Obtaining and evaluating downhole samples with a coring tool

• US 8,621,920 B2
• Filed: 05/18/2010
• Issued: 01/07/2014
• Est. Priority Date: 09/18/2006
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Reid, Lennox, Goodwin, Anthony R. H., Hegeman, Peter S., Woodburn, Charles
• Primary Examiner(s): Chang, Leonard
• Assistant Examiner(s): BELLAMY, TAMIKO D
• Application Number:
  US12/782,398
• Publication Number:
  US 20100223989A1
• Time in Patent Office: 1,330 Days
• Field of Search: 7315211-15217, 702/6, 702/7, 702/11
• 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:

obtaining a core sample from the formation via a coring tool disposed within a downhole tool;

actuating a core pusher to transfer the core sample to a core holder; and

measuring, via engagement of the core pusher with the core holder, at least one of a dielectric constant of the core sample at a plurality of frequencies, a thermal diffusivity of the core sample, or a heat capacity of the core sample, wherein measuring comprises propagating electro-magnetic waves through the core sample via antennae disposed in the core pusher.

2. The method of claim 1 further comprising determining a frequency range for operation of a radiant heater based on the measured at least one of a dielectric constant of the core sample at a plurality of frequencies, a thermal diffusivity of the core sample, or a heat capacity of the core sample.

3. The method of claim 2 further comprising heating the formation using the radiant heater and the frequency range.

4. The method of claim 1 further comprising determining a parameter that corresponds to a heating process of the formation based on the measured at least one of a dielectric constant of the core sample at a plurality of frequencies, a thermal diffusivity of the core sample, or a heat capacity of the core sample.

5. The method of claim 1, wherein measuring comprises measuring the dielectric constant of the core sample at a plurality of frequencies.

6. The method of claim 1, wherein actuating a core pusher comprises transferring the core sample from a coring bit of the coring tool to the core holder, wherein the measuring is performed while the core sample is disposed within the core holder.

7. The method of claim 1, wherein obtaining a core sample comprises operating a coring bit and wherein actuating a core pusher comprises extending the core pusher through the coring bit to move the core sample from the coring bit to the core holder.

8. The method of claim 1 further comprising extending a distal end of the core pusher into an opening of the core holder to engage the core pusher with the core holder.

9. The method of claim 1, wherein the distal end of the core pusher comprises a conductive cap electrically coupled to the core holder, and wherein the

antennae are electrically coupled to the cap and disposed around a conductive core extending through the cap.

10. A method for evaluating an underground formation, comprising:

obtaining a core sample from the formation via a coring tool disposed within a downhole tool;

actuating a core pusher to transfer the core sample to a core holder; and

measuring, via engagement of the core pusher with the core holder, at least one of a dielectric constant of the core sample at a plurality of frequencies, a thermal diffusivity of the core sample, or a heat capacity of the core sample, wherein measuring comprises flowing electric current through a resistive wire disposed in the core pusher.

11. The method of claim 10 further comprising determining a parameter that corresponds to a heating process of the formation based on the measured at least one of a dielectric constant of the core sample at a plurality of frequencies, a thermal diffusivity of the core sample, or a heat capacity of the core sample.

12. The method of claim 10, wherein measuring comprises measuring the thermal diffusivity of the core sample.

13. The method of claim 10, wherein measuring comprises measuring the heat capacity of the core sample.

14. The method of claim 10, wherein actuating a core pusher comprises transferring the core sample from a coring bit of the coring tool to the core holder, wherein the measuring is performed while the core sample is disposed within the core holder.

15. The method of claim 10, wherein obtaining a core sample comprises operating a coring bit and wherein actuating a core pusher comprises extending the core pusher through the coring bit to move the core sample from the coring bit to the core holder.

16. The method of claim 10 further comprising extending a distal end of the core pusher into an opening of the core holder to engage the core pusher with the core holder.

17. The method of claim 10 wherein the distal end of the core pusher comprises a cap disposed in contact with thermally insulated walls of the core holder, and wherein the resistive wire is disposed in a block extending between the cap and the core sample.