Method of achieving a preferential flow distribution in a horizontal well bore

• US 6,533,038 B2
• Filed: 12/08/2000
• Issued: 03/18/2003
• Est. Priority Date: 12/10/1999
• Status: Expired due to Term

• Current Assignee: Regent Technologies Limited
• Original Assignee: Regent Technologies Limited
• Inventors: Kaiser, Trent, Venning, Laurie
• Primary Examiner(s): Bagnell, David
• Assistant Examiner(s): BOMAR, THOMAS S
• Application Number:
  US09/732,851
• Publication Number:
  US 20020170717A1
• Time in Patent Office: 830 Days
• Field of Search: 166/50, 166/369, 166/305.1, 166/307, 405/44, 405/129.85, 405/129.7, 405/129.57, 405/184.2
• US Class Current: 166/369
• CPC Class Codes: E21B 43/12 Methods or apparatus for controlling the flow of the obtained fluid to or in wells E21B43/25 takes precedence; valve arrangements E21B34/00
• CPC Class Codes: E21B 43/32 Preventing gas- or water-coning phenomena, i.e. the formation of a conical column of gas or water around wells

Abstract

A method of achieving a preferential flow distribution in a horizontal well bore. This method consists of the step of positioning in a horizontal wellbore a slotted liner having a plurality of slots which provide a flow area. The slot open flow area of the slotted liner varying along its length in accordance with a selected strategy of flow distribution. The preferred strategy being to create an overbalanced condition in the wellbore which promotes promote a higher flow at the toe portion than at the heel portion.

Claims

1. A method of achieving a preferential flow distribution in a horizontal wellbore, comprising the step of:

positioning in a horizontal wellbore, having a heel portion to a remote toe portion, a slotted liner having a plurality of slots which provide a slot open flow area, the slot open flow area being the product of slot geometry selected to provide sand control and slot density, the slot open flow area of the slotted liner varying along its length in accordance with a selected strategy of flow distribution, the slot open flow area of the slotted liner in the heel portion of the wellbore being less than 0.4% of the area of the slotted liner in order to create a slot induced radial flow loss.

2. The method as defined in claim 1, the slot open flow area of the slotted liner increasing from the heel portion to the toe portion to create an overbalanced condition designed to promote higher flow at the toe portion than at the heel portion.

3. The method as defined in claim 2, the slot open flow area at the toe portion being at least twice the slot open flow area at the heel portion.

4. The method as defined in claim 2, a plug being set in the toe portion of the wellbore when one of water coning or gas break through occurs in order that oil may continue to be produced by that portion of the wellbore not experiencing such water coning or gas break through.

5. The method as defined in claim 1, the slot open flow area being reduced along portions of the wellbore passing through water zones.

6. A method of achieving a preferential flow distribution in a horizontal wellbore, comprising the step of:

positioning in a horizontal wellbore, having a heel portion to a remote toe portion, a slotted liner having a plurality of slots which provide a slot open flow area, the slot open flow area being the product of slot geometry selected to provide sand control and slot density, the slot open flow area of the slotted liner varying along its length, the slot open flow area of the slotted liner in the heel portion of the wellbore being less than 0.4% of the area of the slotted liner in order to create a slot induced radial flow loss, the slot open flow area of the slotted liner increasing from the heel portion to the toe portion to create an overbalanced condition designed to promote higher flow at the toe portion than at the heel portion.

7. The method as defined in claim 6, the slot open flow area at the toe portion being more than twice the slot open flow area at the heel portion.

8. The method as defined in claim 6, the slot open flow area being reduced along portions of the wellbore passing through water zones.

9. The method as defined in claim 6, a plug being set in the toe portion of the wellbore when one of water coning or gas break through occurs in order that oil may continue to be produced by that portion of the wellbore not experiencing such water coning or gas break through.

10. A method of achieving a preferential flow distribution in a horizontal wellbore, comprising the steps of:

positioning in a horizontal wellbore, having a heel portion to a remote toe portion, a slotted liner having a plurality of slots which provide a slot open flow area, the slot open flow area being the product of slot geometry selected to provide sand control and slot density, the slot open flow area of the slotted liner varying along its length, the slot open flow area of the slotted liner in the heel portion of the wellbore being less than 0.4% of the area of the slotted liner in order to create a slot induced radial flow loss, the slot open flow area of the slotted liner increasing from the heel portion to the toe portion to create an overbalanced condition designed to promote higher inflow at the toe portion than at the heel portion in accordance with a flow distribution strategy intended to restrict water coning or gas break through tendencies to the toe portion of the wellbore where water coning can be more readily mitigated, the slot open flow area at the toe portion being more than twice the slot open flow area at the heel portion; and

positioning a plug in the toe portion of the wellbore when one of water coning and gas break through occurs in order to isolate the toe portion and permit oil to continue to be produced from that portion of the wellbore not experiencing such water coning or gas break through.

11. The method as defined in claim 10, the slot open flow area being reduced along portions of the wellbore passing through water zones.