Oil production using multistage surfactant polymer chemical flood
AssigneeShell Oil Company
InventorJeffrey George SOUTHWICK
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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).
Claims7
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
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.
Dependencies are inferred from the claim text.