Issues of the journals Геофизика 2015 y. issue 2

Interesting scientific fact - high SP anomalies without redox process

(Shevnin V.A. Ryjov A.A. Kvon D.A. )

In different countries were discovered local self potential anomalies above 1200 mV that didn't related with red-ox processes in rocks. Such anomalies were found in mountains, they have inverse correlation with relief, underground water has low mineralization and high electrical resistivity. Possible cause of these anomalies can be electrokinetic or streaming potentials due to water filtration. Calculation of electric field intensity on Helmholtz formula shows that these anomalies could resulted at water resistivity above 100 Ohm-m at filtration in loose gravel-sand ground.......

  • 2015  № 2, pp. 2-8

Modelling of influence of near-wellbore zone properties modification on resistivity logs

(Makarova A.A. Mikhailov D.N. Shako V.V. )

During drilling and completion operations, mud filtrate and different mud components (particles, clay, polymers etc.) invade into the near-wellbore zone of the reservoir due to the ‘over-balance’ pressure and interact with the reservoir fluids and rockforming minerals. /Is a result, these processes can cause significant changes of reservoir properties in the affected region and lead to higher values of skin factor, and also reservoir resistivity significantly changes due to the different electrical conductivities of mud filtrate, formation water and oil, that impact on the resistivity log data. The numerical model of the resistivity logging for a multilayer reservoir is described. This model takes into account the influence of the wellbore, the invaded zone and the finite thickness of the formation layers and influence of near-wellbore zone properties modification. The paper discusses the modification of the nearwellbore zone properties due to mud filtrate invasion, fines migration, wettability alteration, capillary imbibition, and the impact of these processes on resistivity log data by typical lateral logs. The simulations are carried out on the base of synthetic cases.......

  • 2015  № 2, pp. 9-15

Ground-penetrating radar (GPR) researches in solving soil geophysics problems

(Zolotaya L.A. Kosnyreva M.V. )

The article is devoted to the applications of GPR in studying of structure and heterogeneity of soil profiles. Authors have developed methodology of GPR research of heterogeneous soil profiles in their natural bedding. Scientific basis for practical application of georadar on different frequences for studying soils was given by the results of mathematical simulation. GPR profiles, reflecting spatial heterogeneity and depth of different genetic horizons of the soil cover, were recieved for the first time by the example of studying of the gray forest soils complex of Vladimir Opolye (VNIISH). Possibilities and constraints of GPR method application in studying soils are shown.......

  • 2015  № 2, pp. 16-22

Geophysical investigations of archaeological mounds on South Urals

(Noskevich V.V. Fedorova N.V. Vdovin A.G. )

Magnetic and Ground Penetrating Radar (GPR) survey were carried out on several mounds of the South Ural which are expected to apply to archaeological sites. On the magnetic maps and the GPR sections abnormalities characteristic of a funerary complexes were revealed. The proposal for conducting geophysical research on these mounds includes only non-destructive techniques.......

  • 2015  № 2, pp. 23-30

Evaluation of crustal deformation in the Chirkeysk HPP area from seasonal reservoir loads based on geophysical data

(Idarmachev Sh.G. Musaev M.A. Idarmachev I.Sh. Cherkashin V.I. )

For analysis of the results of long-term observations of apparent electric connection resistance of rocks in the well, located near the dam Chirkey HPP made numerical estimates of deformation of rocks under the reservoir. Deformation estimations confirm possibility of change of apparent resistance from seasonal weight of reservoir.......

  • 2015  № 2, pp. 31-37