SELF-REPAIRING CEMENTS Russian patent published in 2015 - IPC C09K8/467 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of maintaining formation separation in a subterranean well, wherein the well bore penetrates one or more hydrocarbon-containing formations, the method comprising: (i) pumping a cement slurry comprising thermoplastic block-copolymer particles into the well, wherein the block-copolymer has the structure (A-b-B-b-A), where A is a glass-like or polycrystalline block, B is an elastomeric block; and (ii) allowing the cement slurry to set in order to form a cement sheath, wherein the occurrence of microannuli, cracks or defects in the cement sheath allows hydrocarbons from the formation to come into contact with the particles, allowing the particles to swell, and enabling the cement sheath to have self-healing properties. The invention also relates to use of said thermoplastic block-copolymer particles to self-healing properties to a cement formulation which is placed in a subterranean well penetrating one or more hydrocarbon-containing formations, wherein once set, the cement forms a cement sheath in which the particles swell upon coming into contact with hydrocarbons from the formation.

EFFECT: invention is developed in subclaims.

14 cl, 5 dwg, 10 tbl, 5 ex