BOTTOM FOR SYSTEM OF SECURING OF EXTENSIBLE LINER AND METHOD OF WELL COMPLETION Russian patent published in 2008 - IPC E21B17/14 

FIELD: mining.

SUBSTANCE: bottom of cased column consists of case with running through channel and at least one interior groove, and of deformed screen installed over groove; screen comes into said channel forming circular space between inside surface of groove and screen and preventing groove from blockage at cementing of case in well. The screen is capable to bend in response to changes of hydrostatic pressure when the case is lowered into a well; after cementing it can be removed opening the said groove. The method of well completion consists in following stages: a tube element is lowered into the well; this element is equipped with a bottom at its lower end; the interior groove is cut in the bottom; the deformed tube screen is used for closing the said groove. The tube screen is inserted into the channel running through the bottom thus forming the circular space between the screen and the tube element and allowing the screen to bend in response to changes of hydrostatic pressure at lowering into the well; then the tube is cemented in the well, after what the tube screen is removed with opening the groove.

EFFECT: protection of installation section of cased column at well cementing.

20 cl, 23 dwg