Method of using overbased sulfonate water flood additive derived from heavy coker gas oil

Claim 2

The method of claim 2 wherein the ratio is about 0.20 to about 1.0.

Claim 3

The method of claim 3 wherein the base component is selected from the group consisting of NaOH, LiOH, KOH, Na2CO3, Li2CO3 and K2CO3.

Claim 4

The method of claim 4 which includes the step of injecting into said formation subsequent to said anionic water flood additive an additional amount of from about 10 to 1,000 volume percent, based on the total volume of the sulfonate containing slug, of an aqueous base component solution, said base component solution containing from about 0.5 to 50 weight percent of the base component.

Claim 5

The method of claim 4 which includes the step of admixing an effective amount of an aqueous brine solution with said overhead anionic water flood additive to provide a salt level of about 0.5 to 10 weight percent in the aqueous liquid of the formation following injection.

Claim 6

The method of claim 6 wherein the sulfonation step in the preparation of said additive is carried out in a batch-type process and the aqueous brine solution admixed with said additive in an amount sufficient to provide a brine solution containing from about 0.1 to 4 weight percent salt in said formation.

Claim 7

The method of claim 6 which includes the steps of forming said anionic water flood additive in situ by the sequential steps of: a. injecting into said formation an effective amount of a neutralized sulfonic acid derivative of said heavy coker gas oil, b. injecting into said formation an effective amount of base component selected from the group consisting of an aqueous alkali metal hydroxide solution and an aqueous alkali metal carbonate solution to produce an overbased mixture from said sulfonate and said base component, said overbased mixture containing an excess of base component such that the ratio: weight of excess base component/weight of sulfonate is about 0.20 to about 1.0, and c. recovering from said formation hydrocarbon displaced by said overbased mixture.

Claim 8

The method of claim 8 wherein said heavy coker gas oil has a boiling range of from about 410* to 910* F, and the base component is selected from the group consisting of an alkali metal hydroxide and an alkali metal carbonate.

Claim 9

The method of claim 8 wherein said base component is selected from the group consisting of NaOH, LiOH, KOH, Na2CO3, K2CO3 and Li2CO3.

Claim 10

The method of claim 10 which includes the step of admixing a brine solution with said anionic water flood additive sufficient to provide about 0.5 to 10 weight percent salt in the aqueous liquid in the formation after injection of the additive.

Claim 11

The method of claim 11 wherein the sulfonation step in the preparation of the additive is carried out in a batch-type process and the brine solution and salt concentration thereof admixed with the additive is in an amount sufficient to provide an aqueous brine solution in the formation having a salt concentration of about 0.1 to 4 weight percent.