Microseismic Data Acquisition Array and Corresponding Method

• US 20130100769A1
• Filed: 10/19/2011
• Published: 04/25/2013
• Est. Priority Date: 10/19/2011
• Status: Active Grant

• Current Assignee: Ambient Reservoir Monitoring, Inc.
• Original Assignee: Global Microseismic Services, Inc. (Global Geophysical Services Incorporated)
• Inventors: Fleure, Thomas John, Gillooly, John F. Jr., Riley, Duncan W., Sicking, Charles John
• Granted Patent: US 9,354,336 B2
• Time in Patent Office: Days
• US Class Current: 367/37
• CPC Class Codes: G01V 1/20 Arrangements of receiving elements, e.g. geophone pattern

Abstract

Disclosed are various embodiments of methods, devices and systems for performing a microseismic survey. According to some embodiments, microseismic signals are detected at seismic sensor stations deployed in two sets of seismic sensor lines, the seismic sensor lines within each set being substantially parallel to one another and the two sets of seismic sensor lines being mutually orthogonal. According to other embodiments, microseismic signals are detected at seismic sensor stations deployed in a hexagonal pattern. Such sensor geometries offer advantages over linear or radial arrays, including noise reduction, data acquisition flexibility as new wells are added to the survey area, and an improved distribution of data points above points in the subsurface.

Claims

1. A sensor array for performing a microseismic survey, comprising;

a first plurality of sensor locations, the first plurality of sensor locations being substantially equally spaced at a first sensor spacing along a first plurality of sensor lines, the first plurality of sensor lines being substantially parallel to one another and substantially equally spaced from one another at a first sensor line spacing;

a second plurality of sensor locations, the second plurality of sensor locations being substantially equally spaced at a second sensor spacing along a second plurality of sensor lines, the second plurality of sensor lines being substantially parallel to one another and substantially equally spaced from one another at a second sensor line spacing, wherein the sensor lines in the second plurality of sensor lines are substantially orthogonal to the sensor lines in the first plurality of sensor lines

2. A method of performing a microseismic survey, comprising;

detecting the microseismic signals at a first plurality of sensor locations, the first plurality of sensor locations being substantially equally spaced at a first sensor spacing along a first plurality of sensor lines, the first plurality of sensor lines being substantially parallel to one another and substantially equally spaced from one another at a first sensor line spacing;

detecting the microseismic signals at a second plurality of sensor locations, the second plurality of sensor locations being substantially equally spaced at a second sensor spacing along a second plurality of sensor lines, the second plurality of sensor lines being substantially parallel to one another and substantially equally spaced from one another at a second sensor line spacing, wherein the sensor lines in the second plurality of sensor lines are substantially orthogonal to the sensor lines in the first plurality of sensor lines.

3. The method of claim 2, further comprising performing 2-dimensional noise filtering on the microseismic signals.

4. The method of claim 2, further comprising performing 3-dimensional noise filtering on the microseismic signals.

5. The method of claim 2, wherein the sensor lines in the first plurality of sensor lines and the sensor lines in the second plurality of sensor lines intersect at a well location.

6. The method of claim 2, wherein the sensor lines in the first plurality of sensor lines and the sensor lines in the second plurality of sensor lines intersect at points equidistant from sensor locations on the first plurality of sensor lines and sensor locations on the second plurality of sensor lines.

7. The method of claim 2, wherein the sensor lines in the first plurality of sensor lines and the sensor lines in the second plurality of sensor lines intersect at sensor locations common to the first plurality of sensor lines and the second plurality of sensor lines.

8. The method of claim 2, wherein the first sensor line spacing is substantially equal to the first sensor spacing.

9. The method of claim 2, wherein the first sensor line spacing is a multiple or fraction of the first sensor spacing.

10. The method of claim 2, wherein the second sensor line spacing is substantially equal to the second sensor spacing.

11. The method of claim 2, wherein the second sensor line spacing is a multiple or fraction of the second sensor spacing.

12. The method of claim 2, wherein the second sensor spacing is substantially equal to the first sensor spacing.

13. A sensor array for performing a microseismic survey, comprising a plurality of sensor locations, the plurality of sensor locations being substantially equally spaced at a predetermined sensor spacing, each sensor location being substantially equidistant from up to six other sensor locations at the vertices of a hexagon centered about the sensor locations.

14. A method of performing a microseismic survey, comprising detecting the microseismic signals at a first plurality of sensor locations, the plurality of sensor locations being substantially equally spaced at a predetermined sensor spacing, each sensor location being substantially equidistant from up to six other sensor locations at the vertices of a hexagon centered about the sensor location.

15. The method of claim 14, wherein at least one sensor location corresponds to the location of a well.

16. The method of claim 14, further comprising performing 2-dimensional noise filtering on the microseismic signals.

17. The method of claim 14, further comprising performing 3-dimensional noise filtering on the microseismic signals.