Apparatus and Method for Formation Evaluation

• US 20070209793A1
• Filed: 04/24/2007
• Published: 09/13/2007
• Est. Priority Date: 10/07/2004
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Zazovsky, Alexander, Briquet, Stephane, Del Campo, Christopher, Ervin, Steve, Nold, Raymond
• Granted Patent: US 7,584,786 B2
• Time in Patent Office: Days
• US Class Current: 166/264
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers

Abstract

A method for acquiring a sample of a virgin fluid from a subsurface formation penetrated by a wellbore surrounded by a layer of contaminated fluid is disclosed. The method includes abutting a first packer against a wall of the wellbore, and extending at least a portion of a second packer beyond the first packer, wherein the second packer is at least partially disposed in the first packer. An inlet to a first flowline is at least partially defined by the first packer, and an inlet to a second flowline is defined by the second packer. The method further includes drawing one of virgin fluid, contaminated fluid and combinations thereof into the first flowline; and drawing virgin fluid into the second flowline.

Claims

1. A probe assembly for employment by a downhole tool disposed in a wellbore surrounded by a layer of contaminated fluid, the wellbore penetrating a subsurface formation having a virgin fluid therein beyond the layer of contaminated fluid, the probe assembly comprising:

a probe body extendable from the downhole tool;

an outer packer disposed in the probe body for sealingly engaging a first portion of the wellbore, the outer packer having a bore therethrough;

an inner packer disposed in the bore of the outer packer and forming an annulus therebetween, the inner packer being extendable beyond an outer surface of the outer packer for sealingly engaging a second portion of the wellbore within the first portion;

a first inlet in the probe body fluidly communicating with the annulus for admitting one of virgin fluid, contaminated fluid and combinations thereof into the downhole tool; and

a second inlet in the probe body fluidly communicating with the inner packer for admitting virgin fluid into the downhole tool.

2. The probe assembly of claim 1, wherein the probe body is extendable under hydraulic pressure delivered from the downhole tool.

3. The probe assembly of claim 1, wherein at least one of the outer packer and the inner packer is elastomeric.

4. The probe assembly of claim 1, wherein a sampling tube is operatively connected to the inner packer.

5. The probe assembly of claim 4, wherein the sampling tube is moveable relative to the outer packer.

6. The probe assembly of claim 1, wherein a flow line is fluidly coupled to the first inlet and includes a filter for filtering particles from the fluid.

7. The probe assembly of claim 1, wherein a flow line is fluidly coupled to the second inlet and includes a filter for filtering particles from the fluid.

8. The probe assembly of claim 4, further comprising a piston disposed within the sampling tube.

9. The probe assembly of claim 8, wherein the piston comprises an axial passageway therein and one or more perforations in a sidewall thereof for conducting virgin fluid admitted to the sampling tube to the axial passageway, the axial passageway fluidly communicating with the second inlet in the probe body.

10. A method for acquiring a sample of a virgin fluid from a subsurface formation penetrated by a wellbore surrounded by a layer of contaminated fluid, comprising:

abutting an outer surface of a first packer against a first portion of a wall of the wellbore;

abutting an outer surface of a second packer against a second portion of the wall of the wellbore, wherein the outer surface of the second packer penetrates a plane defined by the outer surface of the first packer;

drawing one of virgin fluid, contaminated fluid and combinations thereof from an annular portion of the wall between the first and second packers; and

drawing virgin fluid from a portion of the wall at least partially defined by the second packer.

11. The method of claim 10, further comprising creating a seal against the first portion with the outer surface of the first packer.

12. The method of claim 10, further comprising creating a seal against the second portion with the outer surface of the second packer.

13. The method of claim 10, further comprising filtering at least one of the fluid drawn from the annular portion and the portion at least partially defined by the second packer.

14. The method of claim 10, wherein drawing the fluid includes pumping the fluid with a pumping system.

15. The method of claim 14, further comprising flowing the virgin fluid into a sample chamber.

16. A method of acquiring a sample of virgin fluid from a subsurface formation penetrated by a wellbore surrounded by a layer of contaminated fluid, comprising:

abutting a first packer against a wall of the wellbore, wherein an inlet to a first flowline is at least partially defined by the first packer;

extending at least a portion of a second packer beyond the first packer, the second packer being at least partially disposed in the first packer, wherein an inlet to a second flowline is defined by the second packer;

drawing one of virgin fluid, contaminated fluid and combinations thereof into the first flowline; and

drawing virgin fluid into the second flowline.

17. The method of claim 16, further comprising pumping fluid through at least one of the first and second flowlines.

18. The method of claim 17, further comprising obtaining a fluid property of the fluid using at least one sensor.

19. The method of claim 17, further comprising flowing the virgin fluid into a sample chamber.

20. The method of claim 17, further comprising commingling the fluids of the first flowline and the second flowline into a third flowline.