1. On-ground electric jobs
Electric profiling (EP) and profiling using the natural electric field (NEF)
For identifying and delineation at land surface of geological heterogeneities, tectonic faults, and karst areas, search and mapping of water-bearing strata for water supply, delineation and tracking of all kinds of underground utilities and communications (oil, gas, and product pipelines, water supply and sewage networks, heating mains ), as well as for evaluation of soil corrosion activity by specific electrical resistance, existing and incomplete underground metal pipelines, determining the amount of vagabond currents and electromagnetic fields of industrial frequency of 50 and 100 Hz, identification and mapping of flaws in insulation of existing pipelines, electric grids, etc.
ERA-MAX electromagnetic system
Vertical electrical sounding (VES) for mapping the geological section to a depth of up to 100–150 m, its division into lithological layers determining the depth of the confining layer of bed rock, mapping of buried river valleys, and the position of ground water level in section. VES is used as a system with the EP and NEF methods.
The charge method is used to identify places of water filtering from waterworks (reservoirs, canals), and to delineate pipeline product leaks (in presence of insulation flaws) on the map at land surface.
Digital log recorder
2. Geophysical investigations of wells
Gamma logging (GL) for lithological division of the section by natural radioactivity, evaluation of argillaceous rocks.
Apparent resistance logging (ARL) for lithological division of the section by specific apparent electrical resistance, determining the capacity of layers, and identifying fractured and weakened section intervals.
Self-potential logging (SPL) for more information about the structure of the section in the case of insufficient differentiation of the section according to ARL and GL data.
In studies of hydrogeology characteristics of the section, the following logging methods are used along with the ARL, SPL, and GL methods:
Flow measurement for evaluating the performance of water-bearing strata in open and cased wellbores with filters installed, of their production rate as a whole and by individual layers, identifying flows between different water-bearing strata.
Resistivity measurement for evaluating the total mineralization of ground water, identifying water-bearing (water-absorbing) strata in section, and evaluating the filtration properties of water-bearing strata.
Temperature measurement for determining the temperature conditions of water in the wellbore under steady dewatering (filling) conditions, for determining the filtration properties of soils.
Digital logging recorder
seismological observations within the radius of 30-40 km around the NPP site
In accordance with the design standards of
earthquake resistant nuclear power plants at the stage of pre-project
investigations the geophysical service of the company performs a seismological
monitoring of NPP sites placement by the local seismological network composed
of 7-9 observation points within 9-12 months.
There are the following main objectives of
seismological monitoring carried out in the area near NPP site:
estimation (prediction) of emergency situation
risks related to the natural and man-caused earthquakes;
determination of modern local seismicity
presence (or absence) and its parameters;
clarifying of seismic geological structures
clarifying of seismic area estimates for П3 and МР3 levels.
The record of seismic events is performed by
4-Channel Digital Video Recorders "Delta-03" in a continuous mode.
The oscillation sensors are the seismic detector СК-1П operating in the seismic signal frequency band
of 0.5-30 Hz.
In order to determine the degree of seismic
hazard for developed areas the update of seismic zoning data is performed
according to local tectonic, geomorphological and soil conditions, the result
of which is to determine the increment of sea state.
To do this the distribution of velocity values
for longitudinal and transverse waves in the volume of 30 meter subsurface
formation. The instrumental observations concerning amplitude and a spectral
composition of soil microvibrations are observed.
The modern 32-bit digital multi-channel
recording telemetry equipment TELSS-3 (72 channels), X, Y, the seismic detector
GS - 20DX, the broadband (1-1600 Hz) seismological recorder ZET - 048-C,
equipped with a three piezoelectric accelerometer VS-1313 are used.