bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Results Confirmation of Simultaneous Inversion for East Siberian Terrigenous Reservoirs
Authors: Emelyanov Pavel , Ostankov Andrei 
Published: October 2018

Abstract
New exploration projects with a scarcity of drilling data give much consideration to advanced high-density 3D seismic studies. Updated high-density seismic data is presumed to be utilized to build detailed geological reservoir models and substantially enhance further exploration drilling.
The latest developments in seismic data interpretation stem from inverse transformations of seismic data. Seismic data can be reviewed and interpreted by themselves, without inversion, however, this does not allow us to obtain the most detailed understanding of the structure of the formation, and under certain conditions can lead to an unreliable result. Benefiting from the efficiency and quality of seismic inversion, most oil and gas companies currently employ inversion technologies to enhance seismic data resolution and improve the prediction reliability and reservoir rock properties assessment accuracy, including with regard to porosity and net pay thickness. There are a host of various inversion technologies with some of them to be selected for the quantity and quality of prior geological and geophysical data, as well as for the specific needs to be addressed and the rock properties of of the section under study.
The key objective of this publication is to assess the potential of inversion transformations in predicting sweet-spots in terrigenous reservoirs forming part of a challenging seismogeological environment in Eastern Siberia. The simultaneous inversion validity analysis is based on the data obtained from two pilot boreholes of a newly drilled well.
Hydrocarbon Detection Method and Application Based on Two-Wide and One-High Seismic Technique
Authors: Zhen Wang , Junzhang Zheng , Yankun Wang , Jiquan Yin , Man Luo , Shuang Liang 
Published: October 2018

Abstract
The "Two-Wide and One-High" (wide-band, wide azimuth and high-density) Seismic Technique provided high-quality seismic data for more accurately identify the lithologic reservoirs, with low frequency information and broadband data being beneficial to the petroleum detection in the reservoirs. Hydrocarbon reservoir is a typical two-phase (solid and fluid phases) media. The seismic wave can display the characetristics of obvious low-frequency resonance and high-frequency attenuation in the seismic record after propagating through the two-phase media. Based on the theory and the "Two-Wide and One-High" Seismic data, the hydrocarbon detection is carried out in AMG block's two carboniferous sets of main reservoirs in the eastern Precaspian Basin. Three methods are useded to analyze variation in the low-frequency and high-frequency after the seismic wave propagating through the exploration target strata, such as area difference method, time-frequency method of three primary colors method, instantaneous bandwidth method. The petroleum detection result accords well with the drilling testing data in the area, which means that this detection method based on the "Two-Wide and One-High" Seismic data could lower the exploration drilling risk and provides the advantageous basis for well location deployment of hydrocarbon reservoir exploration in the area.
Organizational Model of Management Seismic Survey Projects in PJSC Gazprom Neft
Authors: Dakirov Valikhan , Litvichenko Dmitry , Zhukov Vladislav 
Published: October 2018

Abstract
"The era of easy oil comes to the end" – this phrase can be heard with increasing frequency today, and "hard-to-recover" reserves become the target of development. And presently, the seismic community is facing the challenge to survey complex geological features and improve the level of detail and reliability of the models: ➢A vast number of fields are near-depleted:The share of complex lithology deposits is growing;Have to drill into edge zones;Find hidden layers;➢New assets with complex geology:Geology forecasting of complex reservoirs;Forecasting the fracturing and anisotropy.
Advanced Modeling of Production Induced Pressure Depletion and Well Spacing Impact on Infill Wells in Spraberry, Permian Basin
Authors: Xu Tao , Lindsay Garrett , Zheng Wei , Yan Qiyan , Escobar Patron Katherine , Alimahomed Farhan , Panjaitan Maraden Luigie , Malpani Raj 
Published: October 2018

Abstract
Since early 2016, commodity prices have been gradually increasing, and the Permian Basin has become the most active basin for unconventional horizontal well development. As the plays in the basin are developed, new infill wells are drilled near pre-existing wells (known as "parent wells"). The impact of pressure depletion caused by adjacent existing producers may have a larger role in the performance of these new infill wells. How the various well spacing impact with the degree of reservoir pressure depletion from parent well is more important than ever for operators to optimize the completion design. Through data analytics and comprehensive fracture/reservoir modeling this paper studies how changes in well spacing and proppant volume in the Spraberry, a main formation in the Permian Basin, will impact new infill well performance. The studies in this paper are focused on the Midland Basin.
A public database was used to identify the number of parent and child wells in the Midland basin. Data analysis of production normalized by total proppant and lateral length shows that parent wells outperform infill, or child, wells. To further understand the relationship between parent and child wells, a reservoir dataset for the Spraberry formation was used to build a hydraulic fracture and reservoir simulation model for both the parent well and a two-well infill pad. After production history matching a P50 type well as the parent well, three periods of production depletion were modeled (6 months, 3 years and 5 years) to understand the timing impact on the infill well production. A geomechanical finite-element model (FEM) was then used to quantify the changes to the magnitude and azimuth of the in-situ stresses from the various reservoir depletion scenarios. A two-well infill pad was then simulated into the altered stress field next to the parent well at various spacings between the parent and child wells. A sensitivity was then performed with different stimulation job sizes to understand the volume impact on created complex fracture propagation and total system recovery.
This study can help operators understand how well spacing, reservoir depletion, and completion job size impact the infill well performance so they can optimize their infill well completion strategy.
Advanced Petrophysical Log Suite Support for Acid Stimulation Design Optimization
Authors: Petrov Alexander , Khuzin Rinat , Shevko Nikolay 
Published: October 2018

Abstract
Enhanced oil recovery methods, i.e. acid stimulation, are widely used to increase well productivity in oilfield development. The necessity for reservoir stimulation is linked with negative processes related to well drilling and perforation. The correct estimation of damaged zone parameters is the key problem for acid stimulation planning. The proposed petrophysical methodology is based on available data integration: core data, drilling data, well logging, well testing etc. Modern well logging suite allows to solve following task with high accuracy.
Sonic radial profiling based on compressional and shear waves registration and multisonde resistivity logging are the key methods to prognose wellbore damaged zone radius and parameters. The methodology based on integration of both these logging data is proposed in this paper. Currently, fullwave acoustic logging provides comprehensive data to estimate drilling mud penetration zone and character of the damage. The approach is based on alteration of sonic waves – compressional and shear waves.
But not all the wells logged with sophisticated modern acoustic log tools. Therefore, estimation of mud filtrate penetration and damaged zone is possible based on multiarray resistivity measurements which are primary methods in all well logging suites. At least three different sondes with different radius of investigation are run in a well. These data are enough to use for accurate damaged wellbore zone radius estimation. Calculated results were supported by other available information and verified by data from modern sonic tools. Thus, allows to improve the methodology and use it widely in all wells in a field.
Modern fullwave acoustic logging was performed by Schlumberger in few wells of carbonate field of the Company. In rest of the wells wellbore damaged zone estimation based on proposed integrated approach applied for multiarray resistivity interpretation. This workflow allowed to optimize acid near wellbore zone stimulation for the oil recovery enhancement.
Progression Through Technology: Results of Acid Systems Application to Improve Injectivity of Horizontal Wells in Caspian Offshore Oilfield
Authors: Golenkin Mikhail , Khaliullov Ildar , Vereschagin Sergey , Ovsyannikov Dmitry , Kobets Vladimir , Kulinich Nikolay 
Published: October 2018

Abstract
Yuri Korchagin field, located in the Russian sector of the Caspian Sea, is one of the largest field on the Caspian shelf with proven reserves stand at 29 million tons of oil and 63 billion cubic meters of gas. Since the beginning of commercial operation, in the spring 2010, the field production passed eight million tons of oil. The operator company conducts development of Yu. Korchagin field by a system of horizontal wells with a length up to 8000 m, from a fixed offshore ice-resistant platform, installed in the dome area of the structure. The main challenges in the field development are associated with premature water and gas breakthroughs at high permeability intervals of horizontal wells. Currently, as a result of the sharp increase in the field water cut, the oil production is constrained due to the existing limitations on volume of produced water that can be utilized in the conditions of the offshore field. Two water-injection wells were drilled and commissioned to utilize produced formation water into the aquiferous zone of the carbonate reservoir. In order to restore and increase the injectivity factor, small-volume acid treatments are carried out yearly on the carbonate reservoirs in the lower horizontal sections of the water-injection wells. Since 2014, more than 20 matrix and hydrochloric acid treatments were performed with application of acid systems of different compositions and volumes. In some cases, the wells injectivity increase after matrix acidizing treatments with traditional acid systems was below expectation, demonstrating limited and short-term effect. Therefore, with constantly increasing volume of produced water at the field, it was required to increase the frequency of acid treatments to maintain the appropriate level of injectivity of the water-injection wells. The additional treatments are associated with significant time and financial costs because of the offshore platform standby and production suspension. The need exists to improve efficiency of acid stimulation treatments performed in the field to achieve sustainable increase in injectivity index of existing wells.
The purpose of this study is to analyze acid stimulation treatments carried out on carbonate reservoirs of the horizontal water-injection wells in 2014-2017, evaluate the efficiency of the treatments with different acid systems to change the injectivity factor, discuss the prospects for their application in Yu. Korchagin field and formulate recommendations for further efficiency improvements of acid stimulation treatments in the field.
Dynamic Fluid Diversion with Advanced Pressure Monitoring Technique – New Era of Multistage Refracturing in Conventional Reservoirs of Western Siberia
Authors: Borisenko Alexey , Parkhonyuk Sergey , Danilevich Elena , Loginov Arkadii , Butula Kreso , Fedorov Andrey , Tetyuk Dmitry , Kapkaev Aleksandr , Makhmutov Ruslan , Tsygulev Ivan , Ibragimov Kenes , Letko Ivan , Mingazov Artur , Volkov Alexey , Ivanov Alexey , Samoilov Ivan 
Published: October 2018

Abstract
Drilling of the horizontal wells in Russia is increasing both regarding the numbers of wells and meterage. Recently, one of the NOC reported 47% increase in a number of horizontal wells. It is clear now that shift towards horizontal wells completed with multi-stage hydraulic fracturing is increasing.
On the other hand, an economic lifetime of these wells not always met.
For the vertical well, a well-known and successful technique for the well revitalization is re-fracturing. Vertical wells have been responding so positively, that some operators perform refracturing up to four times on the same well.
In case of the horizontal well, one of the most significant uncertainties is the fluid entry point. Starting from uneven depletion of the horizontal part of the well, not knowing the fluid entry point may lead to ineffective well re-stimulation and absence of any positive effect.
In this paper, we will demonstrate integrated approach towards horizontal well re-stimulation: starting from proper reservoir evaluation and candidate selection to engineered treatment design. Several novel methods and techniques have been used: dynamic diverting agent, that has been developed to fit particularities of the conventional reservoirs, and high-frequency pressure monitoring technique, which has served as an engineering tool for fluid entry point validation.
Propped Fracturing in Deep Naturally-Fractured Tight Carbonate Reservoirs
Authors: Che Mingguang , Wang Yonghui , Peng Jianxin , Meng Leifeng , Zhu Raoyun , Huang Longcang , Wang Liao 
Published: October 2018

Abstract
Over the last ten years, thirty wells were performed by proppant fracturing in deep naturally fractured tight carbonate reservoir in Tarim oilfield, including twenty-two hydraulic fracturing wells and eight acid-carrying-proppant fracturing wells. This paper will introduce what we have done for the proppant fracturing, what affect the fracturing and post-production, and why acid-carrying-proppant fracturing was tested and its result.
Natural fractures and vugs are the main hydrocarbon reservoirs in Tarim oilfield, and acid fracturing was used to increase the production. But post acid-fracturing production was low in the tight carbonate with fissures, so proppant fracturing was referred to the poor formation with the purpose of increasing prop- length, enlarging discharge area and maintaining post rate in vertical wells.
In order to realize the successful hydraulic fracturing in deep openhole wells, some measurements were taken to ensure the treatments such as large scale pad-fluid, 2-6 stages slugs, high pumping rate under the safe treating pressure, small-sized high-strength ceramic proppants and long step concentration with low-medium proppant. There were eight wells sand screenout or sand screenout behavior during treatment in the twenty-two hydraulic fracturing wells, which is mainly attributed to the presence of natural fractures. The hydraulic fracturing's difficulty was depended on natural fractures, there were seven fracturing wells with annulus pressure no packer, four wells' casing pressure increased 10 MPa-25 MPa because of the natural fractures and three wells' casing pressure increased only 4 MPa-6 MPa for no or poor natural fractures while fracturing. Micro seismic results showed that multi-fractures propagated while fracturing, the extending direction of secondary fractures had a large angle with the principal fracture, which ultimately leads to complex propped fractures. The post-fracturing temperature logging shows that the fracture height is about 30 m. The post-fracturing evaluation demonstrates that the half-length of the artificial fracture is 100 m-150 m. Meanwhile, seven acid-carrying-proppant fracturing with the purpose of acid etching fracture and propping fracture were treated in the fissure-matrix carbonate, and the results were not all good for the deep vertical carbonate wells.
Natural fractures and holes are important for post-rate of proppant fracturing, some well even has been producing for 10 years, for reservoirs with rare natural fractures and dissolved pores and caves, the post-fracturing production is low or declines rapidly.
Breakdown Pressure Considering Infiltration and Pre-Existing Fracture in Tight Sandstone Formation
Authors: Guo Jianchun , Li Mei , Deng Yan , Yang Ruoyu , Liu Yuxuan , Zhou Chao 
Published: October 2018

Abstract
Fracturing stimulation in deep tight gas reservoir in Eastern Sichuan Basin China shows that natural fractures obviously affect the treatment pressure. Accurate determination of breakdown pressure in the presence of pre-existing fracture can assist engineers better manage expected fracture gradients. The available fracture models for breakdown pressure prediction did not consider possible failure mode of hydraulic fracture influenced by pre-existing fracture. In addition, Elsworth indicates that breakdown pressure is a strong function of fracturing fluid infiltration. Infiltration due to pre-existing fractures is non-negligible to breakdown pressure prediction.
To overcome the limitation of current models, a model considering pre-existing fracture is applied to predict breakdown pressure. The stress distribution of pre-existing fracture intersected with perforation hole considering fluid infiltration is described based on stress distribution model of ellipsoid. The breakdown pressure prediction model is built considering uniform stress distribution and 3 possible failure mode, which are tensile failure of matrix, tensile failure of pre-existing fracture and shear failure of pre-existing fracture, described by corresponding failure criterion.
Sensitivity studies are conducted to investigate the influence of pre-existing fracture dip angle, orientation and location on failure mode and breakdown pressure. It indicates that the distribution of pre-existing fracture has great effect on hydraulic fracture failure mode and corresponding breakdown pressure. The breakdown pressure (1) increases with increasing dip angle and decreases with increasing orientation when matrix fails, and (2) doesn't always show the same tendency when pre-existing fracture fails. The novel model is further verified against measured breakdown pressure from field fracturing treatment of M3 well in deep sandstone formation in eastern Sichuan Basin.
Expanding Boundaries of Multistage Hydraulic Fracturing with Coiled Tubing in Novoportovskoe Field
Authors: Belov Alexander , Tishkevich Sergey , Simakov Sergey , Kichigin Anatoly , Burdin Konstantin , Maskhadov Movsar , Ishangaliev Askhat 
Published: October 2018

Abstract
Today, when most reservoirs have low productivity, the question of whether hydraulic fracturing can be applied to the oil rims becomes very important. It was revealed that the efficient way to compensate the fractures and formation contact area under conditions of a necessary hydraulic fracturing reduction was the implementation of a special well completion technology, during which renewable frac sleeves were installed in the fullbore diameter of a liner, with sleeve density being increased for a reliable coverage of the well horizontal spacing with longitudinal fractures (Ishangaliev et al., 2017).
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, that was detailed described by Kazakov et al., 2017.
An outstanding example of oil rim stimulation and application of new technology was a project in Novoportovskoye field where 30- and 27- stage mulstistage fracturing operations were successfully performed with shifting ports comopletion operated by coiled tubing.
Features of the Well Testing and Plt Works During Well Construction From SSDR in Okhotsk Sea
Authors: Magerova Anna , Semenov Yury , Ershov Nikolay 
Published: October 2018

Abstract
Inorder to confirm calculated values of operating production rates for new wells, flow coefficients A and B, draw-down pressure it is crucial to ensure the variation range of production rate reaching the design value at the stage of well development and initial gas dynamic testing at steady flow modes.
Increased volume and improved quality of received data at the stage of well drilling and development allows to enhance reliability of design solutions and avoid time and financial expenditures for additional survey.
Upon construction of exploration and high-rate production wells in offshore fields it is not possible to conduct full-scale initial gas dynamic testing in course of well development. Therefore, the required accuracy of forecast calculation of well operation mode and, subsequently, customization of the hydrodynamic model, cannot be assured to the full extent. Gas dynamic well testing offshore is limited due to specific nature of work performance and specifications of development units of semisubmersible drilling rigs.
The limits are primarily associated with the throughput capacity of the utilized separation equipment of semisubmersible drilling rig (maximum allowable rate), well design and the time allowed for well development.
Kirinskoye gas condensate field is located in the shelf of the Sea of Okhotsk along the north-east coast of the Sakhalin is land within Sakhalin-3 project Kirinskiy prospective site. The field is the first hydrocarbon development site of Gazprom in the shelf of the Russian Federation where subsea development system was utilized, which demands higher standards for development project design performance control.
The construction of production wells was being conducted with the utilization of semisubmersible rigs Polyarnaya Zvezda (Polar Star) and Severnoye Siyaniye (Northern Lights). In 2017 two gas condensate production wells were completely constructed and temporarily shut down until connection to the subsea gathering and transportation system for produced formation fluid.
During exploration drilling of the wells in Kirinskoye gas condensate field gas dynamic testing was carried out selectively and cannot be used to the full extent for forecasting and correlation with the results of gas dynamic testing of production wells.
Short-Time Periodical Well Operation in LLC LUKOIL-West Siberia Fields. Implementation Experience and Prospects for Development
Authors: Abdullin Artur , Abdulin Ilnur , Sokolyanskaya Yekaterina 
Published: October 2018

Abstract
Basic constituents of oil production costs include production specific volumes, electric power consumption, equipment costs and costs for production operations and well survey. Methods to increase oil production profitability currently used are usually aimed at improving only one of the above mentioned factors and often to the detriment of another factor. Short-time periodical operation of oil production wells using an ESP unit allows improving all the basic constituents of oil production profitability.
In the work presented we chose to analyze the fields of LLC LUKOIL-West Siberia.
The scope of the work is to examine the implementation experience of this technology, reveal its advantages and disadvantages and perform a technical and economic assessment of the advisability of the technology further implementation in LLC LUKOIL-West Siberia fields including a wide-scale implementation.
The performed assessment and work results will be further used to reduce costs for downhole pumping equipment operation and maintenance.