Patent Application
20240117717
The present invention relates to perforating gun systems having penetrating shaped charges to generate entrance holes through a wellbore casing.
In oil and gas operations, it is a known practice to install a well casing into a borehole that has been drilled into a geologic formation. A gun string is then lowered into the wellbore on a wireline opposite a hydrocarbon formation. The gun string includes shaped charges that, when fired, are formed into high-velocity jets that penetrate through the wellbore casing. The resulting perforations allow a fluid (oil or gas) to flow into the wellbore.
A gun string will typically include multiple perforating guns, each with opposing box ends having female threads. Tandems having male threads are threaded to one or both ends of each perforating gun in the gun string. In this fashion, multiple perforating guns can be connected end-to-end and simultaneously detonated within the wellbore. Despite their acceptance, however, there remains a continued need for improved perforating gun systems. In particular, there remains a continued need for improved perforating gun systems having a secure ground connection between each tandem and perforating gun in the gun string.
An improved perforating gun system is provided. The perforating gun system includes a perforating gun having a shaped charge positioning tube that is securely received within a female opening in a tandem to provide a 360-degree connection to ground. The shaped charge positioning tube includes segmented end portions that extend over first and second contact housings. Each contact housing includes a contact pin that is biased outwardly by a spring, the spring comprising a portion of an electrical path for a firing signal.
In one embodiment, the perforating gun includes a first contact housing and a second contact housing that are received within respective first and second ends of the shaped charge positioning tube. Each contact housing includes a spring-biased contact element therein. The spring-biased contact element including a first plate-and-pin biased away from a second plate-and-pin, each being electrically conductive. At least one of the contact housings includes an addressable switch therein. Each contact housing also includes a ring that is supported by a plurality of spokes. The segmented end portions of the shaped charge positioning tube extend beneath the ring and surround the contact housings, providing 360-degrees of contact with each tandem.
In another embodiment, each tandem includes an anodized pass-through element. Each pass-through element is secured within a cylindrical opening in the respective tandem by a retainer nut. As an alternative construction, each tandem includes a signal transfer pin surrounded by an insulating sleeve. The signal transfer pin is optionally die-cast or machined. The insulating sleeve includes a first half and a second half that collectively surround the signal transfer pin. The insulating sleeve includes socket openings to receive a contact pin protruding from the perforating gun. A signal transfer spring urges the contact pin into engagement with the signal transfer pin, thereby creating a positive connection.
The gun string can be assembled on-site by threadably engaging perforating guns and tandems in an alternating sequence. The tandems includes a socket opening for receiving a spring-biased contact pin, which is in electrical communication with an addressable switch within a perforating gun. The gun string is then lowered into a wellbore having a wellbore casing, and a firing signal causes the shaped charges to detonate, creating a plurality of perforations through the wellbore casing. These and other features and advantages of the present invention will become apparent from the following description of the invention, when viewed in accordance with the accompanying drawings and appended claims.
The following detailed description is merely exemplary in nature and is not intended to limit the oilfield perforating systems and methods as described herein. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. The description is not in any way meant to limit the scope of any present or subsequent related claims.
As used here, the terms “above” and “below”; “up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or diagonal relationship as appropriate.
Referring now to
The outer gun barrel 18 includes opposing box ends, and the tandems 14, 16 are threaded to the respective box ends of the outer gun barrel 18 so that two or more perforating guns can be joined in series in a gun string. The outer gun barrel 18 is cylindrical and includes a length that is greater than the length of the shaped charge positioning tube 20, such that the outer gun barrel 18 extends beyond the shaped charge positioning tube 20.
The shaped charge positioning tube 20 is generally formed from an electrically conductive material, for example stainless steel. Each end portion of the shaped charge positioning tube 20 defines a plurality of longitudinal slots 26, such that the shaped charge positioning tube 20 includes castellated or segmented end portions having a plurality of flanges 28. As shown in
The shaped charge positioning tube 20 also includes a cylindrical body having multiple shaped charge openings 32 that receive a corresponding number of shaped charges. The openings 32 are angularly offset from each other in the current embodiment, but can be in axial alignment in other embodiments. The shaped charge positioning tube 20 includes two shaped charge openings 32 in the illustrated embodiment, while other embodiments the internal tube 20 can include greater or fewer number of shaped charge openings.
As noted above, the perforating gun 12 includes a first contact housing 22 and a second contact housing 24. Each contact housing 22, 24 is formed from an electrically insulating material, for example molded plastic. In addition, each contact housing 22, 24 is partially received within the shaped charge positioning tube 20. Each contact housing 22, 24 includes an outer portion 34, a ring 36 (supported by spokes), and an inner portion 38. The outer portion 34 of the second contact housing 24 also includes an addressable switch housing 40. The inner portion 38 of each contact housing 22, 24 includes an outer diameter that is approximately equal to the inner diameter of the outer gun barrel 18. Each contact housing 22, 24 also includes a top contact element 42, a signal transfer spring 44, and a bottom contact element 46. As shown in
As also shown in
Referring now to
In operation, the firing signal is passed through the first tandem 70 to the perforating gun 12 and subsequently to the second tandem 72 (to adjacent perforating gun). In particular, the firing signal passes through the signal transfer pin 74 to a first contact pin 48 of the perforating gun 12. The firing signal is passed to an addressable switch (within addressable switch housing 40) and is passed by a second contact pin 48 to a second signal transfer element 74 in the second tandem 72. A signal fire wire (not shown) extends between inner contact pins 52 to allow the firing signal to directly pass to adjacent perforating guns.
The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any reference to elements in the singular, for example, using the articles “a,” “an,” “the,” or “said,” is not to be construed as limiting the element to the singular.
This application claims the benefit of U.S. Provisional Application 63/132,594, filed Dec. 31, 2020, the disclosure of which is incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/065359 | 12/28/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63132594 | Dec 2020 | US |
