Disintegrating agglomerated sand frack plug
First Claim
1. A removable plug for subterranean use, comprising:
- a mandrel made of a mandrel material that can be structurally compromised after a predetermined time with exposure to existing well conditions upon running in or later created well conditions;
a sealing element comprising at least one granular material external to and in direct contact with said mandrel for a run in and a set position created by an actuation assembly in direct contact with said at least one granular material that defines the shape of said sealing element said actuation assembly remaining clear of a borehole wall while selectively axially crushing said sealing element against the borehole wall or crushing said sealing element axially while forcing said at least one granular material radially along a ramp to contact a surrounding borehole wall for resisting applied differential pressure in said set position;
whereupon setting said sealing element in said set position and application of said differential pressure, exposure of said mandrel to existing or subsequent well conditions causes said structural compromise of said mandrel to allow said granular sealing element material to disperse so that the plug is removed from a subterranean location.
4 Assignments
0 Petitions
Accused Products
Abstract
The frack plug has a sealing element that reforms when set to hold differential pressure. The element is granular with adhesive to hold the granular particles together but allow the shape to reform under setting force. The adhesive can be broken down with a chemical agent or in other ways to allow the seal to reform to the sealing position at the desired depth. As a result the structural components can disintegrate and the seal assembly can fragment into small pieces that can be circulated out of the well or allowed to drop to the hole bottom. The seal can have particles of controlled electrolytic materials (CEM), natural or synthetic sand, swelling or non-swelling rubber. The assembly can contain pellets that selectively release to initiate the breakdown of the structural components of the frack plug.
-
Citations
39 Claims
-
1. A removable plug for subterranean use, comprising:
-
a mandrel made of a mandrel material that can be structurally compromised after a predetermined time with exposure to existing well conditions upon running in or later created well conditions; a sealing element comprising at least one granular material external to and in direct contact with said mandrel for a run in and a set position created by an actuation assembly in direct contact with said at least one granular material that defines the shape of said sealing element said actuation assembly remaining clear of a borehole wall while selectively axially crushing said sealing element against the borehole wall or crushing said sealing element axially while forcing said at least one granular material radially along a ramp to contact a surrounding borehole wall for resisting applied differential pressure in said set position; whereupon setting said sealing element in said set position and application of said differential pressure, exposure of said mandrel to existing or subsequent well conditions causes said structural compromise of said mandrel to allow said granular sealing element material to disperse so that the plug is removed from a subterranean location. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. A removable plug for subterranean use, comprising:
-
a mandrel made of a material that can be structurally compromised after a predetermined time with exposure to existing well conditions upon running in or later created well conditions; a granular sealing element externally mounted to said mandrel for a run in and a set position created by an actuation assembly that selectively axially compacts said sealing element or pushes the sealing element radially to contact a surrounding borehole wall; said sealing element essentially comprising at least one material, such that upon setting said sealing element in said set position said structural compromise of said mandrel allows said sealing element material to disperse after a time of applied differential pressure against said plug so that the plug is removed from a subterranean location; said sealing element comprises pellets that encapsulate a chemical for release when said sealing element is placed in said set position; said chemical undermines at least one of a binder for said granular sealing element, and said mandrel.
-
-
21. A removable plug for subterranean use, comprising:
a mandrel made of a material that can be structurally compromised after a predetermined time with exposure to existing well conditions upon running in or later created well conditions; a sealing element externally mounted to said mandrel for a run in and a set position created by an actuation assembly that selectively axially compacts said sealing element or pushes the sealing element radially to contact a surrounding borehole wall; said sealing element essentially comprising at least one material, such that upon setting said sealing element in said set position to a set position length and application of differential pressure against said plug while said sealing element maintains said set position length, said structural compromise of said mandrel from exposure to existing or subsequent well conditions allows said sealing element to disperse so that the plug is removed from a subterranean location; a cover over an exterior face of said sealing element and configured to begin failing with exposure to existing well conditions upon running in or later created well conditions; wherein failing of said cover allows said sealing element material, which is granular, to disperse after a time of applied differential pressure against said plug as said sealing element material maintains a length associated with the set position so that the plug is removed from a set subterranean location; said cover fully surrounds said sealing element. - View Dependent Claims (22, 23, 24, 25)
-
26. A removable plug for subterranean use, comprising:
-
a mandrel made of a material that can be structurally compromised after a predetermined time with exposure to existing well conditions upon running in or later created well conditions; a sealing element externally mounted to said mandrel for a run in and a set position created by an actuation assembly that selectively axially compacts said sealing element or pushes the sealing element radially to contact a surrounding borehole wall; said sealing element essentially comprising at least one material held with a binder, such that upon setting said sealing element in said set position said structural compromise of said mandrel allows said sealing element material to disperse after a time of applied differential pressure against said plug so that the plug is removed from a set subterranean location; said sealing element contains a chemical that is released to defeat the binder or structurally compromise said mandrel.
-
-
27. A completion method for subterranean use, comprising:
-
setting a barrier against a surrounding borehole wall, said barrier comprising at least one mandrel made of a mandrel material that can be structurally compromised after a predetermined time with exposure to existing well conditions upon running in or later created well conditions; a sealing element comprising at least one granular material external to and in direct contact with said mandrel for a run in and a set position created by an actuation assembly in direct contact with said at least one granular material that defines the shape of said sealing element; keeping said actuation assembly clear of a borehole wall while selectively axially crushing said sealing element against the borehole wall or while axially crushing said sealing element and forcing said at least one granular material radially along a ramp to contact a surrounding borehole wall; performing a completion operation against said sealing element in said set position; initiating structural compromise of said mandrel to allow said at least one granular material to disperse after said performing so that the plug is removed from a subterranean location. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34, 35)
-
-
36. A removable plug for subterranean use, comprising:
-
a mandrel made of a mandrel material that can be structurally compromised after a predetermined time with exposure to existing well conditions upon running in or later created well conditions; an anchor element comprising at least one granular material external to and in direct contact with said mandrel for a run in and a set position created by an actuation assembly in direct contact with said at least one granular material that defines the shape of said anchor element said actuation assembly remaining clear of a borehole wall while selectively axially crushing said anchor element against the borehole wall or crushing said anchor element axially while forcing said at least one granular material radially along a ramp to contact a surrounding borehole wall; said anchor element resisting applied differential pressure thereto; whereupon setting said anchor element in said set position said structural compromise of said mandrel allows said at least one granular material of said anchor element to disperse after a time of applied differential pressure against said plug so that the plug is removed from a subterranean location. - View Dependent Claims (37, 38)
-
-
39. A removable plug for subterranean use, comprising:
-
a mandrel made of a material that can be structurally compromised after a predetermined time with exposure to existing well conditions upon running in or later created well conditions; a sealing element externally mounted to said mandrel for a run in and a set position created by an actuation assembly that selectively axially compacts said sealing element or pushes the sealing element radially to contact a surrounding borehole wall; said sealing element essentially comprising at least one material, such that upon setting said sealing element in said set position said structural compromise of said mandrel allows said material to disperse after a time of applied differential pressure against said plug so that the plug is removed from a set subterranean location against the surrounding borehole wall without further mechanical intervention at the subterranean location; a cover over at least an exterior face of said sealing element and configured to begin failing with exposure to existing well conditions upon running in or later created well conditions; wherein failing of said cover allows said material, which is granular, to disperse after a time of applied differential pressure against said plug so that the plug is removed from a subterranean location; said cover is impervious.
-
Specification