bluuebunny/crossref_metadata_2025_split huggingface dataset:
Calculating Prediction Uncertainty using Posterior Ensembles Generated from Proxy Models
Authors: Fillacier S. , Fincham A. E. , Hammersley R. P. , Heritage J. R. , Kolbikova I. , Peacock G. , Soloviev V. Y. 
Published: September 2014

Abstract
Most hydrocarbon fields have been operating for long enough to have significant production history. To quantify uncertainty in future yields it is essential to have a workflow that includes reservoir uncertainties in a way that respects the history. This starts with a simulation model, or more generally a forward model, that has been parameterised by uncertain input parameters with prior distributions. Proxy models can then be created to approximate chosen simulation outputs for all valid parameter combinations, based on a relatively small number of simulator runs. Each combination can be appropriately "weighted", using Bayesian methods, on the basis of the production history. This generates a probability distribution over the range of all possible history matches. Using the proxy models and Markov Chain Monte Carlo techniques it is possible to sample correctly from this probability.
Prediction uncertainty can now be calculated using two related and complementary mechanisms. The first is to take a moderately small sample (say 100) of parameter combinations to create a posterior ensemble of simulation runs. The prediction uncertainty can then be calculated directly from the ensemble of runs. The second is to create new proxy models which approximate the prediction responses of interest. The complementary benefits of the two approaches are discussed in this paper.
New Approach to PVT Correlation Selection
Authors: Khabibullin R. , Khasanov M. , Brusilovsky A. , Odegov A. , Serebryakova D. , Krasnov V. 
Published: September 2014

Abstract
This paper attempts to provide engineer with GOR PVT correlation selection rules. Rules based on comparison of standard PVT correlations with calculations based on Equation of State, which believed to have wider applicability range and be more general from physical point of view.
To make that comparison synthetic oils data bank where generated. Ranges for synthetic oils properties were chosen to cover all the real oils of interest (mainly from Western Siberia). All synthetic oils where analyzed using Peng Robinson equation of state with shift parameter and widely spread PVT correlations.
Results provided as GOR PVT correlation Applicably Maps and New Procedure calculation GOR by selected PVT correlation. Result was checked during PVT study of few Western Siberia oil fields.
Development and Deployment of Technology Complex of Use of Associated Gas for Increase in Oil Recovery
Authors: Kokorev V. , Darishchev V. , Akhmadeyshin I. , Bugaev K. , Shchekoldin K. 
Published: September 2014

Abstract
In article the main development stages and implementations of the equipment for associated petroleum gas use for the purpose of oil recovery increase are stated. The main difference of the developed equipment is the compressorless technology of pumping gas in the form of finely divided water gas mix.
Identification of Behind-Casing Flowing Reservoir Intervals by the Integrated High-Precision Temperature and Spectral Noise Logging Techniques
Authors: Lutfullin A. A. , Abdrahimov A. R. , Shigapov I. N. , Aslanyan I. Yu. , Aslanyan A. M. , Kuzyutin R. K. 
Published: September 2014

Abstract
Hydrocarbon production from low permeability reservoirs has been steadily growing in the Russian Federation lately. The reservoir sweep efficiency and behind casing integrity has become even more important than it was in conventional formations – mainly because the target oil/gas pays has experienced tough competition from higher permeable water pays. In high permeability formations one can normally track production profile with a conventional production logging tool based on a mechanical spinner and based on that schedule the treatment to arrest water cut growth. In low permeability formation most communication happen behind the casing and those flowing inside the borehole are usually too slow to be captured by the mechanical spinner.
This paper shows how high-sensitivity broadband Spectral Noise Logging [1–4], High-Precision Temperature Logging [1] and flow modeling in combination with conventional production logging can produce valuable information on gas, oil and water flow profile and behind casing communication (whether a cement rim channeling or a reservoir fracture flow). The technology is illustrated with three case studies from the East-Tarkosalinskoye field of the Yamalo-Nenets Autonomous Region (North Russia). One case was a vertical well and the two others are horizontal wells with multi-zone hydraulic fracturing. An integrated analysis of acquired data identified the sources of water production and also revealed the non-producing reservoir zones. Special attention was paid to the analysis of annular and behind-casing cross-flows.
One horizontal well was worked over with a cementing job around the zone identified as the water source from the HPT-SNL survey and resulted in total shut-down of water production with no impact on oil production.
Building of a Multiple Layer Oil and Gas Condensate Field Integrated Simulation Model
Authors: Kuzevanov M. A. , Buchinskiy S. V. , Glumov D. N. , Reitblat E. A. 
Published: September 2014

Abstract
Specific of gas field development suggests a constant level of gas production in order to provide stable loading of gas field processing and transport facilities. At this point, when production of major development objects commences to fall, start of minor objects production is supposed to occur. Having united surface facility and separate reservoir simulation of segregated layers with joint well stock a question of accuracy in measurement of hydrocarbon production is arisen. In addition, at the entry of production of minor objects with distinctive reservoir pressure a problem of appropriate distribution of wellhead and downstream pressures can be revealed.
In this paper mechanism of building of a multiple layer oil and gas condensate field integrated simulation model (ISM) is described. Construction of integrated model will allow resolving the problems outlined above. Besides, running of field development simulation cases with different order and tempo of production will be significantly simplified.
Separate compositional models made for each development object have been selected for integration in the ISM. However, consolidation of these models is complicated by the issue of demanding a lot of resources for storage and computation time. Therefore, a transition from compositional to black oil models has been performed in order to obtain production data. Detailed gas composition required for integration with a gas processing system can be gained by a delamping procedure.
As a result of building integrated simulation model a flexible tool of effective management of field development has been obtained that makes it possible to run simulations for both major and minor objects simultaneously and taking into account the field infrastructure (gathering and compressor facility); to assess the possibility of joint production of separate layers and consider the impact of gathering system on hydrocarbon production as well. When comparing the simulation time in different types of models, without significant loss of simulation quality, the average acceleration is about twenty times. This allows obtaining results much faster and further improving it.
The Solution of Problems of a Nonequilibrium Nonlinear Filtration on Commercial Simulators
Authors: Cheremisin A. N. , Cheremisin N. A. , Kostuchenko S. V. , Toropetsky K. V. , Ryazantsev A. E. 
Published: September 2014

Abstract
Summary
Results of computing experiments have shown that influence of effects of a nonequilibrium filtration (nonlinearity of the law of Darcy for liquids, existence of a limiting gradient of shift, creeping deformation of the steam environment) on results of hydrodynamic modelling and design of systems of development of oil fields and gas considerably. For the accounting of these factors, authors have developed methodical receptions, algorithms and the applied software for the solution of actual problems of a nonequilibrium multiphase filtration with use of commercial simulators. In the report, examples of the solution of such tasks for models of real fields are given and necessary recommendations are made.
Practice of Complex Architecture Well Construction at the Oil Fields of OAO LUKOIL in Western Siberia
Authors: Bakirov D. L. , Fattakhov M. M. , Bondarenko L. S. 
Published: September 2014

Abstract
The paper presents the designs of complex architecture wells applied in the oil fields of OAO LUKOIL in Western Siberia and presents some experience in construction of these wells.
Best Practice of Horizontal Well Construction Operations for the Challenging, High-Pressure Achimov Formation – Urengoyskoe Field
Authors: Dobrokhleb P. , Ablaev A. , Chetverikov D. , Zavarigin S. , Inyushina A. , Petrakov Y. , Sobolev A. , Zadvornov D. , Tarasov O. , Milushkin A. , Milenkiy A. , Grigoryev M. , Sidorov D. 
Published: September 2014

Abstract
Achimov deposits extend over 12,000 square kilometers around the city of Novy Urengoy. These deposits are characterized by high reservoir pressures, and a narrow range of drilling fluid densities that creates complicated conditions for drilling and completion of wells. Due to the high accident rate of drilling horizontal wells only S-shape wells were drilled for this formation.
The first successful horizontal production well was drilled in 2013 in cooperation Arcticgaz, ERIELL, Schlumberger.
The first well to drill a horizontal wellbore on Achimov formation, has been planned to open Ach3,4 and Ach5 layers of Achimov formation.
In close cooperation with project operator - Arcticgaz company, engineering group of Schlumberger drilling contractor and drilling contractor developed and successfully implemented comprehensive solutions for drilling and completion of horizontal wells Achim. One of the key factors of success was the use of drilling muds Megadril-D with constant control of equivalent circulating density. Application of rotary steareable system with optimally balanced PDC bits, allowed to drill horizontal wells through Achimov deposits in record time.
An additional factor for drilling risks reduction was implementation of geomechanic model, as in the preparation of the preliminary model and real-time control for wellbore stability with the latest technology logging measurements (LWD) – acoustic and density neutron formation properties.
In the period for 2013 to the 2nd quarter of 2014 have been successfully constructed more than 10 similar wells. Esteblished new records: maximum closure – 2403 meters, the length of the longest subhorizontal section reached 1233 meters. Set a record duration of well construction time of 62 days vs 100 planned, which could not been reached before by anyone in the region (formerly similar wells with shorter intervals of subhorizontal sectionhave been constructed in evarage about 150 days). Recently were successfully run two completion liners for 3-stage hydraulic fracturing (MSF) and one of MSF was successfully done. For completion purposes was used OBM with the weighting agent of mikro size, provided an unprecedented stability to settlement for a long time.
This article devoted to the description of technologies and solutions that have been used for the construction of sub-horizontal wells.
Preliminary production index of subhorizontal wells shows that current PI higher than S-shape wells (even with frac).
Positive experience in the construction of subhorizontal wells change plans to develop Achimov deposits and opens new perspectives of hydrocarbon production in the region.
Unique Water Shut-Off Solution for Water Producing Interval in a Horizontal Well Completed with Multistage Fracturing System Using Two CT Inflatable Bridge Plugs
Authors: Golovanev A. S. , Potryasov A. A. , Kovalev V. N. , Yunusov R. R. , Burdin K. V. , Mazitov R. N. , Bravkov P. V. , Serikov D. A. , Klimenko V. N. 
Published: September 2014

Abstract
The widespread application of multi-stage fracturing technology in Russia is already known not only due to increase of production rates and increase of recoverable reserves but also due to premature water flooding of some intervals. Several reasons could lead to that result, while, perhaps, the main one is a breakthrough in the aquifers in the process of the fracturing.
Objective of the job given by the client was to isolate water producing interval in a horizontal well completed with 8-stage MSF completion. To determine position of water-flooded zone, coiled tubing production logging tool (PLT) was used. Based on CT logging data 6th frac port of 8-stage MSF completion was found to be water flooded. Moreover, while total production rate of the well was equal to 500 m3/day (data was received during nitrogen lift while logging) with 95% WC, 68% of total production came from 6th frac port.
This article includes detailed study of planning process, complex and unambiguous decision-making aimed at technical and practical challenges, risk assessment and methods to reduce them, the stages of the work and planning in different situations that arise in the process of water shut-off and received lessons learned.
Anti-Stick-Slip Drilling Strategy for Horizontal Wells in Medium-to-Hard Heterogeneous Rocks
Authors: Kamatov K. A. 
Published: September 2014

Abstract
Though stick-slip phenomenon has been under intent research in recent years, high-level bottomhole and drillstem torsional oscillations still remain one of the main penetration rate (ROP) and tool life limiters in a wide variety of drilling conditions, such as an increasing amount of horizontal drilling with PDC drill bits. The heterogeneity of geological cross-section further complicates drilling environment leading to periodical depth-of-cut (DOC) and torque fluctuations.
The paper represents the study of field-collected drilling data from the challenging application of interbedded medium and hard carbonate rocks. First, similarity of most wide-spread constructions of drillstem in terms of drill string dynamics is discussed. Then, equations for different drill string dynamics zones are given for rotary and PDM BHAs. Finally, an example of drill string dynamics calculations from field data is given for multipart BHA. To account for different stiffness and length of the elements in used multipart assembly at hand, 2 drillstems are picked as boundary conditions for dynamic calculations; one consisting of drill pipes only, the second including BHA of planned length, but consisting of the most stiff element only, e.g. HWDP. The described method allows identification of zones (depth intervals) along borehole measured depth (MD) with high probability of torsional dynamic dysfunction appearance. Different drilling parameters can be applied to the calculation to change these zones’ size and position on MD. Finally, drilling strategy is developed to avoid BHA work in vibration-generating intervals. This can be done by proper and timely adjustment of surface and related downhole drilling parameters to vault over incompatible areas. The described method allows to significantly reduce and prevent negative impact of stick-slip, therefore improving ROP and overall drilling performance.
Considerations for Optimum Inflow Control Devices (ICDs) Selection and Placement in Horizontal Sections
Authors: Akbari Morteza , Gonzalez Jose R. , Macklin Nadine 
Published: September 2014

Abstract
Inflow Control Devices (ICDs) are used as a permanent part of the well completion to control and to effectively equalize the inflow from the reservoir to the wellbore along the length of horizontal section. Key consideration in ICD optimization are good reservoir modeling using in-house and commercially available Petroleum Engineering software, complete geological data from the existing wells and accurate permeability profiles (minimum and maximum permeability values and well test analysis).
Successful design and implementation of ICDs in horizontal sections depends on identifying and evaluating the correct Key Parameter Indicators sets (KPI's). The optimum ICD selection and placement is achieved by evaluating both non-ICD completion as a basic scenario and, a set of scenarios with varying pressure drop through the identified isolated zones along the horizontal wellbore (compartmentalization). Selection is governed by the appropriate ICDs selection and Flow Restriction Ratings (FRR) setting.
The ultimate goal is to the maximize the recovery factor by generating a uniform flow pattern through the drainage area in long horizontal wellbores, despite the differences in the frictional pressure drop from toe to heel, which is of major concern regarding water and gas coning.
In addition to a good understanding of both reservoir behavior and sand control completion technology, the process under discussion will help to overcome the geological challenges and to maximize the production.
Optimization of Cement Spacer System for Zonal Isolation in High-Pressure High-Temperature Wells
Authors: Tabatabaee Moradi Seyyed Shahab , Nikolaev Nikolay Ivanovich 
Published: September 2014

Abstract
Cementing a wellbore is a major stage in well completion and an initiation for production operations. One of the primary objectives of the cementing operations is zonal isolation. For effective zonal isolation and optimum hydrocarbon production during the life of the well, the entire drilling fluid, which presents in the annulus between the hole and the casing, should be removed. Over the years, several practices have been employed to help achieve mud removal and successful zonal isolation. From industry practices, efficient mud removal can be achieved with the use of spacers and flushes before cement is placed. The spacer system is designed according to different conditions including geological condition of the well. With the increasing tendency to drill high-pressure high-temperature wells, the design of robust and stable spacers is becoming more critical. Various spacer systems are available, but they may not be suitable for these conditions. The efficiency of spacer system is largely dependent on the rheological properties of the spacer at elevated temperatures. In this paper based on the laboratory investigations, the performance of specially designed spacer systems, their compatibility with mud systems and mud removal efficiency are compared in various temperatures. The spacers are weighted spacers, which are specially designed to meet the existed geological conditions of the well. The spacers contain a suitable surfactant package to increase its surface cleaning ability, a weighting agent (e.g. hematite) to adjust the spacer's density and a rheological modification agent. The proportions of these components in a spacer system will control the rheological properties of the final mixture, and thus, performance of the spacer. The spacers systems show a reliable performance in a wide temperature range.
The Results of Horizontal Well Drilling Using Invert-Emulsion Fluid at Kharyaginskoe Field
Authors: Khvoshchin P. , Lyadova N. , Iliasov S. , Nekrasova I. , Garshina O. , Kuznetsov A. 
Published: September 2014

Abstract
This work is devoted to the solution of the problem of well drilling on the sediments of the Devonian system known to lots of the world and Russian oil-and-gas regions. The well drilling on the Devonian sediments, especially with the horizontal borehole, is difficult due to the lithological composition and peculiar geomechanic properties of the clay formations composing the drilling intervals. This work covers the approach to solving the problem of keeping the Devonian sediments stability, starting from the integrated study of core of the problem intervals through the end of the testing of the developed technology concepts.
Hydrocarbon-based muds and relating invert emulsions are concerned to be unsurpassed in terms of keeping borehole stability, nevertheless they have got some disadvantages concerning the significant change in their structure-rheological properties during the change in thermobaric conditions. The solution of the stated problems is in the usage of the reagent, described in this report, which is aimed to regulate the rheological profile of the system under high bottom-hole temperature conditions. Due to the nano-size of the polymer particles, contained in the reagent, the filter cake is formed to colmatage micropores and microfractures in the formations as well as to prevent their spread.
The work covers the results of the practical-field testing of the improved invert-emulsion drilling mud formula at Kharyaginskoe oilfield. The leading foreign service company that conducted the drilling mud during the building of the horizontal wells at this oilfield before, has faced the problem connected with the loss of bore hole walls stability while opening the Devonian sediments at the zenith angles more than 60 degrees. The use of the drilling mud formula, presented in the report, has given the opportunity to avoid the problems stated above.
The field testing results, presented in the report, can be useful for the choice and reasoning of the drilling mud formula while constructing horizontal wells on the Devonian sediments by other companies especially those of them working in the Komi Republic and in the Nenets Autonomous District.
Express Method to Estimate Target Bottomhole Pressure in Pumping Oil Well
Authors: Khasanov M. M. , Khabibullin R. A. , Musabirov T. , Sokolov S. , Krasnov V. A. 
Published: September 2014

Abstract
Most of the oil wells in Western Siberia using electric submersible pumps (ESPs). Selection of the optimal mode of operation for wells equipped with ESP and selection of proper ESP technologies capable to maintain this mode highly important for effective oil production.
For many fields in Western Siberia the lowest bottom-hole pressure achievable is an optimal well operating mode. It gives maximum flow rate of fluid and oil. However, reducing pressure below bubble point leads to liberation of large amount of free gas in flow. It cause one of the major constraints to reduce the bottom hole pressure – artificial lift technologies limitations for working with a high content of free gas in the flow. That increase significance of the accounting of free gas presence in the flow while analyzing oil production systems, designing downhole equipment, calculating target bottomhole pressure.
Despite the fact that modern software can calculate the characteristics of multiphase flow and take into account the presence of free gas in the well and downhole equipment its influence often underestimated by engineers. Probably due to the complexities of quick multiphase flow calculations and lack of intuitive results, visualization tools which could help for decision-making.
In this paper we propose a set of simple graphical tools (pallet and graphs), and methods for calculating the gas fraction in the well and downhole equipment, target bottomhole pressure, applicability limits of technologies. Tools proposed aims to provide quick operational decisions for production analysis and artificial lift design. The paper discusses the experience of using the tools developed on real fields.