Chevron
has
ploughed
billions
of
dollars
in
investment
into
the
field
to
coax
the
heavy
crude
up
its
producing
wells
and
to
turn
the
development
into
a
model
of
how
technology
can
bring
hard-to-reach
heavy
oil
reservoirs
within
its
grasp.
Long
history
Kern
River,
covering
about
20
square
miles
(52
square
kilometres),
is
one
of
the
older
producing
fields
in
the
US.
The
discovery
well
for
the
field
was
dug
with
a
shovel
in
1899
to
about
75
feet
deep
but
the
workers
had
already
hit
oil
about
45
feet
below…