Expandable tubular technology is a system for increasing the diameter

Diameter

In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...

 of the casing or liner of an oil well

Oil well

An oil well is a general term for any boring through the earth's surface that is designed to find and acquire petroleum oil hydrocarbons. Usually some natural gas is produced along with the oil. A well that is designed to produce mainly or only gas may be termed a gas well.-History:The earliest...

 by up to 30% after it has been run down-hole.
Two challenges facing the Oil & Gas industry are accessing new reservoirs that currently cannot be reached economically and maintaining profitable production from producing older fields. Expandable tubular technology is considered one of the most revolutionary technologies that has benefited the oil and gas industry during the last 10 years.