Venture Chemicals, Inc.

Venture Innovations, Inc.

Masi Technologies, Inc.

Actisystems, Inc.

Jack C Cowan

Roy F House

Victor M Granquist

Tommy F Brookey

Tommy Thrash

Mike Kilchrist

Jerry R Rayborn

Tammy L Rodrigue

Andree' H Harrington

Andree H Harrington

Frederick B Growcock

Michael J Kilchrist

Catherine G Benoit

Andre′ N Blanchard

Tony Rea

Andree H Wilkinson

Disclosed is a process for the deacetylation of chitin and a process for the treatment of chitinaceous materials to obtain chitin which processes are conducted in a non-saponifiable, non-aqueous, water insoluble liquid having a flash point greater than about 100&#xb0; C., preferably a non-aromatic hydrocarbon. The process for the deacetylation of chitin comprises suspending chitin in the hydrocarbon liquid, preferably from about 0.02 g/cc to about 0.2 g/cc, mixing therewith an alkali metal hydroxide solution, and heating the suspension at a temperature at least about 70&#xb0; C. for a period of time sufficient to obtain the desired degree of deacetylation. The concentration of alkali metal hydroxide in the alkali metal hydroxide solution is at least 30% by weight, preferably at least 40% by weight, and most preferably at least 50% by weight, and the quantity of alkali metal hydroxide is sufficient to provide an alkali metal hydroxide to chitin weight ratio from about (0.35)(AMHMW)/40 to about (2.5)(AMHMW)/, 40 where AMHMW is the molecular weight of the alkali metal hydroxide.

Process for the treatment for chitinaceous materials and for the deacetylation of chitin

The present invention generally relates to improved clay-based compositions comprising colloidal or colloidal-like phases (e.g., emulsions, aphrons) and methods of using those compositions. The compositions generally comprise an aqueous continuous phase, one or more palygorskite-sepiolite group clays, one or more surfactants, aphrons and optionally one or more Aphron Stabilizers. The compositions of the present invention are capable of being used in high-pressure applications.

Colloidal and colloidal-like systems in aqueous, clay-based fluids

The present invention generally relates to compositions of matter and methods of using those compositions. More particularly, and as part of one of the preferred embodiments, the present invention relates to compositions and methods of use of fluids useful for sealing formation fractures and/or inhibiting downhole fluid loss. The present invention is useful as a pill or series of pills that can be formulated and spotted to a particular formation zone.

Compositions and methods for sealing formations

The invention provides an organic diacid anhydride-modified chitosan and a method of preparing the same under high shear conditions which eliminates the use of solvents and excessive amounts of aqueous liquids. Also provided are organic diacid anhydride-modified chitosans containing an inorganic basic material which enhances the aging stability thereof. The invention also provides fluids useful in various well drilling and servicing operations comprising an alkaline aqueous liquid containing an organic diacid anhydride-modified chitosan, as well as a method of drilling wells therewith.

Anhydride-modified chitosan, method of preparation thereof, and fluids containing same

Disclosed is a composition for and method of reducing the loss of fluid from well drilling, completion, or workover fluids during well drilling, completion, or workover operations, particularly for reducing or overcoming the lost circulation of drilling fluids. The composition comprises an aqueous liquid containing partially hydrated chitosan particles wherein the chitosan particles have been partially hydrated at a pH less than about 4.5, and wherein the aqueous liquid has a pH of at least about 6.5 such that any further solublizing of the chitosan is prevented. The aqueous liquid, preferably when mixed with a drilling, completion, or workover fluid, is effective in decreasing the loss of such fluids after introducing the partially hydrated chitosan-containing liquid or fluid into the flow passages in a well to which such fluids are being lost.

Method of and composition for reducing the loss of fluid during well drilling, completion or workover operations

Disclosed are a process for the preparation of pseudoplastic, shear thinning chitosan-containing fluids, and a method of enhancing the thermal stability of such fluids. Pseudoplastic fluids useful oil and/or gas wells, particularly drilling fluids, drill-in fluids, workover fluids, completion fluids, perforating fluids, filter cake removal fluids, various pills, and the like, are prepared by solublizing chitosan in an acidic solution and thereafter raising the pH above about 7.0 by the addition of a basic compound thereto. The thermal stability of such fluids is enhanced by incorporating into the fluids certain aldose or ketose sugars, oligosaccharides of such sugars, and mixtures thereof, optionally together with a water soluble bisulfite compound.

Chitosan-containing well drilling and servicing fluids

Aphron-containing oil based well drilling and servicing fluids are disclosed which seal microfractures and the like during drilling and well servicing operations, thus decreasing the volume of fluid lost to the formations contacted by the fluids.. The fluids comprise an oleaginous liquid as the continuous phase, a viscosifier which imparts a low shear rate viscosity to the fluids of at least 10,000 centipoise, an aphron-generating surfactant, and aphrons. The fluids are used in a conventional method of drilling an oil and/or gas well or in conventional methods of servicing or treating such wells, such as in completion, workover, sand control, and frac pack operations, and as spotting fluids to release stuck pipes or tools in a wellbore.

Aphron-containing oil base fluids and method of drilling a well therewith

Aphron-containing spotting fluids and their use in releasing pipe or tools stuck in the filter cake on the sides of a borehole are disclosed. The spotting fluids comprise a liquid, either aqueous, oleaginous, or mixtures thereof, a viscosifier which imparts a low shear rate viscosity to the fluids of at least 10,000 centipoise, an aphron-generating surfactant, and aphrons. The spotting fluids are used in a conventional method of releasing pipes or tools stuck in the filter cake on the sides of a borehole during conventional drilling or well servicing operations.

Method of releasing stuck pipe or tools and spotting fluids therefor

Disclosed is a process of manufacturing a lightweight particulate cementitious composition particularly adapted to the sorption of liquids comprising adding to a foamed cement slurry a particle forming agent, and aging the treated foamed slurry for a period of time sufficient for the particles to form and harden for subsequent handling. The bulk density, particle size distribution, and concentration of the agent are selected such that the cementitious composition has the desired density and such that at least 65% of the particles obtained after aging have the desired particle size.

Lightweight particulate cementitious materials and process for producing

The invention provides well working compositions containing a particulate additive to decrease the seepage loss of the fluid to fluid permeable formations contacted by the compositions. The additive comprises: (1) a cellulosic material selected from the group consisting of oat hulls, citrus pulp, beet pulp, paper, bagasse, peat, corn cobs, kenaf, rice hulls, rice bran, straw, cottonseed hulls, soybean hulls, and mixtures thereof (2) a particulate mixture of a first cellulosic material selected from the group consisting of oat hulls, cotton burrs, and mixtures thereof, and a second cellulosic material selected from the group consisting of beet pulp, paper, bagasse, wood, peat, kenaf, rice hulls, rice bran, cottonseed hulls, soybean hulls, straw, peanut shells, nut shells, cotton, and mixtures thereof; or (3) a particulate mixture of an oleaginous liquid and a cellulosic material selected from the group consisting of oat hulls, cotton burrs, citrus pulp, beet pulp, paper, bagasse, wood, corn cobs, kenaf, peat, rice hulls, rice bran, cottonseed hulls, soybean hulls, nut shells, straw, and mixtures thereof; provided that the cellulosic materials have a certain particle size distribution as set forth in the specification.

Reduction of seepage losses in well working compositions

The invention provides well working fluid compositions containing cotton burrs ground to certain particle size ranges to decrease the seepage loss of the fluid to fluid permeable formations contacted by the compositions. Also provided is a seepage loss additive comprising the ground cotton burrs in combination with one or more of ground oat hulls, ground corn cobs, hydrophobic organophilic water wettable cotton, ground citrus pulp, ground peanut shells, ground rice hulls, and ground nut shells.

Seepage loss reducing additive for well working compositions and uses

The invention provides well working fluid compositions containing oat hulls ground to certain particle size ranges to decrease the seepage loss of the fluid to fluid permeable formations contacted by the compositions. Also provided is a seepage loss additive comprising the ground oat hulls in combination with one or more of ground corn cobs, hydrophobic organophilic water wettable cotton, ground citrus pulp, and ground cotton burrs.

Well working compositions, method of decreasing the seepage loss from

Organophilic polymer adducts which are effective fluid loss control additives for oil base well-working fluids are prepared from an anionic or cationic water soluble polymer and one or more phosphatides. Preferred phosphatides are phosphoglycerides obtained from vegetable oils, most preferably commercial lecithin. Preferred polymers comprise polysaccharides or derivatives thereof and synthetic polymers.

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Lafayette, LA, United States of America

Jack C Cowan