The present invention relates to a system and method for a power charge.
Power charges are inserted downhole for a variety of purposes. The power charges are inserted downhole via wireline or other device and are used to provide a force downhole. Often the power charges require a primary igniter to function. Consequently, there is a need for an improved power charge.
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
Several embodiments of Applicant's invention will now be described with reference to the drawings. Unless otherwise noted, like elements will be identified by identical numbers throughout all figures. The invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.
Power charges have widespread use in the oil and gas industry. They can be used in setting tools such as plugs, packers, etc. When burned the power charge creates pressure greater than 10,000 psi. The pressure causes a tool to stroke, setting it in the desired place or performing any such desired task.
The power charge 100 has an outer wall 102. The outer wall 102 serves several functions. First, the outer wall 102 acts to secure the contents of the power charge 100, as discussed in more detail below. The power charge 100 can be handled, moved, etc. without spilling the contents because of the outer wall 102. Second, the outer wall 102 provides a structure, and specifically a void which can be filled with a self-ignitable secondary igniter.
The outer wall 102 can comprise virtually any combustible material. The outer wall 102 can comprise paper, plastic, cardboard, etc. Virtually any material which can burn can be utilized as the outer wall 102. While one embodiment utilizes a separate outer wall 102, in some embodiments the outer wall 102 is the same material as the power charge 100. Thus, the outer wall 102 and the power charge 100 comprise the same material.
In one embodiment the outer wall 102 extends longitudinally along the entire length of the power charge 100. In this fashion, the outer wall acts to contain the internal contents.
As depicted the power charge 100 comprises a first end 111 and an opposing second end 112. In one embodiment the combustible contents of the power charge 100 extends continuously from the first end 111 to the opposing second end 112. In one embodiment the power charge 100 is filled so as to ensure there are no bubbles, gaps, or voids, within the outer wall 102.
The power charge 100 can comprise virtually any combustible substance. The ratio and contents of the ingredients can be adjusted depending upon the application. The ingredients can include potassium nitrate, sodium nitrate, strontium nitrate; ammonium nitrate, hydroxylammonium nitrate, ammonium perchlorate; Pydrodex, wheat flour, white flour, various other flours, and other ingredients. The ingredients can form a consistency similar to dough. The ingredients can further include a binder or epoxy to help the dough harden or cure. In one embodiment the power charge 100 comprises two parts epoxies and plasticizer to give the power charge 100 the characteristics of a bare or naked power charge.
As shown, coupled to the power charge 100 is a centralized-contact spring 103. The shape of the centralized-contact spring 103, in one embodiment, is more easily seen in
The centralized-contact spring 103 serves to mate with the outer wall 102 and to ground the self-ignitable secondary igniter 105. In one embodiment the centralized-contact spring 103 is cast onto the power charge 100 at one or both ends. Because in some embodiments, it is manufactured with the power charge 100, it is intimately coupled with the power charge 100 and serves as a ground for the self-ignitable secondary igniter 105.
As depicted, the centralized-contact spring 103 has four separate contact leaves 108 which surround and contact the periphery of the power charge 100. The contact leaves 108 can have various lengths depending upon the application. As shown they comprise a curve which provides the spring force to ensure the leaves 108 maintain proper contact with the power charge 100 sufficiently to ground the self-ignitable secondary igniter 105.
Part of the centralized-contact spring 103 is a head 110 from which the one or more contact leaves 108 extend. In one embodiment the head 110 coincides with an end of the power charge 100.
As shown, the centralized-contact spring 103 further comprises a recess 109. The recess 109 is sized to receive a self-ignitable secondary igniter 105.
In one embodiment, the power charge 100 is manufactured as shown in
While a centralized-contact spring 103 has been described, this is for illustrative purposes only and should not be deemed limiting. In some embodiments the spring 103 comprises any grounding mechanism which grounds the self-ignitable secondary igniter 105 with the power charge. As noted, while an external spring has been described, the device can comprise any mechanism which grounds the self-ignitable secondary igniter 105 with the power chare.
Turning back to
As can be seen, the self-ignitable secondary igniter 105 on the first end 111 comprises an exposed outer face. As noted, this means the self-ignitable secondary igniter 101 has an external face which is accessible, and visible, on the first end. This allows for the ignition of the secondary igniter 105. The self-ignitable secondary igniter 105 then extends downstream into power charge 100 within the outer wall. As used herein, upstream and downstream refer to relative locations along the power charge. An item closer to the first end will be referred to as the upstream end whereas an object further away from the first end will be referred to as downstream. Thus, the second end 112 is downstream of the first end 111. As can be seen, the self-ignitable secondary igniter 105 extends downstream into the power charge.
The length of the self-ignitable secondary igniter 105 can vary depending upon the application. As depicted, the length of the self-ignitable secondary igniter is less than about 10% of the total length of the power charge 100. As noted, this is for illustrative purposes only and should not be deemed limiting.
In each of these embodiments the self-ignitable secondary igniter 105 comprises an internal resistor 104 or resistors connected in parallel or series. When sufficient current, voltage, etc. is applied to the resistor, it produces sufficient heat to ignite the self-ignitable secondary igniter 105. The ignition of the self-ignitable secondary igniter 105 causes the power charge 100 to ignite.
The self-ignitable secondary igniter 105 and power charge 100 disclosed herein has several benefits. First, in one embodiment the centralized-contact spring 103 can be made and cast simultaneously with the power charge 100. This ensures the centralized-contact spring 103 has an intimate coupling relationship with the power charge 100. As noted, the centralized-contact spring 103, and its contact with the power charge 100, creates an electrical ground. Additionally, in one embodiment, and as depicted, the centralized-contact spring 103 also serves the dual purpose of being a built-in housing/recess 109 for the subsequently added self-ignitable secondary igniter 105. This is a benefit in that the secondary igniter 105 need not be added until it is ready for use. By storing and transporting the power charge 100 separately from the secondary igniter 105, the possibility of an accidental ignition is greatly reduced.
Additionally, in embodiments wherein the centralized contact-spring 103 has a built-in recess 109, it is abundantly clear where the self-ignitable secondary igniter 105 is installed with the power charge 100. Incorrect installation or coupling of the self-ignitable secondary igniter 105 with the power charge 100 is decreased. Further, because the recess 109 is electrically coupled/grounded with the spring, so too is the self-ignitable secondary igniter 105 in contact with the recess 109.
In one embodiment the secondary igniter 105 is self-ignitable. This is a benefit because the secondary igniter 105 can be ignited directly rather than having to go through a primary igniter. This results in increased flexibility, versatility, and decreased cost.
In one embodiment the secondary igniter 105 is casted in a metal cup providing the bottom of it to be opened to allow the flame to travel once it is set. The metal cup allows the bottom end of the resistor to be electrically coupled, such as via soldering or the like, onto the cup. Then, the self-ignitable secondary is inserted in the centralizer spring making contact to the wall of the chamber creating ground for firing.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
The present invention claims priority to U.S. Provisional Application No. 63/055,141 filed Jul. 22, 2020, the entirety of both of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63055141 | Jul 2020 | US |