Displacing fluid for enhanced oil recovery

Patent metadata

Field	Value
Publication number	US-2021172311-A1
Application number	US-201916706400-A
Country	US
Kind code	A1
Filing date	Dec 6, 2019
Priority date	Dec 6, 2019
Publication date	Jun 10, 2021
Grant date	—

Abstract

A process directed toward enhanced oil recovery in an oil-containing formation, the process comprising the steps of removing a water/oil emulsion from an oil-water separator, wherein the water/oil emulsion comprises a stable emulsion, wherein a temperature of the water/oil emulsion is less than 120 deg C., wherein a pressure of the water/oil emulsion is greater than the saturation pressure at the temperature of the water/oil emulsion, wherein the water/oil emulsion comprises an alkali content, and introducing the water/oil emulsion into the oil-containing formation as an enhanced oil recovery stream, wherein the enhanced oil recovery stream is used in enhanced oil recovery.

First claim

That which is claimed is:

1 . A process directed toward enhanced oil recovery in an oil-containing formation, the process comprising the steps of:
removing a water/oil emulsion from an oil-water separator, wherein the water/oil emulsion comprises a stable emulsion, wherein a temperature of the water/oil emulsion is less than 120 deg C., wherein a pressure of the water/oil emulsion is greater than the saturation pressure at the temperature of the water/oil emulsion, wherein the water/oil emulsion comprises an alkali content; and introducing the water/oil emulsion into the oil-containing formation as an enhanced oil recovery stream, wherein the enhanced oil recovery stream is used in enhanced oil recovery.

2 . The process of claim 1 , further comprising the steps of:
introducing the water/oil emulsion to a desalter mixer; introducing a desalter water to the desalter mixer, wherein the desalter water comprises an alkali content, wherein the alkali content is the range between 26,000 ppmw and 367,500 ppmw; mixing the water/oil emulsion and the desalter water in the desalter mixer to produce a stabilized emulsion; and introducing the stabilized emulsion into the oil-containing formation as an enhanced oil recovery stream, wherein the enhanced oil recovery stream is used in enhanced oil recovery.

3 . The process of claim 2 , further comprising the steps of:
introducing the stabilized emulsion to a production mixer; introducing a produced water stream to the production mixer, wherein an alkali content of the produced water stream is in the range between 20,000 ppmw and 600,000 ppmw; mixing the stabilized emulsion and the produced water stream in the production mixer to produce a mixed recovery water; and introducing the mixed recovery water into the oil-containing formation as an enhanced oil recovery stream, wherein the enhanced oil recovery stream is used in enhanced oil recovery.

4 . The process of claim 1 , further comprising the steps of:
separating a separated water stream from the water/oil emulsion; introducing the separated water stream to a waste water treatment facility; treating the separated water stream in the waste water treatment facility to produce a treated water stream, wherein the treated water stream comprises fewer contaminants than the separated water stream; and mixing the treated water stream with a pressurized water feed to a produce mixed water feed.

5 . The process of claim 1 , further comprising the steps of:
increasing a pressure of an oil feed in an oil pump to produce a pressurized oil feed, wherein an alkali content of the oil feed is less than 300 pounds per thousand barrels; increasing a temperature of the pressurized oil feed in an oil heater to produce a pre-heated oil feed, wherein the temperature of the pre-heated oil is in the range between 50 deg C. and 250 deg C.; introducing the pre-heated oil feed to a mixer; increasing a pressure of a water feed in a water pump to produce a pressurized water feed; increasing a temperature of the pressurized water feed in a water cross-heater to produce a pre-heated water feed; increasing a temperature of the pre-heated water feed in a water heater to produce a supercritical water feed, wherein a temperature of the supercritical water feed is in the range between 374 deg C. and 600 deg C.; introducing the supercritical water feed to the mixer; mixing the pre-heated oil feed and the supercritical water feed to produce a mixed feed, wherein a volumetric ratio of the volumetric flow rate of the supercritical water feed to the volumetric flow rate of the pre-heated oil feed is in the range between 5:1 to 1:1; introducing the mixed feed to a supercritical water (SCW) reactor; treating the mixed feed in the SCW reactor to produce a reactor effluent, wherein a reaction temperature in the SCW reactor is in the range between 380 deg C. and 600 deg C., wherein a reaction pressure is in the range between 22 MPa and 30 MPa, wherein a residence time in the SCW reactor is in the range between 10 seconds and 60 minutes; reducing a temperature of the reactor effluent in the water cross-heater to produce a pre-cooled effluent; reducing a temperature of the pre-cooled effluent in a process cooler to produce a cooled effluent, wherein a temperature of the cooled effluent is less than 120 deg C.; reducing a pressure of the cooled effluent in a pressure reducing element to produce a depressurized effluent, wherein the depressurized effluent is at a pressure greater than the saturation pressure at the temperature of the cooled effluent; and separating the depressurized effluent in the oil-water separator to produce a gas product stream, an upgraded oil product, and the water oil emulsion, wherein the upgraded oil product contains upgraded hydrocarbons relative to the hydrocarbons in the oil feed.

6 . The process of claim 1 , wherein the alkali content of the water/oil emulsion is in the range between 20,000 ppmw and 600,000 ppmw.

7 . The process of claim 5 , wherein the oil feed comprises oil recovered in the enhanced oil recovery.

8 . The process of claim 1 , wherein the amount of oil in the water/oil emulsion is in the range between 30,000 ppmw and 400,000 ppmw.

9 . The process of claim 1 , wherein the operating conditions in the oil-separator are maintained such that greater than 95 wt % of the water in the oil-water separator is in the liquid phase.

10 . A system for producing an enhanced oil recovery stream for enhanced oil recovery, the system comprising:
a supercritical water (SCW) reactor, the SCW reactor configured to treat a mixed feed to produce a reactor effluent, wherein the mixed feed comprises a pre-heated oil feed and a supercritical water feed, wherein a reaction temperature in the SCW reactor is in the range between 380 deg C. and 600 deg C., wherein a reaction pressure is in the range between 22 MPa and 30 MPa, wherein a residence time in the SCW reactor is in the range between 10 seconds and 60 minutes; a water cross-heater fluidly connected to the SCW reactor, the SCW reactor configured to reduce a temperature of the reactor effluent to produce a pre-cooled effluent; a process cooler fluidly connected to the water cross-heater, the process cooler configured to reduce a temperature of the pre-cooled effluent in to produce a cooled effluent, wherein a temperature of the cooled effluent is less than 120 deg C.;
a pressure reducing element fluidly connected to the process cooler, the pressure reducing element configured to reduce a pressure of the cooled effluent to produce a depressurized effluent, wherein the depressurized effluent is at a pressure greater than the saturation pressure at the temperature of the cooled effluent; and
an oil-water separator fluidly connected to the pressure reducing element, the oil-water separator configured to separate the depressurized effluent to produce a gas product stream, an upgraded oil product, and a water oil emulsion, wherein the upgraded oil product contains upgraded hydrocarbons relative to the hydrocarbons in the oil feed, where the water/oil emulsion comprises a stable emulsion, wherein a pressure of the water/oil emulsion is greater than the saturation pressure at the temperature of the water/oil emulsion, wherein the water/oil emulsion comprises an alkali content.

11 . The system of claim 10 , further comprising an oil-containing formation fluidly connected to the oil-water separator, wherein the water/oil emulsion is operable to be injected into the oil-containing formation as the enhanced oil recovery stream.

12 . The system of claim 10 , further comprising a desalter mixer fluidly connected to the

Assignees

• Saudi Arabian Oil Co

Inventors

• Fathi Mazin M
• Choi Ki-Hyouk
• Alqarzouh Muneef F

Classifications

• E21B43/40 Primary

  Separation associated with re-injection of separated materials {(E21B43/385 takes precedence)} · CPC title

• E21B43/20

  Displacing by water · CPC title

• C10G31/06 Primary

  by heating, cooling, or pressure treatment · CPC title

• C10G31/08

  by treating with water · CPC title

• C10G2300/1033

  Oil well production fluids · CPC title