bluuebunny/crossref_metadata_2025 huggingface dataset:
Successful Application of a New Generation of Clay Inhibitor Polymers While Drilling a Deep Exploration Well in the Astrakhan Region
Authors: Ryabtsev Petr Leonidovich , Popov Sergey Viktorovich , Korolev Andrey Vladimirovich , Urakov Samat Maratovich , Akvilev Andrey Aleksandrovich
Published: October 2021

This paper presents the results of laboratory studies and field application of a drilling fluid based on a new generation of polymer inhibitors. The summarized results of the application confirm the effectiveness of the new polymer type used.

The body of the article is devoted to the experience of using an innovative drilling fluid system for drilling an exploration well in the Astrakhan gas condensate field. One of the features of the Astrakhan gas condensate field is a number of intervals of possible complications: lost circulation zones, prone to clay swelling and caving, and presence of salts and hydrogen sulfide in the reservoir. One of the solutions for ensuring trouble-free drilling in such conditions is using an oil-based drilling fluid (OBM). However, OBM is often avoided when drilling exploratory wells due to environmental and technological limitations. In this connection, the project team carried out work on selection and development of a water-based drilling fluid formulation, which would ensure the most trouble-free and cost-effective drilling operations.

Considering these studies, a drilling fluid was selected based on a new generation of inhibitor polymers. The key feature of the proposed formulation is the use of a new polar inhibitor polymer. The selected formulation showed the best laboratory test results after which it was approved for application. The main risk of using the new drilling fluid formulation was lack of filed experience in using this system in similar geological conditions. At the same time, laboratory tests showed that the proposed alternative mud formulations did not provide the required level of contamination resistance and inhibiting ability.

Over the period from April to September of 2020, the exploration well was successfully drilled at the Astrakhan gas condensate field using the selected drilling fluid based on a new polymer type. Using the same drilling fluid type, four intervals - from the surface pipe to the production liner, - were drilled.
An Integrated Approach to Efficient Drilling through Unstable Coal Intervals Using Different Types of Mud in the Yamal Region
Authors: Kabanov Alexander Viktorovich , Galimkhanov Aydar Ramilevich , Kharitonov Andrey Borisovich , Matsera Alexander Mikhailovich , Pogurets Valery Viktorovich , Mavlyutov Ruslan Shamilevich , Dolmatov Denis Vladimirovich , Sokovnin Sergey Anatolyevich
Published: October 2021

This article is a description of an integrated engineering approach to solutions selection for efficient and safe drilling of unstable intervals represented by interbedded coal and argillite layers. Due to specific features of these formations, any significant mechanical stress, as well as penetration of drilling fluid filtrate, may lead to wellbore instability regardless of the drilling mud type used. The paper presents a description of the features of drilling in unstable intervals with various types of drilling muds (WBM/OBM) in Yamalo-Nenets Autonomous Okrug (YNAO).

Experience has shown that drilling through coal intervals prone to instability may cause significant non-productive time (NPT). Such wells should be designed with an integrated engineering approach, which covers the entire cycle: starting with the well path planning, casing setting depths selection, BHA design and drilling regimes of the risk interval. No less important, detailed development of solutions for drilling muds.

During the study the main causes of issues in wells drilled through the interbedded formations of coal and argillites in two fields were identified. As a result, a set of measures was developed to minimize risks for each type of mud (OBM and WBM):

– Revision of the initial well design solutions. Selection of optimal mud weight based on the experience gained and the geomechanical model – Revision of chemicals concentrations together with the use of additional additives – Placement of stabilizing pills across unstable intervals – Well path optimization – Development of safe drilling procedures.

The measures developed for various types of drilling muds allowed minimizing the NPT and successfully completing the wells on time. The experience gained formed the basis for recommendations to prevent issues associated with the coal layers instability in the region.
Hollow Glass Spheres HGS in Drilling Fluid: Case Study of Preventing and Mitigating Total Losses
Authors: Sherishorin Vitaly , Rylance Martin , Tuzov Yevgeniy , Krokhaleva Olga , Tikhonov Evgeny , Chirkov Oleg , Ivanov Ruslan
Published: October 2021

The paper describes the first deployment of HGS in Eastern Siberia as a mud additive. The technology was utilized for reducing drilling fluid density for prevention and mitigation of losses; while drilling through a producing reservoir section with low pore pressure, unconsolidated and fractured sands. The engineering considerations, fundamentals of the approach and major risks involved were reviewed with application to the Sredneboutobinskoye Oilfield as a pilot field application for broader future plans.

Key planning, delivery and execution principles of the initial application will be reported in the paper. Initially deployed on three wells, including multi-laterals (Rylance et al., 2021), the paper will walk through the engineering considerations during the planning and execution phases. Key sections include the data gathered and the many lessons learned during the incremental and stepwise deployment. The paper will also report on post drilling productivity and comparisons with the offset wells drilled with conventional mud systems, which suffered severe losses.

The results of this pilot have exceeded expectations. There have been many insights and the Team are now looking to set a timetable to scale-up across the Taas-Yuryakh Neftegazodobycha (TYNGD). After many hours of laboratories study and preparation works, the general plan was to reduce the static density and ECD to mitigate fluid losses. However, the applied results showed additional effects from HGS. Data will be provided that demonstrated loss-free drilling was achieved where this had not been the case before, with a material reduction in NPT, lost circulation material (LCM) needs and costs. Much has been learned, recovered HGS material has been demonstrated to be an effective LCM pill and centralization of mud processing may offer additional cost savings and improvements. Further efficiencies are also expected to be achieved and future potential is considerable.

HGS for cementing is well documented, yet application for drilling fluids has been less well reported and almost exclusively related to single wells. The TYNGD application is innovative as this is a major development with 10 active drilling rigs. The application is on multi-laterals and offset wells are available for direct comparison. The results of the approach demonstrate a new way of performing well construction in an effective manner for major field developments where losses are prevalent.
Engineering Fluids and Hydraulics to Drill the First Sub-Horizontal Well with Narrow ECD Window in Eastern Urengoy License Area
Authors: Sergeev Pavel Nikolayevich , Mordyukov Alexander Fyodorovich , Kozyrev Alexander Sergeyevich , Bembak Evgeny Vasilyevich , Matsera Aleksander Mikhailovich , Kabanov Alexander Viktorovich , Tikhonov Evgeny Vladimirovich , Kharitonov Andrey Borisovich
Published: October 2021

The Operator's challenge was the construction of a sub-horizontal well with 1500 m liner section in area with limited offset experience. The main development difficulty of the East Urengoy license area is the abnormally high pore pressure Achimov deposit. The widely used practice of drilling for these reservoirs with S-shaped profile wells has been utilized for a long while. However, the construction of sub-horizontal wells is still a challenge, and often accompanied by high incident rates.

Before drilling the well, all necessary fluid engineering modelling was performed. According to the hydraulic calculations, drilling of the horizontal well with traditional fluid properties was not possible due to exceeding the maximum ECD range. Multiple laboratory tests were performed to optimize the drilling fluid parameters and rheological properties with respect to ECD reduction and reducing potential for weight fluctuations due to barite sag. Based on the data obtained, recommendations were issued to predict ECD levels while drilling and tripping. At the same time, step-by-step action plans were developed for trouble-free drilling.

While utilizing this optimized fluid, with close interaction and cooperation between the project Operator (ROSPAN International), the Customer's research and development center, technical support service and the drilling contractor, the first sub-horizontal well on this licensed site has been successfully drilled.

The following main actions were developed and executed during the well construction process:

Maintained the hydraulic pressure (marginally) above the pore pressure through careful fluid management. The rheological properties of the drilling fluid were maintained to the developed (lab verified) specifications. Careful hydraulic pressure management during tripping. Extensive planning of the tripping operations included increasing the mud weight before tripping to create the necessary margin and optimization of the tripping rate. Ensuring effective drilling parameters and preparing the wellbore for the casing run according to hydraulic calculations. Recommended optimized drilling fluid parameters aimed at preventing barite sag under abnormally high pore pressure and high bottom hole temperatures (up to 110 deg C). Use of specialized pills to assist prevent the loss of circulation and wellbore instability.

This article is devoted to the development of drilling fluid solutions and practical techniques for effectively drilling wells in the area with challenging formations. This case study, as well as the lessons learned will be used for ongoing drilling projects in the area.
Remote Reservoir Exploration in Odoptu-More Field by Delivering ERD Wells Using Multilateral Drilling Technology
Authors: Shakhova Anna , Lisyutina Natalia , Lebedeva Irina , Valshin Oleg , Savinov Roman , Famiev Robert , Dementyev Alexander , Marushkin Dmitry , Bochkarev Vladimir , Surmin Vladimir , Bolychev Evgeny
Published: October 2021

This paper provides the results that were achieved and shares the drilling unique practices that were implemented to deliver the first complex bilateral extended reach drilling (ERD) well in Odoptu-more field (North Dome).

Well design driven by geological objectives considered drilling 215.9mm main and pilot holes (PH). Well complexity was governed by the type of a profile having ERD ratio of 5.22 (main hole) / 4.60 (PH) and trajectory's 3D nature (turn in azimuth of 90 degrees) compared to previous wells in the project drilled mainly with 2D profiles. Apart from the problems connected with drilling and casing upper sections key challenges comprised kicking off in 215.9mm open hole at 5955m MD and 1512m TVD with rotary steerable system, setting cement plugs at shallow true vertical depth (TVD) at 89 degrees of inclination to abandon laterally drilled PH, delivering 168.3mm production liner to bottom with a risk of entering a lateral while running in hole.

An effective collaboration between integrated engineering team and customer departments went far beyond ERD standard set of operations already existing in the project thus allowing to break its own records and to set new achievements due to integrated technological approach. The longest 444.5mm section (2975 m) was drilled in one run achieving the record daily drilling rate and rate of penetration (ROP). Cementing of 244.5mm floated liner resulted in the highest good cement bond integrity percentage ever achieved among other wells in project due to new ways of casing standoff and fluid rheology hierarchy modeling. For the first time in the project 215.9mm main horizontal hole in extreme reach ERD well has been drilled by kicking off in open hole from the pilot horizontal one with push-the-bit rotary steerable system without a kickoff plug with pilot hole being abandoned by setting cement plugs. Project-specific risk assessment conducted by team allowed successful deployment of 168.3mm liner into the main hole. Moreover, due to thorough engineering planning electrical submersible pump (ESP) was run without extending 244.5mm liner to surface by tie-back thus saving additional 7 days.

Drilling first bilateral ERD well unlocked opportunities for the operator to reach, explore and develop different extended geological targets thus eliminating well construction process of additional wells on drilling upper sections.
TAML-3 Multilateral Wells Construction with Multi-Stage Fracturing in Producing Wells
Authors: Tuzhilkin Stanislav Vladimirovich , Brednev Filipp Igorevich , Yastreb Andrey Vladimirovich , Uchuev Ruslan Pavlovich , Parshakov Andrey Evgenievich , Zubaidullin Rustam Ravilievich , Islamov Azamat Ildarovich , Burkov Andrey Alexeevich
Published: October 2021

The article presents geological substantiations, the process and the results of the construction of a multilateral well with multistage fracturing from the existing producing well in the Yuzhno-Priobskoye field. The scope of construction of a multilateral TAML-3 well as per the international classification with a saved mainbore was to prove the effectiveness of the multilateral technology and its economic feasibility in the conditions of an extensive stock of producing wells.

Every year we are seeing an increasing number of new wells being drilled in reservoirs with worsening characteristics which is caused by low permeability. Sharp production declines (up to 70% in the first year) and an increasing amount of periodic wells highlight the need to advance well stimulation methods. Well workovers by drilling a horizontal lateral while keeping the mainbore in operation allows to increase the production rate by 30% compared to a conventional sidetracking. While keeping the production rate of the mainbore, this technology provides for an additional production from a lateral bore and allows to operate the well at the planned bottomhole pressure.
Development and Implementation of the Method of Cementing Production Casing 178 mm with Pressure on the Cement Slurry on the East Part of the Orenburg Oil and Gas Condensate Field
Authors: Miklyaev Maxim Viktorovich , Denisov Ivan Vyacheslavovich , Gavrilin Ivan Mikhailovich
Published: October 2021

Well construction in the Volga-Ural Region faces different sorts of complications, the most common ones being the loss of drilling fluids and rockslides. Such complications may cause considerable financial losses due to non-productive time (NPT) and longer well construction periods. Moreover, there are complications, which might occur both during well construction and during its exploitation. The commonest complications are sustained casing pressure (SCP) and annular flow.

The complications, which occur when operating a well, also have a negative effect on the economic efficiency of well operation and call for additional actions, for example, repair and insulation works, which require well shutdown and killing, though a desired outcome still cannot be guaranteed; moreover, it is possible that several different operations may have to be carried out.

In addition, the occurrence of SCP during well life is one of the most crucial problems that may cause well abandonment due to high risks posed by its operation. It is known that the main reasons for SCP are as follows:

Channels in cement stone Casing leaks Leaks in wellhead connections

To resolve the problem of cement stone channeling, several measures were taken, such as revising cement slurry designs, cutting time for setting strings on slips, applying two-stage cementing, etc. These measures were not successful, besides, they caused additional expenses for extra equipment (for example, a cementer). In order to reduce the risk of cement stone channeling, a cementing method is required that will allow to apply excess pressure on cement slurry during the period of transition and early strength development. To achieve this goal, a well-known method of controlled pressure cementing may be applied. Its main drawback, however, is that it requires much extra equipment, thus increasing operation expenses. In addition, the abovementioned method allows affecting the cement stone only during the operation process and / or during the waiting on cement (WOC) time.

Upon receiving the results of the implemented measures and considering the existing technologies and evaluating the economic efficiency, the need was flagged for developing a combined cementing method. The goal of this method is to modify the production string cementing method with a view to applying excess pressure on cement stone during strength development and throughout the well lifecycle. The introduction of this lining method does not lead to an increase in well construction costs and considerably reduces the risks of losing a well from the production well stock.
Successful Implementation of the PMCD Technology for Drilling and Completing the Well in Incompatible Conditions at Severo – Danilovskoe Oil & Gas Field
Authors: Krivolapov Dmitry , Masalida Ivan , Polyarush Artem , Visloguzov Vyacheslav , Averkin Alexey , Rudykh Artem , Ivanov Pavel
Published: October 2021

This paper discusses the successful implementation of PMCD (Pressurized Mud Cap Drilling) technology at Severo – Danilovskoe oil and gas field (SDO) located in the Irkutsk region. The abnormally high-pressure reservoir B1 and the abnormally low-pressure reservoir B5 are the target layers in this field. Wells drilling at SDO is accompanied with simultaneous mud losses and inflows conditions, especially if the strata B1 is being penetrated. Pumping lost circulation materials (LCM) and cement plugs do not solve lost circulation complications which subsequently lead to oil and gas inflows. As a result, most of such wells are getting abandoned.

It was assumed that complications in this formation occurs due to the narrow safe pressures’ operating window (ECD window), therefore, the managed pressure drilling technology (MPD) was initially used as a solution to this problem. However, after the penetration of the abnormally high formation pressure B1 horizon with a pore pressure gradient of 1.86 g/cm3 it was found that there is no operating window. In this regard, there were simultaneous mud losses and oil and gas inflows during the circulation. The well was gradually replaced by oil and gas, regardless of the applied surface back pressure value in the MPD system. The mixing of the mud and reservoir fluid was accompanied by catastrophic contamination. As a result, the drilling mud became non - flowing plugging both the mud cleaning system and the gas separator. On the other hand, the plugging of the B1 formation with LCM did not bring any positive results. Bullheading the well followed by drilling with applied surface back pressure and partial mud losses gave only a temporary result and required a large amount of resources.

An implementation of PMCD technology instead of MPD has been proposed as an alternative solution to the problem. This technology made it possible to drill the well to the designed depth (2904 - 3010 m interval). For tripping operations, as well as the subsequent running of the production liner it was necessary to develop an integrated plan for well killing and completion in extreme instability conditions. As a result of various killing techniques application, it became possible to achieve the stability of the well for 1 hour. Oil and gas inflows inevitably occurred when the 1 hour lasted. Based on these conditions, the tripping and well completion process was adapted, which in the end made it possible to successfully complete the well, run the liner and activate the hanger in the abnormally high-pressure reservoir.
Innovative Approach to Analysis Drilling Tool Works
Authors: Gubaidullin Ramil Ilshatovich
Published: October 2021

Information technologies have long been an integral part of our lives, and the oil and gas industry has also undergone natural IT evolution. Modern technologies have allowed to automate the basic processes and structure the existing order of work, but there are still unresolved problems, one of which is monitoring the full life cycle of drill pipes and predicting the accumulation of fatigue damage. In most cases, the failure of the drill pipes is associated with fatigue destruction, which begins with microcracks as a result of exposure to variable stresses during the construction of the well (drilling).

Currently, there are no effective methods to control accumulated fatigue damage or residual durability of the pipe at a given level of stress. In this regard, a system is required for a more reliable assessment of the condition of the drill pipes, which will take into account the whole list of factors influencing the rate of accumulation of fatigue damage in the body of the pipe and will allow to calculate (predict) the accumulated fatigue of the drilling pipes, using data from drilling regimes and well parameters.

Understanding the mechanism of accumulation of fatigue wear, which leads to the failure of drilling pipes, makes it possible to manage this process, significantly reduce the cost of maintenance of the drilling pipe fund and reduce incidents with drilling pipes.
Analytical Resources of Digital Procedures in Monitoring and Controlling the Processes in Drilling the Wells
Authors: Kozhin Vladimir Nickolayevich , Patorov Aleksey Anatolevich , Lunin Evgeniy Alekseevich , Davletov Kamil Rafikovich
Published: October 2021

Drilling is traditionally considered as one of the most challenging and expensive areas in oil and gas industry, and its efficiency, against the background with the of unstable forecast in current situation with growing oil prices, both defines the efficiency of capital investments at well construction stage and the cost of production as a whole. Changing drilling conditions, such as well depths, their complicated architectures due to reservoir depletion and their complex localization conditions, pose the task of attracting advanced technologies aimed at modifying the labor process, reduction in costs and increase in production efficiency ("GazpromNeft", 2015). However, not all such procedures are mass-produced due to high price that you need to pay for them, as well as possible limitations of obtaining these technologies. There is a need to implement the tasks in short term with the available resources without involving any expensive equipment and additional personnel (Litvinenko et al., 2017). This opportunity is opened by effective data management in the progress of well construction as well as in information and analytical supporting tools that allow you to receive, process and control this data in a short time and to take the appropriate management decisions based on it (Ivanov, 2017).

Of course, one of the foundations in the controlling over the industrial processes is the reference book of time standards to perform basic operations in drilling and casing the wells (Unified Time Regulations in Process, 1987), which is mainly aimed at preventing unjustified costs during the process of well construction (excess time), planning the duration of operations, conducting procedures to select the applicants for work.
Development and Implementation of Green Inhibitors of Gas Hydrate Formation in the Fields of Western Siberia
Authors: Voloshin Aleksander , Nifantiev Nikolay , Egorov Mikhail , Alimbekov Robert , Dokichev Vladimir
Published: October 2021

The effect of biodegradable polysaccharides – sodium (NaCMC) and ethanolammonium salts of carboxymethylcellulose, dextran and arabinogalactan on the process of gas hydrate formation was studied in order to search for new "green" inhibitors of low-concentration gas hydrate formation. The ability of polysaccharides to inhibit gas hydrate formation was studied in a quasi-equilibrium thermodynamic experiment. A mixture of hydrocarbon gases with a composition typical of the composition of petroleum gas and containing 78% methane was used as a gas-hydrate-forming model medium. It was found that in concentrations of 0.005, 0.0065 and 0.008%, dextran, NaCMC and arabinogalactan as thermodynamic inhibitors exceed methanol by 170-270 times in inhibitory properties. Dextran is superior to NaCMC and arabinogalactan in terms of inhibition efficiency, reduction of gas hydrate formation rate and induction time. Since with an increase in the concentration of polysaccharides, the pressure drop of gas hydrate formation increases and the rate of formation of gas hydrates decreases according to the mechanism of action, the studied polysaccharides can be attributed to both thermodynamic and kinetic inhibitors. It is established that the molecular weight of water-soluble polysaccharides has a significant effect on their inhibitory properties. A polysaccharide with a molecular weight of 250,000 demonstrated the highest inhibitory activity among the studied samples of NaCMC, which is 400 times more effective than methanol. NaCMC with a mass of 700 thousand did not have any effect on the formation of hydrates. Among the ethanolammonium salts, the monoethanolammonium salt CMC showed the greatest effectiveness in inhibiting the formation of tetrahydrofuran hydrates. An increase in its concentration from 0.02 to 0.1% leads to an increase in the induction time required for the nucleation and subsequent growth of crystals by 10 times. When switching from mono - to di - and triethanolammonium salts of carboxymethylcellulose, the inhibition efficiency decreases. It is shown that sodium and ethanolammonium salts of carboxymethylcellulose, arabinogalactan and dextran are promising for creating new "green" highly effective inhibitors of gas hydrate formation on their basis. The results of laboratory and field tests of the preparative form of the "green" gas hydrate formation inhibitor at the fields of Western Siberia are presented. It was found that at dosages of 500 g/m3 or less, there is no formation of hydrate plugs in the annulus of wells.
Development of an Innovational Multiphase X-Ray Flowmeter
Authors: Zubakin Andrey Anatolievich , Davydov Aleksandr Igorevich , Gogolev Aleksey Sergeyevich , Chistyakov Sergey Gennadievich , Filatov Nikolay Alexandrovich , Boyev Artem Sergeyevich , Rukavishnikov Valeriy Sergeyevich
Published: October 2021

Non-separation measurement of a multiphase mixture coming from an oil well is traditionally considered a complex measurement, for which rather expensive solutions are used, including non-trivial maintenance.

This work aims to describe a new technology in the area of measuring multiphase oil and gas-water mixture, which is being finalized by specialists of the Tomsk Polytechnic University for conducting pilot tests at the facilities of Zarubezhneft JSC, and to indicate a more informative level of measurement of oil and gas industry production, which allows measuring the amount of oil, gas and water with high precision without the use of radioactive sources and constriction devices.

The purpose of measuring a multiphase mixture is to determine the amount of oil, gas and water. In order to do this, it is required to determine the total flow rate of the mixture and the distribution of the flow by substances and phases: oil gas, oil and formation water. The total flow rate in the developed multiphase X-ray flowmeter is based on cross-correlation analysis of radiograms from two linear detectors. Measurement of the component composition for the purpose of the distribution of the flow by substances and phases is carried out by the method of two-wave absorptiometry.
Modern Solution for Oil Well Multiphase Flows Water Cut Metering
Authors: Sottsau Aliaksei , Akbashev Ramir , Peratsiahin Alexandr , Garnaev Vadim
Published: October 2021

An innovative technology for determining the water cut in well products (without preliminary separation into liquid and gas fractions) uses the results of electrical impedance measurements and its dependence on the alternating current frequency. Water cut meter's sensor includes measuring and current electrodes, between which there is a well's multiphase flow. Imaginary and real components of the impedance quantitatively describe the component composition of the studied oil and gas-water mixtures. In this process, machine learning methods and developed algorithms for features extraction are used. Depending on the type of emulsion, two independent sensors are used in the oil pipeline, one of which measures in a direct emulsion, the other in an inverse emulsion.

Tests of the described water cut meter on flow loops in the Russian Federation and in the Netherlands, as well as studies of well flows in oil production facilities in the Russian Federation and the Kingdom of Saudi Arabia, have shown high measurement accuracy in the full range of water cut, with high gas content, as well as at high salinity and in a wide range of flow rates. To do so, modern methods of data classification based on neural networks and regression modeling implemented using machine learning are employed. It was found that the flow rates of liquid and gas do not affect the results of measuring the water cut due to the high frequency of the impedance measurements - up to 100 thousand measurements per second. Use of in-line multiphase water cut meter makes it possible to apply intelligent methods of processing field information and accumulate statistical data for each well, as a big data element for predicting and modeling in-situ processes. It will also allow to introduce promising production processes aimed at increasing oil production and monitoring the baseline indicators of the well.

Novelty of the presented technology:

Solution of the problem of high-speed determination of water cut in a multiphase flow without preliminary separation using impedance metering. Creation of mathematical models of multiphase flow and methods for determining the type of flow and the type of emulsion. Machine learning methods and neural networks employment for high-speed analysis of flow changes. Development, successful testing and implementation of an affordable multiphase water cut meter of our own design, which has no analogs in industrial applications.
The Local Corrosion Rate Determination According to Weight Measurements Corrosion Coupons in Oilfield Conditions
Authors: Tkacheva Valeriya Eduardovna , Markin Andrey Nicolaevich , Markin Ignaty Andreevich , Presnyakov Alexandr Yuryevich
Published: October 2021

Complications associated with a corrosive environment, according to Rosneft's data as of 01.01.2020, are among the prevailing at oil and gas production facilities and rank fourth among other factors complicating production - 12% the complicated mechanized wells. Failures due to corrosion are the second largest complicating factors. Based on the results of approbation, the article proposes a method for calculating the maximum rate of local carbon dioxide corrosion, applicable in oilfield conditions, including to complicated stocks of oil wells and pipelines of oil gathering systems. Based on the approbation results, a method for calculating the maximum rate of local carbon dioxide corrosion, applicable in oilfield conditions, including to complicated stocks of oil wells and oil gathering pipelines systems is proposed in the article. The proposed technique is realizable according to the results one of "traditional" methods the corrosion monitoring - weight (or gravimetric). The approbation results and application possibility the technique in the pilot tests process in assessing the protective ability of corrosion inhibitors and the selection the effective dosages in relation to local damages, which are the main cause the oilfield equipment failures according the factor "Corrosive aggressiveness" (one of the complicating factors in terms of gradation, adopted in the Rosneft Company regulations). On practical examples the oilfield equipment operation, the results of corrosion monitoring and the summary statistics the corrosive stock of wells (using the example of an oil Company), the current situation with respect to this type of complication and relevance the issue under consideration is shown.
Selection and Justification of Technologies for Enhanced Oil Recovery Methods Using Inter-Well Tracer Survey
Authors: Galimzyanov Artem , Naydensky Konstantin , Huseby Olaf Kristoffer
Published: October 2021

Justified application of enhanced oil recovery (EOR) methods is one of the key tasks of oil operating companies for the effective development of not only brown oil fields at a mature stage of production, but also for green fields. The selection and justification of one or another method of enhanced oil recovery for certain geological conditions often requires not only looking for worldwide experience, conducting laboratory tests on a core, but also performing pilot tests at a polygon area. The subsequent full-field implementation of EOR method requires confirmation of its effectiveness based on the increase in oil recovery factor.

This article describes both the experience of using interwell tracer studies to substantiate the effectiveness of EOR technologies in pilot areas, and the experience of evaluating the effectiveness of EOR technologies with full-field implementation in various fields. The work carried out on the integrated use of tracer studies makes it possible to apply a scientific and engineering approach to the selection of an enhanced oil recovery method by assessing the sweep efficiency before and after the application of the EOR technology. Examples of the use of this integrated approach for different oil fields are given.

The presented technologies and experience of the work performed will significantly speed up the choice of the EOR technology for certain geological conditions and verify the effectiveness of the selected EOR method.
New Generation of Formation Testers – New Horizons: First Experience in Russia
Authors: Novikov Sergey Vasilevich , Charupa Mikhail Viktorovich , Dzhalatyan Yakov Eduardovich , Kuzmin Stanislav Sergeevich , Kaipov Yermek Talgatovich , Kazakevich Eduard Yurevich , Smetanin Yuri Nikolaevich , Kishauov Abilkassym Kalievich , Snokhin Alexey Alexandrovich , Ibragimov Oleg Raisovich
Published: October 2021

As the production of oil and gas in major regions has been declining, exploration efforts are shifting towards hard-to-reach understudied areas with lack of necessary infrastructure. In addition to that, hydrocarbon fields that are being explored today, typically have more complex geological structure than the ones discovered decades ago and are characterized by the presence of multiple reservoirs with individual fluid contacts. The abovementioned reasons cause significant increase in time required to test these reservoirs and estimate their production potential. Therefore, there is a real need for reliable technologies that would expedite the testing of such complex fields.

New wireline formation testing platform has an updated hardware architecture enabling to use it for both traditional formations testing applications as well as the development of new testing procedures deviating from conventional practices. This paper describes the novel testing approach implying the use of wireline formation tester (WFT) in conjunction with a surface multiphase flowmeter, which was implemented at one of the large gas fields located on the Gydan peninsula. A key feature of the new formation testing platform compared to its predecessors is its ability to pump an order of magnitude greater volumes of reservoir fluids, which allows to estimate permeability in the uninvaded zone of the reservoirs and their productivity. Combination of the wireline formation tester with the surface multiphase flowmeter enables measuring surface rates and capture surface samples of reservoir fluids thus making this type of testing comparable to traditional well testing.

At the beginning of the paper we provide a brief description of the acquired formation testing results with stress on key features of the new wireline formation testing platform. The rest of the paper is devoted to Deep Transient Testing (DTT), more specifically, to its design and planning, required hardware and description of results acquired during such tests. We also demonstrate an approach that can be used to estimate reservoir productivity based on the obtained data.
Water-and-Gas Shutoff Technologies in Horizontal Wells on North Komsomolskoe Field: Screening and Successful Trial
Authors: Nigmatullin Timur Eduardovich , Nikulin Vladislav Yurievich , Shaymardanov Airat Rafaelevich , Mukminov Rinat Rifkhatovich , Ivanov Alexandr Yurievich , Akhmadullin Marat Edgarovich , Soltanov Dzheykhun Kamaleddinogly
Published: October 2021

The article describes the choosing a water-and-gas shutoff technology in horizontal wells (HW) drilled in terrigenous reservoirs of the North Komsomolskoye field. The well completion system is characterized by the use of liners equipped with external liner packers and inflow control devices (ICD). To solve the problem, the world experience in the use the water-and-gas shutoff technologies in HW was studied. A matrix for choosing a technology with the use of technical means and combined effect was developed based on the type of isolated fluid, the type of reservoir and the method of well completion. The technology of installing a straddle system with cup packers and a blind inter-packer pipe in a horizontal wellbore was selected to increase the success of work on isolating the inflow of water and gas in difficult geological conditions of the North Komsomolskoye field. The technology was successfully tested: a producing well with almost 100% water cut was return to effective production. A similar straddle system, but with a perforated spacer pipe, was used for directional injection of sealants selected for the conditions of the North Komsomolskoye field into the water cut zone of the horizontal wellbore. The results of pilot field tests indicate that there is a prospect of using water-and-gas shutoff technologies to limit water and gas inflow at the North Komsomolskoye field.
Oil Production Enhancement by EOR Candidates Optimization
Authors: Pisarev Denis Yurievich , Sharipov Ildar Fanurovich , Aslanyan Artur Michailovich , Gulyaev Danila Nikolaevich , Nikonorova Anastasiya Nikolaevna
Published: October 2021

The study field is located in the Nizhnevartovsk district of the Khanty-Mansi autonomous region. The deposit is located in the Nizhnevartovsk crest zone. The geological section of this deposit features a thick layer (2740-2870 meters) of Meso-Cenozoic era sedimentary rocks starting from the Jurassic period up to and including the Quaternary period, and rests unconformably on the surface of the deposits of the folded Paleozoic basement. The pay zones of study oil and gas fields features mainly sandstone-siltstone reservoirs.

The study formation XX11-2 features interleaved rocks with a high clay content. In the west and south-west of the field, the oil-saturated thicknesses vary on average from 5-10 m, and in the north, the thickness increases to 10-20 m.

This field has a long-lasting production history as a result of drilling vertical and horizontal wells but is currently at production decline stage. The existing reservoir pressure support system assumes that the water-cut trend at the wells will increase. In recent years, there has been advanced flooding in some areas, resulting in a drop in oil production, while the reasons for the advanced flooding are not always clear. This is often due to the progressing spontaneous fracturing in the injector wells (Aslanyan, Akimov et al., 2020).
Formation of a Methodology for Calculating the Optimal Number of Wells in the Development of Lenticular Formations to Achieve Maximum NPV
Authors: Rubailo Vadim Andreevich , Isakov Kirill Dmitrievich , Osipenko Alexey Stanislavovich , Akhmadiev Marcel Mansurovich
Published: October 2021

The work is devoted to the analytical methodology for the development of oil lenticular formations. The method is based on the theory of potentials for vertical and horizontal wells. The work takes into account the interference of wells, geological and petrophysical parameters of lenses, as well as the properties of the reservoir fluid, and a new equation for estimating the inflow to a horizontal well is derived. An assessment of the correctness of this work on the company's assets was made. The dependence for the express estimation of the number of wells depending on the economic parameters at the early stages of project development is obtained.
Challenging Water Channeling in Unconsolidated Heavy Oil Reservoirs: Risks and Management
Authors: Gudz Anton , Ilyasov Ilnur , Podkorytov Alexander , Tomashevskiy Maksim , Glushchenko Nikolai
Published: October 2021

The paper describes the basic features of the East-Messoyahskoe oil field that are important for efficient reservoir development, the key of which are high oil viscosity (111 cP), high heterogenieity and permeability contrast, and the presence of aquifer with a different strength.

The review of the experience in proactive breakthrough risks identification is presented. The actual breakthroughs during waterflooding of the PK-13 reservoir of the East-Messoyahskoe oil field are described and analyzed. The backgrounds and regularities increasing the risks of breakthroughs are identified. The analytical calculations have been made and key influencing factors have been defined.

Based on the obtained results, the methodology of the proactive breakthrough identification was developed. The methodology has been tested in the real conditions of the East-Messoyahskoe oil field. The first results have been received, which confirm the operational efficiency of the developed methodological approach. All wells were rated according to their breakthrough risk, and measures for operative and proactive breakthroughs risk management has been proposed. All listed are combined into a system which permits minimization of breakthrough risks and manages them for the increase of unconsolidated heavy oil reservoirs development efficiency.
Implementation and Intermediate Monitoring Outcomes of the First Commingled Up-Dip SMART Water Injection Well in PA-B Platform Piltun-Astokhskoye Offshore Oil and Gas Field
Authors: Tsarenko Alexander Vitalyevich , Tarsky Valentin Nikolaevich , Robson Lisa Jane
Published: October 2021

The objective of this article is to share an evaluation of the background, drilling outcomes and production and reservoir pressure impacts from two years of monitoring the first commingled up-dip SMART water injector drilled in the Piltun area of the Piltun-Astokhskoye offshore oil and gas field, located in Sakhalin, far east of Russia.

The unique aspect of this water injector is that it was drilled into the up-dip gas caps of two separate reservoirs to provide pressure support to commingled oil producers, complementing the down-dip water injectors already in place. This article highlights some details of the well maturation decisions and expectations based on output of the dynamic modelling studies. Drilling outcomes and well performance is compared to expectations. Initial results of the surveillance programme and field data analysis based on a two-year monitoring period are discussed to show intermediate outcomes of up-dip water injection in the Piltun area. Finally, remaining questions and uncertainties are shared.

Piltun-Astokhskoye is a complex multi-reservoir offshore oil and gas field with sizeable gas caps, significant heterogeneity both between and within reservoirs and a complex production history involving commingled oil producers and water injectors. Limited data is available to assess the impact of development decisions. Integrated analysis using multiple data sources and back-to-basics geology and reservoir engineering is required to understand how the reservoirs are responding to up-dip water injection, in order to predict future performance and make informed decisions to optimise the Piltun development over the long term.

Surveillance data shows that up-dip water injection is effective in increasing reservoir pressure and oil recovery in one of the reservoirs, whilst having little impact on the other. Analysis shows that variable impact is due to the influence of gas cap size on up-dip water injection efficiency and the risk of trapped gas volumes due to water injection into the gas cap. The importance of integration between different sources of surveillance data and analytical tools to complete a comprehensive and reliable analysis is shown.
Geological and Field Feasibility Study of Field Development Management Using Marker-Based Production Profiling Surveillance in Horizontal Wells: The Case Study of the Yuzhno-Vyintoiskoye Field
Authors: Dulkarnaev Marat Rafailevich , Kotenev Yuri Alexeyevich , Sultanov Shamil Khanifovich , Chibisov Alexander Viacheslavovich , Chudinova Daria Yurievna , Katashov Alexander Yurievich , Malyavko Evgeny Alexandrovich , Buyanov Anton Vitalievich , Semyonova Ekaterina Evgenievna , Gorbokonenko Oksana Alexandrovna
Published: October 2021

In pursuit of efficient oil and gas field development, including hard-to-recover reserves, the key objective is to develop and provide the rationale for oil recovery improvement recommendations. This paper presents the results of the use of the workflow process for optimized field development at two field clusters of the Yuzhno-Vyintoiskoye field using geological and reservoir modelling and dynamic marker-based flow production surveillance in producing horizontal wells.

The target reservoir of the Yuzhno-Vyntoiskoye deposit is represented by a series of wedge-shaped Neocomian sandstones. Sand bodies typically have a complex geological structure, lateral continuity and a complex distribution of reservoir rocks. Reservoir beds are characterised by low thickness and permeability. The pay zone of the section is a highly heterogeneous formation, which is manifested through vertical variability of the lithological type of reservoir rocks, lithological substitutions, and the high clay content of reservoirs. The target reservoir of the Yuzhno-Vyintoiskoye field is marked by an extensive water-oil zone with highly variable water saturation. According to paleogeographic data, the reservoir was formed in shallow marine settings. Sand deposits are represented by regressive cyclites that are typical for the progressing coastal shallow water (Dulkarnaev et al., 2020).

Currently, the reservoir is in production increase cycle. That is why an integrated approach is used in this work to provide a further rationale and creation of the starting points of the reservoir pressure maintenance system impact at new drilling fields to improve oil recovery and secure sustainable oil production and the reserve development rate under high uncertainty.