Expanding a tubular element to different inner diameters

A method of expanding a tubular element having a first portion to be expanded to a first inner diameter and a second portion to be expanded to a second inner diameter larger than the first inner diameter, comprising:

• a) arranging an expandable sleeve of selected wall thickness in said second portion;
• b) positioning an expander in the tubular element;
• c) operating the expander so as to expand said first portion to the first inner diameter, and operating the expander so as to expand the sleeve to an inner diameter substantially equal to the second inner diameter minus double the wall thickness of the sleeve;
• and
• d) retrieving the sleeve, including the portion of the sleeve that was expanded in step c), from the tubular element through the first portion, thereby reducing the diameter of the sleeve.