Obtaining and evaluating downhole samples with a coring tool

• US 7,748,265 B2
• Filed: 09/10/2007
• Issued: 07/06/2010
• Est. Priority Date: 09/18/2006
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Woodburn, Charles, Reid, Lennox, Goodwin, Anthony R. H., Hegeman, Peter S.
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): Bellamy; Tamiko D
• Application Number:
  US11/852,390
• Publication Number:
  US 20080066534A1
• Time in Patent Office: 1,030 Days
• Field of Search: 731/521.1, 175/20, 175/58, 175/78
• US Class Current: 73/152.11
• CPC Class Codes: E21B 25/08 Coating, freezing, consolidating cores E21B25/06 takes precedence; Recovering uncontaminated cores or cores at formation pressure
• CPC Class Codes: E21B 36/001 Cooling arrangements
• CPC Class Codes: E21B 49/06 using side-wall drilling tools pressing or scrapers
• CPC Class Codes: E21B 49/081 with down-hole means for trapping a fluid sample E21B49/10 takes precedence

Abstract

Samples of hydrocarbon are obtained with a coring tool. An analysis of some thermal or electrical properties of the core samples may be performed downhole. The core samples may also be preserved in containers sealed and/or refrigerated prior to being brought uphole for analysis. The hydrocarbon trapped in the pore space of the core samples may be extracted from the core samples downhole. The extracted hydrocarbon may be preserved in chambers and/or analyzed downhole.

Claims

1. A method for evaluating an underground formation comprising:

conveying a coring tool to the formation;

obtaining a core sample from the formation;

receiving the sample in the tool;

extracting at least a portion of hydrocarbon from the core sample, the extraction being performed in the tool, wherein extracting at least a portion of the hydrocarbon from the core sample includes lowering the viscosity of the hydrocarbon; and

analyzing at least a portion of the extracted hydrocarbon.

2. A method according to claim 1, wherein analyzing the extracted hydrocarbon is performed at one of the surface and downhole.

3. A method according to claim 1, further comprising preserving at least a portion of the extracted hydrocarbon in a container.

4. A method according to claim 1, wherein extracting at least a portion of the hydrocarbon includes grinding the core sample.

5. A method according to claim 1, wherein obtaining a core sample from the formation includes obtaining a core sample from a sidewall of a borehole penetrating the formation.

6. A method according to claim 1, wherein lowering the viscosity of the hydrocarbon includes heating the core sample using at least one chemical, resistive, radiant, and conductive heating.

7. A method according to claim 1, wherein lowering the viscosity of the hydrocarbon includes injecting at least one of solvent, hot water, and steam into the core.

8. A method according to claim 1 further comprising performing a measurement on one of the core or the core rock material.

9. A method for evaluating an underground formation comprising:

conveying a coring tool to the formation;

obtaining a core sample from the formation;

placing at least a portion of the core sample into a processing chamber of the coring tool;

at least partially flooding the core sample;

extracting fluid from the core sample; and

analyzing at least a portion of the core.

10. A method according to claim 9, wherein flooding the core sample includes injecting fluid into the processing chamber.

11. A method according to claim 9 further comprising analyzing at least a portion of the extracted fluid.

12. A method according to claim 11, further comprising lowering the viscosity of a hydrocarbon contained in the core.

13. A method according to claim 12, wherein lowering the viscosity of the hydrocarbon includes heating the core sample using at least one chemical, resistive, radiant, and conductive heating.

14. A method according to claim 9, wherein obtaining a core sample from the formation includes obtaining a core sample from a sidewall of a borehole penetrating the formation.

15. A method according to claim 12, wherein lowering the viscosity of the reservoir fluid includes injecting at least one of solvent, hot water, and steam into the core.

16. A method according to claim 9, wherein analyzing at least a portion of the core includes taking a resistivity measurement before and after flooding the core sample.

17. A method according to claim 9, wherein analyzing at least a portion of the core includes characterizing at least partially an elemental composition of the core.