Oil production using multistage surfactant polymer chemical flood

Patent metadata

Field	Value
Publication number	US-2018002591-A1
Application number	US-201515538424-A
Country	US
Kind code	A1
Filing date	Dec 21, 2015
Priority date	Dec 23, 2014
Publication date	Jan 4, 2018
Grant date	—

Abstract

A process for recovering oil from an oil-bearing formation is disclosed comprising providing a first oil recovery formulation comprising a first surfactant able to create low interfacial tension with reservoir crude oil; injecting the first oil recovery formulation into the oil-bearing formation via an injection well ( 201 ); providing a second oil recovery formulation having a second surfactant with a higher solubility in water than the first formulation; injecting the second oil recovery formulation into the oil-bearing formation via the injection well; and producing oil to a production well ( 203 ).

First claim

1 . A process for recovering oil from an oil-bearing formation, comprising:
providing a first oil recovery formulation comprising a first surfactant formulation able to create an oil-water interfacial tension less than 0.01 mN/m in a mixture of the first oil recovery formulation and oil of the formation; injecting the first oil recovery formulation into the oil-bearing formation via an injection well; providing a second oil recovery formulation comprising a second surfactant formulation, where the second surfactant formulation has a higher solubility in water than the first surfactant formulation; injecting the second oil recovery formulation into the oil-bearing formation via the injection well; and producing oil to a production well after injection of the first oil recovery formulation and the second oil recovery formulation into the formation

2 . The method of claim 1 , wherein the first oil recovery formulation and the second oil recovery formulation mix to form a combined oil recovery formulation in the formation, where the combined oil recovery formulation mixes with oil in the formation to form a Winsor type-III microemulsion.

3 . The method of claim 1 , wherein the first oil recovery formulation and the second oil recovery formulation are aqueous.

4 . The method of claim 1 , wherein the first oil recovery formulation has a total dissolved solids content within 10 wt. % of the total dissolved solids content of the second oil recovery formulation.

5 . The method of claim 1 , wherein the first oil recovery formulation comprises divalent cations in a concentration of at least 50 mg/L.

6 . A process for recovering oil from an oil-bearing formation comprising:
providing a first oil recovery formulation comprising a first water and a first surfactant formulation mixed in the first water, wherein the first oil recovery formulation is effective to form a type-III Winsor microemulsion in a mixture with oil of the formation; introducing the first oil recovery formulation into the oil-bearing formation; adsorbing surfactant from the first oil recovery formulation into the oil-bearing formation, wherein sufficient surfactant is adsorbed from the first oil recovery formulation to remove a mixture of the first oil recovery formulation and oil of the formation from a type-III Winsor microemulsion environment; providing a second oil recovery formulation comprising a second water and a second surfactant formulation mixed in the second water, wherein the second surfactant formulation is more hydrophilic than the first surfactant formulation; combining the second oil recovery formulation with the mixture of the first oil recovery formulation and oil within the oil-bearing formation to form a type-III Winsor microemulsion; and producing oil from the oil-bearing formation after combining the first oil recovery formulation and the second oil recovery formulation with oil in the oil-bearing formation.

7 . The process of claim 6 wherein the second oil recovery formulation is effective to form a type-I Winsor microemulsion in a mixture with oil of the formation.

Assignees

• Shell Oil Co

Inventors

• Southwick Jeffrey George

Classifications

• C09K8/584 Primary

  characterised by the use of specific surfactants · CPC title

• E21B43/20 Primary

  Displacing by water · CPC title

• E21B43/16 Primary

  Enhanced recovery methods for obtaining hydrocarbons · CPC title