Wellbore system

Patent metadata

Field	Value
Publication number	US-10408032-B2
Application number	US-201615279150-A
Country	US
Kind code	B2
Filing date	Sep 28, 2016
Priority date	Sep 28, 2016
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A system and method of producing a deposit of gas and liquid hydrocarbons from a subterranean formation, where a pressure of the gas hydrocarbons is regulated. Strategically regulating a pressure of the gas hydrocarbons prevents the gas hydrocarbons from expanding into a path of the liquid hydrocarbons flowing to a wellbore. The liquid hydrocarbons are produced through a production well that is drilled from surface and into a zone within the subterranean formation containing the deposit. A gas expansion circuit is also drilled through the formation, and has a portion that terminates proximate an interface between the gas and liquid hydrocarbons. Thus as the gas hydrocarbons expand into spaces left empty by draining the liquid hydrocarbons, the expanding gas is diverted into the gas expansion circuit rather than into the path of liquid hydrocarbons still in the zone. The gas expansion circuit can have a “fish-bone” configuration.

First claim

What is claimed is:

1. A system for producing from a subterranean formation comprising:
a production wellbore that intersects a zone in the subterranean formation containing a deposit of gas and liquid hydrocarbons that contact one another along a gas and liquid interface;
perforations on a portion of the production wellbore that is disposed on a liquid side of the interface;
a gas expansion circuit that intersects the zone and is in selective pressure communication with the deposit, and that comprises,
a motherbore,
a deviated portion extending from the motherbore, and
lateral wells that project from sides of the deviated portion and that have ends terminating at a depth greater than the interface when the lateral wells are formed, so that when the liquid hydrocarbons flow into the production wellbore and the gas hydrocarbons expand, at least some of the expanding gas hydrocarbons flow into the gas expansion circuit, the interface is maintained in a planar configuration, and liquid hydrocarbons are between the perforations and gas hydrocarbons remaining on a gas side of the interface that is opposite from the liquid side; and

an inlet on a portion of a gas control wellbore that is on the gas side of the interface.

2. The system of claim 1 , wherein at a time after liquid hydrocarbons are being produced from the subterranean formation, the interface between the gas and liquid hydrocarbons moves to a depth away from terminal ends of the lateral wells so that terminal ends of the lateral wells are in communication with the gas hydrocarbons.

3. The system of claim 1 , wherein the lateral wells and deviated portion comprise a fishbone gas conduit.

4. The system of claim 1 , wherein the deviated portion is oriented oblique with the interface.

5. The system of claim 1 , wherein the deviated portion is oriented substantially parallel with the interface.

6. The system of claim 1 , wherein the zone comprises a gas cap, and wherein the gas expansion circuit comprises a plurality of motherbores that have ends at surface, and opposing ends disposed in flank sections of the zone.

7. The system of claim 6 , wherein the ends in the flank sections of the zone are oriented substantially parallel with a contour of a periphery of the zone proximate the ends.

8. A method of producing from a subterranean formation comprising:
directing a liquid hydrocarbon from within a gas cap and into a wellbore that intersects the subterranean formation;
preventing gas hydrocarbon in the formation from expanding into a path of liquid hydrocarbons flowing to an inlet to the wellbore by controlling a pressure of the gas hydrocarbon that is in the gas cap and at a lesser depth than the liquid hydrocarbon; and
balancing a pressure in the gas cap by venting at least some of the gas hydrocarbon.

9. The method of claim 8 , wherein the liquid hydrocarbon and the gas hydrocarbon define a deposit in the zone.

10. The method of claim 8 , wherein gas hydrocarbon is vented from the zone through a gas control well that intersects the zone, wherein an interface between the gas hydrocarbon and liquid hydrocarbon is at a depth in the formation that changes over time, and wherein a portion of the gas control well is at a depth greater than the depth of the interface when the gas control well is formed.

11. The method of claim 10 , wherein the gas control well comprises a motherbore, and lateral wells that project radially outward from the motherbore and into the zone.

12. The method of claim 11 , wherein the lateral wells comprise fishbone wells.

13. The method of claim 11 , wherein venting the gas hydrocarbons controls a pressure of the gas in the cone so that an interface between the liquid hydrocarbons and gas hydrocarbons is maintained in a planar orientation.

14. A method of producing from a subterranean formation comprising:
producing liquid hydrocarbons through a liquid hydrocarbon production wellbore and from within a gas cap in the formation in which gas hydrocarbons resides at a lesser depth than the liquid hydrocarbons, and is in contact with the liquid hydrocarbons along an interface;
producing gas hydrocarbons from the gas cap through a gas hydrocarbon wellbore that is spaced away from the liquid hydrocarbon production wellbore; and
controlling a pressure of the gas hydrocarbons in the gas cap with the gas hydrocarbon wellbore.

15. The method of claim 14 , wherein the interface intersects openings in subterranean rock disposed in the gas cap.

16. The method of claim 14 , wherein the step of controlling a pressure of the gas hydrocarbon in the gas cap maintains the interface away from an inlet to the liquid hydrocarbon wellbore.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al-Muraikhi Ahmad J
• Wang Yanhui A
• Ramirez Ivan G

Classifications

• E21B43/32

  Preventing gas- or water-coning phenomena, i.e. the formation of a conical column of gas or water around wells · CPC title

• E21B43/18 Primary

  Repressuring or vacuum methods · CPC title

• E21B43/305 Primary

  comprising at least one inclined or horizontal well · CPC title

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• E21B43/14

  Obtaining from a multiple-zone well · CPC title