Piet has been working on a project onshore
Albania for most of 2012. He visited the office in the capital Tirana twice
(see post of 13 October 2012), and had a chance to visit a seismic crew in the
hills near the town of Berat. This crew is acquiring data to image the
subsurface, which will allow Piet’s team to make estimates about the potential
for oil exploration.
For this specific project it works as
follows: geologists determine for what area they need more information, and
draw a number of lines on a map; across these lines seismic data is acquired.
Then a company goes out, scouts the area, and drills a number of holes along
these lines, typically 10-20 meters deep, and 40-80 m apart. These drilling
rigs are quite small, but very heavy. On this campaign these rigs were mounted
on the back of a tractor, for easy accessible terrain, but there were also
loose units that had to be moved by helicopter in more difficult areas. After
drilling these holes are loaded with dynamite, which is then detonated. This
sends a sound wave down into the earth, that bounces off deeper layers and gets
recorded by geophones, which are planted at surface. This data can then be
processed to create a geological image of the subsurface.
Piet and two colleagues witnessed all these
steps, and also had a chance to see the terrain and the logistics, in
preparation for a 2013 project. They were impressed; a large number of people
and crews were moving round the area, with roads in poor condition and limited
daylight hours. Unfortunately, due to a re-organisation within Shell, Piet will
leave his team early 2013, and will not have a chance to use the end result of
this seismic campaign.
The town of Berat at dawn
Conditions on the main road between Berat and Tirana
A helicopter is moving a drilling rig in the hills near Berat
Detonating 10 kg of dynamite, to send a sound wave into the earth
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