Method for determining fracture network volume using passive seismic signals

1. A method for determining a volume of a discrete fracture network, comprising:

detecting seismic signals deployed over an area of the subsurface to be evaluated during pumping of hydraulic fracturing fluid into at least one wellbore drilled through the area;

in a computer, determining a hypocenter of each fracture induced by the pumping of the fracture fluid using the detected seismic signals;

in the computer, determining a facture network using the determined hypocenters and seismic moments determined from the detected seismic signals, the determining a fracture network comprising determining a fracture volume associated with each hypocenter using the determined seismic moments;

in the computer, determining a maximum value of a scaling factor based on a subset of the hypocenters having a highest cumulative seismic moment, the scaling factor determined by relating a pumped volume of the fracturing fluid with respect to the determined fracture volumes;

in the computer, scaling dimensions of each fracture using the maximum value of the scaling factor; and

in the computer, recalculating the fracture volumes using the scaled dimensions.

2. The method of claim 1 wherein the maximum value of the scaling factor is selected to exclude values related to tectonic features in the subsurface.

3. The method of claim 1 wherein the scaling factor is selected such that the pumped volume of fracturing fluid multiplied by a fluid efficiency factor substantially equals the total fracture volumes.

4. The method of claim 1 wherein a fracture area of each fracture is determined by a moment determined from detected seismic signal amplitudes.

5. The method of claim 1 wherein the scaling factor is determined by relating a pumped volume of fracture fluid multiplied by a fluid efficiency to the determined fracture volumes.

6. A method for determining a volume of a discrete fracture network, comprising:

conducting to a computer recorded seismic signals detected by a plurality of seismic sensors deployed over an area of the subsurface to be evaluated during pumping of hydraulic fracturing fluid into at least one wellbore drilled through the area;

in the computer, determining a hypocenter of each fracture induced by the pumping of the fracture fluid using the detected seismic signals;

in the computer, determining a facture network using the determined hypocenters and seismic moments determined from the detected seismic signals, the determining a fracture network comprising determining a fracture volume associated with each hypocenter using the determined seismic moments;

in the computer, determining a maximum value of a scaling factor based on a subset of the hypocenters having a highest cumulative seismic moment, the scaling factor determined by relating a pumped volume of the fracturing fluid with respect to the determined fracture volumes;

in the computer, scaling dimensions of each fracture using the maximum value of the scaling factor; and

in the computer, recalculating the fracture volumes using the scaled dimensions, wherein the maximum value of the scaling factor is selected to exclude values related to tectonic features in the subsurface.

7. The method of claim 6 wherein the scaling factor is selected such that the pumped volume of fracturing fluid multiplied by a fluid efficiency factor substantially equals the total fracture volumes.

8. The method of claim 6 wherein a fracture area of each fracture is determined by a moment determined from detected seismic signal amplitudes.

9. The method of claim 6 wherein the scaling factor is determined by relating a pumped volume of fracture fluid multiplied by a fluid efficiency to the determined fracture volumes.

10. A method for determining a volume of a discrete fracture network, comprising:

conducting to a computer recorded seismic signals detected by a plurality of seismic sensors deployed over an area of the subsurface to be evaluated during pumping of hydraulic fracturing fluid into at least one wellbore drilled through the area;

in the computer, determining a hypocenter of each fracture induced by the pumping of the fracture fluid using the detected seismic signals;

in the computer, determining a facture network using the determined hypocenters and seismic moments determined from the detected seismic signals, the determining a fracture network comprising determining a fracture volume associated with each hypocenter using the determined seismic moments;

in the computer, determining a maximum value of a scaling factor based on a subset of the hypocenters having a highest cumulative seismic moment, the scaling factor determined by relating a pumped volume of the fracturing fluid with respect to the determined fracture volumes;

in the computer, scaling dimensions of each fracture using the maximum value of the scaling factor; and

in the computer, recalculating the fracture volumes using the scaled dimensions, wherein the scaling factor is determined by relating a pumped volume of fracture fluid multiplied by a fluid efficiency to the determined fracture volumes.

11. The method of claim 10 wherein the maximum value of the scaling factor is selected to exclude values related to tectonic features in the subsurface.

12. The method of claim 10 wherein the scaling factor is selected such that the pumped volume of fracturing fluid multiplied by a fluid efficiency factor substantially equals the total fracture volumes.

13. The method of claim 10 wherein a fracture area of each fracture is determined by a moment determined from detected seismic signal amplitudes.