Patent Application
20240287877
Generally, when completing a subterranean well for the production of fluids, minerals, or gases from underground reservoirs, several types of tubulars are placed downhole as part of the drilling, exploration, and completions process. These tubulars can include casing, tubing, pipes, liners, and devices conveyed downhole by tubulars of various types. Each well is unique, so combinations of different tubulars may be lowered into a well for a multitude of purposes.
A subsurface or subterranean well transits one or more formations. The formation is a body of rock or strata that contains one or more compositions. The formation is treated as a continuous body. Within the formation hydrocarbon deposits may exist. Typically, a wellbore will be drilled from a surface location, placing a hole into a formation of interest. Completion equipment will be put into place, including casing, tubing, and other downhole equipment as needed. Perforating the casing and the formation with a perforating gun is a well-known method in the art for accessing hydrocarbon deposits within a formation from a wellbore.
Explosively perforating the formation using a shaped charge is a widely known method for completing an oil well. A shaped charge is a term of art for a device that when detonated generates a focused output, high energy output, and/or high velocity jet. This is achieved in part by the geometry of the explosive in conjunction with an adjacent liner. Generally, a shaped charge includes a metal case that contains an explosive material with a concave shape, which has a thin metal liner on the inner surface. Many materials are used for the liner; some of the more common metals include brass, copper, tungsten, and lead. When the explosive detonates, the liner metal is compressed into a super-heated, super pressurized jet that can penetrate metal, concrete, and rock. Perforating charges are typically used in groups. These groups of perforating charges are typically held together in an assembly called a perforating gun. Perforating guns come in many styles, such as strip guns, capsule guns, port plug guns, and expendable hollow carrier guns.
Perforating charges are typically detonated by a detonating cord in proximity to a priming hole at the apex of each charge case. Typically, the detonating cord terminates proximate to the ends of the perforating gun. In this arrangement, an initiator at one end of the perforating gun can detonate all the perforating charges in the gun and continue a ballistic transfer to the opposite end of the gun. In this fashion, numerous perforating guns can be connected end to end with a single initiator detonating all of them.
The detonating cord is typically detonated by an initiator triggered by a firing head. The firing head can be actuated in many ways, including but not limited to electronically, hydraulically, and mechanically.
Expendable hollow carrier perforating guns are typically manufactured from standard sizes of steel pipe with a box end having internal/female threads at each end. Pin ended adapters, or subs, having male/external threads are threaded one or both ends of the gun. These subs can connect perforating guns together, connect perforating guns to other tools such as setting tools and collar locators, and connect firing heads to perforating guns. Subs often house electronic, mechanical, or ballistic components used to activate or otherwise control perforating guns and other components.
Perforating guns typically have a cylindrical gun body and a charge tube or loading tube that holds the perforating charges. The gun body typically is composed of metal and is cylindrical in shape. Charge tubes can be formed as tubes, strips, or chains. The charge tubes will contain cutouts called charge holes to house the shaped charges.
An example embodiment may include a perforating gun system having a first perforating gun having a housing with a first end, a second end with first alignment mechanism, and a first set of scallops aligned with the alignment mechanism, a second perforating gun having a housing with a first end with a second alignment mechanism coupled to the first alignment mechanism of the second end of the first perforating gun, and a second set of scallops aligned with the second alignment mechanism, wherein the coupling of the first perforating gun to the second perforating gun aligns the first set of scallops with the second set of scallops.
A variation of the example embodiment may include the first alignment mechanism being timed male threads. The second alignment mechanism may be timed male threads. It may have at least one o-ring seal between the second end of the first perforating gun and the first end of the second perforating gun. It may have a positive stop at the point of full engagement between the second end of the first perforating gun and the first end of the second perforating gun. The positive stop may be an angled face that resists rotation beyond a predetermined point of thread engagement. The positive stop may be a 45-degree angled face. The timed male threads and timed female threads may be self-sealing. It may include a positive stop at the point of full engagement between the second end of the first perforating gun and the first end of the second perforating gun. The positive stop may be an angled face that resists rotation beyond a predetermined point of thread engagement. The positive stop may be a 45-degree angled face.
An example embodiment may include a perforating gun system having a first perforating gun having a housing with a first end, a second end with timed male threads, and a first set of scallops aligned with the timed male threads, a second perforating gun having a housing with a first end with timed female threads coupled to the second end of the first perforating gun with timed threads, and a second set of scallops aligned with the timed female threads, wherein the full engagement of the timed male timed with the timed female threads aligns the first set of scallops with the second set of scallops.
A variation of the perforating gun system may include at least one o-ring seal between the second end of the first perforating gun and the first end of the second perforating gun. It may include a positive stop at the point of full engagement between the second end of the first perforating gun and the first end of the second perforating gun. The positive stop may be an angled face that resists rotation beyond a predetermined point of thread engagement. The positive stop may be a 45-degree angled face. The timed male threads and timed female threads may be self-scaling.
An example embodiment may include a method for assembling a perforating gun string including threading a first timed threads of a first perforating gun into a second timed threads of a second perforating gun, aligning a first set of scallops on the first perforating gun with a second set of scallops on a second perforating gun, engaging the first timed threads of the first perforating gun with the second timed threads of the second perforating gun fully, wherein the full engagement of the first perforating gun with the second perforating gun aligns the first set of scallops with the second set of scallops.
A variation of the example embodiment may include engaging a positive stop when engaging the first timed threads of the first perforating gun with the second timed threads of the second perforating gun. It may include the full engagement of the first perforating gun with the second perforating gun provides a pressure seal between the inside of the perforating gun string and the outside of the perforating gun string.
For a thorough understanding of the example embodiments, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings in which reference numbers designate like or similar elements throughout the several figures of the drawing. Briefly:
In the following description, certain terms have been used for brevity, clarity, and examples. No unnecessary limitations are to be implied therefrom and such terms are used for descriptive purposes only and are intended to be broadly construed. The different apparatus, systems and method steps described herein may be used alone or in combination with other apparatus, systems and method steps. It is to be expected that various equivalents, alternatives, and modifications are possible within the scope of the appended claims.
Terms such as booster may include a small metal tube containing secondary high explosives that are crimped onto the end of detonating cord. The explosive component is designed to provide reliable detonation transfer between perforating guns or other explosive devices, and often serves as an auxiliary explosive charge to ensure detonation.
Detonating cord is a cord containing high-explosive material sheathed in a flexible outer case, which is used to connect the detonator to the main high explosive, such as a shaped charge. This provides an extremely rapid initiation sequence that can be used to fire several shaped charges simultaneously.
A detonator or initiation device may include a device containing primary high-explosive material that is used to initiate an explosive sequence, including one or more shaped charges. Two common types may include electrical detonators and percussion detonators. Detonators may be referred to as initiators. Electrical detonators have a fuse material that burns when high voltage is applied to initiate the primary high explosive. Percussion detonators contain abrasive grit and primary high explosive in a sealed container that is activated by a firing pin. The impact of the firing pin is sufficient to initiate the ballistic sequence that is then transmitted to the detonating cord.
Initiators may be used to initiate a perforating gun, a cutter, a setting tool, or other downhole energetic device. For example, a cutter is used to cut tubulars with focused energy. A setting tool uses a pyrotechnic to develop gases to perform work in downhole tools. Any downhole device that uses an initiator may be adapted to use the modular initiator assembly disclosed herein.
As shown in the example embodiments of
The male and female threads may also be timed (also referred to as clocked) so that the scallops 12 and/or perforating charges of adjacent perforating guns are aligned with each other when the threaded connection between guns is made up. Having the threaded connection timed to align the perforating charges and/or scallops 12 of the adjacent perforating guns allows the orientation of an entire string of perforating guns without the use of alignment or orienting subs and/or locking collars between perforating guns.
Perforating guns often, but not always have scallops 12, or machined thin wall areas, that are aligned with the exiting jet of the perforating shaped charges. The examples of this description could be made with or without scallops 12.
As seen in
In the example of
Alternatively, the perforating gun may not include a switch. In that example, the electrical connections would still pass electrical signals from one perforating gun to another without the presence of a switch in each perforating gun.
These example features are further shown in
In some examples, not all of these features will be present. In various examples, the key features may be present in any combination. For example, a tool string may have perforating guns with timed threads that are not necessarily self-sealing and may use traditional sealing mechanisms such as o-rings. In another example, a tool string may have perforating guns without timed threads, but whose threads are self-scaling and may not use traditional sealing mechanisms such as o-rings. In another example, a tool string may include perforating guns that have a positive stop, or a positive stop with an angled face, without requiring timed threads and self-scaling threads, or without either timed threads or self-sealing threads.
These improvements could also be combined with an orientation sensor or orientation sensing switch to provide confirmation of each perforating guns orientation before firing and/or when fired.
Although the example embodiments have been described in terms of embodiments which are set forth in detail, it should be understood that this is by illustration only and that the example embodiments are not necessarily limited thereto. For example, terms such as upper and lower or top and bottom can be substituted with uphole and downhole, respectfully. Top and bottom could be left and right, respectively. Uphole and downhole could be shown in figures as left and right, respectively, or top and bottom, respectively. Generally downhole tools initially enter the borehole in a vertical orientation, but since some boreholes end up horizontal, the orientation of the tool may change. In that case downhole, lower, or bottom is generally a component in the tool string that enters the borehole before a component referred to as uphole, upper, or top, relatively speaking. The first housing and second housing may be top housing and bottom housing, respectfully. In a gun string such as described herein, the first gun may be the uphole gun or the downhole gun, same for the second gun, and the uphole or downhole references can be swapped as they are merely used to describe the location relationship of the various components. Terms like wellbore, borehole, well, bore, oil well, and other alternatives may be used synonymously. Terms like tool string, tool, perforating gun string, gun string, or downhole tools, and other alternatives may be used synonymously. The alternative embodiments and operating techniques will become apparent to those of ordinary skill in the art in view of the present disclosure. Accordingly, modifications of the example embodiments are contemplated which may be made without departing from the spirit of the claimed example embodiments.
This application is a U.S. National Phase application of PCT/US22/72711, which claims the benefit of U.S. Provisional Application No. 63/197,257, filed Jun. 4, 2021.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US22/72711 | 6/2/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63197257 | Jun 2021 | US |
