Clare H Kucera

43820034, May 3, 1983

Feb 2, 1981

6/230490

Clare H. Kucera - Tulsa OK
Richard B. Connell - Perryton TX

The Dow Chemical Company - Midland MI

E21B 4326

252 855R

Aqueous compositions having properties making them suitable for use as a hydraulic fracturing fluids are disclosed. These compositions comprise (a) an uncrosslinked aqueous polysaccharide solution, and (b) a 4,4'-thiodiphenol. Ingredient (b) acts as a "breaker" and causes the composition to lose viscosity at a controlled rate.

46830685, Jul 28, 1987

Oct 20, 1984

6/683974

Clare H. Kucera - Tulsa OK

Dowell Schlumberger Incorporated - Tulsa OK

C09K 300
E21B 4326
E21B 4316

252 8551

Novel aqueous crosslinked gels are described herein which are useful for fracturing subterranean formations. The novel gels are comprised of a solvatable polysaccharide and a soluble zirconium crosslinking agent. The zirconium crosslinking agents are novel and are prepared by reacting a zirconium alkoxide with certain alkanolamines under anhydrous conditions. The zirconium compounds are activated by contact with water. As an example, a zirconium crosslinker was prepared by reacting zirconium tetra(n-propoxide) with triethanolamine in an n-propanol solvent under anhydrous conditions. The zirconium compound thus prepared was activated with water and used to form a stable aqueous crosslinked gel by blending the aqueous crosslinker into an aqueous hydroxypropylguar solution.

50250400, Jun 18, 1991

Jun 11, 1990

7/535625

Stefano C. Crema - Ypsilanti MI
Clare H. Kucera - Tulsa OK
Gerd Konrad - Limburgerhof, DE
Heinrich Hartmann - Limburgerhof, DE

BASF - Porsippany NJ

C09K 700
C08B 11193
C08B 1100
C08B 1112

523130

A cementing composition useful in cementing oil, gas and water wells, comprising water, hydraulic cement and an effective amount of water soluble fluid loss additive comprised of a blend of a copolymer of acrylamide/vinyl imidazole in a weight percent ratio of from about 95:5 to 5:95, said copolymer having a molecular weight range of from about 100,000 to 3,000,000, and a terpolymer of acrylamide/acrylamidomethylpropane sulfonic acid sodium salt/vinyl imidazole in a weight percent ratio of 60:20:20, said terpolymer having a molecular weight range of from about 100,000 to 3,000,000. The blend is comprised of a weight percent ratio of copolymer to terpolymer in the range of 20:80 to 80:20. The composition can also optionally include a dispersant such as sodium or potassium salts or a sulfonated naphthalene formaldehyde condensate.

50465627, Sep 10, 1991

Jan 22, 1991

7/645912

Stefano C. Crema - Ypsilanti MI
Clare H. Kucera - Tulsa OK
Gerd Konrad - Limburgerhof, DE
Heinrich Hartmann - Limburgerhof, DE

BASF Corporation - Parsippany NJ

E21B 3314

166293

A cementing composition useful in cementing oil, gas and water wells, comprising water, hydraulic cement and an effective amount of water soluble fluid loss additive comprised of a blend of a copolymer of acrylamide/vinyl imidazole in a weight percent ratio of from about 95:5 to 5:95, said copolymer having a molecular weight range of from about 100,000 to 3,000,000, and a terpolymer of acrylamide/acrylamidomethylpropane sulfonic acid sodium salt/vinyl imidazole in a weight percent ratio of 60:20:20, said terpolymer having a molecular weight range of from about 100,000 to 3,000. 000. The blend is comprised of a weight percent ratio of copolymer to terpolymer in the range of 20:80 to 80:20. The composition can also optionally include a dispersant such as sodium or potassium salts or a sulfonated naphthalene formaldehyde condensate.

42579031, Mar 24, 1981

Oct 19, 1978

5/952875

Clare H. Kucera - Tulsa OK
Donald N. DeMott - Tulsa OK

The Dow Chemical Company - Midland MI

C09K 702

252 85C

A drilling fluid having extremely desirable physical properties which comprises an aqueous solution of a hydroxyalkyl polysaccharide derivative and a water soluble ionic aluminum crosslinking agent, preferably sodium aluminate.

52289150, Jul 20, 1993

Nov 23, 1992

7/981921

Stefano C. Crema - Ypsilanti MI
Clare H. Kucera - Tulsa OK
Gerd Konrad - Limburgerhof, DE
Heinrich Hartmann - Limburgerhof, DE

BASF Corporation - Parsippany NJ

C09K 700

106724

A cementing composition useful in cementing oil, gas and water wells, comprising water, hydraulic cement and an effective amount of water soluble fluid loss additive comprised of a blend of a copolymer (i) of acrylamide/vinyl imidazole in a weight percent ratio of from about 95:5 to 5:95, said copolymer (i) having a molecular weight range of from about 100,000 to 3,000,000, and a copolymer (ii) of vinyl pyrrolidone and the sodium salt of vinyl sulfonate in a weight percent ratio of 80:20 to 20:80, said copolymer (ii) having a molecular weight range of from about 100,000 to 3,000,000. The blend is comprised of a weight percent ratio of copolymer (i) to copolymer (ii) in the range of 20:80 to 80:20. The composition can also optionally include a dispersant such as sodium or potassium salts or a sulfonated naphthalene formaldehyde condensate.

50929356, Mar 3, 1992

Feb 26, 1990

7/484324

Stefano C. Crema - Ypsilanti MI
Clare H. Kucera - Tulsa OK

BASF Corporation - Parsippany NJ

C04B 2412
C09K 700

106808

A cementing composition useful in cementing oil, gas and water wells, comprising water, hydraulic cement and an effective amount of water soluble fluid loss additive comprised of a copolymer of acrylamide/vinyl formamide and derivatives thereof in a weight percent ratio of from about 95:5 to 5:95, said copolymer having a molecular weight range of from about 100,000 to 3,000,000. The composition can also optionally include a dispersant such as sodium or potassium salts or a sulfonated naphthalene formaldehyde condensate.

47802235, Oct 25, 1988

Nov 10, 1986

6/929567

Sandra E. Baranet - Broken Arrow OK
Richard M. Hodge - Sand Springs OK
Clare H. Kucera - Broken Arrow OK

Dowell Schlumberger Incorporated - Tulsa OK

E21B 4326

252 8551

Various organometallic crosslinkers containing titanium or zirconium atoms in the +4 oxidation (valence) state have been used to crosslink solvatable polysaccharides (e. g. , hydroxypropyl guar) in aqueous media. The crosslinked gels are useful as fracturing fluids. Aqueous solutions of the organometallic crosslinkers are stabilized against deterioration upon storage by adding an alkanolamine (e. g. , triethanolamine). Additionally, the alkanolamines also stabilize the crosslinked gels against shear degradation at elevated temperatures.