Drilling fluid
AssigneePhillips Petroleum Company
InventorsJeffrey A. Russell, Bharat B. Patel
Life of this patent
Estimating the term…
Abstract
In an aqueous drilling fluid, an improved thinning effect is obtained by adding a first agent comprising a mixture of a sulfoalkylated tannin or polyvalent metal complex thereof with a lignite, optionally in combination with a second agent comprising a metal compound of chromium, titanium, iron, zinc, strontium or magnesium which is at least partially soluble in water.
Claims28
A drilling fluid additive mixture consisting essentially of a sulfoalkylated tannin in admixture with a non-sulfoalkylated alkali-solubilized lignite wherein the weight ratio of the sulfoalkylated tannin to said non-sulfoalkylated lignite is in the range from about 2:1 to about 1:1, wherein the sulfoalkylated tannin has been sulfoalkylated with at least one --C(R).sub.2 --SO.sub.3 M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals.
A method of preparing a composition useful as a drilling fluid additive, consisting essentially of the steps of:
- (a) preparing a sulfoalkylated tannin solution wherein the sulfoalkylated tannin has been sulfoalkylated with at least one --C(R).sub.2 --SO.sub.3 M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals;
- (b) adding non-sulfoalkylated alkali-solubilized lignite to the solution to form a mixture wherein the weight ratio of said sulfoalkylated tannin to said non-sulfoalkylated lignite is in the range from about 2:1 to about 1:1;
- and
- (c) drying the resulting mixture.
A method of preparing a composition useful as a drilling fluid additive, consisting essentially of the steps of:
- (a) preparing a sulfoalkylated tannin wherein the sulfoalkylated tannin is sulfoalkylated with at least one --C(R).sub.2 --SO.sub.3 M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals;
- (b) drying said sulfoalkylated tannin;
- and
- (c) dry blending said sulfoalkylated tannin with a non-sulfoalkylated alkali-solubilized lignite to form a mixture blend wherein the weight ratio of said sulfoalkylated tannin to said non-sulfoalkylated lignite is in the range from about 2:1 to about 1:1.
In a process for the drilling of a well with well drilling tools wherein a drilling fluid is circulated in said well in contact with the wall thereof, the improvement comprising circulating in said well as said drilling fluid an aqueous drilling fluid which contains an additive which consists essentially of a sulfoalkylated tannin component and a non-sulfoalkylated alkali-solubilized lignite;
- wherein the weight ratio of said sulfoalkylated tannin to said non-sulfoalkylated lignite is in the range from about 2:1 to about 1:1, wherein the sulfoalkylation is with at least one --C(R).sub.2 --SO.sub.3 M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals;
- wherein the total amount of said additive added to said drilling fluid is effective to reduce at least one of
- (a) the plastic viscosity,
- (b) the yield point,
- (c) the shear strength,
- (d) the water loss due to filtration and
- (e) the 10-minute gel strength of said drilling fluid.
A drilling fluid additive consisting essentially of a mixture of a sulfoalkylated vegetable tannin and a non-sulfoalkylated alkali-solubilized lignite, wherein the weight ratio of said tannin to said lignite is about 2:1, wherein the sulfoalkylated tannin has been sulfoalkylated with at least one --C(R).sub.2 --SO.sub.3 M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals.
A method of preparing a composition useful as a drilling fluid additive, consisting essentially of the steps of:
- (a) preparing a sulfoalkylated vegetable tannin solution;
- (b) adding non-sulfoalkylated alkali-solubilized lignite to the solution to form a mixture, wherein the weight ratio of said tannin to said lignite is about 2:1, wherein the sulfoalkylated tannin has been sulfoalkylated with at least one --C(R).sub.2 --SO.sub.3 M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals;
- and
- (c) drying the resulting mixture.
A method of preparing a composition useful as a drilling fluid additive consisting essentially of the steps of:
- (a) preparing a sulfoalkylated vegetable tannin;
- (b) drying said sulfoalkylated vegetable tannin;
- and
- (c) dry blending said sulfoalkylated vegetable tannin with a non-sulfoalkylated alkali-solubilized lignite to form a mixture blend, wherein the weight ratio of said tannin to said lignite in said mixture is about 2:1, wherein the sulfoalkylated tannin has been sulfoalkylated with at least one --C(R).sub.2 --SO.sub.3 M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals.
In a process for the drilling of a well with well drilling tools wherein a drilling fluid is circulated in said well in contact with the wall thereof, the improvement comprising circulating in said well as said drilling fluid an aqueous drilling fluid which contains an additive which consists essentially of a sulfoalkylated vegetable tannin component, and a non-sulfoalkylated alkali-solubilized lignite component, wherein the ratio of said tannin to said lignite is about 2:1, wherein the sulfoalkylated tannin has been sulfoalkylated with at least one --C(R).sub.2 --SO.sub.3 M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atos, and M is selected from the group consisting of ammonium and the alkali metals;
- wherein the total amount of said composition added to said drilling fluid is effective to reduce at least one of
- (a) the plastic viscosity,
- (b) the yield point,
- (c) the shear strength,
- (d) the water loss due to filtration, and
- (e) the 10-minute gel strength of said drilling fluid.
Dependencies are inferred from the claim text.