Method for CO2 EOR and storage and use thereof

Patent metadata

Field	Value
Publication number	US-10024149-B2
Application number	US-201414784368-A
Country	US
Kind code	B2
Filing date	Apr 17, 2014
Priority date	Apr 17, 2013
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A method of Enhanced Oil Recovery from oil zones in a subterranean geological formation, and from oil zones. The method including: a first injecting step of injecting a first composition including CO2 into the subterranean geological formation for a period of time; a second injecting step of injecting a second composition including CO2 and a hydrocarbon into the subterranean geological formation for a period of time, wherein the first composition and the second composition are different; and extracting oil from the subterranean geological formation.

First claim

The invention claimed is:

1. A method of Enhanced Oil Recovery (EOR) from paleo or residual oil zones in a subterranean geological formation; the method comprising:
a first injecting step of injecting a first composition comprising CO 2 , the first composition being injected at or near its supercritical state, into the subterranean geological formation for a period of time;
a second injecting step of injecting a second composition comprising CO 2 and a hydrocarbon, the second composition being injected at or near its supercritical state, into the subterranean geological formation for a period of time, wherein the first composition and the second composition are different and have viscosity and density at the site of injection that are different;
extracting oil from the subterranean geological formation; and
cycling alternately between the first injecting step and the second injecting step.

2. A method as claimed in claim 1 , wherein the hydrocarbon in the second composition comprises an intermediate or heavy hydrocarbon.

3. A method as claimed in claim 1 , wherein the hydrocarbon in the second composition comprises a light hydrocarbon.

4. A method as claimed in claim 1 , wherein the first composition is injected in a gas-like phase and the second composition is injected in a liquid-like phase.

5. A method as claimed in claim 1 , wherein the first composition is substantially pure CO 2 .

6. A method as claimed in claim 1 , wherein the method comprises extracting one or more of at least some of the injected CO 2 and hydrocarbons.

7. A method as claimed in claim 1 , wherein the time periods are each between one month and one year.

8. A method as claimed in claim 1 , wherein the hydrocarbon which is in the second composition is selected to make the second composition miscible with residual oil in the subterranean geological formation.

9. A method as claimed in claim 8 , wherein the proportion of hydrocarbon is selected to make the second composition miscible with residual oil in the subterranean geological formation.

10. A modified CO 2 Enhanced Oil Recovery (EOR) method for oil production from paleo and residual oil zones combined with optimized CO 2 storage in which a CO 2 composition to be injected at or near its supercritical state into a subterranean geological formation is changed in cycles to create gas-like and liquid like states, wherein to achieve the liquid-like state intermediate and heavy hydrocarbons are added to the CO 2 containing composition to modify the density and viscosity of the injected stream.

11. An installation for Enhanced Oil Recovery (EOR) from paleo or residual oil zones in a subterranean geological formation, the installation comprising an injection well leading into the subterranean geological formation for injecting compositions into the subterranean geological formation, a supply of CO 2 , a supply of a hydrocarbon, a means for controlling the composition injected via the injection well such that the composition can be cyclically alternated between a first composition injected at or near its supercritical state comprising CO 2 and a second composition injected at or near its supercritical state comprising CO 2 and the hydrocarbon, and a production well for extracting oil from the subterranean geological formation, wherein the first composition and the second composition have viscosity and density at the site of injection that are different.

Assignees

• Statoil Petroleum As

Inventors

• Nazarian Bamshad
• Ringrose Philip Sefton

Classifications

• C09K8/58

  Compositions for enhanced recovery methods for obtaining hydrocarbons, i.e. for improving the mobility of the oil, e.g. displacing fluids · CPC title

• C09K8/594

  Compositions used in combination with injected gas {, e.g. CO2 orcarbonated gas}(C09K8/592 takes precedence) · CPC title

• E21B43/166

  Injecting a gaseous medium; Injecting a gaseous medium and a liquid medium (CO2 injection E21B43/164; steam injection E21B43/24) · CPC title

• E21B41/0064

  Carbon dioxide sequestration (storing fluids in porous layers B65G5/005) · CPC title

• E21B43/164 Primary

  Injecting CO2 or carbonated water (in combination with organic material C09K8/594) · CPC title