Exxon Production Research Company

Exxonmobil Upstream Research Company

James R Bragg

Ramesh Varadaraj

Sergio A Leonardi

Shan H Yang

Dennis G Peiffer

Chester W Elspass

Harry A Deans

Scott E Hommema

Joseph P Lederhos

Amy L Chen

Robert D Kaminsky

Cornelius Hendrick Brons

Walter W Gale

John Huang

Donald B Siano

Monte K Dobson

A waxy oil-external emulsion is provided for injection into a selected zone of a subsurface formation. The selected zone is typically a high permeability zone. The emulsion generally comprises oil, added wax, and water. The emulsion may also include an emulsifying agent and a solvent. The emulsion is formulated to be a liquid at a temperature greater than a targeted temperature in the subsurface formation, but a solid at the targeted temperature. The targeted temperature is typically the maximum operating temperature for the formation. A method of formulating the emulsion is also provided. Further, a method of plugging a high permeability zone using the emulsion is disclosed.

Composition and method for using waxy oil-external emulsions to modify reservoir permeability profiles

An improved method of producing hydrocarbons from a subterranean formation in which a solids-stabilized emulsion (SSE) is formed, the SSE comprising oil as a first liquid, droplets of a second liquid suspended in the oil, and solid particles that are insoluble in both the oil and the second liquid at the conditions of the subterranean formation. The SSE with dissolved gas is injected into the subterranean formation as a drive fluid, and at least a portion of the SSE is placed into one or more area of the subterranean formation having an in situ pressure sufficiently lower than the selected partial pressure to permit evolution of at least a portion of the gas from the oil. Furthermore, a method of making the foamy SSE is also provided.

Method of oil recovery using a foamy oil-external emulsion

A method for enhancing the stability of a water-in-oil emulsion pretreating at least a portion of the oil prior to emulsification. The pretreatment step may consist of adding polymers to the oil, biotreating the oil, photochemically treating the oil, or combinations thereof. The emulsion may be used in various enhanced oil recovery methods including using the emulsion as a flooding agent to displace hydrocarbons in a subterranean formation, and using the emulsion as a barrier fluid for diverting flow of fluids in the formation.

Stability enhanced water-in-oil emulsion and method for using same

A solids-stabilized oil-in-water emulsion and a method for preparing the solids-stabilized oil-in-water emulsion. The oil-in-water emulsion is formed by combining oil, water, solid particles and a pH enhancing agent and mixing until the solid-stabilized oil-in-water emulsion is formed. The low viscosity oil-in-water emulsion can be used to enhance production of oil from subterranean reservoirs. The low viscosity oil-in-water emulsion can also be used to enhance the transportation of oil through a pipeline.

Solids-stabilized oil-in-water emulsion and a method for preparing same

A method for enhancing the stability of a solids-stabilized water-in-oil emulsion by pretreating the oil prior to emulsification. The pretreatment step can be accomplished by adding dilute acid to the oil, adding a lignosulfonate additive to the oil, sulfonating the oil, thermally oxidizing the oil, thermally treating the oil in an inert environment, and combinations thereof. The emulsion can be used in enhanced oil recovery methods, including using the emulsion as a drive fluid to displace hydrocarbons in a subterranean formation, and using the emulsion as a barrier fluid for diverting flow of fluids in the formation.

Solids-stabilized water-in-oil emulsion and method for using same

The disclosed invention provides a method for recovering hydrocarbons from a subterranean formation by injecting an emulsion, comprising oil and water, into the formation. More specifically, the emulsion is stabilized using undissolved solid particles, which are preferably at least partially oleophilic. The solids-stabilized emulsion may be used either as a drive fluid for displacing hydrocarbons from the formation or to produce a barrier for diverting flow of fluids in the formation. Such solid particles may be either formation solid particles (i.e., indigenous to the formation) or nonformation solid particles (i.e., obtained from outside the formation). Nonformation solid particles may either be naturally occurring or synthetic. Some preferred solids include clays, quartz, feldspar, gypsum, coal dust, asphaltenes, and polymers.

Oil recovery method using an emulsion

The disclosed invention is a solids-stabilized emulsion and method for making same for use in recovering hydrocarbons from a subterranean formation. More specifically, the emulsion comprises oil and water and is stabilized using undissolved solid particles, which are preferably at least partially oleophilic. Carbon dioxide or another gas is added to the emulsion to adjust the emulsion's viscosity to the desired level. The solids-stabilized emulsion may be used either as a drive fluid for displacing hydrocarbons from the formation or to produce a barrier for diverting flow of fluids in the formation. Such solid particles may be either formation solid particles (i.e., indigenous to the formation) or nonformation solid particles (i.e., obtained from outside the formation). Nonformation solid particles may either be naturally occurring or synthetic. Some preferred solids include clays, quartz, feldspar, gypsum, coal dust, asphaltenes, and polymers.

Solids-stabilized emulsion

The disclosed invention provides a method for recovering hydrocarbons from a subterranean formation by injecting an emulsion, comprising oil and water, into the formation. More specifically, the emulsion is stabilized using undissolved solid particles, which are preferably at least partially oleophilic. The solids-stabilized emulsion may be used either as a drive fluid for displacing hydrocarbons from the formation or to produce a barrier for diverting flow of fluids in the formation. Such solid particles may be either formation solid particles (i.e., indigenous to the formation) or nonformation solid particles (i.e., obtained from outside the formation). Nonformation solid particles may either be naturally occurring or synthetic. Some preferred solids include clays, quartz, feldspar, gypsum, coal dust, asphaltenes, and polymers. Carbon dioxide or another gas may be added to the emulsion to adjust the emulsion's viscosity to the desired level.

A method is disclosed for removing spilled oil from shorelines, other solid surfaces, or from the surface of a body of water by adding to the surface a mixture of fine hydrophilic mineral solids dispersed in an aqueous liquid that interacts with the oil to form buoyant mineral fines-oil floccules. These floccules reduce the tendency of the oil to adhere to solid surfaces or to recoalesce, thus facilitating dispersion and removal of the oil.

Method for forming mineral solids-oil floccules

A method is disclosed for concentrating surfactant in an aqueous solution. The method comprises adding to the solution a component incompatible with the surfactant, such as a water-soluble polymer, thereby displacing the surfactant from the aqueous phase of the solution. The component remains in the aqueous phase and the surfactant goes into a surfactant-rich phase. The surfactant-rich phase can then be separated from the aqueous phase by conventional separation devices or techniques. This method is particularly applicable to concentrating surfactant recovered from a reservoir following an enhanced oil recovery process employing surfactant. The method may be practiced in the field or off-site.

Method for concentrating surfactant from a brine solution

To improve the separation of a produced oil-water emulsion containing a surfactant, the emulsion parameters of temperature and salinity are brought within certain critical limits. The emulsion will separate into an injectable brine/surfactant phase and a pipeline quality crude oil phase. The operable salinity range is from about 70% to about 130% of the reservoir salinity, and the operable temperature range is from about 75.degree. F. lower to about 75.degree. F. higher than the temperature of the reservoir from which the emulsion was produced.

Method for treating oil-water emulsions and recovering surfactants

An aqueous heteropolysaccharide solution is treated to improve its injectivity into a subterranean hydrocarbon reservoir by passing the solution through a colloid mill.

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Houston, TX, United States of America

James R Bragg