Method and apparatus for generating seismic pulses to map subterranean fractures

A method comprising:

• a) pumping from a surface and injecting, concurrently, a plurality of reactive particles and proppant into fractures in a zone of a subterranean formation, each reactive particle comprising:
• a reactive material;
• a protective coating comprising a fatty acid;
• an rf-blocking coating;
• and
• a charge-storage device;
• b) discharging, within the fractures, a charge stored on each charge-storage device;
• c) triggering a reaction of the reactive material of each reactive particle in response to the step of discharging;
• d) creating a plurality of micro-seismic events in the fractures in response to the plurality of reactions;
• e) charging the charge-storage device by radio frequency emission;
• and
• f) removing, in the fractures, the protective coating, wherein step (e) occurs after step (a).

A method comprising:

• a) pumping from a surface and injecting, concurrently, a plurality of first reactive particles, a plurality of second reactive particles, and proppant into fractures in a zone of a subterranean formation, wherein each first reactive particle comprises:
• a first reactive material,
• a first protective coating, and
• a first charge-storage device;
• and
• wherein each second reactive particle comprises:
• a second reactive material,
• a second protective coating, and
• a second charge-storage device;
• and
• b) removing, in the fractures, the first protective coating by exposing the first reactive particles to a high salinity fluid;
• c) discharging, within the fractures, a charge stored on each first charge-storage device;
• d) triggering a reaction of the first reactive material of each first reactive particle in response to the step of discharging each first charge-storage device;
• e) creating a plurality of first micro-seismic events in the fractures in response to the plurality of reactions of the first reactive material;
• f) removing, in the fractures, the second protective coating by exposing the second reactive particles to a hydrocarbon-based fluid;
• g) discharging, within the fractures, a charge stored on each second charge-storage device;
• h) triggering a reaction of the second reactive material of each second reactive particle in response to the step of discharging each second charge-storage device;
• and
• i) creating a plurality of second micro-seismic events in the fractures in response to the plurality of reactions of the second reactive material.