2
Reading tasks:
Task 5 Read the text and translate it into Uzbek.
How to find oil traps
Drilling is expensive.
So
oil
companies
plan
carefully before they start
drilling. First they make 3D
maps
of the rocks below the
surface. Then they study these
maps carefully. They look for
possible oil traps. How do
they make these maps? How
do they find out what is below
the surface?
The answer is
'seismic waves'.
Seismic waves are sound waves, and they can travel through rock layers.
Most oil companies use vibrator trucks to make seismic waves. These heavy trucks
make
vibrations on the surface, and the vibrations send waves down to the rocks
below.
Each
rock layer reflects some of
the waves. The reflected waves travel up
to geophones on the surface. Geophones
are like microphones:
they convert the
waves into electrical signals. A machine
in the recording truck records the signals.
Computers
can
convert
these
signals into 3D maps.
Seismic reflection
works at sea too. But the crews use
hydrophones, not geophones, and they
use an underwater
gun to make seismic
waves.