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Saint Petersburg, Russia

Gelfgat M.,Weatherford | Chizhikov V.,Weatherford | Kolesov S.,Weatherford | Alkhimenko A.,Saint Petersburg State Polytechnic University | Shaposhnikov V.,Krylov State Scientific Center
Society of Petroleum Engineers - SPE Arctic and Extreme Environments Conference and Exhibition, AEE 2013 | Year: 2013

This article continues and extends the topic addressed at the last conference held in Moscow in 2011 - prospects of aluminum tubes in well construction in the Arctic1. In addition to well-known successful practices of using aluminum drill pipes, it highlights the results of manufacturing and application of tubing and casing, as well as risers made of structural aluminum alloy tube semis (SAA). Attention is also paid to the fact that though there are some obvious and proven SAA advantages in comparison with conventional tube semis, application of aluminum tubular products remains rather limited. This circumstance can be explained by certain conservatism of the engineering community that still relies on generally accepted dogmas of aluminum alloy deficiencies. These include low hardness contributing to increased wear of the surface in contact with rock or other material and limited corrosion resistance in some conditions, for example, with increased chloride content. Many experts believe that these negative circumstances prevail over such advantages as hydrogen sulfide corrosion resistance, stability of properties at low temperatures and, finally, a huge advantage in strength-to-weight ratio of the tubular structure - a freely suspended SAS string is almost twice as long as the string made of steel. Such approach, subject to a wide offering of advanced high-strength steel tubes and special alloy tubes resistant to hydrogen sulfide corrosion, helps to solve current problems in a traditional conservative way. However, increasingly difficult conditions of field development result in substantially higher costs of well drilling, completion and operation, and the Artic is one of the brightest examples of this tendency. This is precisely why the authors again offer to consider alternative "aluminum" solutions of the problems. The article describes the results of using advanced techniques for SAA surface treatment that enable to minimize low strength and wear problems. Among them are ultrasound treatment and different coatings. Also, the examples of solutions are given that enabled adaptation of SAA tubes for use in corrosive environment - 7'' production casing installed in the well with more than 18% hydrogen sulfide content in the produced oil; 22'' offshore drilling riser operated at the water depth of more than 2,000 meters. Business success by enjoying SAA advantages is possible when a comprehensive multidisciplinary approach is used to design tubular or other structures for operations in extreme conditions whether these are drilling pipes, tubing or casing, risers or pipelines. The experience in other industries, for example, in shipbuilding, demonstrates the possibilities for solving great challenges by combining the efforts of experts in the sphere of materials science, metallurgy, machine building and structural design in this industry. In view of the tasks that are set, in particular, in arctic field development, building of specialized expert teams on the base on well-known research centers and scientific communities will allow making effective innovative decisions promptly and with the required reliability. Copyright 2013, Society of Petroleum Engineers. Source


Isaev S.A.,St. Petersburg State University of Civil Aviation | Guzeev A.S.,Krylov State Scientific Center | Sapozhnikov S.Z.,Saint Petersburg State Polytechnic University | Mityakov V.Y.,Saint Petersburg State Polytechnic University | Mityakov A.V.,Saint Petersburg State Polytechnic University
Journal of Engineering Physics and Thermophysics | Year: 2015

Numerical and physical simulations of a laminar separation flow over a single spherical dimple built in the lower wall of the rectangular-section plane-parallel channel of a water tunnel were performed on the basis of the multiblock computational technologies realized in the VP2/3 package. The vortex mechanism of intensification of the heat-transfer processes in this dimple was analyzed with special emphasis on the identification of the vortex-jet structures self-generated in it. © 2015 Springer Science+Business Media New York Source


Isaev S.A.,St. Petersburg State University of Civil Aviation | Guzeev A.S.,Krylov State Scientific Center | Sapozhnikov S.Z.,Saint Petersburg State Polytechnic University | Mityakov V.Y.,Saint Petersburg State Polytechnic University | Mityakovc A.V.,Saint Petersburg State Polytechnic University
Journal of Engineering Physics and Thermophysics | Year: 2015

Numerical and physical simulations of a laminar separation flow over a single spherical dimple built in the lower wall of the rectangular-section plane-parallel channel of a water tunnel were performed on the basis of the multiblock computational technologies realized in the VP2/3 package. The vortex mechanism of intensification of the heat-transfer processes in this dimple was analyzed with special emphasis on the identification of the vortex-jet structures self-generated in it. © 2015 Springer Science+Business Media New York. Source


Avakov V.B.,Krylov State Scientific Center | Aliev A.D.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | Bogdanovskaya V.A.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | Ivanitskii B.A.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | And 6 more authors.
Russian Journal of Physical Chemistry A | Year: 2015

Variations in the characteristics of a membrane-electrode assembly (MEA) are studied during the endurance testing of a hydrogen-air fuel cell (FC) based on a Nafion 212 proton conducting membrane and platinum catalysts. It is shown that the voltage drop observed during MEA testing was mainly due to physicochemical transformations of the cathode catalyst, i.e., the oxidation of platinum and its subsequent recrystallization with nanoparticle coarsening. It is established that the rate of degradation increases along with temperature and loading, and with periodic FC depressurization. It is concluded that the enhancing effects of additional factors of degradation, e.g., platinum ion transport to the proton-conducting membrane and corrosion of the carbon carrier, were responsible for these processes. © 2015 Pleiades Publishing, Ltd. Source


Bogdanovskaya V.A.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | Krasl'nikova O.K.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | Kuzov A.V.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | Radina M.V.,RAS Frumkin Institute of Physical Chemistry and Electrochemistry | And 4 more authors.
Russian Journal of Electrochemistry | Year: 2015

Electrochemical and structure characteristics of PtCoCr/C-catalyst with platinum content 50 wt % under model conditions and in cathode of membrane-electrode assembly (MEA) of hydrogen-oxygen fuel cell are studied. The metal-phase nanoparticles are shown to represent a Pt3Co alloy with partial inclusion of chromium, the nanoparticles surface being enriched with platinum. The platinum mass activity and the PtCoCr/C-catalyst high corrosion resistance do not depend on the amount of platinum deposited onto XC72 carbon black (20 or 50 wt %). Herewith the platinum surface area decreases in the same way as the carbon black specific surface area (measured with the BET method); the latter is 227, 169, and 105 m2/g for pure carbon black and that containing 20 and 50 wt % Pt, respectively. Testing of the 50PtCoCr/C-catalyst in the MEA cathode active layer in hydrogen-oxygen fuel cell showed performance not inferior to MEAs with pure-platinum systems, the catalyst being more stable. © 2015, Pleiades Publishing, Ltd. Source

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