James B Crews

US Patent:

6617285, Sep 9, 2003

Filed:

Jul 3, 2001

Appl. No.:

09/900343

Inventors:

James B. Crews - Willis TX

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

C09K 300

US Classification:

507201, 507273, 507209, 507211, 507266, 507903, 507921, 507922, 166308

Abstract:

It has been discovered that borate crosslinked fracturing fluid breaker mechanisms are improved by the inclusion of a polyol together with an enzyme. In fact, synergistic results may be achieved when both are used together as contrasted to the cases where each are used separately. Removing the borate ion from the crosslinked polymer reduces the pH of the fluid and in turn increases the activity of the enzyme. That is, once the pH is lowered, viscosity reduction (breaking) occurs by uncrosslinking of the polymer within the fracturing fluid, and by initiating or increasing activity of an enzyme breaker, if present. In one embodiment, the polyol has at least two cis-hydroxyl groups. In another embodiment, the polyols are monosaccharides such as glycerols and sugar alcohols, and may include mannitol, sorbitol, glucose, fructose, galactose, mannose, allose, etc. and mixtures thereof. Oligosaccharides and derivatives of monosaccharides and oligosaccharides are also useful.

US Patent:

6642185, Nov 4, 2003

Filed:

Dec 10, 2002

Appl. No.:

10/315430

Inventors:

James B. Crews - Willis TX

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

C09K 300

US Classification:

507273, 507201, 507903, 507922, 166308

Abstract:

It has been discovered that borate crosslinked fracturing fluid breaker mechanisms are improved by the inclusion of a cation-releasing material. When cations are released or liberated within the fracturing fluid, they complex with the hydroxide or carbonate pH buffers used within the borate crosslinked fracturing fluid, which in turn reduces the pH of the fracturing fluid. Once the pH is lowered, viscosity reduction (breaking) occurs by uncrosslinking of the polymer within the fracturing fluid, and by initiating or increasing activity of an enzyme breaker, if present. In one embodiment, the cations are divalent cations. The divalent cations are preferably slowly released over a period of time. Two specific, preferred materials for releasing divalent cations are calcium lignosulfonate and calcium chloride, the latter preferably in encapsulated form.

US Patent:

6706769, Mar 16, 2004

Filed:

Feb 28, 2002

Appl. No.:

10/086963

Inventors:

James B. Crews - Willis TX

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

C09K 300

US Classification:

516113, 507211, 507241, 507921

Abstract:

It has been discovered that aminocarboxylic acids are effective breakers for polymer-gelled aqueous fracturing fluids, particularly in the temperature range between about 120Â F. (49Â C. ) and about 280Â F. (138Â C. ). The aminocarboxylic acids are believed to act directly on the polymer and not to any great extent or not to as an effective extent on a crosslinking agent, if present. The polymer may be a polysaccharide, and the aminocarboxylic acid may be selected from the group including, but not necessarily limited to, tetrasodium ethylenediaminetetraacetic acid (Na EDTA), tetrasodium propylenediaminetetraacetic acid (Na PDTA), trisodium hydroxyethylenediaminetetraacetic acid (Na HEDTA), trisodium nitrilotriacetic acid (Na NTA), salts of these acids, and mixtures thereof.

US Patent:

7052901, May 30, 2006

Filed:

Oct 24, 2001

Appl. No.:

10/041528

Inventors:

James B. Crews - Willis TX, US

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

C12S 1/00
C22S 13/00

US Classification:

435281, 435262, 507101, 507201, 507129, 507132, 507240, 507245

Abstract:

It has been discovered that fluids viscosified with viscoelastic surfactants (VESs) may have their viscosities reduced (gels broken) by the direct or indirect action of a biochemical agent, such as bacteria, fungi, and/or enzymes. The biochemical agent may directly attack the VES itself, or some other component in the fluid that produces a by-product that then causes viscosity reduction. The biochemical agent may disaggregate or otherwise attack the micellar structure of the VES-gelled fluid. The biochemical agent may produce an enzyme that reduces viscosity by one of these mechanisms. A single biochemical agent may operate simultaneously by two different mechanisms, such as by degrading the VES directly, as well as another component, such as a glycol, the latter mechanism in turn producing a by-product (e. g. an alcohol) that causes viscosity reduction. Alternatively, two or more different biochemical agents may be used simultaneously.

US Patent:

7078370, Jul 18, 2006

Filed:

Sep 9, 2002

Appl. No.:

10/238072

Inventors:

James B. Crews - Willis TX, US

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

C09K 8/00
E21B 43/26

US Classification:

507209, 507211, 507219, 507241, 507271, 507273, 507921, 507922, 507903, 1663085

Abstract:

It has been discovered that biodegradable and non-toxic chelant compositions can perform multiple beneficial functions in an aqueous fracturing fluid through the chelation of ions. Some of the multiple functions include various combinations of the following: demulsifier, demulsifier enhancer, scale inhibitor, crosslink delay agent, crosslinked gel stabilizer, enzyme breaker stabilizer, and the like. Some of the chelants used in the compositions include, but are not necessarily limited to, sodium polyaspartate; sodium iminodisuccinate; disodium hydroxyethyleneiminodiacetate (NaHEIDA); sodium gluconate; sodium glucoheptonate; sugar alcohols; monosaccharides; disaccharides; and mixtures thereof.

US Patent:

7084093, Aug 1, 2006

Filed:

Jul 25, 2003

Appl. No.:

10/627391

Inventors:

James B. Crews - Willis TX, US

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

C09K 8/68
C09K 8/60

US Classification:

507209, 507211, 507261, 507266, 507921, 516113

Abstract:

It has been discovered that fracturing fluid breaker mechanisms are improved by the inclusion of a catalyzed polyol alone that directly degrades the polysaccharide backbone, and optionally additionally by removing the crosslinking ion, if present. That is, viscosity reduction (breaking) occurs by breaking down the chemical bonds within the backbone directly. The gel does not have to be crosslinked for the method of the invention to be successful, although it may be crosslinked. In one non-limiting embodiment, the polyol has at least two hydroxyl groups on adjacent carbon atoms. In another embodiment, the polyols are simple sugars and sugar alcohols, and may include mannitol, sorbitol, glucose, fructose, galactose, mannose, lactose, maltose, allose, etc. and mixtures thereof. The catalyzing metal ion may employ a metal selected from Groups VIB, VIIB, VIII, IB, and IIB of the Periodic Table (previous IUPAC American Group notation).

US Patent:

7160842, Jan 9, 2007

Filed:

Jul 25, 2003

Appl. No.:

10/627091

Inventors:

James B. Crews - Willis TX, US

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

C09K 8/52
C09K 8/68

US Classification:

507209, 507211, 507261, 507266, 507921, 516113

Abstract:

It has been discovered that fracturing fluid breaker mechanisms are improved by the inclusion of a polyol alone that directly degrades the polysaccharide backbone, and optionally additionally by removing the crosslinking ion, if present. That is, viscosity reduction (breaking) occurs by breaking down the chemical bonds within the backbone directly, rather than by merely removing the crosslinking ion, if present. The gel does not have to be crosslinked for the method of the invention to be successful, although it may be crosslinked. In one non-limiting embodiment, the polyol has at least two hydroxyl groups on adjacent carbon atoms. In another embodiment, the polyols are monosaccharides such as glycerols and sugar alcohols, and may include mannitol, sorbitol, glucose, fructose, galactose, mannose, lactose, maltose, allose, etc. and mixtures thereof.

US Patent:

7208529, Apr 24, 2007

Filed:

Feb 4, 2004

Appl. No.:

10/771563

Inventors:

James B. Crews - Willis TX, US

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

C09K 3/00
E21B 43/27

US Classification:

516113, 507211, 507241, 507921

Abstract:

It has been discovered that aminocarboxylic acids are effective breakers for polymer-gelled aqueous fracturing fluids, particularly in the temperature range between about 120 F. (49 C. ) and about 280 F. (138 C. ). The aminocarboxylic acids are believed to act directly on the polymer and not to any great extent or not to as an effective extent on a crosslinking agent, if present. The polymer may be a polysaccharide, and the aminocarboxylic acid may be selected from the group including, but not necessarily limited to, tetrasodium ethylenediaminetetraacetic acid (NaEDTA), tetrasodium propylenediaminetetraacetic acid (NaPDTA), trisodium hydroxyethylenediaminetetraacetic acid (NaHEDTA), trisodium nitrilotriacetic acid (NaNTA), salts of these acids, and mixtures thereof.