bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of Unconventional Gas Reservoirs Development by Horizontal Wells with Multiple Hydraulic Fracturing
Authors: Shandrygin Alexander
Published: October 2019

Currently, there is only one realizable technology for development of gas shale and tight gas formations which is based on the applying of the horizontal well systems with multi-stage hydraulic fracturing. The efficiency of shale and tight gas production using this technology in a complex manner depends on some parameters of the wells design, among which, first of all, it is necessary to note: wellbore length, half-length of hydraulic fracture and number of hydraulic fracturing stages. Gas production indicators from shale and tigth formations also significantly depend on the wells grid density. In this paper, we studied the influence of these factors on the shale gas and tight gas production from reservoirs with different permeability. Also, we present the approach to determine the optimal values of wells parameters and the wells grid density
Hydrocarbon Saturation for an Unconventional Reservoir in Details
Authors: Mukhina Elena , Askarova Aysylu , Kalacheva Daria , Leushina Evgenia , Kozlova Elena , Cheremisin Alexander , Morozov Nikita , Dvoretskaya Ekaterina , Demo Vladimir , Cheremisin Alexey
Published: October 2019

The present study is focused on quantitative determination of various groups of organic matter (OM) within an unconventional hydrocarbon (HC) reservoir. The influence of the initial distribution of organic matter groups on reservoir simulation results was estimated in frames of the present research. The results of thermal enhanced oil recovery (EOR) simulation were studied, in particular. The target object of the current research is a field sector around a well, which is related to a deposit of the Western Siberia part of Bazhenov formation.

The organic matter of Bazhenov formation was proposed to be divided in a few groups according to the following criteria. The relation with mineral rock matrix: hydrocarbons in open connected pores (mobile oil); hydrocarbons associated with the rock, or "bonded" HC (BHC); kerogen (solid organic matter) and heavy products of its transformation. The "bonded" hydrocarbons are adsorbed and concentrated in isolated or weakly connected pores and cavities within the organic-mineral matrix. These 3 groups were divided according to a molecular weight of hydrocarbons within the group. The mass and volume content of each group in core samples of Bazhenov formation were studied experimentally.

The evaluated group-model of organic matter within a target object was imported in a thermohydrodynamic simulation (thermo-HDS) as a matrix of initial components distribution. The efficiency of thermal EOR (hot water huff and puff injection) for the target object within Bazhenov formation was estimated with a numerical simulation using various OM saturation matrices. The main research goal was to determine the influence of specification of input parameters on the cumulative oil production.

The result of the study is the conclusion about the influence of the specification of distribution of OM groups on the results of HDS calculations and efficiency of thermal EOR. A new method of a detailed OM distribution for hydrodynamic simulation was proposed. A detailed group-model of OM might improve predictions of thermal EOR numerical simulation for unconventional reservoirs.
Experience in the Use of Horizontal Wells of Various Designs for the Development of Hard-to-Recover Oil Reserves in LLC Lukoil – Western Siberia
Authors: Lozanovich Emil
Published: October 2019

Every year the resource base of the LUKOIL fields located in Western Siberia undergoes changes in the direction of increasing the share of reserves in the deposits with low permeability and more complex geological conditions of their development, the so-called hard-to-recover oil reserves (HRR). Such deposits are confined to the deposits of the Tyumen, Bazhenov, Abalak suites, as well as to low-permeability reservoirs of the Achimov strata and sediments of the yu1 formation. At the beginning of 2019, there are about 290 million tons of oil reserves (figure 1), and the accumulated production of them already exceeds 15 million tons of oil (figure 2).
Wag Design: Miscibility Challenge, Tools and Techniques for Analysis, Efficiency Assessment
Authors: Fedorov Konstantin , Pospelova Tatyana , Kobyashev Alexander , Guzhikov Pavel , Vasiliev Anton , Shevelev Alexander , Dmitriev Igor
Published: October 2019

WAG injection combines advantages of gas drive efficiency with mobility control and sweep enlargement due to simultaneous water-gas flow. A complex preliminary investigation is the basis of successful application of gases. Such investigation determines appropriate and available type of gas, attainability of miscible flood, technology of gas injection.

This paper combines modern achievements in theory and practice of gas application for EOR with new approaches for ternary phase and saturation diagram analysis, comparison of different gas injection technologies on saturation triangle and mobility control during WAG process. The proposed investigation workflow is presented on the example of real field in East Siberia.
Assessment of Efficiency of EOR/IOR Technologies Using Rate Transient Analysis
Authors: Iktissanov Valery , Sakhabutdinov Rifkhat , Bobb Irina
Published: October 2019

Oil industry knows dozens of hundreds of different EOR/IOR methods to improve reservoir recovery efficiency. Among today's priorities are assessment of various EOR/IOR and bottomhole treatment technologies and selection of the most effective ones that will meet the specific reservoir conditions.

For assessment of stimulation efficiency, different techniques can be used: decline curve analysis (DCA), production rates analysis before and after stimulation, analysis of reservoir properties in the near-wellbore zone and in the reservoir using pressure build-up (PUB) curves.

Each technique has advantages and disadvantages. Thus, comparison of production performance ignores bottomhole pressure changes before and after stimulation, pressure buildup curves are not infrequently of a rather low quality, DCA is based on empirical relationships liable to misinterpretation because of subjective estimate.

Devoid of these drawbacks is the rate transient analysis (RTA). The advantage of this method is that it makes allowance for change of production rates always occurring following stimulation. This is achieved through use of diffusion equations.

Practice has shown that RTA provides a comparative analysis of production rates and cumulative oil production through time, porosity and permeability before and after stimulation, being, thus, a comprehensive tool for efficiency evaluation. Variation in oil production is the most reliable parameter, because it accounts for changes in bottomhole pressure and water cut before and after stimulation. To determine this parameter, an algorithm based on the pressure drop change is offered. RTA allows production forecast by two scenarios, the scenario involving stimulation, and the scenario without any production enhancement operations with a view to assess cumulative incremental production.

In conclusion, it can be said that rate/pressure transient analysis allows assessment of efficiency of a large variety of EOR/IOR projects and a long-term production forecast. The offered approach may serve a good alternative to the decline curve analysis and comparison of production rates and PUB curves before and after stimulation.
Three Typical SAGD Horizontal Producer Temperature Modes and Enhanced Measures in Heterogeneous Super Heavy Oil Reservoir-A Case Study in FC Project of Xinjiang Oilfield
Authors: Xi Changfeng , Yang Zhi , Du Xuan , Zhou You , Shi Lanxiang , Sang Linxiang , Li Xiuluan , Ma Desheng
Published: October 2019

Steam assisted gravity drainage (SAGD) technology by dual-parallel horizontal wells is matured commercial technology. In China SAGD was used commercially from 2012, current SAGD production rate is 17,000bbl/d. However, because of reservoir heterogeneity the production performance is not expected, oil rate per well is low, steam oil ratio (SOR) is higher. FC project in Xinjiang Oilfield has been operated for 6 years since 2012, however, the expected oil rate and SOR are still not gained. By analyzing various data about 168 dual-horizontal well patterns, three typical SAGD horizontal producer temperature modes are put forward. They are basically uniform mode (Type I), heel section tending to steam breakthrough mode (Type II), toe section non-start-up mode (Type III) respectively. Different temperature modes represent different recovery and producing characteristics, appropriated enhanced measures should be put forward. Basic uniform mode is 27% (45 well patterns), its characteristic is the temperature difference along the horizontal producer is about 30℃ and the whole well section is utilized basically. Heel section tending to steam breakthrough mode is 47% (79 well patterns), the temperature of heel section is 80℃ higher than that of toe section. There are hotspots near heel section, and steam is easy to break into producer in heel section. Liquid production intensity (t/d/m) of heel section is 5-10 times lower than that of toe section. Toe section non-start-up mode is 26% (44 well patterns), the temperature difference is more than 100℃ along horizontal producer, toe section cannot be start up efficiently.

Different enhanced measures have been applied to these three types. For Type I, sub-cool is lowed from 30-40℃ to 8-15℃ to increase liquid production intensity, then the oil production and SOR are enhanced. For Type II, an appropriated length electric heater is placed in the toe section to increase its temperature and narrow temperature gap between heel and toe section. Liquid production intensity of toe section is increased by this measure. For Type III, assisted vertical injector wells are used to utilize the toe section and make the steam chamber develop uniformly in toe section.
Potential Benefits of Fluid Optimization for Combined Smart-Water and Polymer Flooding: Impact on Remaining Oil Saturation
Authors: Tahir Muhammad , Hincapie Rafael E. , Foedisch Hendrik , Strobel Gion-Joèl , Ganzer Leonhard
Published: October 2019

Design of Smart-Water can be economically attractive owing the presence of excessive water resources (seawater). This paper aims to design Smart-Water in order to analyze its impact on remaining oil saturation reduction and hence improved oil recovery. Moreover, this study evaluates and define the synergies and benefits between high salt smart water and polymer flooding. The paper combines an extensive rheological characterization and core-flooding experiments; performing fluid optimization (change in brine composition and polymer concentration).

Synthetic seawater (SSW) is used as the base brine. Optimization is perform by adding/removing specific chemical components in the SSW. Overall, five brines are utilized: 1) SSW, 2) 2*SSW, 3) SSW with double sulphates 3) SSW with quadruple sulphates and 5) SSW without NaCl. Brine 1 and 2 are used as the formation brines, whereas brine 3 to 5 are used as the injection brines to analyze impact of SO4-2 and Na+1 on remaining oil saturation reduction. Secondary and tertiary-mode experiments are performed to evaluate the feasibility of applying Smart-Water injection and its synergies with polymer flood.

Smart water with spiked sulphates changed the interfacial tension compare to synthetic seawater. Henceforth smart water injection has contributed to extra oil recovery, resulting on a reduction of the remaining oil saturation due to the improved interfacial rheology and slightly higher IFT. Optimized Smart Water with spiked amount of sulphate has produced the highest oil recovery in secondary mode compared to other brines (in case of both formation brines). Furthermore, higher concentration of the divalent cations in formation brine and spiked amount of Na+1 in injected brine has resulted the significant decrease in remaining oil saturation (2*SSW as formation brine). Combination of smart water and polymer flood has shown significant reduction in remaining oil saturation. Polymer injection after smart water with spiked sulphates has contributed to significant extra oil recovery compare to the other brines owing to the combined effect of improved interfacial rheology and enhanced polymer viscoelasticity.
Water Alternating Gas Pilot Design and Results: Yaraktinskiy Field Eastern Siberia
Authors: Burdakov Dmitriy , Wolcott Donald
Published: October 2019

The article describes the design of water alternating gas (WAG) project and the results of implementation within a portion of the Yaraktinskiy field. The technical applicability of using WAG to increase oil recovery was justified from core flood and slim tube experiments in conjunction with PVT fluid studies. The equation of state was tuned to the PVT data and slim tube experiments. Fully compositional modeling was used to generate type curves that demonstrated additional recovery from the WAG process. A systematic criterion was developed to identify and rank the best patterns for WAG response and therefore identify the optimal pilot area. For flood management performance ratios and efficiency criteria were defined.

Pilot response has provided additional recovery, indicating mobilization of previously immobile oil. History matching the pilot response has improved the model and this has been used to justify further scaling of the process to more areas of the field. As well, the model is now used to establish requirements for piping, compressor and other surface upgrades.
Step-Up Concentration Method for Chemical Agents’ Adsorption Measurement in Porous Media
Authors: Lompik Vasilii , Dadakin Nikita , Nukhaev Marat , Rymarenko Konstantin , Makatrov Artem , Zaynullin Ildus , Bikmeev Denis
Published: October 2019

Before implementing any chemical enhanced oil recovery project at the field, it is very important to carry out a feasibility study, which is impossible without determining their effectiveness under laboratory conditions.

The task of laboratory research is to determine all the parameters of surfactant and polymer solutions, necessary for further analytical evaluation and reservoir simulation. It is necessary to conduct laboratory experiments to perform technical and economic assessment of the chemical EORs implementation. One of the most important issues here is to determine the amount of reagent held in the pore space of the reservoir.

The retention parameter determines how much reagent needs to be injected to achieve the required displacement efficiency. It directly affects reagent consumption and economic efficiency.

This paper discusses various methods for determining the amount of reagent retained in the reservoir; it can be surfactant species or a polymer. To solve the problem of reducing the time for the experimental part, an algorithm of an experiment was developed, which makes it possible to determine the retention parameters in a shorter time and with less labor. This method was tested and showed its effectiveness in the course of a technical and economic study on the possibility of implementing polymer flooding for a field in Eastern Siberia.

As a result of the experiments, the relationships between the surfactant or polymer retention and their concentration, and also between permeability and the amount of reagent adsorbed were found. The effect of salinity on the retention parameter was determined, the fact of desorption for both surfactants and polymers was revealed. Inaccessible pore volume for polymer was determined.
Screening In Situ Combustion Applicability for a Heavy Oil Candidate Reservoir with an Accelerating Rate Calorimeter
Authors: Fazlyeva R. R. , Mallory D. G. , Moore R. G. , Mehta S. A. , Cheremisin A. N.
Published: October 2019

Air injection has immense potential for hydrocarbon recovery from various reservoirs. One of the screening techniques which can be applied to evaluate a candidate oil for the air injection process is the accelerating rate calorimeter (ARC). The unique feature of this instrument is that it can provide adiabatic conditions and handle experiments at high pressures. This paper reviews four tests performed in closed and flowing ARCs to fingerprint and observe the thermal behavior of a crude oil. The crude oil used for this study is characterized as a 19.3°API and viscosity of 710 mPa.s at 21°C. The oxidation experiments were performed under two scenarios of oil-only and oil in the presence of native carbonate core. Initial starting conditions of each test were at a temperature of 23°C and a reservoir pressure of 13.8 MPa. Flowing ARC experiments showed that Low-Temperature Oxidation occurs at a temperature of about 150°C, whereas ignition occurs at about 350°C when High-Temperature Oxidation region was dominant. However, when using the closed ARC, the thermal behavior of the studied oil appeared to have different temperature characteristics, and the onset of the maximum self-heat rate occurred at temperature of 288°C. The effect of the vapor phase combustion as well as the calculation of kinetic parameters are also discussed in this work.
Micro-Displacement Mechanism of Divalent Cations Activated Polymer Flooding In A Complex Conglomerate
Authors: Liu Rui , Pu Wanfen , Ushakova Alexandra , Ren Hao , Du Daijun , Luo Qiang , Gou Rui , Luan Huoxin
Published: October 2019

The conglomerate reservoirs of south block Qidong, Xinjiang Oilfield, NW China are one of the largest conglomerate reservoirs worldwide and have employed polymer-based chemical flooding pilot tests since 2016. But the output is less than 10% due to the harsh divalent cations concentration and the complex fluids distribution in microscale. It is important to design a novel divalent cations resistant polymer and then to elucidate its micro-reserve displacement mechanism in a complex conglomerate. A novel core-shell like polymer (CSPAM) composes of nanosilica as the core and polyoxyethylene modified polymeric chains as the shell is synthesized via a facile method. The thickening performance of CSPAM activated by divalent cations is explained using advanced rheometer and scanning electron microscope. A visual conglomerate lamination model combined nuclear magnetic resonance online experiments are conducted to investigate the micro-unrecovered oil displacement mechanism of CSPAM flooding: the distribution of micro-remaining and micro-residual oil after the earlier waterflooding are quantified; latter, the reserve utilization and displacement behavior of CSPAM flooding on the pore space scale are characterized. Within the Ca2+/Mg2+ concentration of 12000 mg/L, the electrostatic bridging between Ca2+/Mg2+ and ethyoxyl groups of CSPAM induces an interlacing transient-network, which activates a tenfold increase of viscosity and of longest relaxation time compared to these of CSPAM solution without adding salt. The conglomerate rock shows a complex pore-and-throat structure, resulting in severe heterogeneity and rapid water cut. The oil recovery by the earlier waterflooding is approximately 35% of OOIP (original oil in place), and the cluster of remaining oil in a disconnected state and oil resident in blinds pores occupies a major proportion of unrecovered oil. Significant reduction of oil saturation is achieved by CSPAM solution at low concentration of 1000 mg/L in harsh brine. Approximately 28% of incremental oil recovery factor with cumulative oil recovery higher than 63% OOIP is achieved by 0.5 pore volume of CSPAM flooding and chase waterflooding. The reserve utilization of CSPAM is 23.1% for large pore spaces, 13.2% for intermediate pore spaces, 11.6% for confined pore spaces, and 5.67% for minimum pore spaces, respectively. This research constructs a novel water-soluble polymer CSPAM with divalent cations activating viscosification, and elucidates the micro-displacement mechanism of CSPAM through quantifying the remaining oil and residual oil distribution, and reserve utilization of CSPAM on the pore spaces scale. The results will provide the substance and technique supports for future application in harsh salinity and complex pore structure conglomerate reservoirs.
Modeling Gelation Time of Organically Crosslinked Polyacrylamide Gel System for Conformance Control Applications
Authors: Al-Anazi Amer , Al-Kaidar Ziyad , Wang Jinxun
Published: October 2019

Gel-based conformance control has been successfully applied in both sandstone and carbonate reservoirs. However, deep conformance-control in high-temperature reservoirs is still a challenge due to fast gelation. Gelation time depends on several factors. Successful modeling of the different parameters’ effects on gelation time is invaluable for formulation optimization to realize sufficient gelation-time for deep-diversion. In this work, a laboratory study was conducted to investigate and model gelation-time for organically-crosslinked Polyacrylamide formulations.

Sulfonated polyacrylamides with different molecular weights were used. The solutions were organically crosslinked using a polyethylenemine (PEI). The effects of different factors including temperature, brine salinity, pH, and polymer and cross-linker concentrations on gelation time were investigated using bottle tests and rheological measurements. For bottle tests, the solutions are prepared and aged in an oven. The vials are then retrieved and visually examined for gelation before being returned to the oven. For rheological measurement, dedicated solutions are prepared in separate vials and aged in the oven. Each vial is then retrieved where the solutions viscous and elastic moduli are measured.

The results indicate that polyacrylamide/PEI gel exhibits good thermal stability and gelation time reaches up to two and a half days at 95°C. The gelation time decreases with increasing temperature, polymer molecular weight, and polymer and crosslinker concentrations. However, there were lower limits for the polymer and crosslinker concentrations below which gels were not observed. Brine salinity and pH showed a wide range of effects on gelation time. Gelation time slightly increases with increasing the solution salinity at a fixed pH of around 8.0. A mathematical model was developed based on the experimental results to capture the effects of the main parameters. The predictable equation of gelation time was constructed using multivariable regression method, and the model successfully predicts the gelation time of the conformance control system at a fixed pH value of around 8.0. The good agreement is illustrated by the R-square value being around 98%. Furthermore, the model shows that temperature posses the highest impact on gelation time followed by the crosslinker concentration and brine salinity.

The developed mathematical model can be used to predict the gelation time of a polyacrylamide-PEI gel system. In addition, it can be utilized to optimize a given gel design and further validate the applicability of a given polymer/crosslinker formulation for deep fluid diversion application.
Development of Low-Permeability Reservoirs by Increasing the Mobility of Water in a Porous Medium Using a Chemical Reagent - Super Fluid Water SFW
Authors: Zatsepin Vladislav , Gubaidullin Farid , Ushakova Alexandra , Miftakhov Salavat
Published: October 2019

The considered "Super Fluid Water" (SFW) is developed aqueous solution of polyelectrolytes with extra low concentration. The aim of the present work is laboratory investigations and field studies of the water with reagent flow in porous media. Change in hydrodynamics of water flow – the mobility increase was observed for the SFW additives.

Filtration studies of changes in the value of the residual resistance factor for core samples with different permeability were carried out. The conducting field tests were held using standard techniques and methods of field geological and geophysical studies. Temperature and profile logging were performed at different flow rates, with water and water with SFW injection (SWF concentration up to 1%).

Laboratory studies have shown that the value of the residual resistance factor is lower than the value of the absolute permeability of the core sample, and the dependence is approximated by the power function. The established laboratory dependence confirmed the possibility of using the SFW reagent for conformance control in injection wells, which determined the goals and objectives of field studies.

The field studies were performed (we provide the information about the success treatments of 4 injection wells, no information about the unsuccessful treatments) and showed that the use of the reagent SFW leads to a dramatic increase of the injection capacity of the wells (210% and more).

Estimation of the injection capacity profile before and after the use of SFW reagent showed the extension of operating intervals by including of extra low permeable layers (less than 1-2 mD) not previously drained by water.

At the same time, the efficiency of SFW technology in these conditions is estimated to be higher than the technologies associated with gas injection into the reservoir.

The achieved results allow us to assert the prospects of using SFW technology for the development of low-permeable reservoirs. The employment of this technology in the practice of oil recovery engineering will increase the efficiency of field development and oil recovery by 15-20%.
Drilling Extended Reach Well with Eight Fishbone Sidetracks: East Messoyakha Field
Authors: Akhmetov Marsel , Maximov Maxim , Lymarev Maxim , Malyshev Yevgeny , Vasilyev Roman , Glushenko Nikolay , Rakhmangulov Farit , Frolov Denis
Published: October 2019

This article describes an experience drilling a multilateral "fishbone" well with eight sidetracks and contains geological substantiation of this technology from the production-increase point of view as well as actual results of the eight-lateral well start up and operation. For fishbone wells where each wellbore is a sidetrack from the previous hole, one of the fundamental drilling aspects is kickoff from the parent wellbore.

This article is based on the analysis of 114 kickoffs in production wells of the East Messoyakha field where kickoffs with a rotary steerable system (RSS) and performance drilling motor (PDM) were determined beneficial. Additionally, strength analysis and hydraulic calculations for drilling of the longest fishbone at the East Messoyakha field with an extended reach drilling (ERD) factor of 2.95 are discussed. Further, this article highlights the main potential of this technology development and its limitations during a further massive application.
Automatic Drilling Fluid Measurements
Authors: Taugbøl Knut , Brevik Jan Ove , Rudshaug Bjørn
Published: October 2019

The drilling fluid properties are critical for drilling parameters such as ECD (equivalent circulating density), surge and swab pressures and hole cleaning properties. To be able to optimize drilling parameters and improve drilling efficiency also the drilling fluid must be at optimum specifications.

To have a more proactive fluid engineering where the drilling fluid at all times is as desired continuous measurements of drilling fluid properties are necessary. This paper will present the development of new equipment for offshore use for automatic viscosity and density measurements. The paper will discuss the technology in use, the implementation and qualification into harsh offshore environment as well as the resulting data obtained, transformed into digital data received at onshore operation centers.

The measurements of drilling fluids properties and chemical compositions have been more or less unchanged for decades. The tests in use are manual and performed by the mud engineer normally four times a day. Based on these tests the fluid properties are engineered within given set points of selected parameters. This limited number of tests will often drive the fluid engineering into a reactive mode, where fluid properties must be adjusted due to drift in measured values.

In this paper the experiences from introducing continuous measurements of drilling fluids density and rheology will be presented. Automatic measurements have been introduced by an operator on several offshore installations, both semi-submersible drilling rigs as well as jack-ups and fixed platforms. The use of the data in the fluid engineering process as well as in the drilling process will be discussed.

Drilling Fluid parameters can now be measured automatically on the rig. The fluid properties can then be monitored from operation centers 24/7.This ensure improved quality of drilling fluid. When this is performed in combination with online hydraulic calculations improved drilling performance is obtained.
Multilateral Wells With 3-String Casing Design as the Next Stage of Drilling Technology
Authors: Sirotin Denis , Mukhametzyanov Ildar , Grunov Ilya , Teregulov Oleg , Sunarchin Marat
Published: October 2019

Continous improvement of technology and operating procedures is a key to the oil and gas industry. One of the ultimate goals of such improvement is to reduce drilling time and, consequently, save well construction costs. Drilling multilaterals in one run, using rotary steerable systems (without pulling out of hole for changing BHA for kick-off proceduce) has become the first step change enabling shorter drilling cycles.

In 2018, a project was designed to drill both horizontal and transport sections of a multilateral well in one run. According to this methodology, one 146mm casing is run instead of two: 178 mm and 114 mm casings. In case of succefull implelemtation, this project will reduce well construction time by more than 15 days.
The Results of Research and Development Project: Mobile Driller. Immediate Provision of Information to The Employees at a Drilling Site
Authors: Andreev Anton , Zimoglyad Mikhail , Gorbunov Aleksei , Sharipov Rafael , Nagovitsin Vladimir , Chuikov Vitalii , Kugatov Petr , Stelmashuk Anton , Abaltusov Nikolay
Published: October 2019

«Mobile Driller» is a part of «Digital Drilling» IT Project aimed at developing and implementing IT solutions, which make it possible to plan, assess and analyze the operations in the process of well construction and response to deviations in real time.

The main target of "Mobile Driller" Project is to find the solutions for immediate provision of the drilling rig employees with information. The project implementation resulted in a set of technologies (audio, video equipment, warning panels, etc.) for operation under real climate conditions of Far North and a completed prototype of the system for informing the employees.

The market of the available hardware solution models was analyzed to develop a set of technologies. The possibility to use in the areas of explosive hazardous atmosphere was taken into account when selecting the models.

The selected equipment package was assembled and tested at a drilling site in Novoportovskoye oil-gas condensate field.

The testing was conducted at temperatures from −39°C to +24°C;

Thirteen equipment usage algorithms were implemented for four types of the employees: supervisor, toolpusher, driller and driller's assistant.

The feedbacks from the users were recorded by means of check-lists and individual interviews.

The list of recommendations was drawn up based on the testing results.

The following results were obtained in the process of the Research and Development Project implementation:

The algorithms were developed to inform drilling rig employees about current status of implementation and changes of a drilling plan, upcoming operations, performance indicators, revealed deviations and critical situations; The optimal means for warning/informing the employees were selected: videowalls, smartphones, tablet computers, fitness bands, visual signal devices, hard buttons, wired and wireless headsets, AR/VR devices; the prototype of the system was developed to control all the devices and implement information provision algorithms.

The tests at the drilling site of Novoportovskoye oil-gas condensate field revealed that the equipment was operating consistently under real climate conditions, which include low temperatures (below −40° C) and precipitation.

The drilling rig employees evaluated every algorithm and equipment. Based on the evaluation results it was determined that the system allows to effectively communicate the information to the employee thereby reducing the information delivery time and improving the response rate.

Based on the project implementation results the objective information about possibilities to use the information provision system under Far North conditions was obtained. Due to "Mobile Driller" the employees are immediately informed about upcoming operations, performance indicators and revealed deviations.
Case study: Saving Days via Change of Connection Practices While Drilling
Authors: Ruzhnikov Alexey
Published: October 2019

One of the most common operations while drilling is the connection of drill pipes after every stand drilled. The main concern during this operation is to ensure that annulus around the BHA and drill string is clean of any cuttings, when often excessive time spent to achieve it. This manuscript discusses modeling, field implementation and operational observations of changing the standard practices, what led to significant time reduction while drilling vertical, deviated and extended reach (ERD) wells.

The most common worldwide practice is to wash / ream a stand up and down prior to connection to remove any potential cuttings around BHA. Having this in mind the objective was set to minimize this time as much as possible towards full elimination. To accurately predict the cuttings lifting forces, annulus cleanliness, hook load fluctuations advanced modeling combining torque, drag and hydraulics was developed. The model considers all the key parameters such as drilling fluid density and rheology, BHA configuration, pumping rates, wellbore geometry, temperature and pressure effects, etc. and can estimate the time required to spend at the end of every stand.

A total of up to one hundred jobs were simulated and followed by the field implementation in the different sections, which were ranged by bit size (from 17-in. to 6-in.), inclination and complexity (from zero to 90 degrees, including ERD wells) as well as other affecting parameters such as losses, wellbore stability etc. The data from the initial wells were crosschecked vs available MWD/LWD data (as equivalent circulating density, annulus pressure while drilling, temperature etc.) to confirm the results of the simulations.

As a result, new connection practices were developed with minimum clean out time prior to a connection. Two examples: in the vertical wells the pre-connection time was reduced almost to zero and only one-minute drill-off now done; in deviated wells including ERD a standard approach of washing up/reaming-down a stand was replaced to 2 − 3 minutes drill-off. Together with other changes it not only allowed the decrease a connection time by up to 90% without the negative incidents like stuck pipe, but also minimized impact on the bottom hole assembly (BHA) components happening due to off bottom stick / slip. This resulted in great time savings, where over 2 days can be saved for 20,000 ft wells vs standard practices.

The manuscript describes an engineering-based approach to connection practices which allows to shorten well construction time and decrease the well cost without additional risk.
Basic Principles of Gazprom Neft'S Modular Strategy for Field Infrastructure Development
Authors: Atnagulov Albert , Panov Roman , Khasanov Mars , Batrashkin Valery , Sugaipov Denis , Ismagilov Rinat
Published: October 2019

Today, complex projects with a high degree of uncertainty relating to the reserves and geology increasingly dominate the portfolios of promising assets of oil producers. Successful development of such oil deposits requires novel approaches. One of these approaches suggests using modular technologies for field infrastructure development purposes that secure effective performance in the face of geological and production uncertainties. The article offers a summary of the basic principles of modular strategy that have been developed and deployed by Gazprom Neft.
Application Rationale of Well Flow Test Complex Modules Covering Well Shut-in at the Bottomhole in terms of Eastern Siberia Carbonate Reservoirs Study
Authors: Arbatsky Timur , Shchurenko Alexander , Dadakin Nikita , Nukhayev Marat , Yamalov Ilnur , Rymarenko Konstantin
Published: October 2019

The paper presents the experience of oil and gas exploration in the fields of the Irkutsk region. The geological features of the studied facilities dictate a practical approach and the use of compact and efficient technological solutions that can later be successfully applied to a large number of fields with similar geology. The paper highlighted an optimized complex of works on the development and testing of wells target objects in a cased wellbore, using the technology of "the well shut-off at the bottomhole".

This arrangement ensures the effective implementation of work on the development of target objects and allows for high-quality registration of the bottomhole pressure dynamics. This engineering solution allows to perform a full cycle of hydrodynamical studies of well (well test) for a target interval in a relatively short time. The use of a tube bank significantly reduces the wellbore storage eand allows to obtain detailed data reliably characterizing reservoir properties and the structure of the reservoir under study.

The article describes the technology of hydrodynamic studies, with the well shut-off at the bottomhole. The article deals with the research problems of highly productive, flowing facilities, with a concrete example and a detailed analysis of technological features, interpretation options, possible complications and measures for optimization. The possibility of replicating technology in various geological and technical conditions is considered.
Involvement in the Development of Undeveloped Areas in Mature Fields
Authors: Asmandiyarov Rustam , Staritsyn Maksim , Zulkarniev Rustem , Studinsky Roman , Vorobyov Dmitry
Published: October 2019

Most of the Russian fields have entered their final stage of development; however, they contain a large amount of remaining recoverable reserves accumulated in unworked areas.

To involve the unworked areas, a selection method has been developed to select wells for in-fill drilling.

The method includes the following main stages: Identify the areas with remaining recoverable reserves; select the least depleted areas; place in-fill wells; assess geological and development risks; calculate potential production rates; develop rating and carry out expert assessment.

The method has been tested on other Brownfields, i.e., - Vyngapurovskoe, Sutorminskoe, Vyngayakhinskoe, Sugmutskoe, Kholmogorskoe, Yety-Purovskoe, Vostochno-Pyakutinskoe and Romanovskoe. Based on the estimated production rates of the wells and geology and development risks, as well as the reserves being involved, a through rating of the wells has been prepared for infill drilling. Expert assessment has identified 265 wells for top priority drilling based on their potential production rates.

A well with smaller-diameter pay string has been designed to reduce construction costs and make the involvement of unworked areas more efficient.

Pilot project starts in June 2019 on Vyngapurovskoe BV8/1 target to drill the first three small-diameter in-fill wells from well cluster No. A. Should the pilot be successful, the technology roll-out on first-train wells only will enable us involve over 8.1 million tons of recoverable oil reserves into development.
Practical Application of Flow Diversion Techniques for Development of Fractured Carbonate Reservoirs
Authors: Chorniy Alexey , Khodakov Ilya , Popov Dmitriy , Tkachev Ivan , Sadreev Ernest , Makarshin Sergey , Petrakov Andrey , Rogova Tatiana , Churanova Nina , Kubrak Mikhail , Kurelenkov Sergey , Pham Khac Dat , Ponomarenko Denis
Published: October 2019

Currently the flow diversion techniques (FDT) are quite often used to enhance the waterflooding efficiency at the late stage of field development. In particular, the issue of waterflooding efficiency improvement is specifically acute for the carbonate reservoirs due to complex structure of the reservoir, heterogeneity of reservoir properties as well as the presence of natural fractures. All listed factors result in significant decrease of waterflooding efficiency due to quick water breakthrough into the wells through the low flow resistance channels (LFR) which results in significant decrease of the oil recovery factor (RF). In many cases waterflooding at the similar fields is not applied at all resulting in the produced water disposal issue.

It is evident that for the purpose of solving such issues application of FDT based on the injection of various polymer gel-forming compounds into the formation allowing decrease in conductivity of LFR channels resulting in increase of swept reservoir volume may seem efficient. Considering the development of chemical industry, the FDT market currently offers a lot of compositions and compounds in a wide price range having different technological characteristics and designed for different conditions. Due to this the selection of the most appropriate compositions with account of all factors is an acute task requiring thorough approach with application of often unique laboratory experiments using unconventional equipment as well as performance of pilot works at individual field areas.

This paper presents the sequence of actions (from laboratory studies for the determination of the suitable polymer compositions to the selection of the specific field areas for the pilot works performance) for complete justification of FDT application at one of the Central Khoreyver Uplift fields located in the Timano-Pechora oil and gas province. Apart from presence of the heterogeneous and fractures carbonate reservoir, the field is characterized by high mineral content of the formation water what imposes significant restriction on the use of a number of polymer compositions as well as requires more thorough approach to the selection thereof. The paper also describes the flow experiments held, inter alia, using the actual core samples with use of high-mineralized formation water and shows their results. As a part of this work the justification of injection of two polymer compositions selected after laboratory studies at 2 pilot areas with assessment of incremental production using the simulation model (SM) developed with the account of the annual tracer studies allowing assessing LFR channels properties was carried out. As a result of the performed work, 2 pilot polymer compositions injection works were included into the company's business plan for 2019.
Iterative Approach in Obtaining the Most Reliable Geological Realization for Reservoir Simulation Runs: Yamal-Nenets Autonomous District Gas Field Case Study
Authors: Zunde Dmitry , Gorlanov Aleksey , Shalamov Ilya , Davletshin Anton , Belyansky Victor , Loznuk Oleg , Zakrevsky Konstantin , Abrashov Vadim
Published: October 2019

Existing approaches to the creation of hydrodynamic model based on a single implementation of the geological model, lead to difficulties in adaptation – there is a need for additional artificial adjustments of the initial data, and, as a consequence, inaccurate assessment of the projected technological parameters of the development. In order to make balanced investment decisions on the development of deposits, it is necessary to take a comprehensive approach to the assessment of possible uncertainties. To solve this problem, the iterative modeling approach is used, which provides a comprehensive assessment of possible variants of geological and technological models and allows you to vary the parameters of the model to assess uncertainty and risks in the calculation process.

The article describes the process of creating and selecting the most likely implementation of the geological model of the PK1 formation, providing the best adaptation to the history of development and minimal uncertainty in the prediction of technological parameters for the medium and long term. Implementations of the model include variations of the seismic base, distribution of the lithology parameter, filtration-capacitance properties of non-collectors, the volume of the aquifer and its activity. In the process of work at the first stage, the basic implementation of the geological model was created, at the second stage of them on the basis of the developed complex parameter characterizing the degree of adaptation of the hydrodynamic model, the most probable was chosen.
Geomechanical Considerations when Planning SAGD Wells, a Case Study from Cuba
Authors: Chettykbayeva Kamilla , Ibragimova Margarita , Osipov Andrey , Petrakov Yuriy , Sobolev Alexey , Tatur Olga
Published: October 2019

This article is the first part of the geomechanical calculations performed in order to optimize the drilling and production operations of the first horizontal wells with target formation M in the Boca de Jaruco field, Republic of Cuba. Here, the analyzed data included regional geology, tectonics and stratigraphy, different types of well logging, the pressure curves while steam operations, core samples and drilling history. The outcome of this part of the work is the assessment of the current stress regime, stress directions and the stability windows for the planned wells. Moreover, the program of additional studies and logs acquisition was elaborated, as at this stage there is not enough data to confidently quantify the stress state, the core samples are not yet tested for rock's deformation and strength properties, and it is hardly possible to find carbonate bitumen deposits under development anywhere in the world which are analogous to the Boca de Jaruco field (with the sole exception of Grosmont in Northern Alberta, Canada).

After the wells are drilled (presumably by the end of 2019) and the required information is collected (such as mechanical core testing under elevated temperatures, image logs in the deviated boreholes, etc.), the second part of the work is to be performed, which would include the analysis of the drilling results and the assessment of the cap rock behavior, pore pressure and porosity-permeability changes due to steam injection.
Experience of Gas Wells Development in Complex Carbonate Reservoirs in Different Stages of Development
Authors: Volkov Vladimir , Turapin Alexey , Ermilov Andrey , Vasyutkin Stanislav , Fomin Denis , Sorokina Anastasia
Published: October 2019

This paper describes practical experience of perforating of producing horizons under conditions that are incompatible for perforating for geological reasons, as well as methods of killing and developing wells with ALRP.