Dual gradient steam foam oil displacement process

Patent · Tue Oct 21 04:00:00 EDT 1986

OSTI ID:5053650

Lau, H C

This patent describes an oil displacement process in which oil is displaced by injecting pretreatment fluid, steam and steam-foaming surfactant into a reservoir in which surfactant transport is impeded by an ion-exchange of multivalent cations from the rocks. The improvement described here comprises: injecting the pretreatment fluid in a volume totalling not more than about the volume of the pore space to be traversed in flowing from the injection location to the location within the reservoir into which the oil is to be displaced; arranging the composition of the pretreatment fluid in correlations with the properties of the reservoir rocks. In this way, the injected volume of the pretreatment fluid contains both (a) sufficient monovalent cations to ion-exchange with at least most of the multivalent cations on the reservoir rocks contacted by that fluid, and (b) enough steam-foaming surfactant to substantially satisfy the surfactant transport-impeding effects of the rocks contacted by the pretreatment fluid; and injecting steam-foaming fluid, comprising steam, steam-foaming surfactants, and monovalent electrolyte, in which the proportions of the surfactant and electrolyte are each less than about half of those contained in the pretreatment fluid.

• Assignee: Shell Oil Co., Houston, TX
• Patent Number(s): US 4617995
• OSTI ID: 5053650
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
CATIONS
CHARGED PARTICLES
COLLOIDS
DISPERSIONS
ELECTROLYTES
ENERGY SOURCES
ENHANCED RECOVERY
FLUID INJECTION
FOAMS
FOSSIL FUELS
FUELS
ION EXCHANGE
IONS
OIL WELLS
PETROLEUM
POROSITY
RECOVERY
RESERVOIR ROCK
STEAM INJECTION
STIMULATION
SURFACTANTS
WELL STIMULATION
WELLS