Technique
Authors: Zhen Wang , Junzhang Zheng , Yankun Wang , Jiquan Yin , Man Luo , Shuang Liang
Published: October 2018

The "Two-Wide and One-High" (wide-band, wide azimuth and high-density) Seismic Technique provided high-quality seismic data for more accurately identify the lithologic reservoirs, with low frequency information and broadband data being beneficial to the petroleum detection in the reservoirs. Hydrocarbon reservoir is a typical two-phase (solid and fluid phases) media. The seismic wave can display the characetristics of obvious low-frequency resonance and high-frequency attenuation in the seismic record after propagating through the two-phase media. Based on the theory and the "Two-Wide and One-High" Seismic data, the hydrocarbon detection is carried out in AMG block's two carboniferous sets of main reservoirs in the eastern Precaspian Basin. Three methods are useded to analyze variation in the low-frequency and high-frequency after the seismic wave propagating through the exploration target strata, such as area difference method, time-frequency method of three primary colors method, instantaneous bandwidth method. The petroleum detection result accords well with the drilling testing data in the area, which means that this detection method based on the "Two-Wide and One-High" Seismic data could lower the exploration drilling risk and provides the advantageous basis for well location deployment of hydrocarbon reservoir exploration in the area.
Organizational Model of Management Seismic Survey Projects in PJSC Gazprom Neft
Authors: Dakirov Valikhan , Litvichenko Dmitry , Zhukov Vladislav
Published: October 2018

"The era of easy oil comes to the end" – this phrase can be heard with increasing frequency today, and "hard-to-recover" reserves become the target of development. And presently, the seismic community is facing the challenge to survey complex geological features and improve the level of detail and reliability of the models: ➢A vast number of fields are near-depleted:The share of complex lithology deposits is growing;Have to drill into edge zones;Find hidden layers;➢New assets with complex geology:Geology forecasting of complex reservoirs;Forecasting the fracturing and anisotropy.
Advanced Modeling of Production Induced Pressure Depletion and Well Spacing Impact on Infill Wells in Spraberry, Permian Basin
Authors: Xu Tao , Lindsay Garrett , Zheng Wei , Yan Qiyan , Escobar Patron Katherine , Alimahomed Farhan , Panjaitan Maraden Luigie , Malpani Raj
Published: October 2018

Since early 2016, commodity prices have been gradually increasing, and the Permian Basin has become the most active basin for unconventional horizontal well development. As the plays in the basin are developed, new infill wells are drilled near pre-existing wells (known as "parent wells"). The impact of pressure depletion caused by adjacent existing producers may have a larger role in the performance of these new infill wells. How the various well spacing impact with the degree of reservoir pressure depletion from parent well is more important than ever for operators to optimize the completion design. Through data analytics and comprehensive fracture/reservoir modeling this paper studies how changes in well spacing and proppant volume in the Spraberry, a main formation in the Permian Basin, will impact new infill well performance. The studies in this paper are focused on the Midland Basin.

A public database was used to identify the number of parent and child wells in the Midland basin. Data analysis of production normalized by total proppant and lateral length shows that parent wells outperform infill, or child, wells. To further understand the relationship between parent and child wells, a reservoir dataset for the Spraberry formation was used to build a hydraulic fracture and reservoir simulation model for both the parent well and a two-well infill pad. After production history matching a P50 type well as the parent well, three periods of production depletion were modeled (6 months, 3 years and 5 years) to understand the timing impact on the infill well production. A geomechanical finite-element model (FEM) was then used to quantify the changes to the magnitude and azimuth of the in-situ stresses from the various reservoir depletion scenarios. A two-well infill pad was then simulated into the altered stress field next to the parent well at various spacings between the parent and child wells. A sensitivity was then performed with different stimulation job sizes to understand the volume impact on created complex fracture propagation and total system recovery.

This study can help operators understand how well spacing, reservoir depletion, and completion job size impact the infill well performance so they can optimize their infill well completion strategy.
Advanced Petrophysical Log Suite Support for Acid Stimulation Design Optimization
Authors: Petrov Alexander , Khuzin Rinat , Shevko Nikolay
Published: October 2018

Enhanced oil recovery methods, i.e. acid stimulation, are widely used to increase well productivity in oilfield development. The necessity for reservoir stimulation is linked with negative processes related to well drilling and perforation. The correct estimation of damaged zone parameters is the key problem for acid stimulation planning. The proposed petrophysical methodology is based on available data integration: core data, drilling data, well logging, well testing etc. Modern well logging suite allows to solve following task with high accuracy.

Sonic radial profiling based on compressional and shear waves registration and multisonde resistivity logging are the key methods to prognose wellbore damaged zone radius and parameters. The methodology based on integration of both these logging data is proposed in this paper. Currently, fullwave acoustic logging provides comprehensive data to estimate drilling mud penetration zone and character of the damage. The approach is based on alteration of sonic waves – compressional and shear waves.

But not all the wells logged with sophisticated modern acoustic log tools. Therefore, estimation of mud filtrate penetration and damaged zone is possible based on multiarray resistivity measurements which are primary methods in all well logging suites. At least three different sondes with different radius of investigation are run in a well. These data are enough to use for accurate damaged wellbore zone radius estimation. Calculated results were supported by other available information and verified by data from modern sonic tools. Thus, allows to improve the methodology and use it widely in all wells in a field.

Modern fullwave acoustic logging was performed by Schlumberger in few wells of carbonate field of the Company. In rest of the wells wellbore damaged zone estimation based on proposed integrated approach applied for multiarray resistivity interpretation. This workflow allowed to optimize acid near wellbore zone stimulation for the oil recovery enhancement.