Page 12 - 4925

Some offshore rigs are self-propelled. Built-in engines and screws (propellers)
move the rig through the water. Rudders like those on a ship allow marine personnel
to steer the rig when it is underway. While a self-propelled rig’s speed is slow –
perhaps 3 or 4 knots per hour at the fastest – generally, the distances traveled are
relatively short, so speed is not a factor. For rigs that are not self-propelled, the
contractor can hire boats to tow them.

For long moves, say from one ocean to another, the contractor may use a
special ship to carry the rig, whether it is self-propelled or not. To load the rig onto
the ship crew members moor the ship next to the rig, usually in the shallow waters of
a port. At first, both the boat and the rig float. They then flood compartments in the
ship to submerge its deck below the waterline. With the deck below the water's
surface, large cranes pull the rig over to the ship’s deck. Pumps remove the water
from the compartments and the ship floats back to the water’s surface with the rig in
place on the deck.
Whether on land or offshore, once the site is prepared for the rig, the next step
is for the drilling crew to rig up – that is, to put the rig components together and
prepare the rig for drilling. So, let’s look next at rigging up.

5 Find synonyms in the text for the following words.

swamp spot
personnel pebble
expenditures shelter
topographer container

6 Find antonyms in the text for the following words.

shallow permanently
unviable frequent
incomes to fire
low-price to rig up

7 Say whether the following statements are true or false.
1 Costs depend on such factors as the size of the reservoir, its productivity, and its
reliability.
2 The company carefully reviews and analyzes seismic records.
3 3. On land, operating personnel usually try to choose a spot directly under the
reservoir.
4 A reserve pit is an open pit that is bulldozed from the land next to the rig.
5 In the early days of drilling, the reserve pit was mainly a place to store a reserve
supply of extracted oil.
6 Sizes vary, but a typical cellar is about to three feet on a side and perhaps to feet
deep.
7 Rigs with kellys require a rathole – a deep hole drilled off to the side of the
mousehole.

11