Oil recovery process using arkyl aryl polyalkoxyol sulfonate surfactants as mobility control agents

A process for recovering oil from a porous, oil-containing subterranean formation penetrated by an injection well and a spaced apart production well, which comprises

• injecting through said injection well and into said formation an aqueous solution containing a surfactant characterized by the formula ##STR6## where R is a linear or branched chain alkyl group with n carbon atoms wherein n ranges from about 6 to about 50, except that if the gas is stream n ranges from about 9 to about 50;
• Ar is a mononuclear or fused ring dinuclear aryl group;
• Z is an ionic group consisting of --SO.sub.3.sup.- M.sup.+ or --R'SO.sub.3.sup.- M.sup.+ wherein M.sup.+ is a cation and R' is a linear or branched chain alkyl group of from one to about six carbon atoms;
• x ranges from 0 to about 20;
• and
• y ranges from 3 to about 100;
• injecting CO.sub.2 as the primary oil displacing fluid through said injection well into said formation to drive the oil from said formation to said production well whereby said CO.sub.2 and said aqueous solution containing said surfactant form a mixture in the formation which significantly reduces CO.sub.2 mobility in more permeable regions of the formation;
• and
• producing oil from the production well.

A process for recovering oil from a porous, oil-containing subterranean formation penetrated by an injection well and a spaced apart production well, which comprises

• injecting through said injection well and into said formation an aqueous solution containing a surfactant characterized by the formula ##STR7## where R is a linear or branched chain alkyl group with n carbon atoms wherein n ranges from about 6 to about 50, except that if the gas is stream n ranges from about 9 to about 50;
• Ar is a mononuclear or fused ring dinuclear aryl group;
• Z is an ionic group consisting of --SO.sub.3.sup.- M.sup.+ or --R'SO.sub.3.sup.- M.sup.+ wherein M.sup.+ is a cation and R' is a linear or branched chain alkyl group of from one to about six carbon atoms;
• x ranges from 0 to about 20;
• and
• y ranges from 3 to about 100;
• injecting steam through said injection well and into said formation to drive the oil from said formation to said production well whereby said stream and said aqueous solution containing said surfactant form a mixture in the formation which significantly reduces steam mobility in more permeable regions of the formation;
• and
• producing oil from the production well.

A method for reducing gas mobility in a subterranean oil-containing formation having regions of varying permeability comprising injecting into the formation through an injection well in communication therewith a gas as the primary oil displacing fluid wherein said gas is selected from the group consisting of carbon dioxide, hydrocarbon gas, inert gas, and steam, and injecting an aqueous solution containing a surfactant characterized by the formula ##STR8## where R is a linear or branched alkyl group with n carbon atoms wherein n ranges from about 6 to about 50, except that if the gas is steam n ranges from about 9 to about 50;

• Ar is a mononuclear or fused ring dinuclear aryl group;
• Z is an ionic group consisting of --SO.sub.3 Hu -M.sup.+ or --R'SO.sub.3.sup.- M.sup.+ wherein M.sup.+ is a cation and R' is a linear or branched chain alkyl group of from one to about six carbon atoms;
• x ranges from 0 to about 20;
• and
• y ranges from 3 to about 100;
• whereby said gas and said aqueous solution containing said surfactant form a mixture in the formation which significantly reduces gas mobility in the more permeable regions of said formation.

A gas flooding operation for recovering hydrocarbons from a subterranean formation comprising injecting through an injection well a drive fluid of a gas as the primary oil displacing fluid to drive the hydrocarbon from the formation to a producing well and injecting into the formation a mobility control fluid consisting essentially of an aqueous surfactant solution in which the surfactant is represented by the general structural formula:

• ##STR9## where R is a linear or branched chain alkyl group with n carbon atoms wherein n ranges from about 6 to about 50, except that if the gas is steam n ranges from about 9 to about 50;
• Ar is a mononuclear or fused ring dinuclear aryl group;
• Z is an ionic group consisting of --SO.sub.3.sup.- M.sup.+ or --R'SO.sub.3.sup.- M.sup.+ wherein M.sup.+ is a cation and R' is a linear or branched chain alkyl group of from one to about six carbon atoms;
• x ranges from 0 to about 20;
• and
• y ranges from 3 to about 100.