Identification of permeable zones based on the borehole observations of seismoacoustic emissions and helium concentrations

Measurements of seismoacoustic emissions in boreholes allow researchers to identify fault zones and zones of cracking and rock shattering. These zones are usually identified from the maximal values of seismoacoustic emission. However, the permeability of the identified zones cannot be estimated solely from the seismoacoustic emission data, especially in the case when seismoacoustic emission sources are located in isolation in the vicinity of a borehole. The experiments have shown that dynamically active permeable zones of tectonic failures can be identified based on joint measurements of seismoacoustic emissions and helium concentrations in fluid.     

Seismoacoustic emission and electromagnetic radiation of fractured rocks in deep wells

The results of simultaneous measurements in seismoacoustic emission (SAE) and electromagnetic radiation (EMR), carried out with the help of a program-apparatus complex developed at the Institute of Geophysics, Ural Division, Russian Academy of Sciences, are considered. Measurements have been carried out in the wells with varied structures located in Karelia, Yamal-Nenets Autonomous Area, and Kamchatka. It has been shown that intervals of fractured rocks are simultaneously recorded in anomalies of SAE and EMR signals. This fact allows us to detect these zones of high tensosensitivity in a geomedium volume for the purposes of monitoring in geodynamic phenomena in the Earth’s crust.     

Temporal variability of ambient seismic noise at great depths

Doklady Earth Sciences -