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We consider modeling wellbore acoustic fields induced by the flow noise in the zone of the formation inflow. The influence of the reservoir’s properties, geometry, and phase composition of the fluid on the acoustic field in the wellbore is investigated. Using numerical modeling, we showed that these factors significantly influence the spatial-frequency pattern of the spectrum, and certain frequencies of the spectrum are strongly amplified. We present the modelling results for various examples of reservoirs with oil and gas wells.

Рассматривается задача моделирования акустических полей, индуцированных течением флюидов в околоскважинной зоне пласта. Проведено исследование влияния свойств пород-коллекторов, геометрии и фазового состава флюида на акустическое поле в скважине. С помощью численного моделирования показано, что эти факторы существенно влияют на пространственно-частотную картину спектра, и выявлено значительное усиление амплитуды на определенных частотах спектра. Представлены результаты моделирования для различных случаев резервуаров с нефтяными и газовыми скважинами.

The first results of the multidisciplinary expedition onboard research vessel “Akademik Nikolaj Strakhov” in the Barents Sea in August-September 2018 are given. On 41 stations the hydrophysical sounding was carried out, sampling of the bottom sediments was done using both grab and gravity corer. As a result of geophysical investigations the areas with the signs of modern dangerous natural processes were identified. Four seismic bottom stations were installed in the Pechora Sea.

704 Systematic investigation of the Caspian Sea in 2009 was conducted in accordance with the Programs of the Presidium of the Russian Academy of Sciences no. 17.1. "System Explorations of the Seas of the European part of Russia" (head, Academician of the Russian Acad� emy of Sciences A.P. Lisitsyn) and no. 17.2 "Inte� grated Studies in the Caspian Sea" (head, Corre� sponding Member of the Russian Academy of Sci� ences L.I. Lobkovskii). Voyage 32 was conducted from September 7 to 16, 2009. The main task of the voyage was to obtain infor� mation on the Transcaspian section for a comprehen� sive study of processes in the system of the Caspian Sea. We measured hydrophysical (CTDand ADCP� sounding, measurements of currents and temperature on submerged buoy stations) and hydrooptical (mea� suring the attenuation of light, the brightness of the rising light, and other subsatellite measurements) characteristics. We sampled aerosols with the help of network method, seawater for hydrochemical studies, and filtering suspensions, as well as samples of depos� ited material from sediment traps. Onboard the vessel, we determined the hydrochemical parameters O 2 , Si, and PO4 pigments of chlorophyll "a" and pheophytin using a Trilogy Fluorometer (mod. 7200�000) and studied the size range of suspension using a Coulter Multisizer 3 counter. One of the highpriority tasks of the expedition was setting up submerged buoy stations (SBSs) with sediment traps and PotokM current meters (3). During the voyage, we conducted constant profile shooting of the bottom using Sparker and SES� 2000 seismoacoustic narrowradial parametric profil� ers and selected bottom sediments. The route of the expedition and the scheme of recovery and staging sta� tions are shown in Fig. 1. The results of CTDsounding (Indronaut Ocean 316) showed that the hydrological structure of the water column of the Caspian Sea during that period was typ� ical for the transition of the summer-autumn season.

One of the main goals of the expedition was the acceptance trial and development of operational techniques for the SES 2000 Light Plus parametric subbottom profiler newly acquired within the frame of the State Contract (produced by Innomar Technolo gie GmbH, Germany) consisting of a new generation acoustic bottom profiler and a sidescan sonar pro duced by the same company and structurally compat ible and combined with the profiler. In addition, the obtained data were compared with the results of the hardware–software complex Teont Shelf, which is a complete system for research by single channel con tinuous seismic profiling (CSP) using a sparker type emitter and a pick up loop 20 m long. The simulta neous operation of the above mentioned systems in close proximity to each other made it possible to clar ify the degree of their mutual influence and enhance the interpretation of the data.

During Cruise 20–3 of the R/V Rift (April, 2006), the area that includes the shelf and slope of the Derbent Basin in the northern Middle Caspian was studied using the continuous seismoacoustic profiling method. In accordance with the previous standpoint, two Pleistocene deltaic complexes formed in the Enotaevian and Mangyshlakian time are defined in this area. The seismoacoustic records obtained for the northern slope of the Derbent Basin demonstrate the development of specific rootless exogenic-gravitational fold structures in the upper (∼150–200 m) Quaternary part of the sedimentary sequence. The Quaternary section encloses angular unconformities indicating the pulsating mode of gravitational processes in the northern slope of the basin. South-dipping gravitational normal faults (and/or normal fault-related flexures) displacing the bottom surface and uppermost sedimentary layers (with vertical amplitudes up to 5–6 m) were defined in the southern part of the study area. Several impulses of the submarine slump structures predated and accompanied the deposition of the upper deltaic sequence (Mangyshlakian), although their most intense formation took place later during the Novocaspian (Holocene) time. Thus, the structural analysis of the seismoacoustic data revealed intense development of different-origin and different-age gravitational structures within the Quaternary sediments in the northern slope of the Derbent Basin. These results should be taken into consideration when designing, building, and operating submarine constructions in order to prevent potential natural hazards and reduce their consequences.

The model of interaction between an electron beam and electromagnetic waves with complex spectra is described. The correct application of the numerical implementation of the proposed model is investigated and numerical results are presented. Simultaneous amplification of several components of a complex electromagnetic signal in an M-type traveling-wave tube is considered and analyzed.