The third step
after installing production caving and tubing is to perforate the well. The casing prevents the hole from collapsing, but it
also prevents the oil or gas from entering the wellbore. Therefore, holes are
made through the casing and into the formation. This is usually accomplished
with an explosive device that is lowered into the well on an electrical wireline
to the required depth. This device, a collection of explosive charges in a
special carrier, is called a perforating gun. An electrical impulse fires the
charges to perforate the casing, surrounding cement and reservoir rock.
Petroleum Communication Foundation. Our Petroleum Challenge: Exploring Canada's Oil and Gas Industry, Sixth Edition. Calgary: Petroleum Communication Foundation, 1999. With permission from the Centre for Energy.