bluuebunny/crossref_metadata_2025 huggingface dataset:
Successful Drilling Well on Middle Jurassic Formation with Severe Geotechnical Conditions on West-Yurkharovskoe Field
Authors: Shakunov Aleksandr Anatolievich , Frolov Andrey Mikhaylovich , Rudoy Viktor Aleksandrovich , Elmurziev Dzhokhar Adalbekovich , Litvintsev Ivan Alekseevich , Chernov Pavel Petrovich , Borodich Maksim Andreevich , Shakurov Rafael Ramilievich , Zaydullin Marsel Olegovich , Murasov Tagir Talgatovich , Klimenko Ilya Sergeevich
Published: September 2020

The paper describes the engineering and technology solutions that used in the well with non-standard casing design and geological conditions on West-Yurkharovskoe field. Drilling characterized by low ROP, high risks of downhole tool failure and problems with wellbore stability. The geological structure is quite complex with coal-zone, high-pressure zones with abnormal pore pressure equal 2.2 g/cm3 and high temperature 125°C of Middle Jurassic formations that limited the choice of applicable tools and demand the optimal solutions in planning.

For successful accomplishment of the project objectives and minimization runs number was carried detailed analysis geological data, possible complications, experience of drilling wells on West-Yurkharovskoe field. Depending on the tasks and goals are set, the following selection was made:

– Downhole tool which have to ensure possibility to drill section with heavy mud and can work with high temperature on bottom; – Drill bit design optimization which can ensure high ROP; – RSS with bit 241mm in tie-back section; – For the first time in Russia was used special liner hanger system which greatly reduces the risk of prematurely setting the hanger while RIH in heavy mud.

Integrated approach and close working relationship has lead to next results:

– Optimal combination rotary steerable system with new drill bit design allowed to increase average ROP for the whole run in liner is 9.4 m/h, that helped to reduce total drilling time by 268% then average results according to previous wells; – Drilling section 241.3mm, 165.1mm, 155.6mm in one run with demanding geological conditions; – Successful using for the first time in Russia special liner hanger system which allowed achieved bottom without prematurely setting in heavy mud with density equal 2.18 g/cm3; – Implementation liner packer. The packer designed to withstand the extreme wellbore conditions. The packer will provide an effective annular seal between the top of the liner and the casing, thus preventing possible formation breakdown, loss of cement slurry and gas migration above the liner top during cement cure.

Successful accomplishment of the project objectives with demanding geological conditions have been achieved due to utilization new completion systems and downhole tools, which was applicable to borehole conditions. This experience allows to get one step closer to making the well construction for Jurassic formation deposits profitable and achievable more longer horizontal section.
Implementation of New Hyperbolic Diamond Elements for Improving Rate of Penetration While Drilling Through Soft and Plastic Formations in Russia
Authors: Fatkulin Sergey Aleksandrovich , Gumich Dmitrii Petrovich , Konysbekuly Galymzhan , Ryabov Ilya Vladimirovich , Zabuga Sergey Vladimirovich , Merzlyakov Alexander Sergeevich , Kotsyumaha Maxim Andreevich
Published: September 2020

Terrigenous intervals usually consist of interbedded sandstone, siltstone, clay and claystone. These intervals can be also difficult to drill even though rocks have low strength. Sticky and plastic rocks are the cause of rate of penetration (ROP) decreasing without drill bit cutting structure wear. A new hyperbolic diamond element (HDE) bit has been developed to improve drilling efficiency in such conditions. HDE has a standard cylindrical carbide substrate as conventional PDC cutter. The main difference is shape of diamond layer, it has hyperbolic profile. HDE has positive rake which helps to improve performance in soft formations: the cutter penetrates deeper in rock under the same loadings. Hyperbolic diamond element also helps to avoid ribbons generation while drilling in soft and plastic formations.

HDE technology was implemented on different oilfields in Russia. Naulskoe oilfield is one of them. It is in the Timano-Pechora oil basin. Development section interval consists of terrigenous rocks: sandstone, clay and claystone. New bit design with HDE cutters was specially developed for oilfield geology. The same well profile, bottom hole assembly (BHA) and drilling parameters (flow rate, weight on bit and drill pipe rotation) were used in bit tests. HDE bits set a new field ROP record which is 70% higher than average result on the drilling pad and 17% higher than the best previous result. This achievement proved HDE technology efficient.

HDE bits were used also on another oilfield which is located in the South part of Russia. Low rate of penetration is observed while drilling soft and plastic clay there even with no bit dull. There were several different tries to optimize drilling process with no success. It was decided to test hyperbolic elements technology on the oilfield. Average ROP increased in 90% as a result after HDE bit implementation. It allowed to reduce well construction time.
A Successful Experience in Using Short Gauge PDC Bits for Drilling with Point-the-Bit Rotary Steerable Systems under Geological Conditions of Verkhnechonskoye Field
Authors: Abaltusov Nikolay Valerevich , Garaev Azat Zyavitovich , Klabukov Andrey Vyacheslavovich , Averkin Aleksey Viktorovich , Pavlenok Maksim Konstantinovich , Smolin Evgeniy Aleksandrovich
Published: September 2020

The investigations, conducted by many companies, show that a long gauge PDC bits, which are used during operations with "point-the-bit" Rotary Steerable Systems (RSS), allows for mitigating the bit vibrations and improve steerability.

But in this paper, we shall present the usage of the short gauge PDC bits when drilling with this type of RSS in a pay zone, which is characterized by hard streaks.

More tight shaled-out interlayers were encountered in pay zone when developing a peripherical part of Verkhnechonskoye field.

On the boundary of the rocks of different hardness a number of formation "pushes" (short intervals with a sharp change of the inclination) increased significantly. A continuous operation in the formation "push" intervals resulted in downhole equipment damages.

When conducting kick-off operations in an open hole in multilateral wells with the use of "point-the-bit" RSS and the long gauge bits a quantity of failures reached 60 %. For that reason, it was necessary to kick off using a BHA with a downhole motor; but in this case additional runs are required.

A hypothesis was made that the usage of short gauge PDC bits will help to promptly correct the wellbore trajectory when formation "push" occurs, as well as allow for drilling a few laterals over one run.

Deviation from the standard design made it possible to reduce a number of runs when drilling multilateral wells, increase an average rate of penetration and significantly reduce frequency of Dogleg Severity exceedance events when passing through hard streaks.
Technology of Oil Production from Marginal Low-Rate Wells
Authors: Grekhov Ivan Viktorovich , Kuzmin Maksim Igorevich , Muzychuk Pavel Stefanovich
Published: September 2020

The biggest part of the Company's asset portfolio consists of mature fields with declining production levels. High water content in produced reservoir fluids, and low production rates become the reason for low economic efficiency of a significant number of production wells that fall into the category of marginal or unprofitable wells. Reducing operating expenses for artificial lift and bringing these wells into the profitable category is the goal of the Technology of Oil Production from Marginal Low-Rate Wells project launched in our Company in April 2017 (Kibirev E.A. and others, 2018).
Prediction of ESPs Failure Using ML at Western Siberia Oilfields with Large Number of Wells
Authors: Khabibullin Rinat Alfredovich , Shabonas Arturas Rimo , Gurbatov Nikolay Sergeevich , Timonov Alexey Vasilievich
Published: September 2020

The development of a technology forecasting ESP failures is one of the key tasks of the oil industry today. Simple statistical methods do not allow to predict the equipment's failure and its cause, which would allow to select and conduct the planned preventive measure in time.

This paper describes the methodology of ESP failure prediction developed based on field data. The main stage of the methodology is the creation of an ensemble model of machine training, the application of which allows for the taking into account of many factors and extensive experience in operating ESPs contained in field data, so considerable time has been devoted to working with them.

The uniqueness of the presented work is the use of field information on well operation in Western Siberia, accumulated for the last 5-7 years from the discrete measurements of one day, in which there was a significant amount of information omission. To improve the quality of forecasting, it required multilevel pre-processing of initial data and formation of additional analytical features, which allowed improvement of the quality of predictions.

The study of the developed model for the prediction of the ESP failures at different prediction horizons was carried out and it was determined that the quality of prediction increases when the interval of prediction decreases. The developed model shows the best results when predicting the ESP failure 1-3 days before its actual stop.

The groups of parameters, on which the duration of failure-free operation of pumping equipment in a well depends to a great extent, have been determined this is information about the well operation mode, information about ESP operation parameters, dynamic information about complicating factors of the ESP operation and additional analytical parameters describing the processes occurring in the system "Wellbore – ESP – Tubing".

The ESP failure prediction model, the development of which is described in this work, can become the basis of the decision support system, its implementation in production will allow to identify in advance the cases of possible downhole pumping equipment failure and to take timely measures based on this information.

Based on the obtained results and high relevance of the problem under consideration, the main directions for further improvement of the developed methodology have been defined.
Optimization of Oil Production Wells Flowing Mode by Ultrasonic and Induction Systems
Authors: Verbitsky Vladimir Sergeevich , Goridko Kirill Alexandrovich , Dengaev Alexey Victorovich , Getalov Andrey Alexandrovich , Sargin Boris Victorovich , Grekhov Ivan Victorovich , Kuzmin Maxim Igorevich , Ahmetgaliev Albert Rinatovich , Lashchev Denis Mikhailovich
Published: September 2020

The current operating conditions of the fields with a high reservoir energy potential (with a high gas factor) are characterized by the onset of a period of reduction in reservoir energy, while the total losses for raising well products from the bottom to the surface may increase. Under these conditions, operating the well in a fountain way is irrational, because the efficiency factor of the winch decreases and can be no more than 10-20%, and serial submersible pumping systems (ESP) are unstable and in most cases, they develop the well and put it into the flowing mode of the well products through the annulus.

The research work has been carried out to justify the technology of acoustic impact on gas-saturated oils of various fields according to the criterion of reservoir energy potential. The flowing wells in the oil and gas condensate field have been analyzed, the dynamics of changes in the efficiency of fountain wells has been presented, and the main reasons for the decrease in the efficiency of flowing have been highlighted. The theoretical studies have been carried out in the field of acoustic methods for influencing gas-saturated oils of various fields. The laboratory samples of ultrasonic and electromagnetic emitters have been developed, with the help of which the oil properties of two fields were studied, the results of which were used in the development of conceptual models of well installations for extending the flow mode in production wells.
Improving the Equipment Efficiency by Using the New Technology for Bulk Material Laying
Authors: Fayzullina Lyaysan Fayzullina , Tumanova Elena Tumanova
Published: September 2020

The article is devoted to increasing the efficiency of using equipment with a solid bulk layer due to the application of the developed technology for dense laying. This technology is applicable for loading solid granular materials, for example, catalysts and adsorbents. The current issue of adsorbent bulk layer compaction in the apparatus for drying associated petroleum gas in the oil field is considered in the article.

The article investigates the hydrodynamics of the gas flow through the adsorbent bulk layer by the computational hydrodynamics method, performed in a specialized software package with finite element analysis, to determine the effective method of laying the material. The numerical calculation results are verified by analytical calculation, and then effective values of the bulk layer porosity are determined. The dependence of the pressure drop in the adsorbent layer on the feedstock flow velocity at the inlet is established.

The dense laying efficiency is confirmed by hydrodynamic modeling, made it possible to develop a new device for bulk material dense laying and the technology for its use in the apparatus. The developed device efficiency has confirmed by experimental studies, expressed by the compaction coefficient.

An industrial device design was developed to increase the industrial equipment efficiency and a verification strength calculation was performed by a stress-strain state modeling method. The technology of the device using in an industrial apparatus has been developed.
The Approbation of Reserves Geochemical Control Technology in Example of AC10 and AC12 Group Formation in Priobskoye Field of LLC Gazpromneft-Khantos
Authors: Morozov Nikita Vladimirovich , Bikkulov Marsel Minullovich , Uchuev Ruslan Pavlovich , Martynov Mikhail Evgenievich , Islamov Ruslan Rishatovich , Shurunov Andrey Vladimirovich , Kalacheva Daria Yurievna
Published: September 2020

In order to improve tools for monitoring the reserves recovery and localization at the Gazprom Neft fields, as part of the technological strategy, a technology for geochemical control of reserves recovery has been developed.

The use of geochemistry methods in identifying the targeted flow of fluids from a reservoir is based on the difference in fluids’ composition and properties from reservoir to reservoir. According to laboratory experiments, the accuracy of the geochemical predictions of miscibility based on a multiple linear regression model varies from 1 to 8% for oils and condensates, from 6% to 18% for gases, and from 15% to 34% for reservoir water (provided there is no pressure maintenance system in a reservoir).

The technology was tested at Priobskoye field of Gazpromneft-Khantos LLC, which jointly operates Zones AS10 and AS12. The pilot program included 5 wells with pre-installed Y-tool assemblies. The advantage of this system is the ability to conduct tests in a well producing in a stable state with induced pressure drawdown. Simultaneous geophysical studies and wellhead sampling for geochemical studies allowed us to confirm matching of the results of dividing the inflow under the conditions of a well draining two or more target zones.

The technology for geochemical control of reserves recovery will allow a breakthrough in the study of wellhead fluid samples in the near future, and such information will increase the success rate and information content of field geophysical studies by an order of magnitude. The advantage of the described technology is 100% coverage of the production well stock and the ability to predict miscibility for all types of fluids (oil, gas, and produced water).
Comprehensive Studies of the Salinized Reservoir Rocks to Expand the Resource Base of the Hydrocarbons in Pripyat Trough
Authors: Grimus Svetlana Ivanovna , Kalejchik Evgenij Albertovich , Soshenko Aleksandr Vasiljevich
Published: September 2020

The article presents the results of the salinized reservoir rocks comprehensive studies, made for the first time at Severo-Domanovichi oil and gas area in Pripyat Trough. The comprehensive studies were carried out in following aspects: the types of rocks salinization and their quantitative parameters were determined; the optimal set of well logging methods was selected to distinguish the salinization intervals and a petrophysical model of the salinized reservoir was constructed. The lithological-facies zoning of pay deposits was completed. Based on the data interpretation on the composition and the density of the injected and associated water, the volumes of halite removal from the well No. 25 Severo-Domanovichskaya were determined. We proposed the method for increasing permeability of a salinized reservoir using the wells of Berezinsky oil field as an example.
Development of Methods for Optimizing the Parameters of the Oil Rim Development System
Authors: Samolovov Dmitriy Alekseevich , Varavva Artem Igorevich , Sandalova Ekaterina Evgenevna , Polkovnikov Fedor Igorevich , Apasov Renat Timergaleevich , Apasov Gaidar Timergaleevich
Published: September 2020

The article is devoted to development of optimization methodology for parameters of oil rims exploitation system by line drive pattern of depletion type horizontal wells. Solution for transformation of flanking oil rim to subjacent oil rim with massive gas cap has been obtained. Moreover, empirical equation which includes gas cone height under exploitation of subjacent oil rim by horizontal well has been also derived. Known analytical solution has been supplemented with derived corrections with a view to convergence of the solution in the case of flanking oil rims. The solution includes set of dimensionless parameters which depend on formation characteristics and economic features of the project. Solution of the problem allows to determine the oil rim profitability without using complicated hydrodynamic computations at the stage of estimation.
Neural Network as a Tool for Predicting and Controlling the Technological Regime of Production Wells
Authors: Vershinin Vladimir Evgenyevich , Ponomarev Roman Yurievich , Strekalov Alexander Vladimirovich
Published: September 2020

The article states the possibility of forecasting the operating modes of production wells through artificial neural networks simulation. The main difficulty in medium- and long-term forecasting is to take into account the influence of adjoining wells and the performance pattern of formations. The flow simulation considers these factors and can be used to teach the artificial neural networks together with the real field data on well operation. The present research paper dwells upon the ways of forming training samples for the artificial neural networks as well as the quality of forecasting operating modes of wells. Training and forecasting of modes was carried out on the data of computational fluid dynamics for the patch with three production and one injection gas well. We compared two types of artificial neural network forecasting capabilities: MLP and LSTM architecture of the recurrent type. We illustrated how qualitative training sample allows forecasting operating modes of well operation with high accuracy over 10 years.
Model Dimensionality Reduction by Upscaling of the Decomposition Spectra of Its Static Parameters
Authors: Rabochiy Pyotr , Shelkov Vasilii , Bogachev Kirill
Published: September 2020

In this paper we propose a novel method of reducing the number of history matching variables required for adequate approximation of static properties associated with reservoir models of hydrocarbons. The method is based on the expansion of the static parameters into discrete orthogonal basis with subsequent parametrization of underling expansion coefficients. The method is demonstrated with application to a simple synthetic example and a sector model of the real oil field. It is shown that utilization of the method described here provides additional degree of model reduction by a factor of ten or more.
Estimation of the Stress Field in a Geological Object Complicated by Disjunctive Dislocations Using Various Approaches
Authors: Yalaev Tagir Rustamovich , Rebetsky Yuri Leonidovich , Kanevskaya Regina Dmitrievna , Kiryachek Vladislav Anatolievich , Pimenov Andrey Andreyevich , Volianskaia Viktoria Vladimirovna
Published: September 2020

In this study various approaches are used to estimate components of the stress fields and the directions of the principal axes of the stress tensor in a geological object complicated by disjunctive disturbances. Two approaches are used: one is the cataclastic analysis method and the other one is finite element method. The initial data for modeling are the results of the interpretation of the seismic cube and the mechanical properties of the layers of the studied object.
Offshore Case: Rapid Assessment the Optimal Parameters for Oil Field Development and Facilities Construction
Authors: Lubnin Alexandr Alekseevich
Published: September 2020

The article covers methodology for rapid assessment of optimal development parameters for offshore fields. The first stage determines maximum allowable expenditures for field construction that make the project efficient, following selection of the offshore facility type required for production. The second stage evaluates the well density for every cost-effective offshore facility considering the best economical option for field development.
Case Studies of Gascondensate Field with Oil Rim Development: Search for Effective Methods of Oil Production from Thin Rims
Authors: Kolbikov Valentinovich Sergey
Published: September 2020

The present work is dedicated to the problem of developing oil and gas condensate pools with thin oil rims for neocomian deposits in the Urengoy region, and to the search for effective methods of oil production from thin rims. The key problems in the development of thin rims are the low cumulative oil production per well, as a result - low profitability and oil recovery ratio. The reasons are known: a sharp decline in initial oil rate due to the rapid increase in water cut and growth of gas factor associated with the water and gas coning.

The results of hydrodynamic modeling at early stage in the development of oil rims often lead to optimistic forecasts that are not confirmed in practice. The paper provides an analysis of the reasons for optimistic calculations, tuning up models for the results of the development and operation of oil wells with different completion relative to the GOC. Obtaining history-matched oil and gas production systems made it possible to obtain a more reliable production forecast for oil wells, to substantiate the preferred target subsea depth for the completed interval in the rim and the type of completion.

Scenarios with the completion of the horizontal section at a distance of one third from the GOC and OWC, or in the middle between the contacts, have been considered and analyzed. A comparison of the calculated performance of the wells with the actual one had been made. An economic evaluation of the operational efficiency of wells drilled on thin rims shows that their profitability based on oil production is marginal. The closer completion intervals of the oil horizontal wells to the GOC the higher economic efficiency of their operation due to additional volumes of gas and condensate production from the gas cap. The use of double-wellbore and multi-lateral completion of horizontal wells in the oil rim increases the economic attractiveness of the project.

The integrated approach proposed in the paper to the organization of production and oil and gas processing systems from such oil wells makes it possible to technologically efficiently operate wells and ensure almost full utilization of associated gas. The joint development of gas condensate pools with thin oil rims allows for the cost-effective development of the ones.
Formation of an Effective Hydrogen Storage in an Aquifer and Control of its Parameters
Authors: Azretovna Abukova Leyla , Nabievich Zakirov Sumbat , Pavlovich Anikeev Daniil , Sumbatovich Zakirov Ernest
Published: September 2020

This article discusses the problem of creating a hydrogen storage in an aquifer. It is assumed that the process of hydrogen injection and the life cycle of its storage should provide the most complete reverse production of the injected gas in a few years. The features of injected gas distribution in an aquifer are considered, taking into account a number of parameters. For example, the effects of gas breaking through a cap rock and fluids migration under influence of natural water flows from aquifers associated with the target reservoir. An effective storage and subsequent production system are proposed allowing to control geometry and volume of gas bubble in the reservoir.

The results are obtained on the basis of large-scale 3D geological and hydrodynamic modeling of filtration through porous medium of a multicomponent system in the form of hydrogen, methane and water mixture on synthetic 3D models. Corresponding studies were performed on a certified hydrodynamic simulator using a composite model.

Large-scale 3D geological and hydrodynamic modeling made it possible to justify the method of compact hydrogen storage in an aquifer. Closed systems, without contact with large volumes of water in adjacent aquifers, do not allow significant gas volumes to be stored under technologically realistic parameters. Presence of an active aquifer dramatically changes injected gas configuration and facilitates its migration from the zone of possible reverse production.

The necessity of creating a permanently operating associated water injection system is substantiated to control geometry of the created hydrogen storage together with methane. It is shown that without controlled injection of water, both at the stage of creating the storage and at the stage of storing hydrogen, it is not possible to ensure its subsequent sufficiently complete production to the surface in a reasonable time with technologically justified costs. Otherwise hydrogen reserves are being scattered due to gas migration over very large distances from gas injection wells. Strong influence of the aquifer system parameters associated with the target reservoir is illustrated for dynamics of hydrogen propagation.
Liquid Loaded Gas Condensate Revitalization by Automated Flow Regime Optimization and Control
Authors: Baranov Vladimir , Rymarenko Konstantin , Nukhaev Marat , Grishchenko Sergey , Karamysheva Tatiana
Published: September 2020

The operation of gas wells is often fraught with complications due to water accumulated in the perforation interval and wellbore, and destruction of the bottom-hole zone. These complications drive up pressure losses and decrease operating well flow rates and production capacities of deposits.

This article presents proposals for unburdening gas wells in the Vostochno-Makarovskoye field.
Determination of Suspension Filtration Parameters from Experimental Data
Authors: Fedorov Konstantin Mikhailovich , Shevelev Aleksandr Pavlovich , Kobyashev Alexander Vyacheslavovich , Zakharenko Vladimir Alexandrovich , Kochetov Aleksey Valentinivich , Neklesa Roman Sergeevich , Usoltsev Anton Valeryevich
Published: September 2020

The article is devoted to determining the filtration parameters of a polymer-suspension system based on experimental data on the injection of polymer and suspension into a core sample. A dimensionless mathematical model of the filtration process based on the law of conservation of mass and Darcy's law is presented. Dimensionless characteristics of the filtration process (dimensionless effective viscosity and dimensionless parameter that determines the velocity of the polymer slug) are introduced and calculated. According to experimental data, the formation damage coefficient and the filtration coefficient during suspension injection were determined, which are in satisfactory agreement with the theories of polymer slug filtration and deep bed migration.
From Qualitative Interpretation to Quantitative Analysis: Prediction of Properties of Geological Bodies by Using the Spectral Decomposition Attribute – Case Study of Achimov Turbidity System in West-Siberia
Authors: Volkov Roman Petrovich , Volkov Dmitrii Sergeyevich , Kozhevnikov Georgii Sergeyevich
Published: September 2020

The spectral decomposition attribute map is one of the most representative data for geological and qualitative geophysical interpretation. The specified technique using RGB mixing allows you to confidently map the seismic recording anomalies that do not appear when analyzing the full spectrum of the signal, as well as evaluate the amplitude response for the center frequency of the analyzed range. However, the question arises the applicability of the results of spectral decomposition in the process of quantitative seismic data interpretation.

There are a number of works, such as Widess (1973), J. Gridley and G. Partyka (1997), Butorin A.V. (2016), which indicate the possibility of using the spectral decomposition results when performing a quantitative assessment of the allocated geological objects thicknesses. This task is relevant because it allows you to add additional information extracted from the amplitudes of a limited frequency range at the stage of dynamic interpretation. Along with, an additional advantage of this technique is the possibility of an independent rapid assessment of the quantitative parameters of geological objects.

In this article, we propose an approach for predicting net thickness using spectral decomposition attribute and apply it to the Achimov wedge-shaped complex. These deposits are characterised by a complex distribution of sands and the occurrence of thin-bed sand bodies that are below the seismic resolution limit.
Study of Mechanical Properties and Analysis of Low Temperatures Influence on Flexible Tank Engineering Structural Material Behavior
Authors: Shirieva Nadezhda Sergeevna , Shiriev Artur Kamilevich , Tlyasheva Rezeda Rafisovna , Naumkin Evgeny Anatolyevich
Published: September 2020

Drill sites belong to hazardous industrial facilities that require increased attention. In the Arctic and Far North regions drill sites are usually located at considerable distances from industrial centers, emergency response teams (ERTs) and fire houses, in summer they may not have any approaches, and in winter transport communication is ensured only via winter roads and by aircraft transport. When drilling wells significant stock of fuel and lubricants is required to ensure autonomous operation of power-generating equipment. For these purposes various vessel equipment is used including soft (flexible) tanks. When designing these facilities engineering solutions aimed at prevention of accidents and incidents must be sufficient, and equipment with high operation reliability must be selected.

The article classifies loads and actions that occur during tank operation. Study of deformation and strength properties of tank material as a tool for determination of equipment reliability including reliability at low temperature is carried out. An approach to assessment of safe remaining operation life of tanks is proposed.

Comparative calculation of thermal radiation intensity values as a result of fire on tanks at various ambient temperatures is carried out. It is determined that air temperature impacts on range of damage effect active zone in case of accident.
Psychological Safety of Oil and Gas Workers in the South and North of the Russian Federation
Authors: Korneeva Yana Aleskandrovna , Simonova Natalia Nikolaevna
Published: September 2020

The study purpose is to identify and describe the psychological safety features of oil workers in the south and north of the Russian Federation. The study was conducted on an offshore ice-resistant platform, the Caspian Sea, 50 people took part (shift duration - 14 days) and an oil and gas field in the Far North, where 70 people participated (shift duration - 28 days). The research method is a questionnaire. The questionnaire developed by us included the following sections: general information about education and work experience; marital status; subjective assessment of the adverse climatic, geographical, industrial and social factors that affect workers during a shift period; features of the organization of free time during the shift period; subjective assessment of their professional effectiveness and professionalism; subjective risk assessment of various situations that may arise during the shift period; subjective assessment of the danger in the workplace and the factors contributing to its formation.

The results obtained allow us to conclude that for workers of both industrial facilities regarding the feeling of safety during the shift period, production factors and situations play an important role. Climatic and geographical factors enhance the effect of exposure to extreme production conditions. A comparative analysis found that the severity of the hazards in the workplace is higher among employees of the offshore platform. Safety at this facility is limited by a large number of factors that are more intense.
Implementing HSSE Competence Framework - Process, Lessons and Results
Authors: Claessen Fons , Samoylova Olga
Published: September 2020

Outstanding HSSE performance is an ambitious goal set forth by the energy sector globally. Salym Petroleum has developed variety of systems and rules to achieve an incident free oil production over the past decades. However, we continue to miss our Goal Zero delivery.

In many interventions and investigations on unsafe activities or incidents we discover that systems and rules are not consistently followed by responsible personnel.

In such cases people's attitude, knowledge and skills are considered the deficient line of defense. And that is why trained and competent employees are integral to our critical safety barriers against a major hazard release.

To become successful in Company's Goal Zero pursuit we need to be 100% sure that our people know, understand and have the right leadership and technical skills for the HSSE critical activities and roles they perform, manage or supervise.

The above is achieved through HSSE Competence Framework implementation.

The paper will provide progress overview on the four corner stones of the Company's HSSE competence process:

– compliance, – development, – assurance, – digitalization.

We will share the lessons and results of our current practical and focused efforts to make all four elements work including our own digital solution.

Salym Petroleum developed and launched a unique HSSE Competence portal which combines the national legislation rules, internal corporate expectations and shareholder's best practice approach.

The portal supports each step of the HSSE Competence process:

– sets competence matrix requirements for the entire Company; – links them with the employees' individual competence profiles/accounts; – contains a calendar to schedule and signup for the training and assessment events; – provides a reporting tool.
Searching Procedure for the Optimum Reservoir Fluid Sampling Towards Production Logging Validity Improvement
Authors: Karpov Valery Borisovich , Ryazanov Arsentiy Alexeyevich , Parshin Nikolay Vasilyevich , Sleptsov Dmitry Igorevich , Lysova Dina Anatolyevna , Buyanov Anton Vitalyevich , Buzin Pavel Vladimirovich , Gazizov Ruslan Rashidovich , Neznanov Vladimir Evgenievich
Published: September 2020

An efficient hydrocarbon field development requires implementing the current field production control accompanied by various surveys. Historically, classic approaches do not yield favourable results and ensure high information value,which results in the necessity for state-of-the-art technologies. One of these technologies could be the production logging using markers.

The goal of this article is to study various sampling techniques for convergence of quantum markers identification results during the horizontal well injection logging. The present article is dedicated to the studies comprising of a comprehensive reservoir fluid sample analysis with subsequent production logging evaluation of a multi-stage horizontal well at Sredne-Nazymskoye oilfield.

The article covers the oil and water inflow monitoring in a horizontal well treated with 15-stage fracturing. The technology, which serves a basis for this analysis, involves using a marked proppant with polymer coating. Flow profiles are evaluated by calculating the markers of different codes in a fluid sample, and every signature (code) corresponds to a particular interval where a man-made crack is induced.

For this study the special sampling schedule was made involving an extensive reservoir fluid sampling in order to perform representative selection and making references to external and engineering factors such as well operation conditions, flow pattern, flow rate, volume components, etc.

Test review allowed getting a general idea of how reservoir fluid will be sampled at non-conventional deposits qualified as the hard-to-recover reserves in order to improve production logging information value both at qualitative and quantitative levels.
Novel Approach for Produced Water Utilisation in Multi-Stage Fracturing Treatments in Western Siberia
Authors: Kiselev Nikita , Vernigora Denis , Borisenko Alexey , Rapeyko Vitaly , Zotov Kirill , Miklin Yuriy , Prokhorov Alexey , Denis Zolnikov
Published: September 2020

Massive implementation of multi-stage fracturing treatments increased demands in water. Huge number of oil fields haven't got access to the fresh water sources. This fact forces service companies to utilize high TDS water sources for hydraulic fracturing. Currently available solutions for preparation of crosslinked fluid based on high TDS water involve implementation of organometallic systems which are too expensive and operationally complicated. This paper describes approach for preparation of borate- based fluid utilising high TDS water.

Thorough laboratory optimization of the fracturing fluid has been performed and novel approach for fracturing fluid composition has been involved to develop next generation of robust borate fracturing fluids being able to withstand high TDS of the water. Fluid was evaluated in terms of both stability and viscosity recovery after application of high shear stress.

Optimized fluid formulation has been used during multi-stage fracturing treatment with 7 stages. High TDS water of Cenomanian formations was utilized as a water source. During treatments as high as 700 kgPA proppant concentration has been reached.

During optimization novel approach involving implementation of low boron containing fluid with massive content of alkali was introduced. Low boron content is required for preventing syneresis in high ionic strength media caused by Debye-Huckel effect. High alkali concentration meantime required to keep fluid at high pH and avoid weakening of bonds between borates and polymer.

Too high alkali concentration worsens viscosity recovery after high shear stress application and this fact dictates implementation of both immediate and delayed alkali compounds.

Pre-job water treatment is also important. Addition of reagents being able to convert natural radical oxidizing aids in less damaging forms is imperative.

During the treatment fluid was additionally tuned to reduce frictional losses in tubing by compensating effect of proppant on the rate of crosslinking components diffusion. And treatment design was modified to address increased efficiency of the fluid caused by filter-cake enhancement by delayed alkali.

The study showed availability of approaches which allow to implement high TDS water sources for preparation of borate crosslinked fluids confirmed by successful field implementation. These practices can be widely used in industry for performing multi-stage fracturing treatments in areas with lack of fresh water sources and to shorten water preparation cycle time.
Intensive Fracture Cluster Completion Strategy using Microemulsion Flowback Technology in a Daqing Tight Oil Field Application: Case Study
Authors: Yang Xiaoling , Qiu Bilan , Qi Dunke , Lv Deqing , He Jian , Zhou Shubo , Wang Zichao , Han Rong
Published: September 2020

A case study is presented discussing a specific completion strategy applied in the Daqing oil field, Block Long26, and the outskirts of tight oil wells. An alternative fracture completion method and enhanced flowback technology were used to develop these tight oil fields. The methodology applied resulted in improved efficiency of the fracture completion strategy and post-stimulation flowback, which reduced operational time and related costs. Optimized fracture cluster spacing length was determined based on the operational time efficiency and engineered fracture completion design. Laboratory testing was performed to select fluid recipes, and field trials were performed for the correlated custom-made microemulsion technology, which enhanced post-fracture flowback to shorten operational time and increase the return on investment ratio and production. Field results and post-fracture completion production are promising.

Several post-fracture completion production surveys have been applied in the Daqing field, Block Long26. The most popular completion strategy applied in this field involves using less than three perforation clusters in each fracture stage, applied using multiple, horizontal fracture stages, with longer and (normally) much greater fracture spacing length, thus requiring less fracture cluster treatments along the horizontal laterals. After stimulation, normally, additional days are necessary to observe the oil drop showing; thus, alternative flowback technology is necessary to enhance post-stimulation flowback to help improve the return on investment ratio.

Limited entry fracture and/or extreme limited entry fracture technology were part of the intensive fracture cluster completion strategy to benefit fracture completion and production. Field operations involved doubling the current perforation and fracture clusters in one fracture stage. Laboratory methods were used to select the appropriate mircoemulsion additives to form a fracturing fluid recipe to aid oil production and enhance flowback.
Application of Oscillation Rheology Method to Studying Fracturing Fluids
Authors: Hiliazitdzinau Tsimur Donalovich , Valenkov Andrei Mikhailovich , Kazak Maksim Vasilyevich , Panin Sergey Igorevich
Published: September 2020

In this paper, rheological properties of fracturing fluid samples on polymer and non-polymer basis are studied. The interdependence between effective viscosity, viscoelastic properties and the proppant carrying capacity of the studied composite systems is shown. The advantage of using the method of oscillatory rheometry in the amplitude sweep mode when predicting the sedimentation rate of proppant is observed. The possibility of using this method to study viscoelastic properties of fracturing fluids,both on the basis of classical and alternative gelling agents, was experimentally confirmed.
Large-Scale Experiments on Slug-Length Evolution in Long Pipes
Authors: Kjølaas Jørn , Unander Tor Erling , Wolden Marita , Schümann Heiner , Leinan Paul Roger , Smith Ivar Eskerud , Shmueli Andrea
Published: September 2020

We present a unique set of two- and three-phase slug-flow experiments conducted in a 766-m-long, 8-in. pipe at 45-bara pressure, using Exxsol™ D60 fluid (ExxonMobil Chemical, Houston, Texas, USA) as the oil phase and nitrogen as the gas phase. The first one-half of the pipe was horizontal, while the second one-half was inclined by 0.5°. A total of 10 narrow-beam gamma densitometers were mounted on the pipe to study flow evolution, and in particular slug-length development.

The results show that the mean slug length initially increases with the distance from the inlet, but this increase slows down, and the mean slug length typically reaches a value between 20 and 50 diameters at the outlet. At low mixture velocities (<3 m/s), the slug-length distributions tend to be extremely wide, sometimes with standard deviations approaching 100%. The longest slugs that we observed were more than 250 pipe diameters (50 m). At higher mixture velocities (>3 m/s), the slug-length distributions are in general narrower. The effect of the water cut (WC) on the slug-length distribution is significant but complex, and it is difficult to establish any general trends regarding this relationship. Finally, it was observed that slug flow often requires a very long distance to develop. Specifically, in most of the slug-flow experiments, the flow regime 57 m downstream of the start of the horizontal section was not slug flow.
Single-Stage Stimulation of Anhydrite-Rich Carbonate Rocks Using Chelating Agent: An Experimental and Modeling Investigation
Authors: Mahmoud Mohamed , Kamal Muhammad Shahzad , Aljawad Murtada Saleh , Ali Abdulwahab , Al-Nakhli Ayman
Published: September 2020

Calcium sulfate (anhydrite) exists in most of the carbonate reservoirs, and its content can reach more than 20%. The high content of anhydrite affects the efficiency of the acidizing process because of the low solubility of calcium sulfate in different acids. Carbonate stimulation, matrix acidizing, or acid fracturing is carried out mostly using hydrochloric acid (HCl)-based fluids. The solubility of calcium sulfate in HCl or HCl-based fluids and organic acids is very low.

In this study, a new formulation was developed to stimulate carbonate rocks with high anhydrite content. A formulation was developed to dissolve both anhydrite and carbonate at the same time. Anhydrite dissolution was achieved by converting anhydrite to calcite using the newly developed formulation. This treatment can be conducted in a single stage, and the formulation consists of a high pH chelating agent such as ethylenediaminetetraacetic acid (EDTA) in addition to potassium carbonate as a converter. Coreflooding experiments were conducted for carbonate rocks with varying anhydrite content. The effluent samples of the coreflooding experiments were analyzed for cations and anions concentration using inductively coupled (IC) and inductively coupled plasma (ICP) measurements. Computed tomography scans were conducted to show the wormholes generated in the samples. Rock mineralogical analysis using X-ray diffraction, thin section, and the QEMSCAN® automated mineralogy solution (FEI Company, Hillsboro, Oregon, USA) was conducted as well. The reaction kinetics were investigated using a rotating disk apparatus (RDA) using a disk that consists of almost 24% anhydrite and 71% dolomite. Also, a two-scale continuum model was built to simulate the reaction between the new formulation and carbonate rocks. The model could capture the experimental outcomes such as the number of pore volumes (PV) to break through and the shape of the wormholes. This provided confidence in the reaction parameters obtained because the model could reproduce the experimental outcomes.

Coreflooding experiments showed that the new formulations were very effective in stimulating carbonate rocks with high anhydrite content in a single stage. The effluent analysis showed high sulfate concentration that indicates the dissolution of anhydrite compared to conventional acid treatments. Reaction kinetics results showed that the new formulation increased the reaction rate with anhydrite through a mass transfer reaction regime. The model reproduced the wormholing behavior obtained from the experiments, indicating that the branched wormhole was due to the anhydrite conversion.