bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selection of Effective Solvents – Universal Modification of Presently Available Enhanced Oil Recovery Methods and Oil Production Stimulation Processes
Authors: Litvin Aleksandr Tarasovich , Terentiyev Aleksey Alekseyevich , Gornov Denis Anatolevich , Kozhin Vladimir Nikolaevich , Pchela Konstantin Vasiliyevich , Kireyev Ivan Ivanovich , Demin Sergei Valeriyevich , Nikitin Aleksandr Valeriyevich , Roschin Pavel Valeriyevich 
Published: September 2020

Abstract
The paper presents various modified technologies to enhance oil production and to stimulate the inflow of high-viscosity oil, based on a combination of the traditional approach and the use of solvents.
The results of laboratory experiments to study the effects of 29 solvents reagents on high-viscosity oil samples from 5 different objects are presented. Based on the analysis of the obtained laboratory data, basic recommendations are formulated to increase the efficiency of extraction of high-viscosity oil using solvents.
In order to determine the potential for modifying oil recovery enhancement and well stimulation methods by adding solvents to their process, a comparative hydrodynamic modeling of 3 treatment options for the bottom-hole zone and subsequent assessment of their economic effect were carried out.
The Application of Drilling Fluid System Based on Salt-Saturated Direct Emulsion in Construction of Wells on Yurubcheno-Tokhomskoye Field
Authors: Tikhonov Evgeny Vladimirovich , Korsunov Evgeny Ivanovich , Kovshov Nikolay Leonidovich , Semenikhin Igor Petrovich , Gassan Alexander Alexandrovich , Pogorelova Svetlana Petrovna , Kharitonov Andrey Borisovich , Zagrivny Fyodor Alexandrovich , Lemeshov Sergey Alexandrovich , Ganiev Denis Fakilevich 
Published: September 2020

Abstract
One of main drilling challenges in the Yurubcheno-Tokhomskoye field is fluid losses. In particular, the requirement of a drilling fluid with minimal mud weight to minimize risks associated with fluid losses when drilling overbalanced, enabling drilling through salt intervals. Historically, the technical column interval has been drilled using generic OBM using local crude oil. However, such fluids carried significant health and safety risks associated with low flashpoints.
Invert emulsion fluids, based on local crude oil as the continuous phase, are characterized by flashpoints of 6-8 °C, which does not address the safety concerns. Alternatively, a drilling fluid, designed based on a salt-saturated, continuous phase, direct emulsion, with up to 30 % local crude oil (as the internal phase) to achieve a mud weight 1.10 SG is characterized by a flash point higher than 100 °C. A flash point &gt;100 C enables significant minimization of these health and safety risks.
As well as improving the fluid flashpoint and avoiding related incidents, direct emulsion fluids can be formulated to present high long-term stability, a stable rheology profile, and superior filtration control.
Five 245 mm casing intervals were drilled to date using the direct emulsion and successfully set at targeted TDs. The solutions applied have assisted to achieve following KPIs:
15% less mud volume due to lower volume lost into the formation. 45% less crude oil used due to significantly lower oil content in the fluid. 15% less losses into the formation presumably due to low Pumps on ECD achieved. 50% less time associated with lost circulations.
These achievements resulted in a three-day reduction in the time of the interval construction (average of five wells drilled) compared to similar intervals drilled using generic invert emulsions.
This paper discusses the development and selection of a new, economical, safe, and efficient drilling fluid, for 245 mm casing intervals in the Yurubcheno-Tokhomskoye field. Supporting laboratory test results, fluid performance achieved, lessons learned and recommendations for further system optimization of the drilling fluid and drilling practices, are presented for consideration.
The positive KPIs and superior mud performance achieved enable expanding the use of the direct emulsion on the field and recommend its application to other fields in the area.
Positive Experience Using Foam Cementing Technology for Production Casing Cementing in the Volga-Ural Field
Authors: Fomenkov Aleksey , Pinigin Ilya , Velikiy Daniil , Denisov Ivan 
Published: September 2020

Summary
The largest discovery of oil and gas in recent years is situated in the Volga-Ural field in Orenburg Oblast. The field was discovered in 2005. The development target is the Devonian Dkt formation which is an aggregate of ancient strata in the Earth's crust that were formed during the Devonian Period of the Paleozoic Era. The Devonian System is divided into a Lower, Middle and Upper series. It consists of alternating layers of sandstone-claystones and siltstones, which have low permeability. Hydraulic fracturing is required to obtain hydrocarbon inflow from this type of rock.
The well design employed in the Volga-Ural field incorporates five casing strings and the main challenge while drilling wells in this field is lost circulation. This ranges from partial fluid loss to no returns and has a significant impact on the cementation of the 178/146 mm production casing. Lost circulation has resulted in a failure to achieve the targeted top of cement, annular pressure, annular crossflows and a poor cement bond with both the casing and formation. Prior to 2015, a stage cementing collar (SCC) technique was used to cement the production casing without losses. However, this cementing technique often resulted in poor zonal isolation resulting in water flows between zones. Additionally, after well completion, poor cement bonding to both the casing string and producing formation created a pathway for annular flow of the formation fluids. These challenges called for an alternate solution. This paper presents how foamed cementing technology was used to solve the challenges in isolation of the sandstones and the subsequent improvement of the cementing bond quality. The foam cementing technique was tested in the Volga-Ural field at the end of 2015 and in early 2016 and became the standard solution for cementing the 178/146 mm production.
Construction of Horizontal Wells on the Salmanovskoye Field: Challenges Encountered, Decisions and Measures Taken to Ensure Trouble-Free Drilling
Authors: Kabanov Alexander Viktorovich , Matsera Aleksander Mikhailovich , Galimkhanov Aydar Ramilevich , Rudenko Sergey Ivanovich , Tikhonov Evgeny Vladimirovich , Kharitonov Andrey Borisovich , Kruchenko Dmitry Viktorovich , Sokovnin Sergey Anatolyevich , Sidorov Dmitry Nikolaevich 
Published: September 2020

Abstract
Several wells have been drilled recently by Arctic LNG 2 at the Salmanovskoye (Utrenneye) field. Horizontal drilling at this field is challenging because of an inclination angle up to 52° in the intermediate section, drilled with a 311.2 mm bit. Drilling of large (311.2 mm) intermediate sections with significant vertical offset is not common for this area. The production wellbore section was drilled at an angle of 86°. Solutions suggested for complex wellbore sections drilling, included the use of oil based mud.
Multiple tests were conducted in order to select the best drilling fluids formulation and an action plan was developed to maintain stability of the wellbore and to optimize wellbore cleaning.
Nevertheless, multiple issues were encountered during the first well drilling, which resulted in a significant extension of the construction period. Lessons learned during the first well were studied thoroughly and included into risk assessments made for drilling of subsequent wells. This contributed to the overall success of drilling these wells and to the significant reduction of their construction periods.
Drilling practices and fluids properties were optimized as follows:
The whole volume of mud was mixed as required for intermediate section drilling. Dedicated software was used for the continuous modeling of wellbore cleaning efficiency and drilling parameters were adjusted promptly in accordance with the modelling results. HPHT filtration rate was reduced to 2 ml/30 min in challenging wellbore sections. The decision tree was revised as required for the efficient response in case of lost circulation.
Newly prepared OBM, combined with the developed and optimized action plan, contributed to the incident-free drilling of complex wells at the Salmanovskoye field.
Located remotely, requirements for proper logistical solutions was vital for success. This is discussed in details below.
With the success of these messures, it is expected that these practices will be implemented at two other fields on the Gydan peninsula and in other areas where traditional drilling practices may be ineffective due to challenging lithology, geological conditions and logistics and HSE risks
New Tailored Spacer System Helps Reduce Lost Circulation and Enhances Cement Bonding during Multistage Cementing Operations in Fractured Formations in Kyumbinskoe Field, Eastern Siberia
Authors: Tcibulskii Mikhail , Massie Iain , Agapiou Kyriacos , Trofimenko Ivan , Lodin Alexey , Khohryakov Vladimir 
Published: September 2020

Abstract
Lost circulation (LC) is commonly encountered in drilling and cementing operations and can significantly contribute to non-productive time (NPT). An operator in the Kyumbinskoe Field faced this challenge in a fractured production section of the formation, and conventional LC solutions had been ineffective at achieving strict regulatory top of cement (TOC) requirements and satisfactory cement bonding. This paper describes a tailored spacer fluid system engineered to effectively and efficiently prevent LC to meet the job requirements. The tailored spacer system includes additives that perform synergistically to help prevent LC in permeable and fractured formations and enables rheological hierarchy to facilitate effective mud displacement. The spacer was designed to meet operational parameters for cementing a production casing string in two stages through the use of a multi-stage tool and was subjected to thorough verification through lab testing and computer simulations to ensure job requirements could be met. The tailored spacer system was used in three trial jobs to assess its ability to minimize losses in a permeable and fractured formation with a history of LC with the ultimate goal to achieve planned TOC and improve cement bond quality as verified by Cement Bond Logs (CBL’s).
Use of this tailored spacer system helped to minimize losses experienced on all three wells. CBL results were also significantly improved with an average of 70% of the cemented interval being classified as "good bond" on wells cemented without the tailored spacer system to 88% on the three wells where it was used. Barrier dependability with the new spacer system was improved through achieving strict regulatory requirements for TOC on two out of three wells and improved cement evaluation results, which is a critical requirement of well construction that allows for maximizing production over the life of the well.
New Opportunities for Multistage Stimulation Design - Frac Sleeves Activated by Single-Sized Dissolvable Balls
Authors: Vikulin Nikita Anatolievich , Rusakov Valeriy Arkadyevich , Aliyev Abdulali Akifovich , Mityaev Oleg Igorevich 
Published: September 2020

Abstract
This article includes review of evolution of multistage fracturing completions for conventional oil reserves in continental Russia and focuses on attempts of the LLC "RN-Yuganskneftegaz", the one of the largest operator company in Russia, to solve the challenge of well life extension by implementing new completion technologies allowing reliable means of re-fracturing on the well after several years of service as well as the means to isolate gas or water break-through.
A comparative analysis of different types of multistage fracturing completions was performed by LLC "RN-Yuganskneftegaz" with the aim to select the most suitable technology to address the above-mentioned goals without sacrifice of time required to drill, complete and stimulate the well.
As the result of the analysis the technology of the frac valves activated by single-sized dissolvable balls was selected as a most appropriate. The successful field trial on 2 wells is described in this paper.
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.