bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hybrid Drill Bit Mitigates Downhole Vibrations, Improving Drilling Efficiency in Challenging Curve Section of a Highly Interbedded Formation
Authors: Simiao Sheng , Jun Zeng , Ming Li , Yubao Shi , Chunliang Gao , Jin Hui , Wang Changhao , Wang Chen , Qi Yue , Li Deqing 
Published: October 2017

Abstract
As the demands of natural gas increase, the quantity of deep natural gas horizontal wells rises by 33% each year in Northeast China. Highly interbedded formations containing claystone and sandstone are located in a curve section that can result in harmful drilling vibrations. Tool face control and downhole tool failure are the key problems in these wells. Various downhole tools and drill bits have been tested for this application, and new design hybrid bits have proved to be the best choice to mitigate harmful vibration and improve drilling efficiency.
Normal polycrystalline diamond compact (PDC) bits often experience strong vibrations and accelerated wear. While roller-cone bits are less aggressive, they deliver lower rate of penetration (ROP) and drill limited distances due to their short bearing life. Because of this, a new technology hybrid drill bit, which combines the advantages of a fixed-cutter and roller-cone bit, was tested in this field. Based on the performance of the first-generation hybrid bits the cutting structure was upgraded to maximize the drilling efficiency and durability, achieving higher penetration rate.
After two years of development and evaluation, the new design hybrid bit has proven to mitigate these harmful vibrations, solving tool face control problems, mitigating downhole tool failures and significantly improve the drilling economics. The new hybrid drill bit increased ROP by a record 2.6 times, with a 160% increase in footage drilled compared to roller-cone bits with the IADC of 627 in the same group formation but drilled in the vertical section. This revolutionary new hybrid design also drilled 1.6 times faster and 1.7 times longer than the original hybrid design. In addition, the bit increased the borehole quality, which would help with casing job in the future operation.
This paper presents a case study of two hybrid bits utilized in the directional and horizontal section in Northeast China. Analysis of the drilling data and the detailed operation situation show the economics and the potential of the new hybrid technology as a tool to mitigate harmful vibrations and step-stage improve in drilling efficiency and rate of penetration.
Performance Challenge Upgrade: 16-in.TCI Design Achieves Multiple Drilled Wells Through Highly Interbedded Anhydrite, Shale, and Carbonate Formations
Authors: Al-Enezi D. , Al-Shelian J. , Muqaddes Z. , Beheiry K. , Linnerud B. , Heiny A. Al , Maouche Z. 
Published: October 2017

Abstract
Drilling a 16-in. section in southeast Kuwait presented several challenges. The formation is highly interbedded with significant variations in compressive strength ranging from 3 to 25 kpsi. Potential loss of circulation zones complicated drilling performance and required the flow rate and other drilling parameters to be controlled. Bit balling of the bit cutting structure was expected in some intervals where water-based mud was typically used. The drilling assembly was a pendulum rotary design.
The variation in formation compressive strength and formation hardness in addition to the highly non-uniform lithology created high impact forces on the roller cone inserts. Additionally, insufficient hydraulics and the high weight-on-bit necessary in the Dammam to Ahmadi carbonates led to the premature failure of the cutting structure and bearings. A durable and reliable bit design was necessary for drilling the entire interval as well as the subsequent well to help reduce overall drilling costs.
Collaboration between the operator's drilling team and the bit supplier resulted in successfully drilling a 16-in. challenging section and multiple additional wells. Rock types and compressive strength were analyzed using an advanced software program to determine the high-impact intervals and expected loss zones with insufficient hydraulics. Previous performances in the interval, as well as bit conditions, were thoroughly analyzed. These studies and finite element analysis were used to develop the new tungsten carbide insert (TCI) bit design featuring improved hydraulics configurations, durable and robust rubber seals, and advanced cutting structure materials. The design was dynamically tested in the laboratory in a similar application environment.
The new bit design exhibited exceptional performance in multiple wells in the 16-in. section in southeast Kuwait. The bit was used to drill three wells with a cumulative footage of more than 9,000 ft in more than 240 drilling hours. Approximately two million revolutions were achieved with effective bearings and slight normal wear to the bit cutting structure elements. The new bit design helped drill longer intervals and multiple wells with no risk of premature failure and helped reduce drilling time and bit costs.
Integrated Casing Surface Casing String Cementing Procedure under the Conditions of High-Intensity Process Liquid Absorption in the Eastern Siberia Oilfield
Authors: Bykov V. V. , Paleev S. A. , Zakharenkov A. V. , Samoylovich A. V. , Medvedev Y. V. , Kolesnikov S. G. 
Published: October 2017

Abstract
Throughout the entire oil fields' development drilling period on the territory of the Eastern Siberia, one of the main problems appearing in the process of well construction remains highly intensive, down to catastrophic, process liquid absorption. Loss of circulation during the well drilling can lead to a number of complications related to the bore-hole stability, possible losses in the mobility of the bottom-hole assembly (BHA), and other complications. To meet the current problems, drilling enterprises constantly test various technologies and materials aimed at solving the problem of well construction in the conditions of high-intensity absorption. The technology using an aerated process liquid and running off intermediate casing strings (directions) was chosen as the basic technology used in drilling the surface casing string interval under conditions of emerging absorptions at the oil fields in Eastern Siberia. When working with this method, there was a possibility of poor-quality casing string cementing in the conditions of absorption of process liquids, leading to significant complications and a decrease in the service life of the well.
The main goal of this work was to identify an approach aimed at solving the problem of low efficiency of standard methods and bridging materials used for surface casing string cementing jobs under the conditions of absorption. An analysis of a number of bridging materials was carried out, the most suitable product was determined, the existing technologies for eliminating the absorption and the possibility of their application in the fields of Eastern Siberia were considered.
This work represents the results of laboratory tests of plugging compositions, pilot-industrial works carried out in a number of fields on the use of complex cementing technology for the surface casing strings in the presence of absorbing horizons, using visco-elastic mud and developed cement-and-gypsum compounds.
Improving Production Efficiency of Liquid-Loading Gas Condensate wells with ESPs at North Urengoy Field
Authors: Epryntsev Anton , Minikaev Farid , Sullagaev Alexey , Yazkov Alexey , Khachaturyan Benik , Vildanov Eldar , Fastovets Andrey , Erdman Andrey , Selivanov Sergey 
Published: October 2017

Abstract
Frequently, production from gas and gas condensate wells is negatively impacted by the wellbore accumulation of liquid – a mixture of water and condensate. As reservoir pressure and tubing gas velocity decline and produced water cut increases, heavier liquids can no longer be effectively removed from the wellbore, resulting in the liquid column build-up at the bottomhole. This creates additional backpressure on the producing formation and leads to gradual production decline, until the well completely stops producing – the condition widely known as "liquid loading". Use of smaller size tubing (velocity string) is often the simplest and most straightforward solution, but depending on reservoir properties (water cut, productivity and pressure) and well completion (vertical, slanted or horizontal) this approach may not be efficient. This paper describes the technical approach to resume continuous production from liquid-loading gas condensate wells at North Urengoy field. It is shown that Electric Submersible Pumps (ESPs) can be successfully applied to unload horizontal wells producing large amounts of water. In this application, water and condensate is lifted by the pump through the tubing string, while gas and condensate mixture is simultaneously produced through the annular space between the tubing and the casing. Reviewed in detail are the technical challenges of modeling the well and pump performance using dynamic multiphase flow simulators, and the ESP design for the pilot application in deep, horizontal gas condensate well in Russia.
Peculiarities of the In-Field Gas Gathering Systems at the Latest Stage of the Development of Cenomanian Deposit Yamburgskoye Gas Field
Authors: Kudiyarov G. , Istomin V. , Egorichev A. , Stonozhenko I. , Rotov A. , Sergeeva D. 
Published: October 2017

Abstract
The latest stage of gas field development is characterized by some exploitation complications, related to reducing of gas rates and as a consequence a water accumulation in gas-gathering systems (in-field gas pipelines). It leads to a formation of ice and/or hydrate deposits in contact with a cold wall of pipeline with negative (on Celsius) temperature as a result of an environmental impact.
Analysis of gas-gathering systems of the Yamburg field (Cenomanian horizon) revealed qualitative differences between ice and hydrates deposition. For instance, ice formations are characterized with higher locality due to significant water accumulations on the lower section of the pipeline and ice growth at the wall of pipeline. Thus, liquid plugs play a key role in the formation of ice plugs that block pipeline's cross-section, reduce the stability of gas collection system's technological regime and gas production.
The purpose of this work is to discuss some technical solutions, efficiently eliminating the accumulation of liquids in gas-gathering systems while having a low exploitation expenses, simple realization and flexibility of applications compared to existing ways.
A technical solution for local diameter reduction facilitates the water plugs removal at most critical in terms of ice formation. An approach, based on the application of lay-flat polymer sleeve for local pipe diameter reduction allows the increasing velocity of gas-liquid flow at a given pipe sector for providing stable liquid removal without its accumulation. Target pipe areas suitable for the technology are chosen based on hydrodynamic modeling, accounting for the actual pipeline route.
Application of an ejector unit and in-tube separator enables to independently decrease pressure at the pipeline by 1.5-3.5 times. This leads to increase of gas-liquid velocity by 2-3 times, which leads to liquid removal. This allows reduction of methanol consumption, which is used for water freezing prevention.
The proposed technologies allow variations in realization dependently on requirements for exploitation modes and for time-changing parameters of gas-gathering systems operation. These technologies can be considered as a part of a complex strategy for gas-gathering system reconstruction at the stage of production drop.
Development, Implementation and the Results of Implementation of Novel Dual Completion Technology, and New Methods of Evaluation of Oil Wells Layers during Dual Completion
Authors: Isaev A. A. , Takhautdinov R. Sh. , Malykhin V. I. , Sharifullin A. A. 
Published: October 2017

Abstract
During operation of oil wells with multiple pay zones having a common filter, a negative factor may occur due to the crossflow of formation fluid from the high-pressure reservoir to the low-pressure reservoir, which leads to insufficient oil production. Currently, different types of dual completion (DC) arrangement are used to operate more than two pay zones. In PJSC Tatneft, dual-lift [1-6] and single-lift units are widely used [7]. But dual-lift DC systems have drawbacks such as high costs on capital investments and maintenance. The drawbacks of a single-lift unit are the following: the high cost of upgrading, as the unit consists of two pumps of the same type and size; plunger twist-offs occur at the place of their connection; there is a difficulty in separating the cylinder depending on the productivity of the formations in case production rate of at least one of the formations changes; the unit can only operate two pay zones apart from each other.
Case Study: Application of On-Off Adaptive ICDs with Inner Sliding Sleeves in a Horizontal Well in Saudi Arabia using 2 3/8-in Coiled Tubing
Authors: Anopov Alexey , Alomair Ahmed , Aseeri Mohammed A. , Ahmed Danish , Molero Nestor 
Published: October 2017

Abstract
Inflow Control Devices (ICDs) are completion hardware often used in horizontal wells to balance flow rates across the completion for the entire length of the interval. This is accomplished by creating an additional pressure drop on each ICD to equalize pressure drawdown along the reservoir to achieve a more homogenous flow profile along the horizontal section. ICDs are also used for selective zonal isolation and for delaying the flow of unwanted fluids such as water and gas into the horizontal wellbore.
The conventional method to shift the ICDs uses a downhole tractor conveyed with an electric line (e-line) cable or a standard coiled tubing (CT) string; the shifting activates the production of horizontal wells equipped with these devices. However, there are some challenging cases, for which neither of these traditional methods represents a reliable alternative to actuate the ICDs for several reasons, including Drag and buoyancy forces encountered in the wellbore close to the operational limits of the e-line cableWellbore severity, tubular restrictions, and well configuration, which hinders the ability for electric line cable to access target depth, even with the use of a downhole tractorThe absence of downhole measurements in standard CT use for accurate depth control and confirmation of ICD status and shifting tool performance.
In a well in Saudi Arabia, electric line was unable to reach target depth, and conventional CT did not provide the confidence needed to act. In this well, CT equipped with real-time downhole measurements was successfully used to actuate up to 10 ICDs in a horizontal well. The real-time downhole measurements included pressure, temperature, depth from a casing collar locator, and tension and compression from a tension-compression sub. The experience gained with this technique in the successful operation in Saudi Arabia yielded recommendations for future similar operations.
New Possibilities of Well Testing and Production Logging in Horizontal Wells with Non-Uniform Inflow Profile
Authors: Kremenetsky M. I. , Melnikov S. I. , Ipatov A. I. , Kolesnikova A. A. , Shorohov A. A. , Buyanov A. V. , Musaleev K. Z. 
Published: October 2017

Abstract
This paper discusses the integrated interpretation of well log data collected in horizontal production (injection) wells with low flow rates and non-uniform inflow (injectivity) profiles. A factor analysis is performed and information value of these methods in horizontal wells is defined.
Development of Automatic System for Decline Analysis
Authors: Kotezhekov V. , Margarit A. , Pustovskih A. , Sitnikov A. 
Published: October 2017

Abstract
Traditional well testing methods applied for production wells for estimation of reservoir porosity and permeability, pressure, and other parameters imply the shutdown of wells to carry out pressure build-up tests. These tests entail significant losses in oil production and, in many cases, do not provide enough information in the event of low-permeability reservoirs because of the insufficient duration of the testing. An alternative to the pressure build-up test is an estimation of well and reservoir parameters based on production data (decline-curve analysis) carried out by means of special software. As compared to the pressure build-up test, the interpretation of decline-curve analysis allows to decrease losses in oil production during shutdowns, assess well interferences and boundary conditions, etc. (Ipatov and Kremenetskiy, 2008). Because of the growing number of wells equipped with high-precision pressure sensors for downhole telemetry and due to ongoing tasks related to monitoring and control of the development process, it is necessary to reduce labor hours required for production data processing.
This thesis provides a description of the system designed to introduce automation into the interpetation of production data by means of the machine learning techniques.
Borehole Acoustics as a Key to Perfect Hydraulic Fracturing in Achimov Formation
Authors: Metelkin D. A. , Snokhin A. A. , Tikhomirov I. A. , Karpekin E. A. , Eremeev A. A. , Korelskiy E. P. , Kalinin V. , Jocker J. 
Published: October 2017

Abstract
For economic production, the heterogeneous low-permeability Achimov formation of the Urengoiskoe field requires stimulation with high-volume hydraulic fracturing. Shales acting as stress barriers are present within the reservoir, dictating the necessity of fracture geometry monitoring and design accounting for local changes in mechanical properties. A new slim dipole sonic tool enables a reliable identification of fracture geometry in the near-wellbore region. The tool dimensions allow it to be run in environments unsuitable for conventional-sized sonic tools such as completions with a small inner diameter.
Analysis of sonic data in three wells reliably identified unintended fracture growth from the lower target Ach6 reservoir through the shale barrier into the upper Ach5 reservoir. Calibration of the fracturing model using the measured fracture height reveals that the main uncertainty in fracture geometry prediction originates from the input formation mechanical properties and stress profile. Therefore, fracture design optimization should include updates to the geomechanical model with account for the presence of structural VTI-anisotropy as well as justified dynamic-to-static conversions, refined pore pressure profiles, etc.
This paper demonstrates the use of dipole sonic pre- and post-frac logs to determine the real fracture height as well as the corresponding impact on the calibrated fracture model. A way forward is proposed to improve geomechanical models by including sonic-based anisotropy parameters to improve fracture geometry predictability in target zones.
Dynamic Reservoir-Pressure Maintenance System Study in Carbonate Reservoir with Complicated Pore Structure by Production Analysis, Production Logging and Well-Testing
Authors: Aslanyan A. , Gilfanov A. , Gulyaev D. , Krichevsky V. , Timerbaev M. 
Published: October 2017

Abstract
To discover remained reserves and recommend production enhancement operations in a carbonate reservoir with long production history it is important to perform not only production analysis, water breakthrough areas, but also areas, that took a lot of injected water during injection history. It's not an easy task in case of complicated formation pore structure especially than injection were carried on with high pressures and overbalancing.
Combined approach was used for remained reserves localization and production enhancement operations. It included complex geology study, production history and surveillance data. Well interference was examined by novel technology - multi-well deconvolution (MWD).
Oil Fingerprinting Technology for Well and Reservoir Management
Authors: Pavlov Dmitry , Vasiliev Anton 
Published: October 2017

Abstract
Oil fingerprinting is a common name for techniques based on geochemical analysis of hydrocarbon fluids composition which could provide valuable and unique information for well and reservoir management. Hydrocarbons in oil and gas deposits are affected by different processes, such as: biodegradation, gas flushing, water washing and evaporation. The degree of change depends on many factors: temperature, reservoir compartmentalization, tectonics, aquifer activity etc. Consequently, hydrocarbons initially migrated from one source rock become different in different reservoirs and compartments. Evaluation of changes in composition allows identification of hydrocarbons from different reservoirs, in other words to identify unique "fingerprints" of hydrocarbons. This information can be very valuable for production allocation between reservoirs and for needs of well and reservoir management. This article summarizes the results of a pilot oil fingerprinting project on Astokh oil field based on High Resolution Gas Chromatography (HRGC). The primary objective of this work was to develop a methodology for production allocation in comingled oil producers based on HRGC as applied for the Astokh area. In the course of work some more opportunities were identified, for instance monitoring of reservoir dynamics which could turn out to be more powerful than the primary objective.
Automated Interwell Connectivity Measuring in the Presence of Self-Induced Fracturing Effect
Authors: Ivaschenko D. S. , Kravets D. A. , Mumber P. S. , Musin A. A. , Sakhibgareev E. E. 
Published: October 2017

Abstract
The paper presents results of injector-producer connectivity analysis provided by means of the specialized software according to the field data – production and injection rates, producer bottomhole pressures. The "capacitance-resistance" model and its integrated modification are used. The suggested method is applicable to low-permeability reservoirs exhibiting self-induced fracturing effect. The problems of producer watering source quick searching and self-induced fracturing risk forecasting in kickoff horizontal sidetracking zones might be considered using this approach.
Improvement of Reservoir Management Effectiveness through Optimization of Bottomhole Pressures of Wells
Authors: Iktissanov Valery , Bobb Irina , Khalimov Rustam , Ganiev Bulat 
Published: October 2017

Abstract
The existing methods of reservoir management based on bottomhole pressure control imply setting of limited bottomhole pressures that are determined either through equations or based on pressure transient analysis (PTA). However use of project profitability metrics commonly applied in oil industry–cumulative oil production and net present value (NPV)–yields more valid results. In doing so, all basic aspects must be taken into consideration: geological setting, current reservoir performance, reservoir fluid properties, well interference, and others. This can be achieved through application of 3D flow simulation and inverse modeling methods.
To this end, we have developed an algorithm and created a few pilot models with different reservoir characteristics and fluid properties identical to conditions of actual reservoirs operated by the Company. The calculation results were analyzed considering specific reservoir conditions. We have revealed some principles and tendencies that can be applied to improve performance of oil and gas fields. The research results show that the choice of optimal bottomhole pressure is largely dictated by presence or absence of gas-cut fluid flow. In case the bubble point pressure is close to the initial reservoir pressure, optimal bottomhole pressures differ significantly from limiting bottomhole pressures and, thus, should be calculated. In case the bubble point pressure is lower than the original in-situ pressure, limiting bottomhole pressure is the right choice for production wells. We also found that in fractured-porous reservoirs the right time of putting injection wells into operation is of critical importance. The revealed principles and recommendations can be applied to improve the effectiveness of reservoir management operations and increase final recovery.