Waterflood oil recovery with chromatographically balanced surfactant

Patent · Tue Oct 30 00:00:00 EST 1973

OSTI ID:7093240

Hill, H J; Thigpen, D R

A surfactant slug for tertiary oil recovery was designed to have a mobility less than the mobility of flowing oil and water in the reservoir, and the ratio of the concentrations of the surfactants to polymer thickener in the surfactant slug was adjusted so that the frontal advance rates were equal, (chromatographic balance). The surfactant slug contained sodium petroleum sulfonate (average molecular weight 460 to 470), sodium petroleum sulfonate (MW 330 to 350, Pyronate 50), Neodol 25-3S, isobutyl alcohol, a polymer thickener, and brine (about 3,900 ppm total dissolved solids--TDS, including about 400 ppm divalent cations). For the first laboratory test a Berea sandstone block (21.7 percent porosity, 855 md permeability) was saturated with brine (3,900 ppm TDS). A recovery of greater than 96 percent of residual oil was predicted for 1.10 PV of the surfactant slug (containing the biopolymer, Kelzan M) followed by a thickened flood of Kelzan M in brine (3,900 ppm TDS). A second test was performed on a Berea core (19.5 percent, 240 md) which had been saturated with brine (77,000 ppm TDS, including about 8,800 ppm divalent cations), flooded with oil, and waterflooded with brine (77,000 ppm TDS). This test recovered 96 percent of residual oil by 1.22 PV of the surfactant slug (containing Pusher 700) followed by a thickened flood of Pusher 700 in fresh water. All tests were performed at 95/sup 0/F. To assure chromatographic stability, the amount of surfactants and polymer were adjusted to allow for adsorption onto the cores.

• Assignee: Shell Oil Co.
• Patent Number(s): US 3768560
• OSTI ID: 7093240
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
OIL WELLS
WATERFLOODING
ALCOHOLS
ENHANCED RECOVERY
MOBILITY
PETROLEUM
PETROLEUM SULFONATES
SANDSTONES
SURFACTANTS
ENERGY SOURCES
ESTERS
FLUID INJECTION
FOSSIL FUELS
FUELS
HYDROXY COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ROCKS
SEDIMENTARY ROCKS
SULFONATES
SULFONIC ACID ESTERS
WELLS
020300* - Petroleum- Drilling & Production