Cluster gun system

Abstract

A method and apparatus for containing one or more shaped charges in a single plane, the one or more shaped charges being arranged about a central axis of a gun body and detonated from a single detonator in a shaped charge cluster assembly.

Description

[0001] Related Applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 946,276, filed on December 10, 2019. Background Art

[0003] Typically, when completing a subterranean well for producing fluids, minerals or gases from a subterranean reservoir, several types of tubulars are placed downhole as part of the drilling, exploration and completion process. These tubulars may include casings, conduits, pipes, liners and devices that are transported downhole through various types of tubulars. Each well is unique, and therefore, a combination of different tubulars may be lowered into the well for a variety of purposes.

[0004] A subsurface or underground well penetrates one or more formations. A formation is a body of rock or formation that contains one or more components. A formation is considered a continuum. Hydrocarbon deposits may be present within the formation. Typically, a wellbore will be drilled from a surface location and a hole will be placed in the formation of interest. Completion equipment will be put in place, including casing, conduit, and other downhole equipment as needed. Perforating the casing and formation with a perforating gun is a method known in the art for accessing hydrocarbon deposits in a formation from a wellbore.

[0005] Explosively perforating a formation using shaped charges is a well-known method of completing an oil well. A shaped charge is a term for a device that, when detonated, produces a concentrated output, a high energy output, and / or a high velocity jet. This is achieved in part by the geometry of the charge in combination with the adjacent liner. Typically, a shaped charge includes a metal shell containing an explosive material having a concave shape, with a thin metal liner on the inner surface. The liner is made of a variety of materials; some of the more common metals include brass, copper, tungsten, and lead. When the explosive is detonated, the liner metal is compressed into a superheated, overpressure 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 a variety of styles, such as strip guns, cartridge-type perforating guns, port-plug perforating guns, and expendable hollow tube perforating guns.

[0006] The perforating charges are usually detonated by a detonating cord near the detonation hole at the apex of each charge box. Typically, the detonating cord terminates near the end of the perforating gun. In this arrangement, the detonator at one end of the perforating gun can detonate all the perforating charges in the perforating gun and continue to transfer the trajectory to the other end of the perforating gun. In this way, all perforating guns can be connected end to end with a single detonator.

[0007] Detonating cords are typically detonated by an initiator that is triggered by a firing head. The firing head can be actuated in a variety of ways, including but not limited to electronic, hydraulic, and mechanical.

[0008] Expendable hollow tube perforating guns are typically made of standard-sized steel tubing with a box end having internal / female threads on each end. Pin-end adapters or subs with male / male threads are threaded on one or both ends of the gun. These subs can connect perforating guns together, connect perforating guns to other tools (such as installation tools and collar positioners), and connect firing heads to perforating guns. Subs often house electronic, mechanical, or ballistic components that activate or otherwise control the perforating gun or other components.

[0009] A perforating gun typically has a cylindrical gun body and a charge tube or loading tube that holds the perforating charge. The gun body is typically made of metal and is cylindrical in shape. The charge tube may be formed as a tube, bar, or chain. The charge tube will contain cutouts called charge holes for holding the shaped charge.

[0010] It is generally desirable to reduce the overall length of any tool to be introduced into the wellbore. Among other potential benefits, reduced tool length reduces the length of the lubricator required to introduce the tool into the wellbore under pressure. Additionally, reduced tool length is also desirable to accommodate turns in highly deviated or horizontal wells. It is also generally preferred to reduce the tool assembly that must be performed at the wellsite, which is often a harsh environment with many distractions and demands on workers at the site.

[0011] Electrical detonators are commonly used in the oil and gas industry to detonate different high energy devices downhole. The most common is the use of a 50 ohm resistor detonator. Other detonator and electronic switch configurations are common. Summary of the invention

[0012] An exemplary embodiment may include a perforating gun assembly comprising a first cylindrical portion having a central axis, the first cylindrical portion having an outer surface, a protruding distal end having a first through hole, a conical end having a second through hole, and at least one first semi-shaped charge container; a second cylindrical portion, the second cylindrical portion along the central axis and adjacent to the first cylindrical portion, the second cylindrical portion having a second outer surface, a through hole and a conical end, and at least one first semi-shaped charge container, which is positioned tangent to the central axis, with an apex end adjacent to the central axis and an open end intersecting the outer surface.

[0013] An exemplary embodiment may include a perforating gun assembly comprising: a first cylindrical portion having a central axis, the first cylindrical portion having an outer surface, a protruding distal end having a first through hole, a conical end having a second through hole, and at least one first semi-shaped charge container; a second cylindrical portion, the second cylindrical portion along the central axis and adjacent to the first cylindrical portion, the second cylindrical portion having a second outer surface, a through hole and a conical end, and at least one second semi-shaped charge container; and at least one shaped charge, the at least one shaped charge being disposed within the first semi-shaped charge container and the second semi-shaped charge container, positioned tangent to the central axis, with an apex end adjacent to the central axis, and an open end intersecting the outer surface.

[0014] A variation of the example embodiment may include a threaded cylindrical interface at the protruding distal end of the first cylindrical portion, wherein the threaded cylindrical interface has an axis common to the central axis and includes a through hole located therein. It may include a contact retaining nut connected to the threaded cylindrical interface. It may include a contact pin having a generally cylindrical body and partially disposed within the through hole, protruding from the threaded cylindrical interface, and constrained by the retaining nut. It may include a spring disposed within the through hole and loading the contact pin against the retaining nut. It may include a contact band that passes over the first cylindrical portion and the second cylindrical portion and is connected to a spring disposed within the conical ends of the first through hole and the second cylindrical portion. It may include a burster bracket having a generally cylindrical body and partially disposed within the second through hole of the second cylindrical portion. The at least one shaped charge may be a plurality of shaped charges arranged around the central axis of the first cylindrical portion. The at least one shaped charge may be adapted to perforate in a plane normal to the central axis.

[0015] Exemplary embodiments may include a method for loading a perforating gun, the method comprising combining a first cylindrical half with a second cylindrical half to form a perforating shaped charge cluster, installing at least one shaped charge in the charge cluster, and installing the charge cluster into a gun body of the perforating gun, wherein the shaped charge cluster is snapped together using a plurality of tabs.

[0016] Variations of the exemplary embodiment may include: connecting the gun body to the first column containing the detonators. The first charge cluster may be connected to the second charge cluster. It may include connecting the contact piston, spring and retaining nut to the first end of the first charge cluster. It may include electrically coupling the first end of the first charge cluster to the second end of the charge cluster. It may include lowering the perforating gun into the wellbore. It may include perforating a first perforation plane orthogonal to the wellbore. It may include rupturing the first perforation plane orthogonal to the wellbore.

[0017] Exemplary embodiments may include a method for perforating a well, the method comprising: combining a first cylindrical half and a second cylindrical half to form at least one perforating shaped charge cluster, installing at least one shaped charge into the charge cluster, installing the charge cluster into a gun body of a perforating gun, connecting the gun body of the perforating gun to an additional tube to form a tool string, lowering the tool string to a predetermined location in a wellbore, and detonating the at least one charge cluster at a first predetermined location.

[0018] Variations of the exemplary embodiments may include at least one shaped charge being a plurality of shaped charges. It may include at least one perforated shaped charge cluster being a plurality of charge clusters. It may include detonating at least one charge cluster at a second predetermined location. It may include plugging the wellbore from a first predetermined location. It may include plugging the wellbore from a second predetermined location.

[0019] An exemplary embodiment may include an apparatus for containing a shaped charge, the apparatus comprising: a first cylindrical half, the first cylindrical half having a through-hole center, a first end, a second end, and at least one semi-conical cutout arranged about the center, the at least one semi-conical cutout being suitable for holding a shaped charge, the shaped charge being oriented to ignite perpendicularly from a central axis; a second cylindrical half, the second cylindrical half having a through-hole center, a first end, a second end, and at least one semi-conical cutout arranged about the center, the at least one semi-conical cutout being suitable for holding a shaped charge, the shaped charge being oriented to ignite perpendicularly from a central axis, wherein the first cylindrical half is connected to the second cylindrical half.

[0020] A variation of the exemplary embodiment may include a threaded cylindrical interface at the protruding distal end of the first cylindrical half, wherein the threaded cylindrical interface has an axis common to the central axis of the through hole. It may include a contact fixing nut connected to the threaded cylindrical interface. It may include a contact pin having a generally cylindrical body and partially disposed within the through hole, protruding from the threaded cylindrical interface, and constrained by the fixing nut. It may include a spring disposed within the through hole and loading the contact pin against the fixing nut. It may include a contact band that passes over the first cylindrical half and the second cylindrical half and is connected to a spring disposed within the conical ends of the first through hole and the second cylindrical half. It may include a bomb expander bracket having a generally cylindrical body and partially disposed within the second through hole of the second cylindrical half. The at least one semi-conical cutout of the first cylindrical half can be combined with the at least one semi-conical cutout of the second cylindrical half to form at least one cutout adapted to receive a shaped charge oriented to perforate orthogonally to the central axis of the wellbore. The at least one cutout can be a plurality of cutouts arranged to form a perforation plane orthogonal to the central axis of the wellbore.

[0021] An exemplary embodiment may include a perforating gun comprising: an outer gun body; a first cluster charge holder; a plurality of shaped charges having an open end and an apex end; a detonating device; wherein the first cluster charge holder comprises: a top end; a bottom end; a housing axis extending from the center of the top end and an outer surface substantially parallel to the housing axis; a central hole extending from the top end of a charge housing along the housing axis; a plurality of charge cavities in the charge housing, the plurality of charge cavities being radially arranged around the housing axis, each charge cavity extending from a shaped charge hole in the outer surface to an apex end proximate to the central hole; a plurality of detonating holes in the charge housing, the plurality of detonating holes connecting the central hole to the apex ends of the plurality of charge cavities; wherein the detonating device is within the central hole of the first cluster charge holder, and the plurality of shaped charges are within the plurality of charge cavities, and wherein an explosive output of the detonating device detonates the shaped charges.

[0022] An exemplary embodiment may include a second cluster charge support; a plurality of shaped charges having an open end and an apex end; an explosion transfer device; wherein the second cluster charge support includes: a top end; a bottom end; a shell axis extending from the center of the top end and an outer surface substantially parallel to the shell axis; a central hole extending from the top end of the charge shell along the shell axis; a plurality of charge cavities in the charge shell, the plurality of charge cavities being radially arranged about the shell axis, each charge cavity extending from the shaped charge hole in the outer surface to the apex end near the central hole; a plurality of detonation holes in the charge shell, the plurality of detonation holes connecting the central hole to the apex ends of the plurality of charge cavities; wherein the explosion transfer device is within the central hole of the second cluster charge support, and the plurality of shaped charges are within the plurality of charge cavities of the first and second cluster charge supports; wherein the explosion output of the detonation device detonates the shaped charges in the first cluster charge support and the explosion transfer device; and wherein the explosion output of the explosion transfer device detonates the shaped charges in the second cluster charge support. The detonation device may include an addressable switch. The detonation device may include a detonator. The detonation device may include an impact detonator. The explosion transmission device may include a spreader. The explosion transmission device may include a detonating cord.

[0023] An exemplary embodiment may include a perforating gun comprising: an outer gun body; a first cluster charge support; a plurality of shaped charges having an open end and an apex end; a detonating device; wherein the first cluster charge support comprises: a top end; a bottom end; a shell axis extending from the center of the top end and an outer surface substantially parallel to the shell axis; a center hole extending from the top end of the charge shell along the shell axis; a plurality of charge cavities in the charge shell, the plurality of charge cavities being radially arranged around the shell axis, each charge cavity extending from a shaped charge hole in the outer surface to an apex end proximate to the center hole; a plurality of detonating holes in the charge shell, the plurality of detonating holes connecting the center hole to the apex ends of the plurality of charge cavities; a detonator circuit embedded in the first cluster charge support, wherein the detonator circuit is electrically coupled to the detonating device; and wherein the detonating device is within the center hole of the first cluster charge support, and the plurality of shaped charges are within the plurality of charge cavities; and wherein the explosive output of the detonating device detonates the shaped charges.

[0024] An exemplary embodiment may include a perforating gun assembly comprising: a first cylinder comprised of an electrical insulator, the first cylinder having a plurality of orthogonal hollow cuts in a first orthogonal perforating plane, each hollow cut further comprising a plurality of shaped charges, one disposed in each cut; a first detonator circuit embedded in the first cylinder; and a first detonator disposed in a center of the cylinder and electrically coupled to the first detonator circuit, wherein the shaped charges perforate in the first orthogonal plane when detonated by the first detonator.

[0025] An exemplary embodiment may include an apparatus for containing a shaped charge, the apparatus comprising: a first cylinder composed of an electrical insulator, the first cylinder having a plurality of orthogonal hollow cuts in a first orthogonal perforation plane, each hollow cut being adapted to contain the shaped charge, and the first cylinder having a groove adapted to receive a detonator circuit; and a center hole adapted to receive a first detonator disposed at the center of the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, wherein reference numerals represent the same or similar elements. Briefly:

[0027] Figure 1 An exemplary embodiment of a side view of a cluster assembly is shown.

[0028] Figure 2 An exemplary embodiment of a side view of a cluster assembly is shown.

[0029] Figure 3 An exemplary embodiment of a side view of a cluster assembly is shown.

[0030] Figures 4A-4D Exemplary embodiments of the cluster assembly are shown in various states of assembly.

[0031] Figures 5A-5C Exemplary embodiments of the cluster assembly are shown in various states of assembly.

[0032] Figure 6A-6B Exemplary embodiments of the cluster assembly are shown in various states of assembly.

[0033] Figure 7 A cross-sectional view of an exemplary embodiment of a cluster assembly is shown.

[0034] 8A-8H depict different types of perforation patterns in a downhole formation that are possible in an exemplary embodiment.

[0035] Fig. 9A A side cross-sectional view of an exemplary embodiment of a charge cluster is depicted.

[0036] Fig. 9B An axial cross-sectional view of an exemplary embodiment of a charge cluster is depicted.

[0037] Fig. 9C Depicted is a side cross-sectional view of an exemplary embodiment of a cluster assembly with two charge clusters connected together.

[0038] Fig.10 A side cross-sectional view of an exemplary embodiment of a charge cluster is depicted.

[0039] Fig.11 A side cross-sectional view of an exemplary embodiment of a charge cluster is depicted.

[0040] Fig. 12A A side view of an exemplary embodiment of a charge cluster is depicted.

[0041] Fig. 12B A side cross-sectional view of an exemplary embodiment of a charge cluster is depicted.

[0042] Fig.13 A side cross-sectional view of an exemplary embodiment of a charge cluster assembly is depicted. DETAILED DESCRIPTION

[0043] In the following description, certain terms are used for brevity, clarity, and illustration. No unnecessary limitations are implied herein, and these terms are used for descriptive purposes only and are intended to be broadly interpreted. The various apparatus, systems, and method steps described herein may be used alone or in combination with other apparatus, systems, and method steps. It is contemplated that various equivalents, substitutions, and modifications are possible within the scope of the appended claims.

[0044] Figure 1 An exemplary embodiment is shown in FIG. The exemplary embodiment includes a short cluster gun 100 having a cylindrical gun body 102 having a center, an inner bore, an outer surface, a first end connected to a bulkhead 101, and a second end connected to a bulkhead 103. Within the gun body 102 are one or more charge clusters, in this case a first charge cluster 104 and a second charge cluster 105. Each charge cluster contains one or more shaped charges. In this example, the first charge cluster 104 contains shaped charges 111 arranged around the center, and the second charge cluster 105 contains shaped charges 112 arranged around the center. The first charge cluster 104 and the second charge cluster 105 are separated by an internal bulkhead 108. The outer surface of the gun body 102 has a scalloped portion aligned with each shaped charge. The scalloped portion provides a thinner body portion for the shaped charges to penetrate. In this case, sectors 109 are aligned with shaped charges 111 and sectors 110 are aligned with shaped charges 112 .

[0045] The first shaped charge 111 is located adjacent to an initiating device 113 (e.g., a detonator) that, when ignited, will ignite the shaped charge 111. The initiating device 113 is coupled to an electronic board 115 that is housed within a detonator assembly 106 that is further housed within adjacent holes in the first charge cluster 104 and the inner barrier 108. The detonator assembly 106 may include an addressable switch. The first shaped charge 112 is located adjacent to an initiating device 114 (e.g., a detonator) that, when ignited, will ignite the shaped charge 112. The initiating device 114 is coupled to an electronic board 116 that is housed within a detonator assembly 107 that is further housed within adjacent holes in the second charge cluster 105 and the barrier 103. The detonator assembly 107 may include an addressable switch. The first shaped charge 111 has a liner 150, which is lined with an explosive material 151 and is enclosed in an inner surface 152 integral with the first charge cluster 104, wherein the first charge cluster 104 serves as a shaped charge shell. The first shaped charge 112 has a liner 160, which is lined with an explosive material 161 and is enclosed in an inner surface 162 integral with the first charge cluster 105, wherein the first charge cluster 105 serves as a shaped charge shell.

[0046] Figure 2 An exemplary embodiment of a cluster gun assembly 200 is shown in FIG. A gun body 202 includes two sets of charge cluster halves, which contain shaped charges that form a shaped charge cluster assembly 280. A first cluster half 222 and a second cluster half 223 are joined together within the gun body 202, and they contain a shaped charge 211 that is adjacent to a diffuser 213 located at a central opening of the two charge halves 222 and 223. A third cluster half 224 and a fourth cluster half 225 are joined together within the gun body 202, and they contain a shaped charge 212 and a detonator 214 located at a central opening of the two charge halves 224 and 225.

[0047] The first column 220 is connected to the first end of the gun body 202. The column 220 has a hollow through hole suitable for receiving the detonator assembly 206, which also includes a circuit board 215 for igniting the shaped charge. The detonator assembly 206 can include an addressable switch. The spacer 229 is connected to the column 220 and is further connected to the detonator assembly 206.

[0048] A second column 221 is connected to a second end of the gun body 202. Column 221 has a hollow through hole suitable for accommodating a detonator assembly 207, which also includes a circuit board 216 for igniting the shaped charge. The detonator assembly 207 may include an addressable switch. A spacer 228 is connected to column 221 and further connected to the detonator assembly 207. The detonator assembly 207 is electrically coupled to a control cartridge 227. The control cartridge 227 is coupled to the detonator 214 for detonating the shaped charge 212 and the expander 213, which then detonates the shaped charge 211.

[0049] A close-up view of an exemplary embodiment of a cluster gun assembly 200 is provided in FIG. Figure 3 2. The first cluster half 222 is combined with the second cluster half 223 to form a shaped charge cluster assembly 280. The conical container portion 236 is adapted to slidably receive the shaped charge disposed therein. The conical container portions 245 and 247 are arranged around the center of the first cluster half 222 and the second cluster half 223. The conical container portions 246 and 248 are arranged around the center of the cluster halves 225 and 224, respectively. The cluster halves 222 and 223 have through holes adapted to allow the expander 213 to be slidably positioned at the end of the conical container portion 236. The expander 213 is held by the expander bracket 242. The expander bracket 242 abuts against the third cluster half 224 by a fixing nut 241. The combined conical container portions 245 and 247 have through holes 237 that allow the explosive output of the expander 213 to impact the shaped charge contained therein.

[0050] The third cluster half 224 is combined with the fourth cluster half 225 to form a shaped charge cluster assembly 282. The conical container portions 246 and 248 are adapted to slidably receive the shaped charge disposed therein and are arranged around the center of the cluster halves 224 and 225. The cluster halves 224 and 225 have through holes adapted to allow the expander to be slidably positioned at the ends of the array of conical container portions 236. The combined conical container portions 246 and 248 have through holes 238 that allow the explosive output of the detonator to impact the shaped charge contained therein. In these examples, the first charge cluster assembly can be detonated by the detonator, and each subsequent charge cluster assembly can be detonated by the expander that transfers the original explosive output of the detonator. Other well-known variations can be used, such as using a detonator for each cluster assembly, or using a detonating cord that passes through the perforating gun from one end to the other. Each cluster assembly can have a unique addressable switch associated with its detonator.

[0051] The contact strip 230 is used to electrically connect the contact pin 232 and the fixing spring 234 to the fixing nut 241 through the conical contact portion 239. In this example, the cluster halves are made of an electrically insulating material. The contact strips 230 and 240 provide electrical communication through the cluster halves 222, 223, 224 and 225. The contact pin 232 rests on the fixing spring 234 through the fixing nut 231. The conical contact portion 249 can be connected to an additional fixing nut.

[0052] exist Figure 4A , 4B , 4C and 4D show additional views of cluster halves 222 and 223. Multiple shaped charges 235 can be contained within cluster halves 222 and 223. Charge tabs 250 are used to secure the shaped charges 235 in place. The expander 213 is aligned with the apex end 249 of each shaped charge 235. The contact pin 232 and spring 234 are electrically connected to the contact band 230, which passes through the axial passages 251 and 258. The two cluster halves 222 and 223 are interconnected by tabs and slots 253. Cluster assembly 280 can be combined with other cluster assemblies by combining tabs 256 and 257 with slots 254 and 255. Through holes 252 provide paths for electrical or auxiliary wire paths. Multiple tabs 254 allow different alignment and orientation relationships between different cluster assemblies, such as aligning shaped charges in different assemblies or offsetting shaped charges by a desired amount.

[0053] refer to Figures 4A-4D , assembly of the tool string will include taking the fully assembled cluster halves 222 and 223 and installing the expander bracket and expander 213. Then, the contact band 230, spring 234 and contact pin 232 are installed and secured by the retaining nut 231, which is screwed directly onto the cluster assembly 280. The shaped charge 235 will then be inserted into the conical cavities 245 and 247 and secured by the tab 250. If an additional cluster assembly is connected to the first cluster assembly 280, the expander can be installed into the contact pin 232.

[0054] refer to Figures 4A-4D , disassembling the cluster assembly 280 would include removing the retaining nut 231, then removing the contact pin 232, then removing the spring 234, then removing the contact band 230, then separating the cluster halves 222 and 223. The shaped charge 235 may be held in place by the retaining clip 260.

[0055] like Figure 5A , 5BAs shown in FIG. 5C , two cluster assemblies 280 and 282 are mounted together and connected using tabs and tab slots 254. The expander 283 is aligned with the shaped charge 235 in the cluster assembly 280. Tabs 256 are provided for engaging with additional cluster assemblies or for engaging the internally threaded portion of the gun housing. Figure 5C 2, conical cavities 245 and 247 combine to form a cavity suitable for receiving and securing shaped charge 235. Conical cavities 248 and 246 combine to form a cavity suitable for receiving and securing shaped charge 284.

[0056] refer to Fig. 6A and 6B , the two clustering assemblies 280 and 282 are combined using the lugs 256 and lug slots 254. The two clustering assemblies 280 and 282 are then slidably positioned into the gun body 290. The gun body 290 has an inner surface 294 and an outer surface 295. In this example, the gun body 290 has no scallops, but in some embodiments it can have a scalloped outer surface. The inner surface 295 has a shoulder 291, which provides a hard stop for the clustering assemblies 280 and 282 when the clustering assemblies 280 and 282 are inserted. The lugs 256 at the ends of the assemblies are not engaged with the corresponding lug slots 254, and the lugs 256 will engage with the threads 297 to provide resistance to prevent the assembly from falling out of the gun body. The snap ring groove 293 also provides an additional mechanical mechanism to keep the clustering assemblies 280 and 282 in place. The external groove 292 provides identification during the tool string assembly in the direction of the gun body 290. Perforating charges 235 are contained in conical cavities 245 and 247, arranged about the centerline of cluster assembly 280. Perforating charges 284 are contained in conical cavities 246 and 248, arranged about the centerline of cluster assembly 282. When the control cartridge is inserted into gun body 290, expander 283 has already been inserted, and the detonator will be inserted into cluster assembly 282. Threads 296 can engage tabs 256.

[0057] refer to Figure 7 , perforating gun assembly 300 includes: gun body 301 having a box end 310 and a pin end 311 in which a cluster assembly 303 is slidably engaged. Shoulder 307 determines the distance the cluster assembly 303 can slide in gun body 301. Key 305 and broach 306 features are used to control the orientation of the cluster assembly within gun body 301. Shaped charge 304 is shown inserted into one of the phases of the cluster assembly, and detonator assembly 302 is shown.

[0058] Referring to Figures 8A-8H, a series of perforation configurations in a formation 400 are shown using exemplary embodiments. In Figures 8A and 8B, a typical horizontal wellbore axis 401 is perforated. There are three perforation planes 402 that are orthogonal to the wellbore axis 401. Each perforation plane 402 has four perforation jets 403 that are uniformly phase-shifted by 90 degrees around the horizontal portion of the wellbore axis 401. The perforation jets 403 are orthogonal to the wellbore axis 401. Figure 8B shows a view of the perforation planes 402 as they exit the wellbore 404 and enter the formation 400. There can be more or less than three perforation planes 402. The perforation planes 402 can be located at different distances from each other. There can be more or less than four perforation jets 403 in each plane.

[0059] In Figures 8C and 8D, a typical horizontal wellbore axis 401 is perforated. There are three perforation planes 402 that are orthogonal to the wellbore axis 401. Each perforation plane 402 has three perforation jets 403 that are uniformly phase-shifted by 120 degrees around the horizontal portion of the wellbore axis 401. Figure 8D shows a view of the perforation planes 402 as the perforation jets 403 exit the wellbore 404 and enter the formation 400. The perforation jets 403 are orthogonal to the wellbore axis 401. There can be more or less than three perforation planes 402. The perforation planes 402 can be located at different distances from each other. There can be more or less than three perforation jets 403 in each plane.

[0060] In Figures 8E and 8F, a typical horizontal wellbore axis 401 is perforated. There are two closely spaced perforation planes 412 that are orthogonal to the wellbore axis 401. There are two additional closely spaced perforation planes 415 that are orthogonal to the wellbore axis 401. Each perforation plane 412 has four perforation jets 413. The perforation planes 412 are out of phase, resulting in a total of eight jets 413 perforating every 45 degrees around the wellbore 414. The perforation planes 415 are in phase, resulting in two perforation jets 413 perforating every 90 degrees around the wellbore 414. Figure 8F shows a view of the perforation planes 412 and 415, with the perforation jets 413 and 416 exiting the wellbore 414 and entering the formation 400.

[0061] In Figures 8G and 8H, a typical horizontal wellbore axis 401 is perforated. There are two closely spaced perforation planes 412 that are orthogonal to the wellbore axis 401. There are two additional closely spaced perforation planes 415 that are orthogonal to the wellbore axis 401. Each perforation plane 412 has three perforation jets 413. The perforation planes 412 are out of phase, resulting in a total of six perforation jets 413 perforating every 60 degrees around the wellbore 414. The perforation planes 412 are in phase, resulting in a total of two perforation jets 413 perforating every 120 degrees around the wellbore 414. Figure 8H shows a view of the perforation planes 412 and 415, with the perforation jets 413 and 416 exiting the wellbore 414 and entering the formation 400. The number and orientation of cluster assemblies disclosed herein allow for a variety of combinations of variability in perforation planes, number of perforations in each plane, phasing of the perforation planes, and distance between each perforation plane.

[0062] The disclosed cluster assembly allows perforations to be made in one or more separate radial planes. This provides a method for fracturing unconventional wells by perforating a series of planes that do not necessarily intersect. A stimulation fluid is injected into the perforations along with a proppant and an appropriate fracturing fluid. The fracturing applies hydrostatic pressure to the formation through the perforations, thereby fracturing the formation substantially in one or more radial perforation planes.

[0063] Figures 9A-9C Depicted are multiple views of an exemplary embodiment of a charge cluster 500. A charge body 505 houses a shaped charge 501, and a control circuit 504 is located in a recess 511 located in the charge body 505 and electrically coupled to a detonator 502 via a wire 503. A feed thru pin 506 allows the charge cluster 500 to be electrically coupled to additional charge clusters. Fig. 9C A side cross-sectional view of an exemplary embodiment of a cluster assembly with two charge clusters connected together is depicted. Fig. 9C As shown, contact plate 507 may engage the distal end of feed-through pin 506. Detonation hole 510 allows shaped charge 501 to be explosively connected to detonator 502. Control circuit 504 may be a plurality of charge circuits located in a plurality of grooves within charge body 505. Control circuit 504 may be arranged around the center of charge body 505.

[0064] Fig.10 A side cross-sectional view of an exemplary embodiment of a charge cluster 520 is depicted. A charge body 525 houses a shaped charge 521, and a control circuit 524 is located within a recess 528 of the charge body 525 and is electrically coupled to a detonator 522 via a wire 523. A booster 526 is located adjacent to the detonator 522. A blast hole 529 provides explosive communication between the detonator 522 and the shaped charge 521.

[0065] Fig.11A side cross-sectional view of an exemplary embodiment of a charge cluster 530 is depicted. A charge body 535 houses a shaped charge 531, and a control circuit 534 is located within a recess 540 of the charge body 535 and is electrically coupled to a detonator 532 via a wire 533. A booster 536 is located adjacent to the detonator 532. A blast hole 541 provides explosive communication between the detonator 532 and the shaped charge 531.

[0066] Figures 12A-12B Multiple views of an exemplary embodiment of a charge cluster 600 are depicted. A charge body 605 is comprised of a first half 602 and a second half 603. The charge body includes a shaped charge support 601. A feed-through pin 606 extends from the charge cluster 600 and is connected to the charge body 605 via a hexagonal nut 607. A rivet 608 connects the first half 602 and the second half 603. Fig. 12B In the cross-section of FIG. 6 , the base end of the feed-through pin 606 engages with a spring 609, which is electrically coupled to a conductive strip 610. The conductive strip 610 is connected to a contact ring 611, which surrounds the hollow opening of the detonator holder 604. This allows an electrical signal to pass from the contact ring 611, through the strip 610 and spring 609, and then to the feed-through pin 606. The contact ring 611 can be electrically coupled to a detonator disposed within the detonator holder 604. The first half 602 and the second half 603 can be constructed of an electrically insulating material, such as plastic.

[0067] Fig.13 A side cross-sectional view of an exemplary embodiment of a charge cluster assembly 620 is depicted. A charge body 605 is comprised of a first half 602 and a second half 603. The charge body includes a shaped charge support 601. A feed-through pin 606 extends from the charge cluster 620 and is connected to the charge body 605 via a hexagonal nut 607. A rivet 608 connects the first half 602 and the second half 603. Fig. 12B 6, the base end of the feed-through pin 606 engages with a spring 609, which is electrically coupled to a conductive strip 610. The conductive strip 610 is connected to a contact ring 611, which surrounds the hollow opening of the detonator holder 604. This allows an electrical signal to pass from the contact ring 611, through the strip 610 and the spring 609, and then to the feed-through pin 606. The contact ring 611 can be electrically coupled to a detonator disposed within the detonator holder 604. The first half 602 and the second half 603 can be constructed of an electrically insulating material, such as plastic. The housing 612 includes a first internally threaded end 613 and a second internally threaded end 616. The tandem connector 614 is connected to the housing 612 via the second internally threaded end 616. The tandem connector 614 includes a hollow through hole 615.

[0068] Terms such as booster may include a small metal tube containing secondary high explosives pressed against the end of a detonating cord. Explosive components are designed to provide reliable explosive transfer between perforating guns or other explosive devices and are often used as auxiliary explosives to ensure detonation.

[0069] Detonating cord is a rope containing high explosive material encased in a flexible casing that is used to connect a detonator to a primary high explosive charge, such as a shaped charge. This provides an extremely rapid detonation sequence and can be used to ignite multiple shaped charges simultaneously.

[0070] A detonator or detonating device may include a device containing a primary high explosive material that is used to initiate the explosive sequence, including one or more shaped charges. Two common types may include electric detonators and impact detonators. Detonators may be referred to as initiators. Electric detonators have a fuse material that burns when a high voltage is applied to detonate the primary high explosive. Impact detonators contain an abrasive and primary high explosive in a sealed container that is activated by a striker. The impact of the striker is sufficient to initiate the ballistic sequence, which is then transmitted to the detonating cord.

[0071] Although the present invention has been described according to the detailed embodiments, it should be understood that this is exemplary only and the present invention is not limited thereto. For example, terms such as upper and lower or top and bottom can be replaced with uphole and downhole, respectively. Top and bottom can be left and right, respectively. Uphole and downhole can be shown as left and right, respectively, or as top and bottom, respectively, in the figure. Typically, downhole tools initially enter the wellbore in a vertical direction, but since some wellbores are ultimately horizontal, the direction of the tool may change. In that case, relatively speaking, downhole, lower, or bottom generally refers to the components in the tool string that enter the wellbore before the components referred to as uphole, upper, and top. The first housing and the second housing can be the top housing and the bottom housing, respectively. In the gun bundle described herein, the first gun can be the same uphole gun or downhole gun as the second gun, and the uphole or downhole references can be interchanged because they are only used to describe the positional relationship of the various components. Terms such as wellbore, wellbore, well, hole, oil well, and other alternatives can be used synonymously. Terms such as tool string, tool, perforating gun string, gun string or downhole tool and other alternatives may be used synonymously. In view of this disclosure, alternative embodiments and operating techniques will become apparent to those of ordinary skill in the art. Therefore, modifications to the present invention are contemplated without departing from the spirit of the claimed invention.

Claims

1. A perforating gun, comprising: Outer gun body; The first cluster charge support; a plurality of shaped charges having an open end and an apex end; Detonating device; Wherein, the first cluster charge support comprises: a top end, a bottom end, a housing axis, the housing axis extending from a center of the top end, and an outer surface, the outer surface being substantially parallel to the housing axis; a central hole extending from the top end of the first cluster charge support along the shell axis; A plurality of charge cavities, the plurality of charge cavities being radially arranged around the axis of the charge shell in the charge shell, each of the charge cavities extending from a shaped charge hole in the outer surface to a vertex end close to the central hole; a plurality of blasting holes, the plurality of blasting holes connecting the central hole to the plurality of charge cavity apex ends in the charge shell; a feed-through pin adapted to engage with a contact plate of an additional cluster charge holder to electrically couple the first cluster charge holder with the additional cluster charge holder; a plurality of detonator circuits, the plurality of detonator circuits being respectively embedded in the plurality of grooves of the first cluster charge support and the plurality of grooves of the additional cluster charge support, wherein the detonator circuits are electrically coupled to the detonating device, and the plurality of detonator circuits are respectively arranged around the center of the first cluster charge support and the additional cluster charge support; and wherein the detonation device is in the central hole of the first cluster charge support, and the plurality of shaped charges are in the plurality of charge cavities; and Wherein, the explosion output of the detonation device detonates the shaped charge.

2. The perforating gun of claim 1 , further comprising: The second cluster charge support; a plurality of shaped charges having an open end and an apex end; explosive delivery devices; Wherein, the second cluster charge support comprises: a top end, a bottom end, a housing axis, the housing axis extending from a center of the top end, and an outer surface, the outer surface being substantially parallel to the housing axis; a central hole extending from the top end of the second cluster charge support along the shell axis; A plurality of charge cavities, the plurality of charge cavities being radially arranged in the charge shell around the shell axis, each of the charge cavities extending from a shaped charge hole in the outer surface to a vertex end close to the central hole; a plurality of blasting holes, the plurality of blasting holes connecting the central hole to the plurality of charge cavity apex ends in the charge shell; wherein the explosion transfer device is in the central hole of the second cluster charge support, and the plurality of shaped charges are in the plurality of charge cavities of the first cluster charge support and the second cluster charge support; wherein the explosion output of the detonation device detonates the first cluster charge support and the shaped charge in the explosion transfer device; and Wherein, the explosion output of the explosion transmission device detonates the shaped charge in the second cluster charge support.

3. The perforating gun of claim 1, wherein: The detonator circuit also includes an addressable switch.

4. The perforating gun of claim 1, wherein: The detonation device further comprises a detonator.

5. The perforating gun of claim 1, wherein: The detonation device also includes an impact detonator.

6. The perforating gun of claim 2, wherein: The explosion transfer device also includes a detonator.

7. The perforating gun of claim 2, wherein: The explosion transfer device also includes a detonating cord.

8. A perforating gun assembly comprising: a first cylindrical body, the first cylindrical body being composed of an electrical insulator, the first cylindrical body having a plurality of orthogonal hollow cutouts in a first orthogonal perforation plane, each hollow cutout further comprising a plurality of shaped charges, one shaped charge being disposed in each cutout; a feed-through pin adapted to engage a contact plate of an additional cylinder to electrically couple the first cylinder to the additional cylinder; a plurality of first detonator circuits, wherein the plurality of first detonator circuits are respectively embedded in the plurality of grooves of the first cylinder and the plurality of grooves of the additional cylinder, and the plurality of first detonator circuits are respectively arranged around the center of the first cylinder and the center of the additional cylinder; as well as A first detonator is disposed within the center of the cylinder and is electrically coupled to the first detonator circuit, wherein the shaped charge perforates in the first orthogonal perforation plane when detonated by the first detonator.

9. The perforating gun assembly of claim 8, wherein the first cylinder comprises a first cylindrical portion having a central axis, the first cylindrical portion having an outer surface, a protruding distal end having a first through hole, a conical end having a second through hole, and at least one first semi-shaped charge container.

10. The perforating gun assembly of claim 9, further comprising a second cylindrical portion along the central axis and adjacent to the first cylindrical portion, the second cylindrical portion having a second outer surface, a through hole and a conical end, and at least one second semi-shaped charge container.

11. The perforating gun assembly of claim 10, further comprising a threaded cylindrical interface at the protruding distal end of the first cylindrical portion, wherein: The threaded cylindrical interface has a common axis with the central axis and includes the first through hole therein.

12. The perforating gun assembly of claim 11, further comprising a contact retainer nut connected to the threaded cylindrical interface.

13. The perforating gun assembly of claim 12, further comprising a contact pin having a generally cylindrical body and partially disposed within the first throughbore, the contact pin protruding from the threaded cylindrical interface and restrained by the retaining nut.

14. The perforating gun assembly of claim 13, further comprising a spring positioned within the throughbore and loading the contact pin against the retaining nut.

15. The perforating gun assembly of claim 14, further comprising a contact band extending across the first cylindrical portion and the second cylindrical portion and connected to the spring disposed within the first throughbore and the conical end of the second cylindrical portion.

16. The perforating gun assembly of claim 15, further comprising a popper bracket having a generally cylindrical body and partially disposed within the second throughbore of the second cylindrical portion.

17. The perforating gun assembly of claim 11, wherein: At least one of the shaped charges is a plurality of shaped charges arranged around the central axis of the first cylindrical portion.

18. The perforating gun assembly of claim 8, wherein: At least one shaped charge is adapted to perforate a plane orthogonal to the central axis.

19. An apparatus for containing a shaped charge, comprising: a first cylindrical body, the first cylindrical body being comprised of an electrical insulator, the first cylindrical body having a plurality of orthogonal hollow cutouts in a first orthogonal perforation plane, each hollow cutout being adapted to receive a shaped charge, and the first cylindrical body having a plurality of recesses adapted to receive a plurality of detonator circuits, the plurality of detonator circuits being arranged about a center of the first cylindrical body; a central hole adapted to receive a first detonator disposed at the center of the cylindrical body; as well as a feed-through pin adapted to engage a contact plate of an additional cylinder to electrically couple the first cylinder to the additional cylinder; The additional cylinder has a plurality of grooves adapted to receive a plurality of detonator circuits, and the plurality of detonator circuits are arranged around the center of the additional cylinder.

20. The apparatus of claim 19, wherein: The first cylindrical body further comprises: a first cylindrical half having a through-hole center, a first end, a second end, and at least one semi-conical cutout arranged about the through-hole center of the first cylindrical half, the at least one semi-conical cutout being adapted to retain a shaped charge oriented to fire perpendicularly from an axis of the through-hole center of the first cylindrical half; a second cylindrical half having a through-hole center, a first end, a second end, and at least one semi-conical cutout arranged about the through-hole center of the second cylindrical half, the at least one semi-conical cutout being adapted to retain a shaped charge oriented to fire perpendicularly from an axis of the through-hole center of the second cylindrical half; and Wherein, the first cylindrical half is connected to the second cylindrical half.

21. The apparatus of claim 20, further comprising a threaded cylindrical interface at the protruding distal end of the first cylindrical half, wherein: The threaded cylindrical interface has the same axis as the central axis of the through hole of the first cylindrical half.

22. The apparatus of claim 21, further comprising a contact fixation nut connected to the threaded cylindrical interface.

23. The apparatus of claim 22, further comprising a contact pin having a generally cylindrical body and partially disposed within the through hole of the first cylindrical half, protruding from the threaded cylindrical interface, and constrained by the retaining nut.

24. The apparatus of claim 23, further comprising a spring positioned within the through hole of the first cylindrical half and loading the contact pin against the retaining nut.

25. The apparatus of claim 24, further comprising a contact band extending across the first and second cylindrical halves and connected to the spring within the through hole of the first cylindrical half and within the conical end of the second cylindrical half.

26. The apparatus of claim 25, further comprising an expander bracket having a generally cylindrical body and disposed partially within the throughbore of the second cylindrical half.

27. The apparatus of claim 26, wherein: The at least one semi-conical cutout of the first cylindrical half combines with the at least one semi-conical cutout of the second cylindrical half to form at least one cutout adapted to receive a shaped charge oriented for perforating orthogonally to a central axis of a wellbore.

28. The apparatus of claim 27, wherein: The at least one cutout is a plurality of cutouts arranged to form a perforation plane orthogonal to a central axis of the wellbore.

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