Inventors:
Roman Loza - Solon OH
Roseann M. Cyngier - Cleveland OH
International Classification:
E21B 4322
Abstract:
A C-branched zwitterionic surfactant represented by the following formula is disclosed: ##STR1## wherein x and y are numbers, x is less than or equal to y+1, and the sum of x+y is in the range of about 7 to about 19, with the provisos that: (1) when the sum of x+y is in the range of about 7 to about 13, x/y is in the range of about 0. 3 to about 1. 2; and (2) when the sum of x+y is in the range of about 14 to about 19, x/y is in the range of about 0. 1 to about 0. 7. An enhanced oil recovery method using the foregoing surfactants is also disclosed.