Milchem Incorporated

Baker Hughes Corporation

Alphonse C Perricone

Dorothy P Enright

Dennis K Clapper

James M Lucas

William M Dye

Darrell P Salisbury

F Martin Smith

A method is provided for the prevention of balling of formation cuttings upon the surface of drilling equipment and for lubrication of said equipment used in conjunction with subterranean well operations. An aqueous system is prepared to which is added a composition of a water insoluble polyglycol having a molecular weight of from between about 1,200 and about 10,000, an emulsifying surfactant having a hydrophilic/hydrophobic balance of about 4 or more, and a hydrotrope. An additive for use in the method also is disclosed.

Drilling fluid methods and composition

The present invention provides a modified liquid phase drilling fluid having desirable properties of shale swelling inhibition, lubrication, and high temperature performance. The fluid does not rely on the incorporation of inorganic salts or high molecular weight water soluble polymers for control of shale swelling or shale disintegration and exhibits performance characteristics, approaching those of oil base drilling fluids, without the objectionable properties of hydrocarbon oils or its potential hazardous impact on the environment. The fluid is comprised of the following: (1) a liquid phase containing; (a) a water phase comprising fresh water, seawater, brine, simulated brine, or mixtures thereof; and (b) a water-soluble component selected from the class consisting of polyhydric alcohols, glycol, glycol ethers, polypropylene glycols, polyethylene glycols, ethylene oxide-propylene oxide copolymers ('EO-PO'), alcohol-initiated EO-PO copolymers and/or mixtures thereof, the ratio of said water-soluble component in the total liquid phase being from about 5% to about 50% by volume; (2) a viscosifier for suspension of solids in said liquid phase; and (3) a filtration control agent. The fluid with the water soluble component will exhibit a lubricity coefficient lower than that for substantially the same fluid without the water soluble component as determined by the American Petroleum Institute's 'Procedure for Determination of Lubricity Coefficient (Tentative)' (1980), and the linear swelling on a reconstituted 'gumbo' shale inserted for about 60 minutes of said drilling fluid being from lower than that for substantially the same fluid without the water soluble component, as measured by the 'Swelling Test', 'Rigsite Shale Evaluation Techniques for Control of Shale-related Wellbore Instability Problems', SPE/IADC Paper No. 16054, pages 52-53, (1987).

Modified non-polluting liquid phase shale swelling inhibition drilling

The present invention provides a modified liquid phase drilling fluid having desirable properties of shale swelling inhibition, lubrication, and high temperature performance. The fluid does not rely on the incorporation of inorganic salts or high molecular weight water soluble polymers for control of shale swelling or shale disintegration and exhibits performance characteristics, approaching those of oil base drilling fluids, without the objectionable properties of hydrocarbon oils or its potential hazardous impact on the environment. The fluid is comprised of the following: (1) a liquid phase containing: (a) a water phase comprising fresh water, seawater, brine, simulated brine, or mixtures thereof; and (b) a water-soluble component selected from the class consisting of polyhydric alcohols, glycol, glycol ethers, polypropylene glycols, polyethylene glycols, ethylene oxide-propylene oxide copolymers ('EO-PO'), alcohol-initiated EO-PO copolymers and/or mixtures thereof, the ratio of said water-soluble component in the total liquid phase being from about 5% to about 50% by volume; (2) a viscosifier for suspension of solids in said liquid phase; and (3) a filtration control agent. The fluid with the water soluble component will exhibit a lubricity coefficient lower than that for substantially the same fluid without the water soluble component as determined by the American Petroleum Institute's 'Procedure for Determination of Lubricity Coefficient (Tentative)' (1980), and the linear swelling on a reconstituted 'gumbo' shale inserted for about 60 minutes of said drilling fluid being from lower than that for substantially the same fluid without the water soluble component, as measured by the 'Swelling Test', 'Rigsite Shale Evaluation Techniques for Control of Shale-related Wellbore Instability Problems', SPE/IADC Paper No. 16054, pages 52-53, (1987).

The present invention provides a modified liquid phase drilling fluid having desirable properties of shale swelling inhibition, lubrication, and high temperature performance. The fluid is comprised of the following: (1) a liquid phase containing: (a) a water phase comprising fresh water, seawater, brine, simulated brine, or mixtures thereof; and (b) a water-soluble component selected from the class consisting of polyhydric alcohols, glycol, glycol ethers, polypropylene glycols, polyethylene glycols, ethylene oxide-propylene oxide copolymers ('EO-PO'), alcohol-initiated EO-PO copolymers and/or mixtures thereof, the ratio of said water-soluble component in the total liquid phase being from about 5% to about 50% by volume; (2) a viscosifier for suspension of solids in said liquid phase; and (3) a filtration control agent.

The present invention relates to a surfactant for use in invert emulsion drilling fluids, the invert emulsion drilling fluid produced therefrom, and a method of drilling, completing and working over a subterranean well utilizing said drilling fluid. The drilling fluid comprises an emulsion formed by producing a diamide having from between about 20 mole percent and about 35 mole percent of a polyamine, and from between about 30 mole percent and about 70 mole percent of a fatty acid having from between about 6 to about 20 carbon atoms therein, the diamide thereafter being further reacted with from between about 15 mole percent and about 35 mole percent of a tricarboxylic acid. The total amine value of said oligamide being from between about 10 to about 30, and the acid value of said oligamide being from between about 26 to about 46. When the surfactant is diluted to about 70 w/w percent concentration with a suitable solvent, the ES.sub.3, as defined herein, of said emulsion drilling fluid will exceed about 400 volts, the ES.sub.5, as defined herein, will be greater than the ES.sub.4, and the ES.sub.5 will be greater than about 1,000 volts. Alternatively, the electrical stability of the emulsion drilling fluid, when using the API Electrical Stability Test, should be at least about 1,000 volts.

Invert emulsion drilling fluid comprising oligamide composition

The invention relates to an aqueous solution of a filtration control agent for utilization in said aqueous drilling fluid, useful in a method of forming a filter cake on the wall of a well for the reduction of filtrate from said drilling fluid, which is effective at high temperatures and pressures, the terpolymer consisting essentially of: (1) an alkali metal acrylate units; (2) hydroxyalkyl acrylate units; and (3) acrylamide.

Aqueous drilling fluid additive

The invention relates to an aqueous drilling fluid composition, a filtration control agent for utilization in said aqueous drilling fluid, and a method of forming a filter cake on the wall of a well for the reduction of filtrate from said drilling fluid, by utilization of a copolymer of: (1) a (meth) acrylamido alkyl sulfonic acid or alkali metal salt thereof; and (2) a (meth) acrylamide or N-alkyl (meth) acrylamide. The copolymer may be cross-linked with a quaternary ammonium salt cross-linking agent.

Drilling fluid containing a copolymer filtration control agent

The invention relates to an aqueous drilling fluid composition, a filtration control agent for utilization in said aqueous drilling fluid, and a method of forming a filter cake on the wall of a well for the reduction of filtrate from said drilling fluid, which are effective at high temperatures and pressures, by utilization of a terpolymer of: (1) a monovalent alkali metal salt of acrylic acid; (2) an hydroxy alkyl acrylate; and (3) acrylamide.

Aqueous drilling fluid additive, composition and process

A continuous process is provided for producing substantially homogeneous, non-tacky solid terpolymers of acrylamide, an alkali metal salt of acrylic acid and a hydroxyalkyl acrylate, and copolymers, optionally cross-linked, of a (meth)acrylamidoalkylsulfonic acid or alkali metal salt thereof and (meth)acrylamide or N-alkyl(meth)acrylamide, by rapidly heating a single phase high solids aqueous solution of the monomers to polymerization initiation temperature immediately prior to depositing a uniform layer of the solution and, at the same time, a solution of a polymerization initiator, onto a moving surface, the surface and the reaction mixture only being heated if necessary to keep the temperature of the polymerizing mixing from dropping substantially below the polymerization initiation temperature.

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Houston, TX, United States of America

Alphonse C Perricone