Shell Oil Comapny

Richard E Dilgren

Kenneth B Owens

George J Hirasaki

Hon C Lau

Harold J Hill

Paul B Ritter

Derrill G Whitten

In a steam-foam-displacement of oil within a reservoir formation having a significant ion-exchange capacity for releasing multivalent cations, the rate of the steam foam propagation is increased by injecting a mixture of steam and a steam-foaming surfactant mixture comprising an independently effective steam-foaming sulfonate surfactant mixed with a lesser amount of an alkyl or alkylarylpolyalkoxyalkylene sulfonate cosurfactant.

Steam-foaming surfactant mixtures which are tolerant of divalent ions

A steam-foam-forming surfactant effective for displacing the oil in a particular reservoir is selected by comparing the capabilities of foams formed by different surfactants for both flowing preferentially into permeable porous materials which contain that reservoir oil and displacing that oil from those materials.

Process for selecting a steam foam forming surfactant

In a process in which steam and steam-foaming surfactant are injected into a subterranean reservoir having significant cation-exchange capacity, the rate of transport of the steam-foaming surfactant is increased by a prior injection of an aqueous liquid solution of surfactant and monovalent cation salt.

Reservoir preflushing process for increasing the rate of surfactant

Steam mobility-reducing capability of an olefin sulfonate-containing surfactant formulation for reducing the mobility of steam of a selected quality within a selected subterranean oil-containing reservoir is tested. Steam of the selected quality and a steam-containing fluid which has substantially the same quality containing the surfactant formulation, an electrolyte and a noncondensable gas upflow through columns of permeable porous mediums containing the reservoir oil. The mass flow rates through the columns are substantially equivalent to a selected flow rate in a near-well portion of the reservoir. Steady-state pressure within the columns are measured and the permeability reducing factor of the surfactant formulation is calculated from the pressure measurements.

Olefin sulfonate-improved steam foam drive

In a steam soak oil recovery process in a heavy oil reservoir which is susceptible to gravity override, improved results are obtained by injecting the steam in the form of a steam-foam-forming mixture which has a chemical selectivity for being more mobile within the reservoir in contact with the reservoir oil than in the absence of that oil.

Selective steam foam soak oil recovery process

A steam foam drive process for displacing oil within a subterranean reservoir is improved by injecting into the reservoir a steam-foam-forming mixture of steam, and an olefin sulfonate-containing surfactant component.

A relatively viscous oil is produced from a subterranean reservoir by establishing a channel of preferential permeability through the reservoir between injection and production locations, then flowing through the reservoir a hot foam of aqueous liquid, noncondensable gas and surfactant, and controlling the mobility of the foam so that heated oil is produced and hot fluid is flowed through portions of the reservoir within and outside the channel of preferential permeability.

Hot water foam oil production process

In a viscous oil reservoir in which the stratification of the rock permeability is insufficient to confine steam within the most permeable strata, oil can be produced by forming and expanding a steam channel through which steam is flowed and oil is produced. Steam is injected and fluid is produced at rates causing a steam channel to be extended between locations that are horizontally separated. A foam-forming mixture of steam, noncondensable gas and surfactant is then injected into the steam channel to provide foam and a relatively high pressure gradient within the channel, without plugging the channel. A flow of steam-containing fluid through the steam channel is continued in a manner such that the magnitudes of the pressure gradient, the rate of oil production, and the rate of steam channel expansion exceed those which could be provided by steam alone.

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Houston, TX, United States of America

Richard E Dilgren