Method and apparatus for reservoir characterization using photoacoustic spectroscopy

• US 7,387,021 B2
• Filed: 05/24/2005
• Issued: 06/17/2008
• Est. Priority Date: 05/24/2005
• Status: Expired due to Fees

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: DiFoggio, Rocco
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US11/135,802
• Publication Number:
  US 20060266108A1
• Time in Patent Office: 1,120 Days
• Field of Search: 731/525.5
• US Class Current: 73/152.55
• CPC Class Codes: E21B 49/08 Obtaining fluid samples or testing fluids, in boreholes or wells
• CPC Class Codes: G01N 2021/1704 in gases
• CPC Class Codes: G01N 2021/1708 with piezotransducers probes for investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves G01N29/24
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids
• CPC Class Codes: G01N 2291/0427 Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever
• CPC Class Codes: G01N 29/2425 optoacoustic fluid cells therefor

Abstract

A method and apparatus are provided that assess reservoir compartmentalization by determining whether there are compositional differences such as whether the isotopic ratios of carbon (13C/12C) or of oxygen (17O/18O) are the same or different in various parts of the reservoir. A quartz enhanced photoacoustic spectrometer is provided for analysis of reservoir samples taken in various parts of the reservoir for comparison of geochemical composition to estimate reservoir compartmentalization.

Claims

1. A method for estimating reservoir compartmentalization comprising:

analyzing a photoacoustic response from a first sample from a first location in the reservoir;

analyzing a photoacoustic response from a second sample from a second location in the reservoir; and

comparing the analysis of the first sample to the analysis of the second sample to estimate reservoir compartmentalization.

2. The method of claim 1, wherein each photoacoustic response comprises a signal from a photoacoustic spectrometer.

3. The method of claim 1, wherein each photoacoustic response comprises a signal from a quartz-enhanced photoacoustic spectrometer.

4. The method of claim 3, wherein analyzing further comprises estimating an isotopic ratio.

5. The method of claim 1, wherein analyzing further comprises estimating sample composition.

6. The method of claim 1, wherein analyzing is performed downhole.

7. The method of claim 1, wherein analyzing further comprises comparing phytane and pristine ratios.

8. The method of claim 1, wherein analyzing further comprises estimating a distinguishing characteristic.

9. An apparatus for estimating reservoir compartmentalization comprising:

a photoacoustic spectrometer (PAS) configured to analyze a first sample from a first location in the reservoir and analyze a second sample from a second location in the reservoir; and

a processor configured to compare the analysis of the first sample to the analysis of the—

second sample to estimate reservoir compartmentalization.

10. The apparatus of claim 9, wherein the PAS further comprises a quartz-enhanced PAS.

11. The apparatus of claim 9, wherein the processor is further configured to estimate compartmentalization using isotopic ratios for the samples.

12. The apparatus of claim 11, wherein the isotopic ratios further comprise at least one of the set consisting of isotopic ratios of carbon (¹³C/¹²C) and isotopic ratios of oxygen (¹⁷O/¹⁸O).

13. The apparatus of claim 9, wherein the processor is further configured to estimate sample composition.

14. The apparatus of claim 9, wherein the analysis is performed downhole.

15. The apparatus of claim 9, wherein the analysis further comprises comparing phytane and pristine ratios.

16. The apparatus of claim 9, wherein the analysis further comprises a comparison of a distinguishing characteristic of the samples.

17. An apparatus for estimating reservoir compartmentalization, comprising:

a downhole tool configured to obtain samples from the reservoir;

a photoacoustic spectrometer (PAS) configured to analyze a first sample from a first location in the reservoir and analyze a second sample from a second location in the reservoir; and

a processor configured to compare the analysis of the first sample to the analysis of the second sample to estimate reservoir compartmentalization.

18. The apparatus of claim 17, wherein the PAS further comprises a quartz enhanced PAS.

19. The apparatus of claim 17, wherein the processor is further configured to estimate compartmentalization from a comparison of isotopic ratios from the first and second samples.

20. The apparatus of claim 17, wherein the processor is further configured to compare a distinguishing characteristic of the first and second samples to estimate reservoir compartmentalization.