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US 4,231,882 AGranted
Treating subterranean well formations
AssigneeHalliburton Company
InventorsEugene A. Elphingstone, Lewis R. Norman
Life of this patent
Estimating the term…
Abstract
A method of treating a subterranean well formation wherein a low pH highly viscous thixotropic treating fluid is introduced into the formation. The treating fluid is formed by combining an aqueous acid solution with an aqueous alkali metal silicate solution and a gelling agent whereby a highly viscous polymerized alkali metal silicate gel of low pH is produced followed by shearing of the gel to impart thixotropic properties thereto.
Claims35
A method of forming a low pH highly viscous thixotropic fluid for use in treating a subterranean well formation comprising the steps of:
- combining an aqueous solution of acid other than hydrofluoric acid with an aqueous alkali metal silicate solution having a pH of greater than about 11 in an amount sufficient to lower the pH of the resulting mixture to the level in the range of from about 7.5 to about 8.5 thereby forming a polymerized alkali metal silicate gel;
- combining a gelling agent with said polymerized alkali metal silicate gel, said gelling agent consisting of a solution of a water soluble organic solvent and a mixture of ethoxylated fatty amines having the general formula:
- ##STR3## wherein:
- R is selected from saturated and unsaturated aliphatic groups having in the range or from about 8 to about 22 carbon atoms, and
- x and y each have a value in the range of from 0 to about 10 but both x and y are not 0;
- and
- said ethoxylated fatty amine is present in said gelling agent in an amount in the range of from about 10% to about 80% by weight of said gelling agent;
- combining additional aqueous solution of acid other than hydrofluoric acid with said polymerized alkali metal silicate gel-gelling agent mixture in an amount sufficient to obtain a mixture containing excess acid in the range of from about 1% to about 28% by weight of said mixture;
- and
- shearing said mixture to thereby obtain a highly viscous thixotropic treating fluid.
7 more elements
A method of forming a low pH highly viscous thixotropic fluid for use in treating a subterranean well formation comprising the steps of:
- combining an aqueous alkali metal silicate solution having a pH greater than about 11 with an aqueous solution of acid other than hydrofluoric acid in a quantity whereby excess acid is present in the resulting mixture in an amount in the range of from about 1% by weight to about 28% by weight and whereby a polymerized alkali metal silicate gel is formed therein;
- combining a gelling agent with said polymerized alkali metal silicate gel, said gelling agent consisting of a solution of a water soluble organic solvent and a mixture of ethoxylated fatty amines having the general formula:
- ##STR5## wherein:
- R is selected from saturated and unsaturated aliphatic groups having in the range of from about 8 to about 22 carbon atoms and mixtures thereof, and
- x and y each have a value in the range of from 0 to about 10 with the average sum of the values of x and y in said mixture being in the range of from about 1.8 to about 2.2;
- said ethoxylated fatty amine is present in said gelling agent in an amount in the range of from about 10% to about 80% by weight of said gelling agent;
- and
- shearing said polymerized alkali metal silicate gel-gelling agent mixture to thereby obtain a highly viscous thixotropic acidic treating fluid.
5 more elements
A method of fracturing and simultaneously acidizing a subterranean well formation comprising the steps of:
- combining an aqueous solution of acid other than hydrofluoric acid with an aqueous alkali metal silicate solution having a pH of greater than about 11 in an amount sufficient to lower the pH of the resulting mixture to a level in the range of from about 7.5 to about 8.5 thereby forming a polymerized alkali metal silicate gel;
- combining a gelling agent with said polymerized alkali metal silicate gel, said gelling agent consisting of a solution of a water soluble organic solvent and a mixture of ethoxylated fatty amines having the general formula:
- ##STR7## wherein:
- R is selected from saturated and unsaturated aliphatic groups having in the range of from about 8 to about 22 carbon atoms and mixtures thereof, and
- x and y each have a value in the range of from 0 to about 10 with the average sum of the values of x and y in said mixture being in the range of from about 1.8 to about 2.2;
- said ethoxylated fatty amine is present in said gelling agent in an amount in the range of from about 10% to about 80% by weight of said gelling agent;
- combining additional aqueous solution of acid other than hydrofluoric acid with said polymerized alkali metal silicate gel-gelling agent mixture in an amount sufficient to obtain a mixture containing excess acid in the range of about 1% to about 28% by weight of said mixture;
- shearing said mixture to thereby obtain a highly viscous thoxitropic acidic treating fluid;
- and
- introducing said treating fluid into said subterranean formation at a flow rate and pressure sufficient to produce a fracture therein.
7 more elements
A method of fracturing and simultaneously acidizing a subterranean well formation comprising the steps of:
- combining an aqueous alkali metal silicate solution having a pH of greater than about 11 with an aqueous solution of acid other than hydrofluoric acid in a quantity whereby excess acid is present in the resulting mixture in an amount in the range of from about 1% by weight to about 28% by weight of said mixture and whereby a polymerized alkali metal silicate gel is formed therein;
- combining a gelling agent with said polymerized alkali metal silicate gel, said gelling agent consisting of a solution of a water soluble organic solvent and a mixture of ethoxylated fatty amines having the general formula:
- ##STR8## wherein:
- R is selected from saturated and unsaturated aliphatic groups having in the range of from about 8 to about 22 carbon atoms and mixtures thereof, and
- x and y each have a value in the range of from 0 to about 10 with the average sum of the values of x and y in said mixtures being in the range of from about 1.8 to about 2.2;
- and
- said ethoxylated fatty amine is present in said gelling agent in an amount in the range of from about 10% to about 80% by weight of said gelling agent;
- shearing said polymerized alkali metal silicate gel-gelling agent mixture to thereby obtain a highly viscous thixotropic acidic treating fluid;
- and
- introducing said treating fluid into said subterranean formation at a flow rate and pressure sufficient to produce a fracture therein.
7 more elements
Dependencies are inferred from the claim text.