Method and apparatus for fracing earth formations surrounding a wellbore

Abstract

A dry powder product comprised of an inorganic silicate-based compound and an organic compound are mixed with fresh water as a catalyst, such that the mixture enters into hydration reaction, and when injected into existing fractures in low permeability formations surrounding earth boreholes, the resulting increase in volume of the mixture from the hydration reaction causes the existing fractures to have increased dimensions. Because the hydrationreactionbetweenwater and the drypowderwill commence almost as soon as the water is mixed with the dry powder, there are various means and methods described to inhibit the hydration reaction from occurring until after predetermined times, for example, such as by using water soluble coatings for encapsulating the dry powder which dissolve after predetermined times, and by using water insoluble coatings over the powder and by causing the capsules to be mechanically disintegrated to allow water to come into contact with the dry powder, and by providing means for transporting the dry powder from the earth's surface in the tubular string down to the formation of interest surrounding the wellbore, the hydration reaction can be inhibited for predetermined periods of time.

Dependencies are inferred from the claim text.