Self-adaptive cements

• US 8,800,656 B2
• Filed: 01/25/2012
• Issued: 08/12/2014
• Est. Priority Date: 02/11/2011
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Le Roy-Delage, Sylvaine, Martin, Laure
• Primary Examiner(s): SUCHFIELD, GEORGE A
• Application Number:
  US13/358,481
• Publication Number:
  US 20120205105A1
• Time in Patent Office: 930 Days
• Field of Search: None
• US Class Current: 166/293
• CPC Class Codes: C04B 2103/0061 Block (co-)polymers
• CPC Class Codes: C04B 24/2676 Polystyrenes
• CPC Class Codes: C04B 24/36 Bituminous materials, e.g. tar, pitch C04B24/243 takes precedence
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C09K 8/467 containing additives for specific purposes
• CPC Class Codes: C09K 8/487 Fluid loss control additives; Additives for reducing or preventing circulation loss
• CPC Class Codes: C09K 8/493 Additives for reducing or preventing gas migration

Abstract

A self-adaptive cement formulation includes cement, water, block copolymer and asphaltite-mineral particles. The set cement demonstrates self-healing properties when exposed to methane, and is particularly suited for well-cementing applications. After placement and curing, the self-healing properties help maintain zonal isolation should bonding be disrupted between the set cement and the formation or a casing string, should cracks or defects appear in the set-cement matrix, or both.

Claims

1. A method for cementing a subterreanean well in which a borehole penetrates one or more hydrocarbon-containing formations, comprising:

(i) placing into the well a composition comprising a settable material, at least particles of an asphaltite mineral, styrene-isoprene-styrene block copolymer particles and sufficient water to form a pumpable cement slurry; and

(ii) allowing the cement slurry to set and form a cement sheath.

2. A method for maintaining zonal isolation in a subterranean well in which a borehole penetrates one or more hydrocarbon-containing formations, comprising:

(i) placing into the well a composition comprising a settable material, at least particles of an asphaltite mineral, styrene-isoprene-styrene block copolymer particles and sufficient water to form a pumpable cement slurry; and

(ii) allowing the cement slurry to set and form a cement sheath;

wherein, should microannuli, cracks or defects occur in the cement sheath, allowing hydrocarbons from the formation to contact the particles, allowing the particles to swell, and enabling the cement sheath to self-repair.

3. The method of claim 2, wherein the hydrocarbon comprises at least 80 mol % gaseous hydrocarbon.

4. The method of claim 2, wherein the hydrocarbon pressure to which the set cement is exposed is higher than about 3.5 MPa.

5. The method of claim 2, wherein the asphaltite mineral comprises uintaite, or unitahite or both.

6. The method of claim 2, wherein the combined concentration of asphaltite mineral particles and styrene-isoprene-styrene block-copolymer particles is between about 10% and 75% by volume of cement-slurry solids.

7. The method of claim 2, wherein the volume ratio between the asphaltite-mineral particles and the styrene-isoprene-styrene block-polymer particles is between 10:

90 and 90;

10.

8. The method of claim 2, wherein the size of the asphaltite mineral particles and styrene-isoprene-styrene block-copolymer particles is between about 50 μ

m and 900 μ

m.

9. The method of claim 2, wherein the particles are coated by a protective layer.

10. The method of claim 2, wherein the composition further comprises an aqueous inverse emulsion of polymer comprising a betaine group, poly-2,2,1-bicyclo heptene (polynorbornene), alkylstyrene, crosslinked substituted vinyl acrylate copolymers, diatomaceous earth, natural rubber, vulcanized rubber, polyisoprene rubber, vinyl acetate rubber, polychloroprene rubber, acrylonitrile butadiene rubber, hydrogenated acrylonitrile butadiene rubber, ethylene propylene diene monomer, ethylene propylene monomer rubber, styrene-butadiene rubber, styrene/propylene/diene monomer, brominated poly(isobutylene-co-4-methylstyrene), butyl rubber, chlorosulphonated polyethylenes, polyacrylate rubber, polyurethane, silicone rubber, brominated butyl rubber, chlorinated butyl rubber, chlorinated polyethylene, epichlorohydrin ethylene oxide copolymer, ethylene acrylate rubber, ethylene propylene diene terpolymer rubber, sulphonated polyethylene, fluoro silicone rubbers, fluoroelastomers, substituted styrene acrylate copolymers or bivalent cationic compounds, or combinations thereof.