Jeffery Milton Dawson

US Patent:

45074402, Mar 26, 1985

Filed:

Jul 19, 1982

Appl. No.:

6/399682

Inventors:

Friedrich Engelhardt - Frankfurt, DE
Steffen Piesch - Oberursel, DE
Juliane Balzer - Frankfurt, DE
Jeffery C. Dawson - Katy TX

Assignee:

Cassella Aktiengesellschaft - Frankfurt am Main
Dresser Industries, Inc. - Dallas TX

International Classification:

C08L 3326

US Classification:

525218

Abstract:

The present invention relates to macromolecular compositions crosslinked by a novel bridge having the formula --NR. sup. x --CH. dbd. N--CO--. This novel bridge is obtained by reacting a macro-molecule, preferably a polymer, having at least two amidocarbonyl groups with a compound having at least two formylamido groups in an aqueous medium under highly acidic conditions. The crosslinking bridge formed by the reaction of this invention is produced in accord with the following formula: ##STR1## Compositions containing macromolecules having at least two amidocarbonyl groups and a compound having at least two formylamido groups can act as viscosifying or gelling agents for aqueous acids where when added to aqueous acids, crosslinking occurs. Acids gelled in this manner have important use in the recovery of oil and natural gas from subterranean formations.

US Patent:

44992327, Feb 12, 1985

Filed:

Sep 24, 1982

Appl. No.:

6/423026

Inventors:

Friedrich Engelhardt - Frankfurt, DE
Steffen Piesch - Oberursel, DE
Juliane Balzar - Frankfurt, DE
Jeffery C. Dawson - Katy TX

Assignee:

Cassella Aktiengesellschaft - Frankfurt am Main
Dresser Industries, Inc. - Dallas TX

International Classification:

C08L 3326
C08L 3906

US Classification:

524548

Abstract:

The present invention relates to macromolecular compositions crosslinked by a novel bridge having the formula --NR. sup. x --CH. dbd. N--CO--. This novel bridge is obtained by reacting a macro-molecule, preferably a polymer, having at least two amidocarbonyl groups with a compound having at least two formylamido groups in an aqueous medium under highly acidic conditions. The crosslinking bridge formed by the reaction of this invention is produced in accord with the following formula: ##STR1## Compositions containing macromolecules having at least two amidocarbonyl groups and a compound having at least two formylamido groups can act as viscosifying or gelling agents for aqueous acids where when added to aqueous acids, crosslinking occurs. Acids gelled in this manner have important use in the recovery of oil and natural gas from subterranean formations.

US Patent:

45004374, Feb 19, 1985

Filed:

Sep 23, 1982

Appl. No.:

6/422276

Inventors:

Friedrich Engelhardt - Frankfurt, DE
Klaus Kuhlein - Kelkheim, DE
Ulrich Riegel - Frankfurt, DE
Sigmar von Halasz - Kelkheim, DE
Jeffery C. Dawson - Katy TX
Anthony R. Reed - Houston TX

Assignee:

Cassella Aktiengesellschaft - Houston
Dresser Industries, Inc. - Houston TX

International Classification:

E21B 4327

US Classification:

252 855C

Abstract:

New copolymers soluble in water and aqueous acids are disclosed comprising in a statistical distribution in the macromolecule at least 5% by weight of entities containing a formylamino functionality and at least 10% by weight of entities containing an amino carbonyl functionality, which are stable in high concentrations of Bronsted-Lowery acids and can be used as friction reducers in the stimulation of oil or gas wells.

US Patent:

45515131, Nov 5, 1985

Filed:

Oct 18, 1984

Appl. No.:

6/663326

Inventors:

Friedrich Engelhardt - Frankfurt, DE
Klaus Kuhlein - Kelkheim, DE
Ulrich Riegel - Frankfurt, DE
Sigmar von Halasz - Kelkheim, DE
Jeffery C. Dawson - Katy TX
Anthony R. Reed - Houston TX

Assignee:

Cassella Aktiengesellschaft - Houston
Dresser Industries, Inc. - Houston TX

International Classification:

C08F 2054

US Classification:

5263071

Abstract:

New copolymers soluble in water and aqueous acids are disclosed comprising in a statistical distribution in the macromolecule at least 5% by weight of entities containing a formylamino functionality and at least 10% by weight of entities containing an amino carbonyl functionality, which are stable in high concentrations of Bronsted-Lowery acids and can be used as friction reducers in the stimulation of oil or gas wells.