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a) lens-shaped f) formation k) porous
b) hydrocarbon-bearing g) permeable (2) l) oil
c) impervious h) anticline m)cuts off
d) fault i) layers n) stratigraphic
e) pinches out j) upward o) truncates
A (1) … is a break in the layers of rock. A fault trap occurs
when the (2) … one it her side of the fault move. Often, an
impermeable formation on one side of the fault moves opposite a
(3)… and (4) … formation on the other side.
An (5) …is an (6) … fold in the (7) … of rock, much like a
domed arch in a building. The (8) … and gas migrates into the folded
porous and (9) …layer and rise to the top. (10) … traps form when
other beds seal a reservoir bed or when the permeability changes
within the reservoir bed itself.
In one stratigraphic trap, a horizontal, impermeable rock layers
(11) …, or (12) …, an inclined layer of petroleum-bearing rock.
Sometimes a petroleum-bearing formation (13) … – that is, an (14) …
layer cuts it off. Other stratigraphic traps are (15) … . Impervious
layers surround the (16) … rock.

8 Scan the text and correct spelling and grammar mistakes.
On the early dais of oil exploration, wildketters (those who dril
wildket wells, which are wells drilled where no oil or gas is known to
exist) often drilled in an area because of a hunch. They will have no
idea how oil and gas occured and probably didnt’ kare. Anybody with
enough money to back up a believ that oil lay under the ground at
some location or that other drilled a well. If they are lacky, they had a
strike. If not, it was on to the next hanch. Soon however, dzeologists
begin applying aerth science to the serch for oil. For example they
looked for features on the surface that indicated sabsurface traps. One
site was at Spindeltopp. An underlying salt dome created a hill, or a
knoll. The knoll seemed out of place on the surrounding coastal

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