James R Dobson

US Patent:

20020028750, Mar 7, 2002

Filed:

Oct 4, 2001

Appl. No.:

09/970831

Inventors:

James Dobson - Houston TX, US
Kim Tresco - Houston TX, US

International Classification:

C09K007/00

US Classification:

507/100000

Abstract:

Disclosed is a method of increasing the low shear rate viscosity and the shear thinning index of aqueous fluids containing a divalent cation salt, a crosslinked amylopectin starch which functions as both a viscosifier/suspending agent and as a fluid loss control additive, and a bridging agent, the fluids resulting from the method, and the use of the fluids in drilling a well, wherein the bridging agent is a sized particulate magnesium carbonate or a mixture of sized magnesium carbonate and sized calcium carbonate. The median (D) particle size of the magnesium carbonate is from about 2 m to about 10 m. The weight ratio of calcium carbonate to magnesium carbonate is from about 70/30 to about 0/100.

US Patent:

20030144154, Jul 31, 2003

Filed:

Dec 16, 2002

Appl. No.:

10/320145

Inventors:

James Dobson - Houston TX, US
Shauna Hayden - Houston TX, US
Belinda Hinojosa - Houston TX, US

International Classification:

E21B001/00

US Classification:

507/200000

Abstract:

Disclosed is a concentrate composition for crosslinking polysaccharide polymers hydrated in an aqueous liquid, and well servicing fluids, preferably fracturing fluids, prepared therewith. Preferred polysaccharide polymers are galactomannan gums or derivatives thereof, preferably hydroxypropylguar. The concentrate comprises an alkali metal formate solution, preferably potassium formate, a crosslinking agent for the polysaccharide polymer, preferably a sparingly soluble alkali metal or alkali metal alkaline earth metal borate, and a suspension agent, preferably a clay mineral selected from the group consisting of smectite clays, palygorskite clays, and mixtures thereof Exemplary clays are hectorite, sepiolite, and attapulgite. The concentrate may, optionally, contain a deflocculant and/or an anti-syneresis additive.

US Patent:

20030236173, Dec 25, 2003

Filed:

Jun 19, 2002

Appl. No.:

10/175589

Inventors:

James Dobson - Houston TX, US
Shauna Hayden - Houston TX, US
Carolina Rangel - Cypress TX, US

International Classification:

C09K007/00

US Classification:

507/110000

Abstract:

Disclosed is a hydrophilic, water soluble polymer concentrate for addition to aqueous liquids to enhance the properties thereof, particularly to increase the viscosity or decrease the fluid loss of well drilling and servicing fluids, the concentrate comprising a hydrophobic, water insoluble liquid, an organophilic clay suspension agent, the water soluble polymer, and a stabilizing agent comprising one or more acids in an amount from about 0.001% to about 1.5%, one or more anionic surfactants in an amount from about 0.001% to about 1.0%, one or more nonionic surfactants in an amount from 0.001% to about 0.625% and, from about 0% to about 0.75% of one or more water soluble organic liquids, wherein the total concentration of the stabilizing agent is from about 0.1% to about 2.5%, these percentages being based on the weight of the concentrate. Preferably the stabilizing agent is a microemulsion comprising the acid(s), the anionic surfactant(s), the nonionic surfactant(s), and the water soluble organic liquid(s), and further comprising from about 0.0005% to about 1.0% of one or more water insoluble solvents, and from about 0.001% to about 2.0% water.

US Patent:

20040067854, Apr 8, 2004

Filed:

Oct 7, 2002

Appl. No.:

10/265346

Inventors:

James Dobson - Houston TX, US
Shauna Hayden - Houston TX, US
Belinda Hinojosa - Houston TX, US

International Classification:

C09K007/02

US Classification:

507/200000

Abstract:

The invention provides an aqueous suspension/concentrate of a sparingly soluble borate, preferably as disclosed in Mondshine U.S. Pat. No. 4,619,776, which is effective in crosslinking aqueous solutions of a water soluble, borate-crosslinkable polymer, preferably guar gum and derivatives thereof. The aqueous suspension/concentrate comprises a saturated aqueous solution of a sparingly soluble borate, a suspension agent, suspended particles of a sparingly soluble borate, and optionally a stabilizing agent, wherein the saturated solution of the sparingly soluble borate is prepared prior to the particles of the sparingly soluble borate being suspended therein. The preferred suspension agent is a palygorskite clay such as attapulgite and sepiolite. The invention further provides a method of hydraulically fracturing a formation with the aqueous borate suspension/concentrate.

US Patent:

20050003966, Jan 6, 2005

Filed:

Jul 29, 2004

Appl. No.:

10/901822

Inventors:

James Dobson - Houston TX, US
Kim Tresco - Houston TX, US
Jorge Fernandez - Houston TX, US

International Classification:

C09K007/02

US Classification:

507100000, 507200000

Abstract:

The invention provides well drilling and servicing fluids, and methods of drilling, completing, or working over a well therewith, preferred fluids comprise an aqueous liquid, a water soluble polymer viscosifier (preferably xanthan gum), a polymeric fluid loss control additive (preferably a partially depolymerized partially crosslinked hydroxyalkyl ether derivative of starch or a hydroxyalkyl ether derivative of a partially crosslinked and partially depolymerized starch), a bridging agent comprising a particulate calcined magnesia that has an Activity Index greater than about 800 seconds, and citric acid in an amount sufficient to increase the low shear rate viscosity of the fluids. The invention further provides a method of increasing the low shear rate viscosity of fluids which contain a water soluble polymer and a calcined magnesia bridging agent which has an Activity Index greater than about 800 seconds.

US Patent:

20060009364, Jan 12, 2006

Filed:

Nov 22, 2004

Appl. No.:

10/948041

Inventors:

James Dobson - Houston TX, US
Ronald Rock - Richmond TX, US

International Classification:

E21B 43/00
C09K 3/00

US Classification:

507110000, 507209000

Abstract:

The invention provides (1) a method of increasing the thermal stability of an oleaginous liquid containing a high surface area silica viscosifier therein by adding a water soluble biopolymer thereto; and (2) a drilling, completion, workover, or well servicing fluid comprising an oleaginous liquid, a water soluble biopolymer, and a high surface area silica viscosifier. The method and fluid may optionally contain a low molecular weight polar additive preferably having a molecular weight less than about 400 and containing one or more polar groups per molecule selected from the group consisting of hydroxyl, amino, and mixtures thereof

US Patent:

20060079405, Apr 13, 2006

Filed:

Oct 8, 2004

Appl. No.:

10/530793

Inventors:

James Dobson - Houston TX, US
Kim Tresco - Houston TX, US
Jorge Fernandez - Houston TX, US
Bradley Todd - Duncan OK, US
Trinidad Munoz - Duncan OK, US

International Classification:

C09K 8/08
E21B 43/00

US Classification:

507110000, 507213000

Abstract:

The invention provides well drilling and servicing fluids, and methods of drilling, completing, or working over a well therewith, preferred fluids comprise an aqueous liquid, a water soluble polymer viscosifier (preferably xanthan gum), a polymeric fluid loss control additive (preferably a partially depolymerized partially crosslinked hydroxyalkyl ether derivative of starch or a hydroxyalkyl ether derivative of a partially crosslinked and partially depolymerized starch), and as a bridging agent a particulate magnesia that has an Activity Index greater than about 800 seconds, preferably from about 800 seconds to about 3000 seconds.

US Patent:

20060079406, Apr 13, 2006

Filed:

Dec 14, 2004

Appl. No.:

11/011659

Inventors:

James Dobson - Houston TX, US
Kim Tresco - Houston TX, US
Jorge Fernandez - Houston TX, US

International Classification:

C09K 8/08
E21B 43/00

US Classification:

507110000, 507213000

Abstract:

The invention provides well drilling and servicing fluids, and methods of drilling, completing, or working over a well therewith, preferred fluids comprise an aqueous liquid, a water soluble polymer viscosifier (preferably xanthan gum), a polymeric fluid loss control additive (preferably a partially depolymerized partially crosslinked hydroxyalkyl ether derivative of starch or a hydroxyalkyl ether derivative of a partially crosslinked and partially depolymerized starch), a bridging agent comprising a particulate calcined magnesia that has an Activity Index greater than about 800 seconds, and an additive selected from the group consisting of citric acid, alkali metal salts of citric acid, ammonium citrate, and mixtures thereof in an amount sufficient to increase the low shear rate viscosity of the fluids, preferably from about 0.05-5 ppb, most preferably from about 0.15-3 ppb. The invention further provides a method of increasing the low shear rate viscosity of fluids which contain a water soluble polymer and a calcined magnesia bridging agent which has an Activity Index greater than about 800 seconds.