bluuebunny/crossref_metadata_2025_split huggingface dataset:
Refinement of the Drillpipe-Slip Mechanical Model
Authors: Tikhonov Vadim , Gelfgat Mikhail , Ring Lev , Bukashkina Olga 
Published: October 2017

Abstract
Slips, slip elevators, spiders, etc. have been widely used as oilfield service tools to grip and hold drill pipe, drill collars and casings by acting as a wedge. A pipe in a slip with a conical bearing surface is subjected to complex loads comprised of tensile, compressional, radial and bending stresses. To increase the holding force, the bearing surface of the gripping device in the form of a dies set is provided with teeth penetrating into the pipe body. This generates additional drag force on the contact surface that supplements the friction force.
This paper presents a new slip model, which uses the dependence of the drag force on the teeth penetration depth. The model is based on an improved dependence of the drag of wedge-shaped die teeth not only on the friction force in the "die-pipe" pair but also on the shearing force arising during teeth penetration in the pipe body. Equation parameters have been verified by multiple finite element (FE) calculations and experimental studies of dependence of the penetration force on the drag of a single tooth. The developed equations are used in the complete drillpipe-slip model. It accounts for pipe wall deformation under compressive stress generated by the slip and the drillstring weight and determines the active bearing length of the slip under load. The paper presents calculations of allowable areas for a slip of a specified length equipped with toothed dies based on the load carrying capacity and pipe strength.
The proposed model can be used for operative calculations of the slip carrying capacity, as well as for the development of new slip designs.
Integrated Project Management Reduces Well Construction Time by 25% while Delivering Complex 3D Extended-Reach Drilling Campaign on Lebedinskoye Field, Sakhalin
Authors: Lebedeva Irina , Mazaev Konstantin , Valshin Oleg , Savinov Roman , Kasumov Ruslan , Shakirova Anastasia , Mikhailitsyn Egor , Leontyev Dmitry , Kim Vitaly , Bochkarev Vladimir , Nikifirova Olga , Surmin Vladimir , Tyan Oleg 
Published: October 2017

Abstract
This paper will present the integrated extraordinary solutions founded during Extended-Reach Drilling (ERD) campaign on Lebedinskoye oilfield, which is located on the Northern East shelf of Sakhalin Island.
As a green field, Lebedinskoye had a high level of geological uncertainty. Specifics of location made the well profiles complex - with a high Directional Difficulty Index – DDI (SPE ref. 59196) up to 7.2 and ERD ratio up to 2.94. Island logistics imposed critical constraints to the project planning.
Rosneft and Schlumberger established the goal to optimize the well construction time to bring additional savings in the period of industry downturn. At the same time, a project team set ambitious goals to plan and execute operations to a safe and high quality standard.
An integrated approach was deemed essential for success of such complex project. Integration provided a seamless interface bridging multi-discipline solutions and technologies to ensure high quality planning together with risk management.
Several technologies in the project were implemented for first time in Russia. A "point the bit" rotary-steerable system enabled drilling the 17 ½" section in the one run of 2168m. A non-cemented liner eliminated the additional cost and time for a cement job as well as the potential impairment of the pay zone. The project team successfully run floated 9 5/8" casing to the final depth and eliminated major risks of the campaign. The Lebedinskoye was the first time the client implemented advanced LWD tools for deep reservoir mapping. In the result, 97% of 1962m horizontal section placed in the target zone, which became a new record for the Client.
Finally, integrated approach, new technologies and solutions reduced well construction time by 25% as compared to similar offset extended-reach wells and made the project economical efficient in the period of downturn.
A Package of Technical and Technological Solutions for Enhancement of Casing Quality during Wells Construction
Authors: Isaev A. A. , Takhautdinov R. Sh. , Malykhin V. I. , Sharifullin A. A. 
Published: October 2017

Abstract
Currently the well casing is performed for different purposes: –strengthening of borehole walls in the intervals of unstable rocks;–isolation of zones of disastrous lost circulation of flushing liquid and zones of possible crossflows of formation fluid along the borehole;–separation of intervals where geologic conditions require implementation of flushing liquid with very different densities;–Separation of productive horizons and their isolation from aquifers;–formation of a reliable channel in a well for extraction of oil or pumping a fluid into the formation;–creation of a reliable foundation for installation of wellhead equipment.
The cement rock behind the casing string should be sufficiently strong and impermeable, have good adhesion to the surface of a casing pipe and to the walls of a wellbore.
Analysis of the complications regarding well strengthening shows that about 30% of wells contain water cut products due to incorrect determination of oil-water contact (OWC); 20% of the complications are due to the absorption of the grouting slurry and, consequently, insufficient lifting of cement mortar; interlayer crossflows account for about 25%, of complications, fluid kicks - 10% and 15% are associated with insufficient running of strings. Liquidation of interlayer cross-flows require significant costs that reach the average of 16% of the well cost (as regards the well stock of Sheshmaoil LLC), therefore the quality of well casing is of significant importance.
Study of Suppression of Gas Bubbles Coalescence in the Liquid for Use in Technologies of Oil Production and Associated Gas Utilization
Authors: Drozdov A. N. , Drozdov N. A. , Bunkin N. F. , Kozlov V. A. 
Published: October 2017

Abstract
The paper is devoted to the investigation of the stability of gas-liquid mixtures.
Investigations of the suppression of the coalescence of gas bubbles in a liquid at various concentrations and composition of dissolved salts were carried out on a facility containing a laser diode with a telescopic system, a glass column, a bubbler, a gas supply system, a laser reception unit with a breaker, a lens and a photodiode, an oscillograph and a computer. The value of coalescence suppression was determined from the change in the transmittance of laser radiation through a column with bubbles in the liquid. In addition, bench tests were carried out on the characteristics of ejectors and a multistage centrifugal pump when creating and pumping gas-liquid mixtures using fresh water as a liquid, as well as aqueous solutions with various concentrations of NaCl.
It has been experimentally determined that there are zones of rational salt concentrations and composition in which the coalescence of gas bubbles is suppressed due to the expression of repulsive forces between bubbles charged negatively in aqueous solutions of electrolytes. At smaller and higher concentrations coalescence suppression does not occur, and gas bubbles actively join with each other. The effect of cations and anions in aqueous solutions of various salts on the process of suppressing the coalescence of gas bubbles in a liquid is revealed.
Investigations of the produced water from Samodurovskoye field showed that its composition helps to suppress coalescence of bubbles, but the addition of a certain amount of NaCl enhances the suppression of coalescence.
When the water-gas mixture prepared by the ejector with using fresh water was pumped was pumped out on bench and the coalescence of gas bubbles was not maintained, the pressure developed by the multistage centrifugal pump decreased greatly with increasing gas content at the pump inlet. When using of NaCl aqueous solutions in the field of rational concentrations, a multistage centrifugal pump began to operate much better on a water-gas mixture. This was due to the suppression of the coalescence of gas bubbles in the liquid and the prevention of the formation of large gas caverns in the inter-blade channels of the pump.
Field studies of the pump-ejecting system for SWAG injection on Samodurovskoye field were also carried out.
The obtained results can be used for utilization of associated gas by water-gas injection, as well as in various oil production technologies, where gas-liquid mixtures move (completion, operation of wells, gathering oil, gas and water).
Multiphase Gas-Condensate Metering Tests with Individual Fluid Properties Model
Authors: Davidovskiy A. O. , Abramochkin S. A. , Lopatina N. G. 
Published: October 2017

Abstract
Gas-condensate production studies are run to determine the paramount data for gas and condensate reserve evaluations, field characterizations and facilities installations.
Currently, there is enough number of workflows, rules, and recommendations to conduct gas-condensate metering tests (GCMT) with data processing and results presenting, however, all such documents imply the use of traditional measurement instruments, which are the conventional separators. Over the last decade, multiphase flowmeters have become widely known and they provide non-separating measurements of all produced phases a single measuring point.
The paper presents a unique GCMT workflow using a Vx multiphase metering technology, which considers the use of individual fluid properties models (or PVT models), designed for accurate flow rate measurements in gas condensate wells, when permanent measurements are arranged for individual or a group of gas condensate wells. The workflow implementation has allowed creating a comprehensive alternative to traditional separation technologies for conducting GCMTs in gas condensate wells of Achimov deposits in Western Siberia.
Geochemical Tools to Correlate Light Petroleum and Evaluate Thermal Maturity: A Case Study of Precambrian Condensates from East Siberia, Russia
Authors: Chakhmakhchev Alexander , Shiganova Olga , Andrus Vlad , Tchistiakov Alexei 
Published: October 2017

Abstract
Geochemical correlations of light oils and condensates represent an analytical challenge because of low concentrations of the longer chain alkanes and polycyclic biomarkers. In this study, several geochemical techniques are shown to be useful tools for the correlation purpose and maturity assessments of condensates from East Siberia. The whole oil GC provides compositional data for a wide range of hydrocarbons (C4-C36) including gasoline range hydrocarbons used to distinguish petroleum families in the study area based on iso-/normal alkane ratios. More unique to the Precambrian petroleum system is a presence of mid-chain methylated alkanes, and their relative concentrations were shown to vary in condensates of the Baykit and Nepa-Botuoba basins. Similar to the previously reported oil samples, condensates in the Nepa-Botuoba Basin are enriched in mid-chain methylalkanes.
The odd/even carbon number predominance in C16-C25 range of alkylbenzenes and alkyltoluenes was also used to differentiate condensates in these two basins. The condensates from the Baykit Basin show a simple slope in C16-C25 range, with almost equal concentrations of odd and even monoaromatic hydrocarbons. The Nepa-Botuoba samples are very different and demonstrate a strong even carbon number predominance in alkylbenzenes and odd carbon number predominance in alkyltoluenes.
Maturity indicators derived from the GC-MS analysis of the aromatic fraction and using distributions of phenanthrene, methylphenanthrenes, dimethylnaphthalenes, methyl-, dimethyl-, trimethyldibenzothiophenes and m-/o-alkyl-toluenes nicely correlate with each other and clearly differentiate overmature condensate from the rest of the group.
The biomarkers findings in a single Verkhnechon sample include predominance of C29 steranes, relatively low diasterane content, very high concentrations of tricyclics vs. pentacyclic terpanes. The biomarkers characteristics along with Pr/Ph &lt;1.0, suggest anoxic depositional environment, predominantly marine algal organic matter source, carbonate lithology of the sources rock, and maturity level corresponding the peak to late oil window. Biomarker distribution in this condensate resembles those of oils discovered in the Nepa-Botuoba Basin suggesting the same source of hydrocarbons in both oils and condensates.
Surprisingly, neither isomer ratios nor absolute concentrations of diamondoids correlate with measured maturity levels in condensates. Additional work has to be done to understand other factors contributing to diamondoid elevated concentrations such as, for example, migration processes.
Applications of Wireline Formation Testers for Through-Casing Reserves Classification
Authors: Blinov V. , Weinheber P. , Shelomikhina I. , Kolomiets A. , Sardarov G. , Kreknin S. , Pushnikov K. , Safin R. 
Published: October 2017

Abstract
The purpose of this paper is to analyze the advantages and disadvantages of using modern Wireline Formation Tester (WFT) tools to refine the geological information and classify hydrocarbon reserves using an example from the Yamal Peninsula.
In order to meet the GKZ reserve classification requirements it is necessary to have production from the reservoir which was traditionally done with the help of open hole DST tools. It has recently been allowed to perform this task with WFT tools. In this paper we will consider a through casing application in a multi-layer reservoir. The combined use of WFT and DST allows us to contrast and compare both technologies.
As a result of this work we will show that the WFT can deliver similar quality information as the DST allowing us to acquire a C1 classification, determine fluid contacts and confirm saturations. The WFT offers the additional flexibility of testing ‘missed’ layers. There are also important differences to be noted, most significantly the higher resolution of the WFT allows pinpoint determination of contacts, however the relatively low flow rates and volumes usually does not allow us to determine reservoir boundaries. The combination of WFT and DST technologies offers the best picture of the reservoir.
Benchmarking of Various Types of Completions and MS Technologies for Horizontal Wells at the Priobskoe Field Southern License Topic
Authors: Sitnikov A. , Asmandiyarov R. , Pustovskikh A. , Sheremeev A. , Zulkarniev R. , Kolupaev D. 
Published: October 2017

Abstract
With each year drilling of new wells is performed in worse and worse reservoir properties conditioned by low permeability and undersaturated reservoir. At the same time, percentage of hi-tech horizontal wells (HW) with multistage hydraulic fracturing (MSHF) is increased, advanced technologies and engineering solutions are deployed; all this allows to maintain and even increase levels of oil production in new wells.
As at beginning of 2017, over 200 MSHF HWs have been drilled in the unique Priobskoe field (South Concession Area) with use of the most advanced technologies. Various completion types and MSHF technologies have been deployed and tried in 50 areas in search of the best technologies and engineering solutions. Wells in such areas were producing for more than 1year and at this stage there is adequate amount of data on cumulative production, liquid and oil decline rates for efficiency benchmarking. Number of commissioned MSHF HWs is increased each year and there will be over 600 MSHF HWs by 2019 (+300% to current number) and results of this paper is a determining vector of development for further decisions applicable to improvement of efficiency of MSHF horizontal wells.
The following main points for increasing efficiency of MSHF HWs were identified by results of the benchmarking: Increase of HW length to max. 1500 m allows to increase productivity, obtain incremental cumulative production over 20% vs. offset wells with HW length ~ 1000 m.Depending on the distance between ports, an optimal number of MSHF stages is ~ 125 m; in some cases, this distance is increased to ~150 m for large volumes of proppant &gt; 90 tons per stage.Increased mass of proppant &gt; 90 tons per stage (maximum 122 tons, up to 10 tons per 1 meter of formation) allowed to obtain incremental cumulative production from 20 to 48% during the first year as compared to offset wells with proppant mass &lt;50 tons per stage.An optimal range of proppant mass identified for the undersaturated reservoir is 50-60 tons per stage depending on the TVDSS. Success of cluster MSHF was reported for some wells.Use of internal-flush cemented liners with targeted initiation of fractures shows good results in some areas. Subject to the quality cementing, this is the most strategically promising and anticipated approach for the repeated targeted MSHF. History of decline rates, operational experience of fraced directional wells show that over 200 re-MSHFs shall be performed in the next 10 years.
Automatic Control Algorithms of Water-Gas Mixture Injection under Implementation of SWAG Technology
Authors: Gladysheva Marina A. , Vinogradov Pavel V. , Lutfurakhmanov Artur G. , Nadezhdin Oleg V. , Efimov Dmitriy V. , Sergeev Evgeniy I. 
Published: October 2017

Abstract
SWAG technology is planned to be implemented in a large oil field currently being at the initial stage of development. SWAG (Simultaneous Water-Alternating-Gas) is a method of the oil fields development by pumping water and gas mixture in reservoir to maintain the reservoir pressure. In addition to maintaining the reservoir pressure, SWAG is also used to enhance the efficiency of field development due to oil recovery increase with disposal of produced associated petroleum gas (APG). The objective of this project is to create automatic control system (ACS) of reservoir pressure maintenance (RPM) pipeline system to ensure stable and steady injection of water-gas mixture (WGM) into reservoir in accordance with the target flow rates of water and gas under potential perturbations.
While performing the work two software complexes were used together: a hydraulic simulator to create mathematical model of RPM pipeline system and special design system to build ACS. Based on the results of dynamic processes analysis, control algorithms were developed both for ACS of a single injection well and for ACS of RPM pipeline system.
The study of the behavior of RPM pipeline system showed that it is a complicated control object having the properties of nonlinearity and multistability. These features were taken into account when choosing the structure of ACS. As a result, low-level multi-loop ACS was created on the basis of PID-regulation with a cascade contour to control wellhead pressure. Also, high-level control algorithm was developed that ensures distribution of incoming gas volumes between injection wells according to their operating regime.
Testing of designed ACS was performed on experimental-industrial site which was created for WGM injection experiments into two wells. Test results confirmed that developed control algorithms were correct and could be scaled up for full implementation of SWAG (i.e. ACS could be quickly rebuilt in case of changes in number of injection wells of RPM pipeline system).
The described approach to the synthesis of ACS of RPM system and developed algorithms can be applied to similar projects of simultaneous water-gas injection into the reservoir using RPM system.
Reservoir Modeling of Complex Structure Reservoirs on Dynamic Adaptive 3D Pebi-Grid
Authors: Filippov D. D. , Kudryashov I. Yu. , Maksimov D. Yu. , Mitrushkin D. A. , Vasekin B. V. , Roshchektaev A. P. 
Published: October 2017

Abstract
The paper presents methods for generation of unstructured adaptive 3D PEBI grids, allowing for effective multiphase filtration modelling of reservoirs with multiple structural and technology features (faults of complex geometry, horizontal wells and wells with hydraulic fractures). We developed the algorithm of local grid rearrangement due to newly opened/shut wells and hydraulic fracturing, reducing simulation time. For problems, requiring accurate flow simulation in vicinity of structural features, an automatic local grid refinement was implemented.
On grids under consideration, three-phase filtration problem is solved numerically, accounting for gravitational, viscous and capillary forces and phase transition of hydrocarbon components. For the discretization of governing equations, two-point approximation is used as well as mimetic finite difference approximation customized for problems being solved. Distinctive feature of the proposed numerical method is direct flow computation in hydraulic fractures.
Experience of MDA Ensemble Smoother Practice for Volga-Ural Oilfield
Authors: Breslavich Ilya D. , Sarkisov Gennadiy G. , Makarova Ekaterina S. 
Published: October 2017

Abstract
More and more hard-to-recover deposits involved into the development, and most of the fields under development are in mature production stage. Therefore, reservoir engineers are faced with task of quantifying the predicted indicators uncertainty.
There are several approaches to achieving this goal, ranging from expert assessment and sensitivity analysis to methods based on proxy modeling, response surfaces, Kalman filter, and ensemble smoothing. In the opinion of the authors Multi Data Assimilation modification of the ensemble smoothing is the most technologically feasible way of solving the problem creating and then analyzing a representative ensemble of model implementations.
This method, in contrast to popular methods based on the response surface, allows, without loss of accuracy, to run parallel calculations throughout the ensemble of implementations, which saves considerable time for making calculations. ES-MDA method application to create a representative ensemble of realizations of the real-field filtration model, which has a long development history is considerate in this paper.
This paper describes the experience of one of the first ES-MDA applications in Russia to such a complex facility as a three-phase multilayer sector filtration model with more than 60 years of development, with more than 150 wells, most of which with casing leakage.
An Experience of Creation Variable Hydrodynamic Models on Example Tyumen Deposits in Case of Geological Structure Uncertainties
Authors: Mett D. A. , Sukhodanova S. S. 
Published: October 2017

Abstract
The article is devoted to the search of ways how to verify existing geological and hydrodynamic models and to improve the quality of forecasting the production indicators at the field. The fact is that experience and practical applications show how often we make mistakes, making preliminary calculations of well production rates and general rates for deposits, even for a near future. However, the use of all the information, that we can get during the reservoir development, can increase the level of accuracy in the forecast calculations and show the actual picture of the potential for any field in particular.
The erroneousness of forecasting is more connected with the uncertainties of the geological formation structure. The use of additional initial data, and the accounting of the current information, obtained from the results of wells testing, can answer the most important question with a high level of probability, when we need to choose the correct hydrodynamic model of a field. This article shows an example of an approach, that allowed us to explain in the real field conditions, how to select among of existing well-matched to the history models the only one, that is the most correct.