Expandable apparatus for drift and reaming borehole
AssigneeWeatherford/Lamb, Inc.
InventorRory McCrae Tulloch
Life of this patent
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Abstract
An expandable reamer shoe is provided for use with expandable casing in a borehole. The reamer shoe has a number of reaming members in the form of blades which remain closed against the body of the shoe when inserted through casing, and can then be expanded to underream below the casing. Additionally, the expandable reamer shoe is made substantially of a drillable material so that the borehole can be extended beyond the point reached by the expandable reamer shoe.
Claims29
An expandable reamer shoe for mounting on a casing string, the shoe having a body upon which are arranged a plurality of reaming members wherein said reamer shoe is substantially constructed from a relatively soft drillable material, wherein the plurality of reaming members are moveable between a first and second position, and wherein the reaming members are closed in a first position and expanded in a second position.
An expandable reamer shoe as claimed in any preceding claim, wherein the reaming members move from the first closed position to the second expanded position by virtue of movement of an activating piston.
An expandable reamer shoe as claimed in any preceding claim, wherein the reaming members are held in the first closed position by a plurality of leaf springs.
An expandable reamer shoe as claimed in any preceding claim, wherein in the second expanded position the reaming members are locked in position by a first and second retaining block at each end of the reaming member(s).
An expandable reamer shoe as claimed in any preceding claim, wherein the reamer shoe includes a rupture means such as a burst disc which permits increased fluid flow from an interior of the reamer shoe to the exterior of the reamer shoe.
An expandable reamer shoe as claimed in any preceding claim, wherein the expandable reamer shoe includes a cementing float valve.
A method of inserting expandable casing into a borehole, comprising the steps of:
- (a) running a first section of expandable casing into a pre-drilled borehole;
- (b) expanding the first section of expandable casing in place;
- (c) underreaming under the in-place first section of expanded casing using a standard underreamer and bit;
- (d) running a second section of expandable casing through the first section of expandable casing with an expandable reamer shoe;
- and
- (e) reaming down the borehole by rotation and/or reciprocation of the expandable reamer shoe to an expected size.
Dependencies are inferred from the claim text.