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added information, which may include additional seismic data as
well as the borehole data.

TEXT №6.

1. Read the text.
2. Find the key sentence in each paragraph and translate it into
Ukrainian.

Entrapment may be in a single reservoir, or in multiple
reservoirs in the same anticline. A single reservoir accumulation
is sometimes referred to as a “pool”, but the terminology is nit
standard over the world. The general term for an accumulation
from which production has started is a field-oil field or gas field,
as the case may be.
The nature of the petroleum and its composition vary
from one field to another; and they may vary from one reservoir
to another in the same field. Variations between petroleums of
different reservoirs in a single field is commonly from heavy oil
with little or no gas near the surface, through intermediate oils,
to light oils with gas, gas and condensates at depth.
Within a reservoir, oil lies on water; and the interface-the
oil/water contact-is a horizontal or nearly horizontal surface. If
free gas is present when the reservoir is discovered, it lies on the
oil and the gas/oil contact will be horizontal. Gas that segregates
as a result of changes in the physical state of the reservoir during
production will not necessarily have a horizontal interface with
the oil because the accumulation will depend on the effective
permeability of the reservoir to gas, and this may not be uniform.
The oil/water and gas/oil contacts of different reservoirs
in the same field are usually at different depths below datum.
Occasionally the oil/water contact of two or more reservoirs is
found at the same depth below datum. When this happens, it is
argued that these reservoirs are connected in some way, leading
to a common plane of physical equilibrium. Gas/oil contacts may
also coincide, but they are more difficult to assess unless they
can be shown to be original gas/oil contacts that have not been
affected by production.