Thread: Mesh of tracks in the desert; please explain.

From my experience in Saudi Arabia they are seismic lines.

They blow up a charge every now and then and a truck with seismometer records the echos.

You jump a RRC for a long way when you hit em at 100Kmh.

Regards Philip A

But why all the tracks to do this? Is it some sort of reference grid? Seems a lot of diesel has been burned to put them there, why not just GPS locations? It has piqued my curiosity as I have no experience of what these companies do out there.

I think that they try to map the extent of the potential reservoirs before deciding whether to drill.
Regards Philip A

They will be seismic lines, and the reason they are not "GPS references" is that they need to have vehicles move along them. A typical land seismic survey today uses vibrators, typically four wheel vehicles weighing 20tonnes or thereabouts, in sets of three, five, or more stopping perhaps every fifty metres to shake the earth for typically ten seconds. Reflections from the subsurface are received by possibly as many as several thousand receivers, spread out over several kilometres, with spacings of typically 25m. These connect to a recording truck by cable (fibre optic), digital radio, or simply record the data and store it until the unit is retrieved.

Line spacing depends on the purpose of the survey, initially tens of kilometres, but over a producing field could be as small as tens of metres. Surveys tend to be repeated over the years with decreasing line spacing, and as technology improves. Over producing fields, surveys may be repeated as often as once a year or even more often to map the extraction of oil or gas.

John

Fascinating work. Bob

how it works




RIGZONE - How Does Land Seismic Work?


https://www.google.com.au/search?q=l...0CCUQsAQ&dpr=1

John, could these also be termed as "shot lines", or are they something totally different?

The tracks that Pete's asking about are about 200mts apart (approx).

Originally Posted by Chops

John, could these also be termed as "shot lines", or are they something totally different?

The tracks that Pete's asking about are about 200mts apart (approx).

Yes - survey lines, shot lines, seismic lines, all different names for the same thing.

200m spacing is close, but is the sort of spacing to be expected on an actual field, or possibly even a potential field that is a difficult target.

Offshore, where data acquisition is much cheaper per kilometre (a single ship can record five or more lines of data simultaneously at 10km/hr 24hrs a day, with fewer people than a land crew.

John