METHOD OF EXPANDING A TUBULAR ELEMENT IN A WELLBORE
A method is provided of radially expanding a tubular element ( 4 ) extending into a wellbore formed in an earth formation, comprising the steps of arranging an expander ( 8 ) in the tubular element ( 4 ), the expander ( 8 ) being operable to exert a radial force to the inner surface of the tubular element ( 4 ), and radially expanding the tubular element by pressurising the interior of the tubular element ( 4 ) and simultaneously operating the expander ( 8 ) to exert said radial force to the inner surface of the tubular element. The expander ( 8 ) is operated to exert said radial force to the inner surface of the tubular element ( 4 ) independently from pressurising the interior of the tubular element.
1 . A method of radially expanding a tubular element extending into a wellbore formed in an earth formation, comprising the steps of:
arranging an expander in the tubular element, the expander being operable to exert a radial force to the inner surface of the tubular element;
radially expanding the tubular element by pressurising the interior of the tubular element and simultaneously operating the expander to exert said radial force to the inner surface of the tubular element,
wherein the expander is operated to exert said radial force to the inner surface of the tubular element independently from pressurising the interior of the tubular element.
2 . The method of claim 1 , wherein the tubular element includes an expanded portion and an unexpanded portion, and wherein the interior of the tubular element is pressurised both in the expanded portion and the unexpanded portion.
3 . The method of claim 2 , wherein substantially the whole interior of the tubular element is pressurised.
4 . The method of claim 1 , wherein the interior of the tubular element is pressurised by pumping a fluid into the tubular element.
5 . The method of claim 4 , wherein the tubular element has an upper end located substantially at surface, and wherein said fluid is pumped into the tubular element at or near said upper end of the tubular element.
6 . The method of claim 1 , wherein the interior of the tubular element is pressurised to a pressure of between 80%-95% of the burst pressure of the tubular element.
7 . The method of claim 6 , wherein the interior of the tubular element is pressurised to a pressure of about 90% of the burst pressure of the tubular element.
8 . The method of claim 1 , wherein the expander has a largest diameter larger than the inner diameter of the unexpanded tubular element, and wherein the expander is operated to exert said radially outward force to the inner surface of the tubular element by moving the expander through the tubular element.
9 . The method of claim 8 , wherein the expander is moved through the tubular element by pulling the expander through the tubular element by means of a pulling string.
10 . The method of claim 1 , wherein the expander is movable between a radially retracted mode and a radially expanded mode, and wherein the expander is operated to exert said radial force to the inner surface of the tubular element by moving the expander from said radially retracted mode to said radially expanded mode.
11 . The method of claim 1 , wherein the tubular element is a wellbore casing or a wellbore liner.
12 . (canceled)