bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Results of Pilot and Industrial Application of Thermal-Gas-Chemical Well Treatment with Binary Mixtures and Development of Mathematical Models for Reservoir Processes in Source Oil Rock
Authors: Lishcuk Alexander Nikolaevich , Kravchenko Marina Nikolaevna , Shesternina Nataliia Viktorovna , Dieva Nina Nikolaevna , Nafikov Askhat Ahtjamovich , Khisametdinov Marat Rakipovich , Kataev Alexey Valerijavich 
Published: September 2020

Abstract
The purpose of this paper is to generalize the experience of applying the thermo-gas-chemical treatment methods (TGCT) using binary mixtures based on ammonium nitrate to enhance the inflow at oil fields. More than a decade of industrial tests of binary mixtures injection into mature fields’ marginal wells showed a multiple long-term increase in oil inflow. The positive experience of TGCT application to Tatarstan oil fields strongly suggests the perspective of its application to the layers with high content of organic substance in rock matrix including Bazhenov formation reservoirs for those technologies have been only battle-tested. The development of mathematical methods for describing the TGCT process considering the multiphase and multi-component nature of the process, chemical reactions and transformation of the reservoir structure allow to respond to the features of each field at the macro scale, to identify micro-scale features and changes in the reservoir matrix structure, using a percolation approach, and allowed to assess the current state of the bottom-hole zone adequately and conduct pilot tests on specific wells in strict accordance with the established technological regulations and control of hydrodynamic parameters.
Integrated Approach to the Analysis of Achimov Deposits for the Purpose of Optimizing Drilling
Authors: Gilmiyanova Alfiya , Sukhova Maria , Andreeva Svetlana , Kulbaeva Diana , Suleymanov Eldar , Mironenko Artem 
Published: September 2020

Summary
This paper presents the results of an integrated approach to the analysis of the geological structure and the subsequent of the productive Achimov deposits development: deposits X and Y located in Western Siberia. The main difficulties in the development of the Achimov deposits are associated with a high heterogeneity, a low degree of prediction of effective thicknesses, the difficulty of correctly calculating well flow rates, saturation behavior and, accordingly, water cut, and high production decline rates identified as a result of putting new wells into operation.
Wait or Get the Oil: How SAGD Technology Implementation Options will Vary Future Production
Authors: Terentiyev Aleksey Alekseyevich , Roschin Pavel Valeriyevich , Nikitin Aleksandr Valeriyevich , Kozhin Vladimir Nikolaevich , Pchela Konstantin Vasiliyevich , Kireyev Ivan Ivanovich , Demin Sergei Valerevich , Litvin Aleksandr Tarasovich , Struchkov Ivan Aleksandrovich 
Published: September 2020

Summary
One of the complications at the stage with steam injection start into the SAGD injection well in the Terrigenous reservoir with extra-heavy oil (EHO) is its injectivity rate. Traditionally, preheating the well bottom-hole (BH) zone with steam and subsequent recovery of hot water or steam through the annulus is used to get adequate injectivity. As an alternative to steam preheating it is proposed to inject an aromatic solvent/reagent to ensure sufficient well injectivity. Calculations were performed with the real reservoir model. The mutual influence of wells in SAGD blocks under the conditions of solvent/reagent injection was studied for this.
Wettability of Carbonate Reservoirs: Effects of Fluid and Aging
Authors: Kumar Sikandar , Burukhin Alexander Alexandrovich , Cheremisin Alexey Nikolaevich , Grishin Pavel Andreevich 
Published: September 2020

Abstract
As the production of hydrocarbons from the carbonate reservoir increases, there is a necessity to enhance oil recovery methods to increase recovery factors and improve the economic efficiency of field development. The knowledge of wettability's role and fluid distribution at the pore scale is required to comprehend the mechanisms for oil displacement from porous media. The X-ray computed micro-CT technology provides opportunities to study the complex fluid displacement process at the pore level.
This work discusses wettability restoration in carbonate cores and its effect on fluid distribution in porous space. Wettability restoration refers to restoring the original wettability of the core after extraction. We investigate wettability change and two-phase fluid distribution at pore-scale with the help of micro-CT technique along with Amott spontaneous imbibition methods.
The Amott spontaneous imbibition experiments performed on the core under ambient pressure. The micro-CT experiments conducted for steady flow core flooding experiments on harsh cleaned cores. The three-dimensional images acquired for dry core, core saturated with brine and kerosene followed by oil injection. For better visualization of the fluid-fluid and fluid-rock surface and to remove voxel artifacts, iodo-octane is mixed with oil with 10 % wt/wt. The experiments allow us to envisage the structures of fluid in each phase during the displacement of fluid in carbonate rocks with high resolution (3 μm/voxel). The novelty of this approach lies in efficiently capturing the CT images of the fluid distribution and its influence on wettability during the "core-aging" procedure and validating the results of it with the Amott imbibition wettability index.
The initial wettability of harsh cleaned carbonate cores was identified as water-wet compare to mixed wettability for mild cleaned carbonates. Nevertheless, all the samples become strongly oil-wet regardless of the cleaning methods after long-term saturation with crude oil. The X-ray CT technique revealed the fast evolution of contact angle of brine corresponding the wettability changes to strong oil-wet after contact with crude oil under the reservoir conditions.
Overcoming Back-Produced Polymer Challenges - Development of an Advanced and Economic Filtration Technology for CEOR Application
Authors: Marx Markus , Grottendorfer Stefan , Krenn Christof , Grillneder Roland 
Published: September 2020

Abstract
The implementation of highly effective polishing filter technologies plays a key role in polymer EOR where reservoir characteristics require extremely good water qualities. Few filter technologies are capable of handling volatile inlet fluid conditions such as back-produced polymer concentrations up to 420 ppm and OIW contents up to 70 ppm while targeting treated water qualities of less than 5 ppm OIW.
A fully integrated field trial was set up in the Matzen field in Austria where producing wells from EOR operations provide sufficiently high polymer concentrations for technology evaluations. A three-phase separator and a multi-chamber flotation unit were used as upstream treatment to supply produced water to the different filtration technologies under evaluation. With this setup, a broad range of entry criteria like OIW, solid content, polymer concentration and oil droplet size could be adjusted to challenge each filtration technology to its limit.
None of the tested technologies such as nutshell filters, conventional multi-media-filters, coated media, or vendor specific technologies were able to handle the challenging inlet water conditions while providing the required water qualities for polymer flooding projects. A new concept was developed, combining conventional multi-media filtration design with a type of media that, thus far, was not common in the oil and gas industry. A system-specific operating envelope was developed, describing the strong impact of inlet water conditions such as oil droplet size D50 values down to 15 micron, OIW concentrations up to 70 ppm, solid contents up to 10 mg/l and viscosities up to 3 cp. Where state-of-the-art technologies did not fulfill the performance criteria, it was possible to achieve less than 5 ppm at the filter outlet. Not only the filter performance but also the crucial aspect of effective media regeneration was solved with a novel filter backwash design, since known backwash systems completely failed with the newly implemented media.
Design, Qualification and Field Deployment of Low ECD Organoclay-Free Invert Emulsion Drilling Fluids
Authors: Wagle Vikrant , Yami Abdullah , Onoriode Michael , Butcher Jacques 
Published: September 2020

Abstract
High pressure and high temperature (HPHT) wells especially those with narrow pore / fracture pressure gradient margins present challenges in drilling. Maintaining optimum and low rheology for such wells becomes a challenge where a slight change in the bottom-hole pressure conditions can lead to non-productive time. However maintaining low viscosity profile for a drilling fluid can pose a dual challenge in terms of maintaining effective hole-cleaning and barite-sag resistance.
This paper describes the formulation of 95pcf medium-density organoclay-free invert emulsion drilling fluids (OCIEF). These fluids were formulated with acid-soluble manganese tetroxide as weighting agent and specially designed bridging-agent package. The fluids were hot rolled at 300°F and their filtration and rheological properties were measured. The paper describes the static-aging, contamination, HTHP rheology measurements and filter-cake breaking studies of the fluids at 300°F. Particle plugging experiments were performed on both the fluids in order to determine the invasion characteristics and the non-damaging nature of the fluids. These organoclay-free invert emulsion fluids were then field-trialed in different wells with good results.
The OCIEFs showed optimum rheology and filtration properties. The fluids gave lower PV, which ensured that the fluid presents low ECD contribution while drilling/circulating. Sag factor analysis for the fluids after static aging for 24 and 48hours showed excellent stability and minimal sag propensity. HTHP rheology showed that the fluids had consistent PV and YP values across a range of temperatures and pressures. Contamination studies showed that the effect of contaminants on the organoclay-free fluid was minimal and any change in properties can be easily controlled using conventional treatments. The paper thus demonstrates the superior performance of the developed fluid in achieving the desired lab and field performance.
Field deployment of the 95pcf organoclay-free invert emulsion fluid helped to maintain the required hole stability in the HTHP well. The well was displaced to 95pcf production screen test (PST) fluid and completed with a 4 ½" sand screen.
The First Implementation of MPD Technology in Conditions of Brine with AHRP at Kovykta Gas Condensate Field
Authors: Tomchenko Andrey Sergeevich , Kulikov Stanislav , Velyiev Gurban , Myazin Oleg Gavrilovich , Kazakov Evgeny Olegovych , Kaasa Glenn-Ole 
Published: September 2020

Abstract
This article describes general information about the geological structure, the identified complications during the construction of wells at the Kovykta gas condensate field associated with abnormally high reservoir pressure (AHRP). Based on the initial data and analysis of previously drilled wells, the requirements for equipment, the choice of drilling fluid density and the applied engineering solutions were formed. The goals and objectives of the project are outlined and the conditions in the process of drilling the section are presented, technological schemes and procedures are compiled during operation. Introductory training on managed pressure drilling technology was conducted with the personnel of the drilling and oilfield service companies. The revealed new mining and geological conditions and the complications that arose with them, and well-timed decisions allowed us to achieve the design depth of the section. The possibility of using brine for drilling the section using mudcap drilling technology was also confirmed. According to the final data, after drilling and fastening the section, new goals have been set for new wells at AHRP intervals.
During the section drilling, various works were repeatedly performed in the presence of wellhead excess pressure, but the developed procedures, analysis, and risk assessment allowed to complete the project without incidents or accidents. Based on the gained experience, a number of decisions were made to optimize the well construction process at the field.
Impact of Casing Pressure Test After Waiting on Cement on Cement Bond Quality
Authors: Vavilov Mikhail Borisovich , Sekacheva Yulia Viktorovna , Chernov Vladimir Igorevich , Lyutikov Kirill Vladimirovich , Perebatov Alexander Sergeyevich 
Published: September 2020

Summary
A high percentage of continuous cement bond with casing is an indicator of high-quality cementing and a good approach to cost efficient construction of oil and gas wells. However, the pressure created inside the casing after waiting on cement (WOC) leads to expansion and contraction of the pipe which has a considerable negative effect on the cement bond quality. This article describes the effect of a casing pressure test on the result of cement bonding, integrity of annular spaces and isolation of formations.
Ensuring the cementing quality prior to the cement job requires an engineering approach to the design of the entire job, namely: duration of circulation after casing running, volume of spacer fluids, design and weight of cement slurry, type and quantity of casing equipment, casing reciprocation or rotation, displacement fluid pumping rate, etc. However, even with all these conditions optimized, the blowout preventer (BOP)/casing pressure test after WOC will apply destructive casing tensile forces on hardened cement because of excessive internal pressure resulting in the loss of a significant percentage of good cement bond.
A study was performed and special attention was drawn to the fact that the casing test after WOC results in instances of micro-annuli which are recognized by the cement bond log (CBL) tool as no bond or partial bond, however these micro-annuli may be non-permeable. The micro-annuli occurrence process is confirmed by hydraulic calculations.
As a result, a joint decision was made to carry out experimental work with casing pressure tests at the bump pressure point and further BOP tests against a wellhead packer, to eliminate casing pressurization. According to the Oil and Gas Industry Safety Regulations this would require the cement slurry to be displaced with water instead of the drilling mud usually pumped for displacement. Immediately after bumping the plug the casing shall be tested for integrity by pressuring up to the required pressure and holding it for 30 minutes. Then, after BOP nippling up, a special wellhead packer is run and the BOPs are pressure tested without any impact on the casing.
CBL results for the operations performed showed a significant increase in good cement bond with casing (from 31% to 56%) as well as a reduction of absent bonding (from 10% to 0.5%) and microannuli. This topic is important, as in most cases BOPs are pressure tested together with the casing. This results in lower quality of the well cementing. In this paper, details of the increase in the bond quality through adjustments to the well construction process are shown to improve well profitability by preventing micro annuli and increasing the productive life of the well.
Russian National Oil Company Successfully Implemented Selective Flotation of 9 5/8-in Production Liner in Ultra-Extended Reach Drilling Well in Sakhalin
Authors: Shakhova Anna , Lebedeva Irina , Valshin Oleg , Famiev Robert , Marushkin Dmitry , Savinov Roman , Dementyev Alexander , Abdullayev Suleiman , Bochkarev Vladimir , Surmin Vladimir 
Published: September 2020

Abstract
This paper provides insights of planning, execution and the results of the application of selective flotation or "mud over air" technique while running 9 5/8-in production liner into an extreme-extended-reach well in Sakhalin, the longest well ever drilled by RN-Sakhalinmorneftegaz to date.
Extreme Reach Drilling (ERD) well has a shallow true vertical depth and a long horizontal departure imposing significant challenges of conveying 9 5/8-in liner to the required depth. When both conventional and full flotation methods cannot guarantee delivering casing to planned depth due to high torque and drag, lack of weight and string buckling, a new operational approach of selective flotation was considered. Mud over air, specifically "air cavity" technique implies running a bottom portion of the casing filled with mud, then an empty portion to reduce drag and a top portion filled with drilling fluid for additional weight to provide some additional push to overcome residual drag.
This article outlines unique practices of selective flotation technique covering the job specific features, its main risks and corresponding mitigation measures.
The selective flotation or "mud over air" concept together with detailed risk assessment and engineering of a single hydro-mechanical liner hanger and flotation collar system enabled successful conveyance of 9 5/8-in liner to its setting depth during drilling the longest extended reach well in the project.
Development and Practical Application of Requirements for Drilling Fluid Based on Geomechanical Modeling and Physicochemical Studies of Unstable Highly Lithified Clay Formations
Authors: Kazakov Dmitry Alexandrovich , Nekrasova Irina Leonidovna , Khvoschin Pavel Alexandrovich , Predein Andrey Alexandrovich , Garshina Olga Vladimirovna , Okromelidze Gennadiy Vladimirovich 
Published: September 2020

Abstract
The requirements to the drilling fluid weight, determined by the geomechanical modeling results, without taking into account all the factors affecting the wellbore stability, cannot guarantee accident-free well drilling in the intervals of unstable terrigenous deposits. The composition and properties of drilling fluid have a significant impact on the wellbore stability.
This article has developed an approach to minimizing the problems associated with loss of wellbore stability, combining modern achievements in geomechanical modeling and physical and chemical studies of the effects of oil-based drilling fluids on core properties, which seems more effective in reducing the probability of the above problems compared to the separate use of geomechanical models and the results of physical and chemical studies.
The proposed approach is based on the joint application of geomechanical modeling, hydraulic calculations and physical and chemical studies with the use of natural core from the intervals of the most unstable deposits, which allows developing a set of requirements to the composition and properties of drilling fluid to penetrate unstable rocks of a particular field. The specified set of requirements includes: requirements for weight, plastic viscosity, dynamic and static shear stresses of drilling fluid, providing mechanical stability of the borehole walls and effective cuttings transport; requirements for aqueous phase composition, the value of voltage stability of the mud, providing minimization of fracturing (according to the X-ray tomography results), softening and swelling of the rocks under consideration due to the hydration process; requirements for the fractional composition of microcolmatants corresponding to the fracture size in the rocks under consideration; requirements for the inhibiting and bridging abilities of the drilling fluid.
This approach has been successfully applied when drilling a well with horizontal completion at one of the fields in the Perm Territory in the interval of unstable Carboniferous terrigenous deposits, which are prone to collapse and are penetrated at inclination angles of more than 70 degrees. The set of requirements for a hydrocarbon-based drilling fluid is established based on the results of geomechanical modeling and the above detailed studies. A drilling fluid formulation that meets the specified requirements has been developed. Engineering and technological support was carried out for the drilling of the considered well using the developed drilling fluid and monitoring of compliance with the specified requirements, which avoided problems associated with the wellbore instability.
High Viscosity Oil Preparation at the Vostochnoye-Messoyakhskoye Field
Authors: Khasanov Irek Zufarovich 
Published: September 2020

Abstract
There are situations where one needs to solve a hard problem, but have limited time, lack of material resources and the necessary information.
In that case we have to rely on one's own experience and all the available resources.
The Vostochnoye - Messoyakhskoye oilfield was put into operation and maintenance phase in September 2016, and from that point on the oil treatment facility is associated with the oil emulsion destruction problem and consequently the quality decrease of the crude oil.
Virtual Flowmetering NovyPort Field Examples
Authors: Vinogradov Dmitrii , Vorobev Daniil 
Published: September 2020

Abstract
Virtual flow meter becomes increasingly relevant due to the need for continuous monitoring of the production system. This need nearly always arises at gas and gas condensate fields, because in many cases gas restricts the pipeline and the processing system, which inevitably results in loss of production. The technology becomes more interesting for oil and gas condensate fields, such as Novoportovskoye field.
Numerous wells, low frequency of production rate tests, the use of mobile test separators, as well as quality of measurements at high and frequently varying gas-oil ratio (GOR) reduce promptness of the operating production management at the field. Virtual flow metering reduces the effect of these factors allowing the information on well performance to be received every minute, and adding elements of modeling to this tool makes it possible to understand quickly the performance of wells and other production objects.
The virtual flow metering technology requires, first of all, a high level of field equipment with online sensors. At Novoportovskoye field, a program has been launched since 2019 to equip wellheads with sensors to measure pressure and temperature. Pressure and temperature measurements from each sensor pass every minute to a model where current production rate of the well is calculated and the result is compared with previous value. If a significant deviation is detected, a specialist from production team gets a warning and finds out a reason of the deviation. As opposed to daily analysis, the every-minute analysis of well performance opens a wide range of opportunities for prompt response to deviations in well operation, especially in combination with well remote control systems. Early detected deviations, such as deposits accumulated in tubing and pipelines, degradation of ESP head and rate, etc., allow considerable reduce production losses, increase promptness of response to deviations, and optimize distribution of resources in advance.
Also, this technology allows to perform production allocation of daily production from processing facility, thus avoiding uniform distribution of errors of measuring devices through the use of back allocation coefficients.
In the future, the use of virtual flow meters can give the opportunity to stop using of several rate measuring devices (like test separators or MPFM), which would result in reduced capital expenditures for well infrastructure development. Also, this technology opens opportunities for automatic control of well performance.
Currently, virtual flow metering is uncommon at gas fields, so the implementation of this technology at an oil and gas condensate facility is a challenge for high-tech companies. Gazpromneft-Yamal have achieved good results in the use of integrated model, and virtual flow meter will be a next step for further achievements.