Down hole gas analyzer method and apparatus

• US 6,627,873 B2
• Filed: 04/16/2001
• Issued: 09/30/2003
• Est. Priority Date: 04/23/1998
• Status: Expired due to Term

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Tchakarov, Borislav J., Civarolo, Marcelo F., Hunziker, James C., Forgang, Stanislav W., DiFoggio, Rocco, Fanini, Otto N.
• Primary Examiner(s): Hannaher, Constantine
• Application Number:
  US09/836,044
• Publication Number:
  US 20020043620A1
• Time in Patent Office: 897 Days
• Field of Search: 250/255, 250/256, 250/269.1, 731/522.8, 731/525.5
• US Class Current: 250/256
• CPC Class Codes: E21B 49/08 Obtaining fluid samples or testing fluids, in boreholes or wells
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/552 Attenuated total reflection
• CPC Class Codes: G01V 8/02 Prospecting

Abstract

A logging while drilling and wire line system for analyzing the concentration of carbon dioxide or another substance, in a sample down hole in a bore hole. A chamber is filled with a sample that may be fluid, or condensate and gas. The interior chamber volume is selectably expandable for decompression of the sample. The sample may alternately be decompressed by allowing a sample at formation pressure to enter the chamber at a lower pressure, thereby decompressing the sample. A sensor measures the absorbance, transmittance or attenuated total reflectance of the infrared light. Mid and near infrared light is utilized to identify carbon dioxide, water and a plurality of hydrocarbons. A wiper cleans the transmitter and sensor between readings to reduce measurement error caused by fluid sample contamination.

Claims

1. A bore hole apparatus for analyzing the carbon dioxide concentration in a sample down hole in a bore hole, comprising:

a chamber having a piston for defining an initial sample volume in the chamber for containing an initial fluid sample wherein the piston is slidably disposed within the chamber for selectively expanding the chamber initial volume of the chamber and decreasing the pressure within the chamber to decompress the fluid sample;

a transmitter for discharging infrared light a first sensor for measuring at least one of absorption, transmittance or attenuated total reflectance of infrared light for the fluid sample and for generating a signal representing the carbon dioxide concentration in the fluid sample; and

a processor for receiving said signal and for determining the fluid sample carbon dioxide concentration.

2. An apparatus as recited in claim 1, wherein the signal is transmitted to the surface for an operator or an intelligent completion system to adjust completion.

3. An apparatus as recited in claim 2 further comprising a second sensor for measuring at least one of infrared absorbance or attenuated total reflectance in a range suitable for detection of selected hydrocarbon gases.

4. An apparatus as recited in claim 3, further comprising a third sensor suitable for detection of an interfering molecule resident within the fluid sample.

5. An apparatus as recited in claim 1, wherein the piston is capable of precisely expanding the expansion chamber initial volume of the fluid sample, and precisely controlling the initial volume of the initial fluid sample until the fluid expands to transform to its substantially one hundred percent gas phase.

6. An apparatus as recited in claim 1, further comprising a wiper disposed inside of the chamber for cleaning the inside of the chamber.

7. An apparatus as recited in claim 6, wherein the wiper is attached to the piston so that the wiper cleans the inside of the chamber during at least one of:

compression or decompression of the chamber so that at least one of a sensor window or a transmitter window is cleaned.

8. An apparatus as recited in claim 1, further comprising a wiper disposed in the chamber, wherein the transmitter and sensor are adjacent the chamber so that the wiper cleans at least one of a transmitter window and a sensor window during at least one of:

compression and decompression of the chamber.

9. An apparatus as recited in claim 1, wherein the piston and an integrated wiper are integrated in the chamber for selectively expanding the initial chamber volume and for returning the apparatus to the initial chamber volume.

10. The apparatus of claim 1 wherein the signal is received by a operator or a processor at an intelligent completion station for determining the completion state of a well.

11. A bore hole apparatus for analyzing the carbon dioxide concentration in a sample down hole in a bore hole, comprising:

a chamber having a piston wherein the piston is slidably disposed within the chamber for defining an initial sample volume in the chamber for receiving an initial fluid sample, wherein the initial sample volume of the chamber is selectively expanded, to reduce the the pressure in the sample chamber to a pressure lower than the pressure of the sample prior to the sample entering the chamber, thereby selectively decompressing the sample as it enters the initial sample volume;

a transmitter for discharging infrared light;

a first sensor for measuring at least one of absorption, transmittance or attenuated total reflectance of infrared light for the fluid sample, the first sensor generating a signal representing the carbon dioxide concentration in the fluid sample; and

a device for receiving said signal and for determining the sample carbon dioxide concentration.

12. The apparatus of claim 11 wherein the signal is received by a operator or a processor at an intelligent completion station for determining the completion state of a well.

13. The apparatus of claim 11 wherein the sample contains condensate and gas, further comprising an orientation device so that the infrared transmitter and sensor are positioned on the high side of the chamber so that the infrared transmitter and sensor are positioned adjacent the gaseous portion of the sample.

14. An apparatus as recited in claim 13, further comprising a wiper disposed in the chamber, wherein the transmitter and sensor are adjacent the chamber so that the wiper cleans at least one of a transmitter window and a sensor window during at least one of:

compression and decompression of the chamber.

15. A method for analyzing the carbon dioxide concentration in a sample down hole in a bore hole, comprising:

providing a chamber having a piston for defining an initial sample volume in the chamber for containing an initial fluid sample wherein the piston is slidably disposed within the chamber for selectively expanding the chamber initial volume of the chamber and decreasing the pressure within the chamber to decompress the fluid sample;

providing a transmitter for discharging infrared light;

providing a first sensor for measuring at least one of absorption, transmittance or attenuated total reflectance of infrared light for the fluid sample and for generating a signal representing the carbon dioxide concentration in the fluid sample; and

providing a processor for receiving said signal and for determining the fluid sample carbon dioxide concentration.

16. The method as recited in claim 15, further comprising:

transmitting the signal to the surface; and

receiving the signal at the surface by an operator or an intelligent completion system to adjust at least one of;

completion, production flow or reinjection.

17. The method as recited in claim 16 further comprising:

providing a second sensor for measuring at least one of infrared absorbance or attenuated total reflectance in a range suitable for detection of selected hydrocarbon gases.

18. The method as recited in claim 16, further comprising:

providing a third sensor suitable for detection of an interfering molecule resident within the fluid sample.

19. The method as recited in claim 15, further comprising:

precisely moving the piston and expanding the expansion chamber initial volume of the fluid sample, and precisely controlling the initial volume of the initial fluid sample until the fluid expands to transform to its substantially one hundred percent gas phase.

20. The method as recited in claim 15, further comprising a wiper disposed inside of the chamber for cleaning the inside of the chamber.

21. The method as recited in claim 20, wherein the wiper is attached to the piston so that the wiper cleans the inside of the chamber during at least one of:

compression or decompression of the chamber so that at least one of a sensor window or a transmitter window is cleaned.

22. An apparatus as recited in claim 15, wherein a piston and an integrated wiper are integrated in the chamber for selectively expanding the initial chamber volume and for returning the apparatus to the initial chamber volume.

23. The method of claim 15 wherein the signal is received by a operator or a processor at an intelligent completion station for determining the completion state of a well.

24. A method for for analyzing the carbon dioxide concentration in a sample down hole in a bore hole, comprising:

providing a chamber having a piston wherein the piston is slidably disposed within the chamber for defining an initial sample volume in the chamber for receiving an initial fluid sample, wherein the initial sample volume of the chamber is selectively expanded, to reduce the the pressure in the sample chamber to a pressure lower than the pressure of the sample prior to the sample entering the chamber, thereby selectively decompressing the sample as it enters the initial sample volume;

providing a transmitter for discharging infrared light;

providing a first sensor for measuring at least one of absorption, transmittance or attenuated total reflectance of infrared light for the fluid sample, the first sensor generating a signal representing the carbon dioxide concentration in the fluid sample; and

providing a device for receiving said signal and for determining the sample carbon dioxide concentration.

25. The method of claim 24 further comprising:

receiving the signal at the surface for determining the completion state of a well by at least one of an operator or a processor at an intelligent completion station.

26. The method of claim 24 wherein the sample contains condensate and gas, further comprising:

receiving a signal from an orientation device to determine the orientation of the sample chamber in order to find the high side of the sample chamber; and

positioning the infrared transmitter and sensor on the high side of the chamber so that the infrared transmitter and sensor are positioned adjacent the gaseous portion of the sample.