Methods and Compositions for Sealing Fractures, Voids, and Pores of Subterranean Rock Formations

Abstract

A region of a borehole with one or more openings to be sealed off, such as one or more fractures, voids, and or pores, may or may not be sealed off around a tubular string with a borehole seal such as a packer or plug. A carrying fluid may be utilized to transport a filtration material into the opening to create a bridge, which at least partially seals the opening, but still provides a flow path that permits fluid flow therethrough. A solid material and/or settable material may then utilize the fluid flow subsequently or be simultaneously spotted with or behind the filtration material to thereby form compositions which effectively seals off the flow path into the one or more openings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view schematic, in cross-section, of a well bore wherein a subterranean fracture is sealed off utilizing a carrying fluid with filtration material to bridge off the flow path to create a filtration mechanism and subsequently positioning solid material behind the bridge to seal the flow path in accord with one possible embodiment of the present invention.

FIG. 2 is an enlarged view of a seal created with the composition of the present invention.

FIG. 3 is a schematic or conceptual view of an individual cellular element that may be utilized as the filtration material.

Claims

1. A composition that can be used to seal one or more subterranean openings in a bore hole, comprising: a filtration material that provides a plurality of fluid flow paths through said filtration material;a solid material to block said fluid flow paths; andat least one carrying fluid for carrying therewith at least one of said filtration material or said solid material into said one or more subterranean openings of said borehole.

2. The composition of claim 1 wherein said filtration material comprises a multitude of foam rubber elements, said foam rubber elements comprising a plurality of cells that permit fluid flow therethrough and define said plurality of fluid flow paths through said filtration material.

3. The composition of claim 2 wherein said multitude of foam rubber elements are elastic to be operable to compress and subsequently enlarge, to thereby conform to said one or more subterranean openings.

4. The composition of claim 3 wherein said plurality of said fluid flow paths are formed by at least 5% of said cells being interconnected with a plurality of connection channels wherein an average of a connection channel diameter is larger than 0.01 millimeters.

5. The composition of claim 1 wherein said solid material comprises a settable material.

6. The composition of claim 1 wherein said filtration material comprises at least one of a group consisting of sponge, foam rubber, cellulose sponge, fiber pads, clustered entangled fibers, open cell polymer foam and open cell foam rubber.

7. The composition of claim 1 wherein said carrying fluid comprises a settable material.

8. A method for sealing one or more subterranean openings in a borehole comprising: forming an initial filter bridge within said one or more subterranean openings by pumping a carrying fluid carrying a plurality of filtration elements into said one or more subterranean openings, said initial filter bridge defining a plurality of flow passages therethrough that permit at least some fluid flow therethrough; andpositioning solid material into said one or more subterranean openings to encounter said plurality of flow passages within said plurality of filtration elements and seal said one or more subterranean openings.

9. The method of claim 8, wherein said step of positioning solid material into said one or more subterranean openings comprises pumping a plurality of solid elements that are sized to be larger than said plurality of flow passages to thereby block fluid flow through said plurality of filtration elements.

10. The method of claim 8, wherein said step of positioning solid material into said one or more subterranean openings comprises pumping a settable fluid into said plurality of flow passages to set and thereby block fluid flow through said plurality of flow passages.

11. The method of claim 8, further comprising providing said plurality of filtration elements wherein an individual filtration element comprises a foam material, said foam material further comprises a plurality of internal cells and interconnections such that at least some of said plurality of internal cells are interconnected to each other and at least some of said internal cells are also interconnected to an outer surface of said individual filtration element.

12. The method of claim 11, further comprising compressing said foam material to conform to a shape of said one or more subterranean openings.

13. The method of claim 8, wherein said plurality of filtration elements are rigid.

14. The method of claim 8, further comprising first pumping said plurality of filtration elements into said one or more subterranean openings and then subsequently positioning solid material into said one or more subterranean openings.

15. The method of claim 8, further comprising simultaneously pumping said plurality of filtration elements and solid material into said one or more subterranean openings.

16. The method of claim 8, further comprising providing that at least said plurality of filtration elements are in a drilling fluid utilized during drilling such that when said one or more subterranean openings are encountered during drilling that said initial filter bridge is formed.

17. A composition that can be used to seal one or more subterranean openings in a bore hole, comprising: a foam filtration material with one or more fluid flow paths therethrough to permit fluid flow through said foam filtration material; andat least one carrying fluid for carrying therewith said foam filtration material into said one or more subterranean openings in said bore hole.

18. The composition of claim 17 further comprising a solid material comprising solid particulates sized to seal off said one or more fluid flow paths.

19. The composition of claim 17 wherein said at least one carrying fluid is a settable fluid.

20. The composition of claim 2 wherein said multitude of foam rubber elements are flexible to be operable to pass through piping, bottom hole assemblies and bit nozzles and get into said one or more subterranean openings with sizes including smaller than the foam rubber elements.