TY  - CONF
ID  - epos1985
UR  - http://meetingorganizer.copernicus.org/EGU2017/EGU2017-3238.pdf
A1  - Marcak, Henryk
A1  - Lasak, Mateusz
A1  - Mirek, Janusz
Y1  - 2017/04//
N2  - Wysin-2-H is a well drilled in the so-called shale gas region of Pomerania, northern Poland. A seismic network
was constructed around the well to study the seismic effects of activating of shale gas deposits by hydro-fracturing.
The network was also used for the measurements of seismic noise, although the net was not speci?cally designed
for this purpose.
The seismic noise directivity strongly in?uences the structure of correlograms. Therefore, this issue was re-
searched intensively. It is presented that arrival times of strong signals in the time intervals greater than 1 month
in frequency range 0,1 ? 0,4 Hz are not disturbed by movement of source of seismic noise.
Due to presence of strong re?ector in geological structure of Wysin region, the coda waves are re?ected downward
and cannot be recorded by the network. It is shown that the only waves recorded in longer time lags, which have
signals visible on the correlograms, are horizontal waves recorded in one station. Using these waves, accuracy of
estimation of the relative velocity changes in geological strata is approximately 0,05 %.
Despite the depth of the shale gas deposits estimated for about 4000 m, it was assumed that correlograms
calculated for the seismic data before hydro-fracturing and correlograms for the data after activation of shale gas
deposits, with high gas production rate, should vary signi?cantly and provide useful information about velocity
changes.
Due to complicated structure of shale gas deposits there was no meaningful gas output from the Wysin well.
Hence, the measurements of seismic noise have not indicate the changes of the velocity distribution before and
after hydro-fracturing.
TI  - Using the velocity of seismic waves estimated from ambient seismic noise
to assess the results of hydro-fracturing and the exploitation of shale-rock
formations
M2  - Vienna, Austria
AV  - public
T2  - EGU General Assembly 2017
ER  -