Waterflood process employing surfactant and graded viscosity

Patent · Tue Mar 25 00:00:00 EST 1969

OSTI ID:7301163

Dotson, B J; Connally, C Jr

A surfactant slug followed by a graded polymer flood is used to recover residual oil after waterflooding. The surfactant is a mixture of petroleum sulfonates having a median molecular weight (MW) of 400 to 430, having molecular weights from 290 to 590, no more than 10 percent by weight with an average MW less than 290 and no more than 15 percent with a MW greater than 590. The surfactant slug should contain between 1 and 2 percent sodium chloride, but be essentially free of divalent cations. Sacrificial inorganics are present in the slug to reduce the tendency of the surfactants to adsorb to the reservoir rock. By decreasing the sodium chloride concentration in floods following the surfactant slug, desorption of the sulfonates can be promoted. The aqueous polymer flood contains Kelzan (polysaccharide B-1459). An areal flow model representing one quarter of a conventional five-spot well pattern was packed with sand (42.9 percent porosity; 7,300 md permeability) from section 67 of Loma Novia field, Duval County, Texas. The model was saturated with water, followed by crude (9.5 cp at 77/sup 0/C), then water all of which were from the Loma Novia field. The waterflood recovered 46.9 percent of the crude. Following aqueous floods of sacrificial inorganics, solutions of surfactant then thickening agent gave 30.5 percent recovery of residual oil after waterflooding.

• Assignee: Mobil Oil Corp.
• Patent Number(s): US 3434542
• OSTI ID: 7301163
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
OIL WELLS
WATERFLOODING
ENHANCED RECOVERY
PETROLEUM
PETROLEUM SULFONATES
POLYSACCHARIDES
SURFACTANTS
VISCOSITY
CARBOHYDRATES
ENERGY SOURCES
ESTERS
FLUID INJECTION
FOSSIL FUELS
FUELS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
SACCHARIDES
SULFONATES
SULFONIC ACID ESTERS
WELLS
020300* - Petroleum- Drilling & Production