bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvement of Drilling Technology for the Yarega Heavy Oil Field Development By SAGD Method with Counter Producing and Injecting Wells
Authors: Chertenkov Mikhail V. , Loparev Denis S. , Buslaev George V. , Yusifov Asif A. , Klyavlin Aleksey V. 
Published: September 2014

Abstract
Utilization of thermal production technologies in Yarega heavy oil field exemplifies a large-scale experiment of paramount importance for future development of oil industry, science, economics and technology. This paper presents a review of over than 75 year history of production technological development in Yarega heavy oil field. It shows that Russia pioneered and advanced in time in heavy oil and bitumen production, the world resources of which greatly exceed the light oil resources. The authors emphasize the LUKOIL-Komi experience, obtained during SAGD technology introduction in Yarega heavy oil field and drilling long horizontals (up to 1000 m) at shallow depths (200-210 m). SAGD technology was an alternative to oil mining, that had been used their since 1939. In 2006 three pairs of horizontals have been drilled in pilot testing area. Steam injectors were 5 m above producers, and average length of horizontal sections was about 300 m with total length of 610 m. In 2011-2012 another five pairs of producers and steam injectors have been drilled from two different clusters located 1400 m apart. Left and right pairs were azimuthally deviated. The problem in drilling of such wells was that the pay zone TVD was up to 220 m, and, therefore, the dog leg severity was 3.50&deg; per 10 m. And the event of azimuth changes it increased up to 4&deg; per 10 m and more. This resulted in problems with pushing BHA and casing, and also with placing fiber optic cable on the outer casing walls. In 2013 started the opposing wells drilling using the rack type rigs with 45-72&deg; spudding angle, which decreased the dog leg severity and provided the longer horizontal sections. The paper provides a comparative analysis of advantages and disadvantages of vertical rigs and rack type rigs based on projected and actual field data.
Best Practices for Horizontal Wells Completion Technology and Multistage Fracturing for High Pressure Achimov Formation at Urengoyskoe Field
Authors: Abalev A. , Zaichenko D. , Tyutikov S. , Inyushina A. , Koncheko A. 
Published: September 2014

Abstract
Reserves of Achimov formation of Urengoyskoe gas field is approximately 3 trillion cubic meters of gas and condensate. (Total reserves of Urengoy gas field 10 trillion cubic meters). About 83 % of Achimov reserves stored in two main reservoirs Ach3-4 and Ach5. Operator Company of the gas field has hard objectives to drill sub horizontal well that will cross both mentioned formations at angle of 80-90 degrees.
Due to the complex geological conditions of Achimov layers with abnormal high pressure, narrow Equivalent Circulating Density window, construction of these types of wells associated with high drilling and completions risks.&nbsp;
In 2013-2014 operator company together with service providers successfully build ten sub horizontal wells with horizontal departure at 2403 meters and a length of sub horizontal section for production liner for 1000-1230 meters.
152.4mm open hole were completed with 114mm perforated liner with cementing stage tool for cementing top section of production liner.&nbsp; Despite a number of technological limitations and risks related to high pressure, all six wells were successfully completed as planned.
This article related to describing experiences of completion technologies for sub horizontal wells with long horizontal departure, also article will provide recommendations for completion systems with the ability to use multi-stage hydraulic fracturing for sub horizontal of horizontal wells for Achimov or other low-permeability formations.
The recommended completion technology will reduce probability of risks and technical incidents during well construction and completion, also proposed completion technology will increase productivity and life cycle of mentioned subhorizontal wells.
Horizontal Well Drilling in Bashneft Oil Company. Current Situation and Prospects
Authors: Khamitov Oleg , Prostyakov Kirill , Khasanov Renat 
Published: September 2014

Abstract
Bashneft Oil Company has rich drilling history. First well in Bashkiria was drilled in Ishimbaiskoe oil field in 1932, the oil flow rate was 20 ton/day. Thereby oil exploration in Bashkiria commenced. Petroleum refinery was founded in Ishimbay city in 1935. The same year Bashneft oil company was founded. Initially the company composed of Ishimbayskoe oil field, logging and exploration facilities. 90 % of total oil production in west part of Soviet Union has been produced on Bashneft in 1939. Cumulative oil production was more than 15 million tons in 1955, Bashneft was the first company in USSR by cumulative oil flow rate per year.
Unsuccessful attempts of horizontal and multilateral well drilling were initiated in the beginning of 20 century in USA. However first multilateral well was completed in Ishimbaiskoe oil field under the guidance of Alexander Grigoryan in 1953. The well had of 9 boreholes, total effective length was 322 meters and initial oil flow rate was about 200 ton/day.
The oil cumulative production peak of 47 million tons was reached in 1967. One billion tons had been produced in Bashneft by 1980. Significant amounts of oil production were huge amounts of new drilling as green fields in region were discovered. In 1935 Bashneft had 19 wells, in 1970 were 7050. In 1980 total number of production wells in Bashneft was about 14 000. Large deposits were drilled the Soviet period. The last decade of the XX century drilling came mainly in new fields, small in size and reserves, as well as at during the main large fields of Bashkortostan. New reserves in old fields discovered due to detailed 3D seismic survey and processing of well data archives.
During period of 2008 – 2013 new well drilling decreased. 220 new wells were drilled in 2008 and 35 new wells were drilled in 2012. Average oil flow rate of new wells increased many times this period (figure 1).
Decision for Optimum Number of Well Pads During Phase of Field Development Design
Authors: Karsakov Valery A. 
Published: September 2014

Abstract
In this paper presented method of optimum well numbers determination based on technical and economics calculations by using advanced software tools. The obtained results allow with arguments to justify quantity and location of well pads for field. Also author point out relations between all aspects during design filed development and indicate valuable and importance of well padding stage for reservoir engineering.
Decision-Making for Fast Start of Offshore Fields Development
Authors: Shandrygin Alexander N. , Dyakonov Igor I. , Dubrovsky Dmytry A. 
Published: September 2014

Abstract
Development of offshore fields at an early stage is connected with significant uncertainties and risks because of poor knowledge of reservoirs characteristics and the low reliability of hydrocarbon reserves. In this paper we present the methodology to assess the possibility to start offshore fields development in condition of limited geological information. The methodology is implemented as a workflow, the result of which is the conclusion about: types of production units, number of wells and their placement boundaries, required minimum reserves density to begin field development, as well as types of exploration work on fields. The application of the methodology and workflow are demonstrated on the examples of assessment of the potential of development of some Russian arctic offshore fields.
Subsea Gas Pipeline Coiled Tubing Intervention for Hydrate Plug Removal
Authors: Nepomiluev M. , Streletskaya V. 
Published: September 2014

Abstract
Subsea pipeline transportation is a subject of hydrates/ice associated problem, risk of exposure of hydrates-related issues is significantly increased in extremely cold arctic condition. In case of emergency situation or technology process failures could result to partial chock or complete hydrates blockage of long part of subsea transportation system. In such case scenario costly and time-consuming replacement of affected pipeline section could not be carry out in safe manner because of presents of high pressure gas pockets distributed in hydrate plug. To reduce the overall risks, new technology and improved operational efficiency are required to meet the ambitions for hydrates plug removal. Coiled Tubing conveyed method is proposed as a light weight and efficient in both mobilization and operations point of view that enables operations to be performed more quickly and put pipeline on stream faster. Coiled Tubing equipment could be installed on wide range of types of marine vessels that helps to perform the job in a more cost and time effective way.
This paper review the engineering and operational challenges related to utilizing Coiled Tubing in offshore pipeline intervention and the solutions required overcoming these issues.
Advantages of usage Coiled Tubing technology: Small footprint;Versatile service offerings;Not rig-dependent;Reduce risk of damaging pipeline;Return pipelines to transportation faster;Lower risk of equipment getting stuck;Reduced personnel;Fewer lifts;Cost-effective;Improved logistics;Increased flexibility;Less people are being exposed to fewer risks;HSE advantages.
Channel Fracturing Improves Stimulation Efficiency by 30% in the Achimov Gas Condensate Formation
Authors: Yudin A. , Tarakanov I. , Klyubin A. , Ablaev A. , Zharikov M. , Vashkevich A. , Yaskin I. , Sabirov L. 
Published: September 2014

Abstract
In the Urengoyskoe field, Russia, the Achimov deposits are found at depths of nearly 4000 m and feature a more complex geological structure when compared to the Cenomanian and the Valanginian deposits. Furthermore, the Achimov deposits feature abnormally high formation pressure (over 600 bar) and are characterized by a multiphase state of hydrocarbons. To achieve economic well production, performing stimulation treatments in the Achimov formation of Urengoyskoe gas condensate field is required.
Hydraulic fracturing proved to be a reliable method for increasing well productivity from the Achimov formation by a factor of 2.5; however, well completion restrictions allow for placing only small-size proppant mesh. Proppant fracturing treatments are conducted with high-polymer loading to ensure fluid stability at high formation temperatures, which leads to further reduction of fracture cleanup efficiency. These effects reduce the effective half-length and compromise the full production potential.
New channel fracturing technology that creates open-flow channels inside the proppant pack was selected to improve production. Channels are created by pulsating proppant at surface. Pulses with proppant are separated by pulses of clean fluid, which creates proppant clusters inside the fracture, holding the walls of the fracture open. Fracture cleanup is conducted through channels without restrictions to fluid and polymer flowback. Thus, the channels improve effective fracture half-length and, consequently, gas condensate rates. The increased drainage area also improves hydrocarbon recovery.
Previously in Russia, channel fracturing was used primarily in oil fields. The largest gas operator in Russia has initiated an extensive pilot campaign for channel fracturing in new areas of the Urengoyskoe field. To date, seven wells have been successfully completed with channel fracturing, leading to a significantly higher productivity of 30% versus offset conventionally stimulated wells and lower drawdown.
Automation of Optimal Well Trajectory Calculations
Authors: Ilyasov R. R. , Svechnikov L. A. , Karimov M. R. , Kravets M. Z. , Solodov A. N. , Porolo I. O. 
Published: September 2014

Summary
Determination of optimal well trajectories constitutes one of the problems of field development planning. This problem must be solved when a well pad pattern is being selected; all existing engineering constraints must be taken into consideration; at the same time the cumulative length of all trajectories must be minimal to reduce capital costs for drilling.
Well trajectories are classified according to the number of wellbore intervals. A well section having a steady dogleg severity is taken as an interval. A number of parameters define every well section: length, dogleg severity, inclination angle change. The values of parameters can be changed within the limits of the engineering constraints. A minimum distance between two wells is 1.5 % of the trajectory length.
A genetic algorithm based on the mechanisms of natural selection and inheritance has been chosen to solve the problem. The algorithm defines values for unknown parameters of the trajectories which must meet the engineering constraints. The purpose of this algorithm is to minimize the trajectory length. The algorithm is searching from the initial population of solutions – trajectory options, their values of parameters being filled in randomly. A pair of solutions is selected from the population in each iteration. Their parameters are combined and set to a new solution. If trajectories created from a new solution are shorter than those created earlier, then the new solution is placed into the population. The performance of the search is provided for by including expert actions on selecting the values of unknown parameters into the mechanism of new solution generating. The algorithm generates new solutions until the desired result is reached.
The algorithm described in this work has been implemented in "Trajectory design" software, and it is included into Rosneft corporate software product. The software calculates optimal well trajectories fast, and automatically prevents possible wellbore collisions.
"Trajectory design" software has been tested using Rosneft oil fields models. Calculated trajectories proved to be shorter than real ones by around 13-15%. This proves high performance of the software for well trajectory computations.
The Effect of Linkage on Genetic Variances within Biparental Simulated and Zea mays Populations
Authors: Khanal R. , Navabi A. , Lee E. A. , Lukens L. N. 
Published: September 2014

ABSTRACTHybrid yield improvement in maize (Zea mays L.) has been attributed in part to the development of elite inbred lines within distinct germplasm groups adapted to distinct environments. Breeding largely within groups has caused the accumulation of distinct favorable alleles for adaptation, yield, and yield component traits. Favorable alleles may be linked to other favorable alleles in coupling phase or linked to unfavorable alleles in repulsion phase. To investigate the effects of linkage on genetic variances, we used a simple, two‐locus model to simulate populations of intermated and standard recombinant inbred lines (RILs) derived from parental lines with coupling or repulsion phase loci. Genetic variances differ between simulated intermated RILs (IRIL) and RIL testcross populations as a function of population size, the effect sizes of linked loci, and the genetic distance between loci. We also generated RIL and IRIL testcross (TC) populations from two short‐season inbred lines from different heterotic groups and evaluated yield, three yield component traits, and five flowering time–associated traits. For all nine traits, the inbred lines have accumulated distinct favorable alleles. Genetic variances are high and transgressive phenotypes are frequent in both testcross populations. Intermating does not increase genetic variation. Genetic variances of six traits within the RIL‐TC population are nominally between 1.25 and 1.75‐fold greater than variances within the IRIL‐TC population. We conclude that the genomes of the parental inbred lines may harbor coupling rather than repulsion phase loci and heterosis is unlikely due to pseudo‐overdominance.
Characterization of Thinopyrum Species for Wheat Stem Rust Resistance and Ploidy Level
Authors: Zheng Qi , Klindworth Daryl L. , Friesen Timothy L. , Liu Ai‐Feng , Li Zhen‐Sheng , Zhong Shaobin , Jin Yue , Xu Steven S. 
Published: September 2014

ABSTRACTIn the tribe Triticeae, several Thinopyrum species have been used as sources of resistance to stem rust (caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & E. Henn., abbreviated as Pgt) and other wheat (Triticum aestivum L.) diseases. To identify novel sources of resistance to Pgt race TTKSK (Ug99), we evaluated and characterized the stem rust resistance of 242 accessions belonging to five Thinopyrum species, including beach wheatgrass [Th. bessarabicum (Savul. & Rayss) A. Löve], diploid tall wheatgrass [Th. elongatum (Host) D.R. Dewey], intermediate wheatgrass [Th. intermedium (Host) Barkworth & D. R. Dewey], sand cough or sea wheatgrass [Th. junceum (L.) A. Löve], and decaploid tall wheatgrass [Th. ponticum (Podp.) Barkworth & D.R. Dewey]. These accessions were evaluated for seedling reactions to nine Pgt races (TTKSK, TTTTF, TRTTF, RTQQC, QFCSC, TCMJC, TPMKC, TMLKC, and TPPKC), genotyped with molecular markers linked to four stem rust resistance genes (Sr24, Sr25, Sr26, and Sr43) derived from Thinopyrum species, and examined for ploidy levels. All accessions but one (Th. elongatum PI 531718) were resistant to all or most races. Most of the Th. elongatum and Th. ponticum accessions showed near‐immunity to all of the races while the accessions of the other three species (Th. bessarabicum, Th. intermedium, and Th. junceum) had varied levels of resistance ranging from near immunity to moderate resistance. Molecular marker analysis showed that most of the markers appeared to be species‐ or genus‐specific rather than linked to a gene of interest, and thus genotyping analysis was of limited value. Comparisons of infection types of accessions based on ploidy level suggested that higher ploidy level was associated with higher levels of stem rust resistance. The results from this study substantiate that the Thinopyrum species are a rich source of stem rust resistance.
Overwinter Low‐Temperature Responses of Cereals: Analyses and Simulation
Authors: Fowler D. B. , Byrns B. M. , Greer K. J. 
Published: September 2014

ABSTRACTWinter survival of cereals is dependent on complex, environmentally induced responses that affect just about every measurable morphological, physiological, and biochemical characteristic of the plant. Simulation models offer a valuable means for the integration of knowledge accumulated from detailed physiological, agronomic, genetic, and genomics studies, thereby improving our understanding of complicated plant responses. A well‐designed model also provides an effective extension and teaching tool and the opportunity for systematic investigation of production risks, cause‐and‐effect processes, genetic theories, and adjustments needed to mitigate the possible effects of climate change. Earlier, we developed and deployed a Winter Cereal Survival Model based on a series of equations that described acclimation, vernalization, dehardening, and damage due to low temperature (LT) stress. A modular design has permitted modification and allowed for interfacing with other simulation models. Recent advances in our understanding of this agronomically important character have provided us with the opportunity to develop a more robust winter survival simulation model with a wider geographic application that now also considers cultivar acclimation threshold induction temperature (Ti), respiration stress, photoperiod, and other developmental factors. The model has been field validated and provides the opportunity for the simulation of a wide range of species and overwinter environments.
Gis Approach to Estimation of the Total Phosphorous Transfer in the Pilica River Lowland Catchment
Authors: Magnuszewski Artur , Kiedrzyńska Edyta , Kiedrzyński Marcin , Moran Sharon 
Published: September 2014

Abstract
In this paper, the Pilica River catchment (central Poland) is analyzed with a focus on understanding the total phosphorous transfer along the river system which also contains the large artificial Sulejów Reservoir. The paper presents a GIS method for estimating the total phosphorous (TP) load from proxy data representing sub-catchment land use and census data. The modelled load of TP is compared to the actual transfer of TP in the Pilica River system. The results shows that the metrics of connectivity between river system and dwelling areas as well as settlement density in the sub-catchments are useful predictors of the total phosphorous load. The presence of a large reservoir in the middle course of the river can disrupt nutrient transport along a river continuum by trapping and retaining suspended sediment and its associated TP load. Analysis of the indirect estimation of TP loads with the GIS analysis can be useful for identifying beneficial reservoir locations in a catchment. The study has shown that the Sulejów Reservoir has been located in a subcatchment with a largest load of the TP, and this feature helps determine the problem of reservoir eutrphication
Sandstone Geomorphology of South-West Jordan, Middle East
Authors: Migoń Piotr , Goudie Andrew 
Published: September 2014

Abstract
In the desert environment of south-west Jordan thick sequences of continental sandstones of Cambrian-Ordovician age support spectacular scenery, comparable with that of the Colorado Plateau of south-west USA or the central Sahara and similar in many aspects to the Danxia landform of southern China. Dissection of a sandstone tableland has given rise to numerous inselbergs and large mesas, rising from the sand-covered desert floor. The height of the hills varies from a few tens to 500-700 m in the Wadi Rum area, whereas their slope shapes are controlled by lithological properties of particular sandstone units. Rock walls of the sandstone inselbergs are subject to frequent rock falls and rock slides and host an impressive array of tafoni and honeycombs due to selective weathering, as well as a number of rock arches. Lithological differences within the sandstone sequence are crucial controls on the shape and evolution of rock slopes, exerting the influence via contrasting patterns of weathering and slope failures. The presence of ferruginous layers in the Umm ‘Ishrin Sandstone is of major importance and explains the fundamental morphological differences between the otherwise similar Umm ‘Ishrin and Disi sandstone units