Mapping and monitoring of hydraulic fractures using vector magnetometers

• US 9,823,381 B2
• Filed: 03/31/2017
• Issued: 11/21/2017
• Est. Priority Date: 03/20/2014
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Meyer, Thomas J.
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): NASIR, TAQI R
• Application Number:
  US15/476,636
• Publication Number:
  US 20170205526A1
• Time in Patent Office: 235 Days
• Field of Search: 324221, 324324, 324333, 324338, 324346, 324351, 324355, 324368, 324372, 324301, 324350, 324389, 32420721, 324244-263, 324307
• CPC Class Codes: G01R 33/032 using magneto-optic devices, e.g. Faraday or Cotton-Mouton effect
• CPC Class Codes: G01V 3/081 the magnetic field is produced by the objects or geological structures characterised by the method of magnetic field measurement G01R33/00
• CPC Class Codes: G01V 3/26 operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device with electromagnetic waves G01V3/30

Abstract

A method for mapping and monitoring of hydraulic fracture includes capturing, using an array of sensors, a first magnetic image of a well pay zone. A second magnetic image is captured using the array of sensors, after a well bore is padded with a fluid. A background is established based on the first and the second magnetic images. A third magnetic image is captured using the array of sensors, after a doped proppant is injected into a stage. The third image is processed to subtract the background and to obtain information regarding distribution of the fluid and the proppant in the stage.

Claims

1. A system for mapping and monitoring a hydraulic fracture, the system comprising:

an array of sensors configured to capture a plurality of magnetic images comprising a first magnetic image comprising a magnetic image of a well pay zone of a well including a baseline magnetic profile including Earth'"'"'s magnetic field, a second magnetic image comprising a magnetic image captured after the well pay zone is padded with a fluid, and a third magnetic image comprising a magnetic image after a doped proppant is injected into the well pay zone, each of the plurality of magnetic images comprising a set of one of more vector measurements using the array of sensors; and

an analyzer in communication with the array of sensors and comprising a processor configured to determine a background image based on the first and the second magnetic images and to process the third magnetic image to subtract the background image to obtain information regarding a distribution of the fluid and the proppant in the well pay zone.

2. The system of claim 1, wherein the array of sensor comprises diamond nitrogen-vacancy (DNV) sensors.

3. The system of claim 2, wherein the doped proppant comprises a magnetically susceptible material.

4. The system of claim 3, wherein the magnetically susceptible material comprises ferrite particles.

5. The system of claim 1, wherein the array of sensors are placed proximate to the well pay zone.

6. The system of claim 1, wherein a sensor of the array of sensors is placed on a surface of the well pay zone.

7. The system of claim 1, wherein a sensor of the array of sensors is placed in a well of the well pay zone.

8. The system of claim 1, wherein the analyzer stores sensor data from the array of sensors.

9. The system of claim 1, wherein each of the plurality of magnetic images comprises a time tag.

10. The system of claim 1, wherein processing the third magnetic image comprises subdividing a subsurface domain surrounding the well pay zone into cells.

11. A system for mapping and monitoring a hydraulic fracture, the system comprising:

means for capturing a plurality of magnetic images comprising a first magnetic image comprising a magnetic image of a well pay zone of a well including a baseline magnetic profile including Earth'"'"'s magnetic field, a second magnetic image comprising a magnetic image captured after the well pay zone is padded with a fluid, and a third magnetic image comprising a magnetic image after a doped proppant is injected into the well pay zone; and

means for determining a background image based on the first and the second magnetic images and processing the third magnetic image to subtract the background image to obtain information regarding a distribution of the fluid and the proppant in the well pay zone.

12. The system of claim 11, wherein the means for capturing a plurality of magnetic images comprises an array of magnetometers.

13. The system of claim 12, wherein the array of magnetometers comprises diamond nitrogen-vacancy (DNV) sensors.

14. The system of claim 11, wherein the fluid comprises a fracking fluid.

15. The system of claim 11, wherein at least one of the fluid or the proppant comprises a magnetically susceptible material.

16. The system of claim 11, wherein determining the background image based on the first and the second magnetic images comprises combining the first and the second magnetic images.

17. The system of claim 11, wherein each of the plurality of magnetic images comprise a set of one of more vector measurements.

18. A system for mapping and monitoring a hydraulic fracture, the system comprising:

magnetic image capturing means for capturing a plurality of magnetic images, the plurality of magnetic images comprising a first magnetic image comprising a magnetic image of a well pay zone of a well including a baseline magnetic profile including Earth'"'"'s magnetic field and a second magnetic image comprising a magnetic image after a doped proppant is injected into the well pay zone; and

magnetic image processing means for determining a distribution of fluid and proppant in the well pay zone.

19. The system of claim 18, wherein each of the plurality of magnetic images comprise a set of one of more vector measurements.

20. The system of claim 19, wherein the means for capturing a plurality of magnetic images comprises an array of diamond nitrogen-vacancy (DNV) sensors.