Crosslinked polymer solutions and methods of use
AssigneeSchlumberger Technology Corporation
InventorsDiankui Fu, Andrey Federov
Life of this patent
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Abstract
A well treatment composition is formed from an aqueous crosslinkable hydrated polymer solution. Combined with the polymer solution is a solid boric acid or borate crosslinking agent and a solid metal oxide or metal hydroxide pH buffering agent that has limited solubility (less than 100 kg/m3 at 20° C.) within the polymer solution that provides the solution with a pH of from about 8 to about 11. The composition may be introduced into a subterranean formation through a wellbore that penetrates the formation. The composition may provide at least one of shortened shear recovery time and an increase in the thermal stability of the aqueous polymer solution.
Claims18
A method of treating a subterranean formation penetrated by a wellbore, the method comprising:
- suspending a solid boric acid or borate crosslinking agent and a solid metal oxide or metal hydroxide in a non-aqueous fluid prior to combining with a crosslinkable hydrated aqueous polymer solution;
- providing the polymer solution;
- combining the crosslinking agent and the solid metal oxide or metal hydroxide that has solubility of less than about 100 kg/m3 at 20° C. within the polymer solution, wherein the metal oxide or metal hydroxide provides the solution with a pH of from about 8 to about 11 as the metal oxide or metal hydroxide solublizes in the solution;
- and
- introducing the solution into the wellbore.
A method of treating a subterranean formation penetrated by a wellbore, the method comprising:
- suspending a solid boric acid or borate crosslinking agent and a solid metal oxide or metal hydroxide in a non-aqueous fluid prior to combining with a crosslinkable hydrated aqueous polymer solution;
- providing the polymer solution;
- combining the solid boric acid or borate crosslinking agent and at least one of a calcium oxide (CaO), calcium hydroxide (Ca(OH)2), silicate oxide and silicate hydroxide pH buffering agent;
- and
- introducing the solution into the wellbore.
A method of at least one of shortening the shear recovery time and increasing the thermal stability of an aqueous polymer solution comprising:
- suspending a solid boric acid or borate crosslinking agent and a solid metal oxide or metal hydroxide in a non-aqueous fluid prior to combining with a crosslinkable hydrated aqueous polymer solution;
- providing the polymer solution;
- combining the solid borate crosslinking agent and a solid metal oxide pH buffering agent that has a solubility of less than about 100 kg/m3 at 20° C. within the polymer solution, to provide a pH of from about 8 to about 11.
Dependencies are inferred from the claim text.