Pre-flush for oil foamers
A method of enhancing oil or gas production comprises injecting into a well penetrating a subterranean formation a pre-flush fluid to increase water wettability of the well, the subterranean formation, a flowline, or a combination comprising at least one of the foregoing; and injecting into the well a foamer composition.
1. A method of enhancing oil or gas production, the method comprising:
injecting into a well penetrating a subterranean formation, a pre-flush fluid to increase water wettability of the well, the subterranean formation, a flowline, or a combination comprising at least one of the foregoing; and
injecting into the well a foamer composition comprising a silicone surfactant and an additive comprising one or more of the following: a diluent; a foamer solvent; or a second foamer surfactant different from the silicone surfactant,
wherein the pre-flush fluid comprises:
about 5 to about 40 wt % of a solvent which comprises an aromatic solvent;
about 5 to about 25 wt % of a surfactant which comprises a blend of polyoxyalkylene sulfate and alcohol ethoxylate;
about 5 to about 30 wt % of a co-solvent which comprises glycol ether, an aliphatic alcohol, or a combination thereof; and
about 40 wt % to about 60 wt % of a brine,
each based on a total weight of the pre-flush fluid,
wherein the pre-flush fluid is a single phase fluid prior to being injected into the well.
2. The method of claim 1 , wherein the foamer composition is injected after the pre-flush fluid.
3. The method of claim 1 , wherein the foamer composition contacts the wellbore fluid in the well to decrease the density of a wellbore fluid.
4. The method of claim 1 , further comprising conveying a wellbore fluid out of the well.
5. The method of claim 4 , wherein the wellbore fluid is conveyed out of the well together with a lift gas.
6. The method of claim 5 , wherein the lift gas is injected into the well and comprises air, carbon dioxide, methane, ethane, propane, nitrogen, or a combination comprising at least one of the foregoing.
7. The method of claim 5 , wherein the lift gas is naturally occurring and comprises carbon dioxide, natural gas, or a combination comprising at least one of the foregoing.
8. The method of claim 4 , wherein the wellbore fluid is a crude oil.
9. The method of claim 4 , wherein the wellbore fluid has an API density of equal to or less than 45.
10. The method of claim 4 , wherein the wellbore fluid has an API density of greater than 45 and up to 55.
11. The method of claim 4 , wherein the wellbore fluid has a water cut of equal to or less than 75%.
12. The method of claim 4 , wherein the wellbore fluid is conveyed out of the well in a foamed state.
13. The method of claim 1 , wherein the pre-flush fluid and the foamer composition are injected via an umbilical, capillary string, gas lift, an annulus for wells without a packer, or a combination comprising at least one of the foregoing.
14. The method of claim 1 , wherein the pre-flush fluid and the foamer composition are applied in a batch treatment.
15. The method of claim 1 , wherein the pre-flush fluid and the foamer composition are applied in a continuous treatment.
16. A method of mitigating liquid loading in an oil well penetrating a subterranean formation, the method comprising:
injecting into the oil well, a pre-flush fluid to increase water wettability of the oil well, the subterranean formation, a flowline, or a combination comprising at least one of the foregoing;
injecting a foamer composition into the oil well subsequent to injecting the pre-flush fluid, the foamer composition comprising a silicone surfactant and an additive comprising one or more of the following: a diluent; a foamer solvent; or a second foamer surfactant different from the silicone surfactant; and
injecting a lift gas into the well or using a naturally occurring gas in the well to remove a wellbore fluid out of the well,
wherein the pre-flush fluid comprises:
about 5 to about 40 wt % of a solvent which comprises an aromatic solvent;
about 5 to about 25 wt % of a surfactant which comprises a blend of polyoxyalkylene sulfate and alcohol ethoxylate;
about 5 to about 30 wt % of a co-solvent which comprises glycol ether, an aliphatic alcohol, or a combination thereof; and
about 40 wt % to about 60 wt % of a brine,
each based on a total weight of the pre-flush fluid,
wherein the pre-flush fluid is single phase fluid prior to being injected into the well.