Stimulation methods and apparatuses utilizing downhole tools
A method of stimulating a subterranean formation. The method begins with positioning a stimulation tool into a wellbore formed through the formation. The stimulation tool includes (i) at least one tubular segment; (ii) an outer sleeve positioned on the tubular segment and forming an annular space between the tubular segment and the outer sleeve; (iii) a propellant positioned within the annular space; (iv) at least one ignitor positioned to ignite the propellant; (v) at least one rupture disc positioned within a wall of the tubular segment; and (vi) the absence of a detonator for detonating the propellant. Thereafter, the propellant is ignited to begin deflagration of the propellant.
1. A method of stimulating a subterranean formation comprising the steps of:
a. positioning a stimulation tool into a wellbore formed through the formation, the stimulation tool comprising:
(i) at least one tubular segment;
(ii) an outer sleeve positioned on the tubular segment and forming an annular space between the tubular segment and the outer sleeve;
(iii) a propellant positioned within the annular space;
(iv) at least one ignitor positioned to ignite the propellant;
(v) at least one rupture disc positioned within a wall of the tubular segment;
(vi) the absence of a detonator for detonating the propellant;
b. igniting the propellant to begin deflagration of the propellant.
2. The method of stimulating according to claim 1 , wherein the stimulation tool further includes a first ignitor positioned within the propellant approximate a first end of the sleeve and a second ignitor positioned within the propellant approximate a second end of the sleeve.
3. The method of stimulating according to claim 2 , wherein the first igniter and second igniter are ignited within 5 msecs of one another.
4. The method of stimulating according to claim 2 , wherein the propellant within the sleeve forms a continuous propellant mass from the first end of the sleeve to the second end of the sleeve.
5. The method of stimulating according to claim 2 , further comprising a third igniter positioned in contact with the propellant between the first igniter and the second igniter.
6. The method of stimulating according to claim 1 , wherein the propellant has a burn velocity of between about 8,000 ft/sec and about 10,000 ft/sec under formation conditions during its deflagration.
7. The method of stimulating according to claim 1 , wherein the rupture disc is a burst disc configured to rupture from pressure created during burning of the propellant.
8. The method of stimulating according to claim 7 , wherein a the tubular segment is flooded with a liquid at the time of ignition.
9. The method of stimulating according to claim 1 , wherein the ignitor is an electrically ignitable titanium perchlorate igniter.
10. The method of stimulating according to claim 1 , wherein the propellant and the ignitor are configured to cause deflagration of substantially all the propellant without detonation of the propellant.
11. The method of stimulating according to claim 1 , wherein the rupture disc is configured to fail at a pressure of between about 500 psi and about 11000 psi.
12. The method of stimulating according to claim 1 , wherein the stimulation tool is cemented into the wellbore after positioning.
13. The method of stimulating according to claim 1 , wherein the propellant is at least one of (i) a composite propellant, (ii) an extruded composite propellant, (iii) an aluminize composite propellant, or (iv) an isocyanate cured HTPB with perchlorates.
14. A method of stimulating a subterranean formation comprising the steps of:
a. positioning a stimulation tool into a wellbore formed through the formation, the stimulation tool comprising:
(i) at least one tubular segment;
(ii) an outer sleeve positioned on the tubular segment;
(iii) a propellant positioned within the sleeve;
(iv) an ignitor positioned to ignite the propellant;
(v) a detonator positioned to detonate the propellant;
b. igniting the propellant to begin deflagration of the propellant;
c. detonating the propellant between about 5 ms to about 400 ms after igniting the propellant.
15. The method of stimulating according to claim 14 , wherein the tubular segment includes at least one burst disc configure to rupture during ignition or detonation of the propellant.
16. The method of stimulating according to claim 15 , wherein the tubular segment is flooded with a liquid at the time of ignition and detonation.
17. The method of stimulating according to claim 16 , wherein the liquid in the tubular is place under a positive pressure greater than hydrostatic pressure.
18. The method of stimulating according to claim 14 , wherein the propellant is at least one of (i) a composite propellant, (ii) an extruded composite propellant, (iii) an aluminize composite propellant, or (iv) an isocyanate cured HTPB with perchlorates.
19. The method of stimulating according to claim 14 , wherein each of the igniter and the detonator have an electronic card with a controller and a transceiver or receiver.
20. The method of stimulating according to claim 19 , further comprising the step of introducing an intelligent plug into the tubular segment wherein the plug includes a controller and a transceiver or transmitter and the plug transmits a signal to each of the igniter and the detonator which establishes the ignition and detonation sequence.
21. The method of stimulating according to claim 14 , wherein the propellant is detonated about 5 ms to about 200 ms after igniting the propellant.
22. The method of stimulating according to claim 14 , wherein the propellant has a burn velocity of between about 500 ft/sec and about 3000 ft/sec during its deflagration.
23. The method of stimulating according to claim 22 , wherein the propellant has a burn velocity of between about 5000 ft/sec and about 10,000 ft/sec after its detonation.
24. The method of stimulating according to claim 22 , wherein the stimulation tool is cemented into the wellbore after positioning.
25. The method of stimulating according to claim 14 , wherein the stimulation tool is cemented into the wellbore after positioning.
26. A method of stimulating a subterranean formation comprising the steps of:
a. positioning a stimulation tool into a wellbore formed through the formation, the stimulation tool comprising:
(i) at least one tubular segment;
(ii) an outer sleeve positioned on the tubular segment and forming an annular space between the tubular segment and the outer sleeve;
(iii) a propellant positioned within the annular space;
(iv) at least one ignitor positioned to ignite the propellant;
(v) the absence of a detonator for detonating the propellant;
b. igniting the propellant to begin deflagration of the propellant.
27. The method of stimulating according to claim 26 , wherein the propellant is at least one of (i) a composite propellant, (ii) an extruded composite propellant, (iii) an aluminize composite propellant, or (iv) an isocyanate cured HTPB with perchlorates.