bluuebunny/crossref_metadata_2025_split huggingface dataset:
Precise Fracturing: Increasing Number of Stages and Reducing Treatments Size in Oil Rims of Novoportovskoe Oil Field
Authors: Kazakov E. , Vereschagin S. , Kichigin A. , Olennikova O. , Ishangaliev A. , Bulatov F. F. , Saifutdinov E. 
Published: October 2017

Abstract
Today, an effective application of multistage fracturing (MSF) became an acute problem for the Yamal Peninsula fields. At Novoportovskoe oil and gas condensate field, in order to achieve an effective reservoir coverage with fractures to increase hydrocarbons recovery, it was decided to revise the concept of horizontal wells completion, increasing the number of MSF stages and decreasing the distance between the stages.
In the complex geological conditions of the Novoportovskoye field, a fundamentally new solution was proposed for horizontal well completion – full bore MSF system with sliding sleeves, operated by hydraulic shifting key with coiled tubing (CT). This completion system allows to perform MSF without pulling CT out of the well to the surface and instantly use CT for well clenout in the case of screenout (SO). This decision is aimed to increas production and achive economic efficiency of the field development by increasing the formation coverage by means of larger number of MSF stages per well, and optimizing costs by reducing the time for the entire range of work at the well.
At the moment, 2 wells at Novoportovskoe field were completed with described MSF system, with total 40 stages fractured.
The technology allowed increasing of stages number to 20 in a 1000 m long horizontal section and installing selectively ports in the most effective zones of the formation. The coefficient of formation coverage was increased due to uniform placement of longitudinal fractures, which could not be achieved with standard "ball" MSF technologies.
As a result, by reducing treatment size and increasing number of stages, positive results were achieved: the water cut was 39%, with an average of 60% and the gas factor was 472 m3 / tonne, with an average of 800-1000 m3 / tonne in neighboring wells.
As a result, with use of integrated completion system with shifting ports, fracture control was obtained in real time due to coiled tubing functioning as a dead string during fracture, and, at the same time, data was stored at memory downhole gauges installed in the CT bottomhole assembly (BHA).
Innovative technology and a comprehensive approach to the design and implementation of fracturing operations in complex geological conditions of the Novoportovskoe field is a unique experience for the region. The possibility to increase an oil production of a horizontal well MSF (HWMSF) without breaking fractures into the gas cap was proved. This system has advantages with respect to standard MSF technologies in conditions of oil rim deposits, and is applicable for other projects where an increase of MSF stages and the completion cycle time reduction is required.
Local Stress Shadow Effect Analysis in Multistage Hydraulic Fracturing Design Considering Small Drillhole Spacing
Authors: Karpov V. , Parshin N. , Ryazanov A. , Moiseenko A. , Bochkarev A. , Mitrushkin D. , Nikitin R. 
Published: October 2017

Abstract
In this paper, the effect of local changes in the stress-strain state of rocks is analyzed, and an appropriate approach is proposed for modeling the geometry of hydraulic fractures on horizontal wells under conditions of a dense drilling network, including Zipper Frac technology. The main source of factual information on the development of cracks are the pressure curves obtained during injection tests, mini-fracs and main frac jobs, including fracs on offset wells and microseismic monitoring of fracturing.
At Vinogradov field as the optimal selected row production system. The analysis of the accumulated experience made it possible to identify promising areas for increasing the efficiency of the production system, including reduction in the distance between rows, a change in well azimuths relative to the principal stresses, and the extension of horizontal sections of the wells.
In this paper, we analyze the results of multi stage HF in conjunction with modeling the geometry of cracks in various software products, taking into account and without taking into account the local change in the stress-strain state of the rocks near hydraulic fractures. The simulation results are cross-validated with actual information on the various wells of the development object under consideration.
Modeling and analysis of the geometry of cracks in neighboring wells, oriented both longitudinally and transversely with respect to the direction of maximum horizontal stress, is carried out. Including the mutual influence of stages of Zipper Frac technology is analyzed.
Taking into account the effect of local stress redistribution made it possible to achieve a high degree of correspondence between the results of modeling available actual information from the target wells and the environment wells (pressure responses, microseismic results and production figures). Without taking this effect into account, it was not possible to achieve such a degree of compliance.
The conclusion is made that the effect of local stress redistribution both during fracturing at adjacent ports of a single horizontal well and fracturing of adjacent horizontal wells has significant influence on geometry and, in particular, to the fracture height, which is critical in the geological conditions of the considered object.
An approach to modeling and planning of the multi stage frac on horizontal wells in conditions of complex reservoirs similar to the object under consideration was developed. In particular, new approaches to the optimization of the sequence of Zipper Frac stages are proposed and recommendations are made for carrying out fracturing in the conditions of both longitudinal and transverse drilling mesh in relation to the direction of the maximum horizontal stress.
Improving SAGD Efficiency in Carbonate Reservoirs by Combining Horizontal, Deviated and Vertical Wells
Authors: Taraskin Evgenii , Ursegov Stanislav 
Published: October 2017

Abstract
The obtained experience of using in carbonates of the Permian - Carboniferous high viscous oil reservoir of the Usinsk field the "classical" options of thermal methods of enhanced oil recovery such as steam cycling and steamflooding injection in a system of vertical wells, and steam assisted gravity drainage in a system of parallel horizontal wells has worse efficiency in comparison with sandstones. First of all, this is due to the inadequate sweep of a massive fractured reservoir with the steam-thermal action. In this regard, the paper proposes a new combined technology of three-dimensional steam assisted gravity drainage based on the conjoint use of horizontal injection and production wells cross-drilled to each other with the deviated production wells and the vertical production wells surrounding them. The paper presents the actual results of the pilot demonstrating that the proposed technology is a real alternative to the "classical" options of the thermal development of the inner zone of the reservoir and the results of hydrodynamic calculations obtained on the sector model of the other pilot which allowed to study the mechanism of the proposed technology more deeply, to optimize the operating modes of wells and their location in the reservoir, as well as to predict the effectiveness of its application in the geological and physical conditions of the reservoir edge zone.
Optimization of Water Injection Policy for Horizontal Wells in Tight Oil with Low Pressure
Authors: Wang Jinfang , Tian Jun , Wang Zhengmao , Tian Changbing , Shi Chengfang , Gao Jian 
Published: October 2017

Abstract
The tight oil is usually developed by horizontal well with volumetric fracture, using depletion type of drive. The recovery rate of tight oil with low pressure is unsatisfactory, because of low natural reservoir drive energy. The horizontal well with volumetric fracture is stimulated traditionally by water-flood huff and puff. However, as the decrease of the permeability and productivity of wells, high decline of produced liquids and reservoir pressure is observed by laboratory and dynamic data, which is called stress sensibility effect. This paper presents an integrated method to supplement formation energy and prevent the stress sensibility.
The method mainly involves laboratory and numerical model. Firstly, to investigate the possibility of using areal water injection method, two cases are simulated in laboratory. One is simulated as square five-spot well pattern, and another one is horizontal well pattern. Both injector and producer are horizontal well. The injector can be instead of vertical well with large scale hydrofracture for cost saving. Finally, numerical simulation with Non-Darcy flow is carried out. The agreement is obtained with numerical simulation and laboratory.
This new method is applied to Chang-7 tight oil in China, with the lower formation pressure factor about 0.8. The reservoir's mid-depth is around 2000m. The tight oil is currently under primary depletion development with an annual production declining rate higher than 50% at the first year. The water-flood huff and puff in Chang-7 tight oil increase productivity to some degree, however, the recovery rate is low finally. The stress sensibility of Chang-7 is measured from lab, and the permeability decrease around 20%. To solve this problem, the method of linear water-drive for tight oil is suggested, using horizontal wells injection-production pattern. The oil productivity increase 3~4 times than vertical wells, and recovery rate increases 5~10% in lab. The reasonable technical policy of linear water-drive is optimized by numerical simulation.
This systematic technique provides a reliable method for decision making of energy supplement for tight oil with low pressure, which is helpful for effective and economic development of tight oil with volumetric fracture.
Best Practices in Managing Lost Circulation Events in Shuaiba Formation, South Rumaila Field, Iraq in Terms Preventive Measures, Corrective Methods, and Economic Evaluation Analysis
Authors: Al-Hameedi Abo Taleb , Dunn-Norman Shari , Alkinani Husam H. , Flori Ralph E. , Hilgedick Steven A. , Torgashov Evgeniy V. 
Published: October 2017

Abstract
Fluid loss in the Shuiaba formation leads to greater expenses from mud loss, difficulty in well control and zonal isolation, and NPT. This paper will provide a comprehensive statistical work, preventive measures, and corrective actions of lost circulation events in the Shuaiba zone, where this problem is significant. The work will provide an integrated analysis regarding the best ranges of key drilling parameters, which have the greatest chance of avoiding or mitigating lost circulation consequences.
The most significant drilling parameters (e.g. MW, ECD, Yp, RPM, SPM, and ROP) at the time of each event are recorded along with lost circulation remedies attempted, and outcomes of those remedies. Practical information from Rumaila field and range of sources are reviewed and summarized to develop an integrated methodology and flowchart for handling lost circulation events in this zone. This paper will be extended work along with previous comprehensive statistical study and sensitivity analysis models about the Shuiaba formation. In addition, economic evaluation analysis is conducted for partial, severe, and complete losses to obtain the best field procedures.
Proactive approaches are made prior entering the Shuaiba formation to prevent or mitigate the occurrence of the lost circulation. A broad statistical work, primitive mechanisms, typical drilling fluid properties, and recommended operational drilling parameters are estimated to use during drilling through this zone. Moreover, corrective actions are determined for each kind of the mud losses to provide efficient remedies, minimize non-productive time, and reduce cost. The best lost circulation strategy to the Shuaiba formation is concluded and summarized depending on a comprehensive statistical work, the most prevalent industry practices, technical papers, textbooks, and economic analysis evaluation to determine successful remedies for each type of the losses. These treatments are classified by relying on the mud losses classifications to avoid unwanted consequences due to inappropriate actions. In addition, engineered solutions and practical techniques are developed, which will contribute to give clear image and coherent understanding in regard this complicated and costly problem in the Shuaiba zone.
This study provides a unique compilation of information regarding traditional approaches and the latest approaches for lost circulation control. The work provides useful guidelines and possible solutions for all situations in terms preventive measures, remedial methods, and analytical economic study. In addition, due to the lack of published studies in regard the Shuaiba formation, this work can serve as a vigorous resource for drilling through this zone.
Well Placement Application to Drill Fishbone Well on Russkoe Field
Authors: Orlov D. , Enikeev R. , Nazipov D. , Kochneva S. , Dunaev V. , Khabibullin R. , Makhambetov A. , Shirshov A. 
Published: October 2017

Abstract
Currently there are very few oil and gas fields left with "simple" geological settings, producing high hydrocarbon rates from vertical or deviated wells. The need for modern effective methods of recovery improvement has become obvious and undisputed. Horizontal drilling is one of well-known and widely accepted methods for obtaining maximum hydrocarbons flow. One of the types of horizontal wells is the fishbone well, which is a multilateral well with the main wellbore and a few sidetracks (ribs). Depending on geological objectives, the sidetracks may be drilled within the same geological object as the main borehole, or a different geological object may be targeted.
While drilling horizontal wells, apart from drilling related challenges, the challenges, connected to geological aspects of the reservoir may be encountered. This article is devoted to the analysis of drilling a fishbone well with well placement utilization in Russkoe field.
New Decisions - New Opportunities: MPD as an Effective Method for High Fractured Carbonate Reservoir in Eastern Siberia
Authors: Soroka T. , Krivolapov D. , Koscher M. , Dobrokhleb P. , Voitenko D. , Polyarush A. , Giniatullin R. , Kireev V. , Krepostnov D. , Chernokalov K. , Zagrivniy F. 
Published: October 2017

Abstract
Yurubcheno – Tokhomskoe oilfield is located in Eastern Siberia, Krasnoyarsk region, where the most part of oil and gas reserves are contained in Riphean high fractured carbonate reservoir. This reservoir contained a lot of secondary interstices and caverns, that are tend to enlarge due to excessive pressure exerted, that leads to loss circulation, differential sticking and associated NPT [1]. In case of conventional drilling on Yurubcheno – Tokhomskoe oilfield, such problems don't allow to reach the project depth in horizontal sections 152.5 mm (6in) – 1 000 m.
The most popular method of struggling loss circulation is using loss circulation materials (LCM), which dramatically affects reservoir production properties. Furthermore, effectiveness of LCM wasn't enough, because volume of lost drilling fluid, which is oil based mud, remained too high.
Managed Pressure Drilling technique was applied for resolving problems while drilling horizontal section in Yurubcheno – Tokhomskoe oilfield that allowed to reach the TD. Compare to conventionally drilled wells, using of MPD in Yurubcheno – Tokhomskoe oilfield resulted in reducing mud losses up to 3 – 5 times, reducing 152.4 mm section drilling time by 20% and increasing well production by 65 – 180%.
New Approach. Dual Casing Design For Horizontal Wells
Authors: Bravkova N. , Truba A. , Sandutsa A. , Zadvornov D. , Grachev O. , Giniatullin R. , Kireev V. , Pilipets E. , Krepostnov D. , Mishakov M. , Gazimov R. , Gallimulin R. , Khlebnikov V. , Medvedev P. 
Published: October 2017

Abstract
Historically most of horizontal wells in Western Siberia have 3 casing string design with liner in horizontal section. Production casing normally was set at the top of productive formation to provide its isolation. Production casing seat selection was affected by unstable shales above productive formation. That was called conventional casing design.
Well cycle optimization process almost reach technical limit with current technologies and under current conditions. In order to allow further optimization new approach was required. JSC Rosneft Oil Company found that extensive field data from wells drilled in the formation demonstrates possibility to optimize some operations by combining production section with horizontal one. The concept was named Dual-casing design. Combined interval should be drilled in one run. Once reaching TD tapered casing string should be run.
Horizontal well cycle with conventional casing design includes following stages: Drilling section for conductorRun and cement 324mm conductorDrilling section for surface casingRun and cement 245mm surface casingDrilling section for production casingReaming trip before running casingRun and cement 178mm production casingLoggingDrilling of horizontal sectionReaming trip before running linerRun 114mm liner
Implementation of dual-casing design will allow to exclude following stages (see Figure 1): Reaming trip before running casingRun and cement 178mm production casingLoggingAdditional trips for BHA changes
As a results of preliminary well time estimation well cycle could be reduced by 40% due to dual-casing design. In order to achieve this ambitious plan Rosneft implemented project management approach that includes following: Proper planning and risk assessmentIntegrated managementOptimization based on lessons learnt
Safe Drilling Technology for Horizontal Wells in Ultra-Thick Salt-Gypsum Rock in The Right Bank of The Turkmen Amu Darya
Authors: Li Wanjun , Zhou Haiqiu , Wang Wei , Wang Gang , Gu Yixin , Xiang Hua , Lin Jiahua , Mu Zihan 
Published: October 2017

Abstract
The formation of Section B, which is on the right bank of the Amu Darya consist of high pressure salt and gypsum formation. The average thickness of the salt-gypsum layer is about 900 meters, the maximum pressure coefficient is 2.3 g/cm3, the salt rock is easy to creep, resolve, and crystallize. The salt layer is close to the reservoir. Wellbore path is difficult to control. The drilling accident rate is 34%, and the success rate of high pressure brine drilling is 0, which leads to the fact that no horizontal well drilling has been carried out. In order to develop the safety technology, it is necessary to carry out the large angle orientation drilling method in the high-pressure salt water and salt-gypsum layer. However, this kind of method has not been widely used, so it is urgent to solve the safe drilling problem and orientation problem of the high pressure salt paste layer.
The proper proportion of drilling mud in the salt-gypsum layer is optimized by establishing the bore shrinkage equation and using the layer control method to determine the pressure of the salt-gypsum layer.
After that, the unsaturated saturated brine drilling fluid system compatible with the salt rock layer is selected. After the salt-gypsum layer is sealed with casing tube, the reservoir will be re-drilled. The slope will be designed in the salt layer, and the tricone bit control will be carried out by adding the cone bit and selecting the MWD directional drilling tool combination.
The proper density of the well drilling mud will prevent the salt rock from creeping and high pressure salt water from flooding. The stable saturated brine drilling mud will then be controlled effectively, and the stability of the well bore caused by salt losing is effectively controlled. The well bore expansion rate dropped from 19% to 2%; with salt-gypsum layer is sealed with 250.8mm thick anti-extrusion casing, and the water expansion packer is installed, which effectively prevent high pressure salt water channeling and casing tubes collapsing. After that, it is easy to control the drill direction angel in the high-pressure salt gypsum formation between 0° and 80°. After putting the directional drilling tool in the centralizer position and combined with other skills, the drilling speed has been increased by 8.7%.
Up till now, the horizontal drilling technology has been widely used in the zone. 50 wells have been using this drilling technology and goes on well.
New Ridge Diamond Elements Improve PDC Bit Efficiency
Authors: Gumich D. , Pak M. , Lomov A. , Gorobchenko M. 
Published: October 2017

Abstract
Rate of penetration is one of the key performance indicator for drilling process. PDC bits have the most efficient rock fracture mechanism: PDC cutters penetrate a rock and shear it layer by layer. Different PDC bit designs are created for special geological conditions during the optimization process. However, it’s not enough just developing bit designs, because the whole potential of diamond cutter elements are uncovered. Researching activity brought us new Ridge Diamond Element (RDE). It has tungsten carbide substrate like a conventional PDC cutter. Unique ridge shape of diamond table is a RDE distinguishing feature. This profile allows RDE to engage the rock more efficiently versus conventional PDC cutter. There is combination of two rock fracture mechanisms – shearing and crushing. Laboratory tests have shown high performance of new diamond element: durability increasing, lower weight for cutter penetration the rock, bigger size of cuttings and higher rate of penetration. Efficiency of this new technology was proved by field tests in different Russian oil and gas regions.