Union Oil Company of California

Paul W Fischer

David S Pye

Julius P Gallus

Horst E Zilch

John W Scheffel

Milan R Skripek

Louis M Dvoracek

Delbert E Pyle

LeRoy W Holm

Stephen D Pye

D Stephen Pye

Jerry C Jones, Deceased

Fouling of metallic surfaces contacted with petroleum oils at elevated temperatures is reduced by adding to the oil small amounts of an oil-soluble N-alkylamino-alkylbenzene sulfonate, a heterocyclic amine, and phenylhydrazine.

Process and compositions for reducing fouling of heat exchange surfaces

A method for conducting foam drilling and workover operations in a bore hole penetrating a subterranean reservoir, particularly a high-temperature reservoir such as a geothermal reservoir, employing an aqueous foaming solution of about 0.08 to 1.0 percent by weight of an amphoteric betaine, about 0.02 to 0.4 percent by weight of a salt of a linear aliphatic or alkyl aryl hydrocarbon sulfonate, and, optionally, from 0.03 to 3.5 percent by weight unneutralized ammonia.

Foam drilling and workover in high temperature wells

A non-damaging variable-density low fluid loss well completion and workover fluid composition which is a dispersion of finely divided slowly oil-soluble, water-insoluble solid particulate matter in a thickened aqueous salt solution. The fluid composition is a mixture of an aqueous solution of a water-soluble inorganic salt, a first high softening point resin fluid loss control additive, a microemulsion fluid loss control additive, and, optionally, a water-dispersible thickening agent and/or a pH control agent. The microemulsion contains water, an oil-soluble surface active agent, a water-dispersible surface active agent, and, as a fluid loss control additive, a mixture of a wax and a second low softening point resin. The microemulsion also optionally contains an additive to prevent phase separation and/or a bactericide. Also disclosed is a method for using this composition in various well drilling, completion and treating operations.

Well completion and workover fluid having low fluid loss

A method for conducting foam drilling and workover oprations in a bore hole penetrating a subterranean reservoir employing an aqueous solution of a biodegradable foaming agent composition containing about 0.1 to 1 part by weight of an N-fatty ethyl sulfate salt having the formula: ##STR1## wherein R is a straight chain alkyl radical having from 10 to 16 carbon atoms and M is an alkali metal or ammonium cation, per part per weight of a fatty acid salt having the formula: ##STR2## wherein R.sub.1 is a straight chain alkyl radical having from 9 to 15 carbon atoms and M.sub.1 is an alkali metal or ammonium cation. A particularly preferred foaming agent composition contains sodium 2-(N-lauryl) ethyl sulfate and sodium laurate.

Biodegradable foaming agent in drilling and workover operations

A method for conducting foam drilling and workover operations in a bore hole penetrating a subterranean reservoir employing an aqueous solution of a biodegradable foaming agent composition containing about 0.3 to 3 parts by weight of an N-fatty ethyl sulfonic acid salt having the formula: ##STR1## per part by weight of an N-fatty propionic acid salt having the formula: ##STR2## wherein R and R.sub.1 are straight chain alkyl radicals having from 10 to 16 carbon atoms, and M and M.sub.1 are alkali metal or ammonium cations. A particularly preferred foaming agent composition contains sodium 2-(N-lauryl) ethyl sulfonic acid and sodium 2-(N-lauryl) propionic acid.

Method for foam drilling using a biodegradable foaming agent

A method for drilling a well through a subterranean formation containing one or more zones of unconsolidated dolomite, wherein the drilling operation is interrupted periodically to consolidate the newly drilled incompetent dolomite by the injection of a sequence of reactant slugs comprised of (I) an aqueous solution containing an acid, a surface active agent and a precipitating agent for silicates, (II) an aqueous solution containing a water-soluble silicate, and (III) an aqueous solution containing a precipitating agent for silicates.

Method for drilling a well through unconsolidated dolomite formations

A composition and method for drilling wells through subterranean strata containing high temperature aqueous fluids using a gas-containing aqueous drilling fluid containing an alkaline material to raise the pH of the drilling fluid to provide corrosion protection in the liquid phase and a volatile water-soluble nitrogen-containing compound to provide corrosion protection in the gaseous phase.

Controlling corrosion in gas-containing aqueous drilling fluid

A method of conducting an enhanced oil recovery process in a subterranean reservoir wherein, as part of the process, there is injected into the reservoir as a sweep fluid a foam containing carbon dioxide, water and a foaming agent having the formula: ##STR1## wherein R is a straight chain alkyl radical having from 10 to 16 carbon atoms; and M is an alkali metal or ammonium cation, with sodium being preferred. A particularly preferred foaming agent is sodium lauryl sulfoacetate.

Carbon dioxide foam flooding

Composition and method for drilling a well into a high temperature subterranean reservoir, such as one containing a geothermal fluid, wherein there is used an aqueous foam drilling fluid containing (1) water, (2) gas, (3) a foaming agent, (4) an erosion and corrosion inhibitor, (5) a water-soluble or water-dispersible carboxyalkyl cellulose ether or polyalkylene oxide polymer which both controls the fluid loss of the foam and toughens it, and, optionally, (6) a bit lubricant and/or (7) an anti-torqueing agent.

Composition and method for drilling high temperature reservoirs

A method for inhibiting the deposition of wax onto a solid surface from wax-containing petroleum and other wax-containing oils in contact with such solid surface comprising adding to such oils a synergistic mixture of a copolymer of ethylene and a monoethylenically unsaturated ester and one or more fatty derivatives, such as a high molecular weight alcohol, a natural wax, or a fatty acid.

Inhibiting wax deposition from a wax-containing oil

A composition and method for drilling a well into a subterranean reservoir containing a high temperature aqueous liquid which composition contains as a scale inhibitor (i) a water-soluble substituted iminodi(methylene phosphonic acid) compound having a carbon-to-phosphorus bond or a water-soluble salt thereof, (ii) a dicarboxylic acid, (iii) a lower alkyl ester or hydroxy derivative of a dicarboxylic acid, (iv) hexamethylenetetramine, (v) thiourea, or (vi) the amide reaction product of a polycarboxylic acid and an aliphatic amine, an aliphatic hydroxyl amine, or a heterocyclic nitrogen-containing compound.

Composition and method for drilling a reservoir containing a high

A method of conducting foam drilling and workover operations in a bore hole penetrating a subterranean formation, particularly a high-temperature formation such as a geothermal formation, employing an aqueous solution of a foaming agent having the formula: ##STR1## wherein R is a straight chain alkyl radical having from 10 to 16 carton atoms; and M is an alkali metal or ammoniun cation, with sodium being preferred. A particularly preferred foaming agent is sodium lauryl sulfoacetate.

Method of foam drilling using a sulfoacetate foaming agent

A method of inhibiting the formation of scale from aqueous solutions containing scale-forming ions at temperatures of up to 400.degree. F. and above during production and utilization of such aqueous solutions comprising adding to the solutions certain amines, amides, thioamides, carboxylic acids or amide reaction products of carboxylic acids and various amines.

Inhibition of scale deposition in high temperature wells

A composition and method for drilling a well into a subterranean formation containing a geothermal fluid utilizing a gas-containing aqueous drilling fluid containing both lignite and a salt of a high molecular weight acrylic polymer.

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Whittier, CA, United States of America

Paul W Fischer