Oriented perforating system

An orientable perforating gun assembly may include a gun housing with a charge carrier and shaped charge positioned within an interior space of the gun housing, in fixed orientation relative to the gun housing. An orientation alignment ring may be connected to a first end of the gun housing. The orientation alignment ring and the gun housing may be rotatable relative to each other when the orientation alignment ring is in an unfixed connection state. The gun housing may be in a fixed orientation relative to the orientation alignment ring in a fixed connection state. A locking ring may be connected to the gun housing first end. A method may include orienting the perforating gun housing relative to the orientation alignment ring and other perforating gun assemblies in a string.

BACKGROUND OF THE DISCLOSURE

Hydrocarbons, such as fossil fuels and natural gas, are extracted from underground wellbores extending deeply below the surface using complex machinery and explosive devices. Once the wellbore is established by placement of cases after drilling, a perforating gun assembly, or train or string of multiple perforating gun assemblies, is lowered into the wellbore and positioned adjacent one or more hydrocarbon reservoirs in underground formations. The perforating gun may have explosive charges which are ignited to create holes in the casing and to blast through the formation so that the hydrocarbons can flow through the casing. Once the perforating gun(s) is properly positioned, a surface signal actuates an ignition of a fuse, which in turn initiates a detonating cord, which detonates the shaped charges to penetrate/perforate the casing and thereby allow formation fluids to flow through the perforations thus formed and into a production string. The surface signal may travel from the surface along electrical wires that run from the surface to one or more initiators, such as ignitors or detonators positioned within the perforating gun assembly.

Assembly of a perforating gun requires assembly of multiple parts, which may include at least the following components: a housing or outer gun barrel within which is positioned an electrical wire for communicating from the surface to initiate ignition, of an initiator and/or a detonator, a detonating cord, one or more charges and, where necessary, one or more boosters. Assembly may include threaded insertion of one component into another by screwing or twisting the components into place, optionally by use of a tandem adapter. Since the electrical wire must extend through much of the perforating gun assembly, the wire may become easily twisted and crimped during assembly. In addition, when a wired detonator is used it must be manually connected to the electrical wire, which may lead to multiple problems. Due to the rotating assembly of parts, the wires can become torn, twisted and/or crimped/nicked, the wires may be inadvertently disconnected, or even mis-connected in error during assembly. This may lead to costly delays in extracting the hydrocarbons. Additionally, there is a significant safety risk associated with physically and manually wiring live explosives.

Accordingly, there may be a need for an initiator that would allow for reliable detonation of perforating guns without requiring physically and manually wiring live explosives.

Additionally, in certain applications, hydraulic fracturing may produce optimal results when perforations are oriented in the direction of maximum principle stress or the preferred fracture plane (PFP). Perforations oriented in the direction of the PFP create stable perforation tunnels and transverse fractures (perpendicular to the wellbore) that begin at the wellbore face and extend far into the formation. However, if fractures are not oriented in the direction of maximum stress, tortuous, non-transverse fractures may result, creating a complex near-wellbore flow path that can affect the connectivity of the fracture network, increase the chance of premature screen-out, and impede hydrocarbon flow. Accordingly, there may be a need for equipment that can allow for orientation verification of the perforating guns to ensure that perforations are formed in the preferred fracture plane. Similarly, there may be a need for perforating guns that can be efficiently connected together and the perforating direction individually oriented relative to other guns in a string.

BRIEF DESCRIPTION

In an aspect, the disclosure relates to an orientable perforating gun assembly, comprising a gun housing, a charge carrier, and an orientation alignment ring. The gun housing may have a first end and a second end opposite the first end, and an interior space between the first end and the second end. The charge carrier may be positioned in the gun housing interior space, in a fixed orientation relative to the gun housing, and the charge carrier may include a first end nearest to the gun housing first end, and a second end opposite the first end and nearest to the gun housing second end. The orientation alignment ring may be connected to the gun housing first end. The orientation alignment ring and the gun housing may be rotatable relative to each other when the orientation alignment ring is in an unfixed connection state, and an orientation of the gun housing may be fixed relative to the orientation alignment ring when the orientation alignment ring is in a fixed connection state.

In another aspect, the disclosure relates to an orientable perforating gun assembly, comprising a gun housing, a charge carrier, an initiator assembly, and an orientation alignment ring. The gun housing may include a first end and a second end opposite the first end, and an interior space between the first end and the second end. The charge carrier may be positioned in the gun housing interior space, in a fixed orientation relative to the gun housing, and the charge carrier may include a first end nearest to the gun housing first end, and a second end opposite the first end and nearest to the gun housing second end. The initiator assembly may be positioned within an initiator holder, in a fixed orientation relative to the charge carrier, at the charge carrier second end. The initiator assembly may include an orientation sensor, and the initiator holder and the initiator assembly may together be configured for the initiator assembly to initiate at least one of a detonating cord and a shaped charge within the gun housing interior space. The orientation alignment ring may be connected to the gun housing first end. The orientation alignment ring and the gun housing may be rotatable relative to each other when the orientation alignment ring is in an unfixed connection state, and an orientation of the gun housing may be fixed relative to the orientation alignment ring when the orientation alignment ring is in a fixed connection state.

In another aspect, the disclosure relates to a method for orienting an individual perforating gun assembly relative to other perforating gun assemblies in a string. The method may comprise providing the perforating gun assembly including a gun housing including a first end and a second end opposite the first end, and an interior space between the first end and the second end, a charge carrier positioned in the gun housing interior space, and retaining a shaped charge, in a fixed orientation relative to the gun housing, and an orientation alignment ring connected to the gun housing first end in an unfixed connection state. The method may further include rotating the gun housing to a desired orientation relative to the orientation alignment ring and fixing the orientation alignment ring to the gun housing first end by engaging a locking structure between the orientation alignment ring and the gun housing first end. The method may also include inserting an initiator assembly including an orientation sensor into an initiator holder on the charge carrier. In addition, the method may include connecting the perforating gun assembly to an adjacent, upstream perforating gun assembly, by connecting the gun housing second end to an orientation alignment ring of the adjacent, upstream perforating gun assembly.

Various features, aspects, and advantages of the exemplary embodiments will become more apparent from the following detailed description, along with the accompanying drawings in which like numerals represent like components throughout the figures and detailed description. The various described features are not necessarily drawn to scale in the drawings but are drawn to emphasize specific features relevant to some embodiments.

The headings used herein are for organizational purposes only and are not meant to limit the scope of the disclosure or the claims. To facilitate understanding, reference numerals have been used, where possible, to designate like elements common to the figures.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments. Each example is provided by way of explanation and is not meant as a limitation and does not constitute a definition of all possible embodiments.

FIGS.1-7show an exemplary embodiment of an initiator head200. The initiator head may include a housing201, a circuit board210, a line-in terminal212, a line-out terminal214, a ground terminal216, a stem250, and a fuse260.

As seen inFIG.1, the housing201may extend in an axial direction302and may define an interior space202. The housing201may be formed of an insulating material, and may be formed by molding, 3D-printing, additive manufacturing, subtractive manufacturing, or any other suitable method. For example, in an exemplary embodiment, the housing201may be formed of a non-conductive plastic material such as polyamide. The housing201may include a first housing piece230and a second housing piece240engaged together. Alternatively, the housing201may be an integral or monolithic piece molded or additively manufactured around the circuit board210.

FIG.1further shows that an exemplary embodiment of the first housing piece230may include a first plate232. A thickness direction of the first plate232may be substantially parallel to the axial direction302. As further seen inFIGS.1-2, an exemplary embodiment of the first plate232may be shaped as an annulus having a substantially circular periphery and a substantially circular through hole236. The through hole236may be structured to expose the line-in terminal212to an exterior204of the housing201. The first plate232may further include a sloped wall220sloping from the first plate in the axial direction302toward the circuit board210. The sloped wall220may help to guide a contact pin to contact with the line-in terminal212. The first housing piece230may further include a first outer peripheral wall234extending from the first plate232in the axial direction302.FIG.1andFIG.4show an exemplary embodiment in which the first outer peripheral wall234extends from an outer periphery of the first plate232.

FIG.1further shows that an exemplary embodiment of the second housing piece240may include a second plate242. A thickness direction of the second plate242may be substantially parallel to the axial direction302. As further seen inFIG.3, an exemplary embodiment of the second plate242may be substantially circular in shape. The second plate242may further include through holes246structured to expose the line-out terminal214and the ground terminal216to an exterior204of the housing201. The second housing piece240may further include a second outer peripheral wall244extending from the second plate242in the axial direction302.FIG.1andFIG.3show an exemplary embodiment in which the second outer peripheral wall244extends from an outer periphery of the second plate242.

As further seen inFIG.1, the first outer peripheral wall234and the second outer peripheral wall244may overlap in the axial direction, such that the interior space202is formed between the first plate232and the second plate242in the axial direction. In other words, the interior space202may be bounded by the first housing piece230and the second housing piece240. In an exemplary embodiment, a first housing piece radius of the first housing piece230may be smaller than a second housing piece radius of the second housing piece240. Thus, the first housing piece230may be received within the second housing piece240with the first outer peripheral wall234being provided between the first plate232and the second plate242in the axial direction302. Alternatively, the first housing piece radius may be larger than the second housing piece radius, and the second housing piece240may be received within the first housing piece230, with the second peripheral wall234being provided between the first plate232and the second plate242in the axial direction302.

The first housing piece230and the second housing piece240may be dimensioned such that the first housing piece230and the second housing piece240fit snugly together so as not to separate under normal operating conditions. Alternatively, the first housing piece230and the second housing piece240may be provided with a coupling mechanism such as hook or protrusion and a complementary recess, so that the first housing piece230and the second housing piece240may snap together. Alternatively, the first outer peripheral wall234and the second outer peripheral wall244may be complementarily threaded so that the first housing piece230and the second housing piece240may screw together. Alternatively, the first housing piece230and the second housing piece240may be bonded together with adhesive.

FIG.1further shows an exemplary embodiment of a circuit board210. A thickness direction211of the circuit board210may be substantially parallel with the axial direction302. As explained in further detail herein, orienting the thickness direction211substantially parallel with the axial direction302allows room for larger firing capacitors and/or surface mounted components270to be mounted on the circuit board210.

In an exemplary embodiment, the line-in terminal212, the line-out terminal214, the ground terminal216, and the fuse260may be in electrical communication with the circuit board210. The line-in terminal212may be provided on a first side of the circuit board210in the axial direction, and thereby the line-in terminal212may be provided on a first side of the housing201in the axial direction (i.e., to the left inFIG.1). The line-out terminal214and the ground terminal216may be provided on a second side of the circuit board210in the axial direction opposite to the first side (i.e., to the right inFIG.1). The line-out terminal214may be configured to output a signal received by the line-in terminal212, either directly or in response to processing by the circuit board210, as described in detail herein, by being in electrical communication with either the line-in terminal212or the circuit board210.

FIG.3shows an exemplary embodiment in which a plurality of line-out terminals214and a plurality of ground terminals216are provided. The plurality of line-out terminals214and the plurality of ground terminals216provide a layer of redundancy to help ensure sufficient connection of the initiator head200to external electrical components, as explained in detail herein. Each line-out terminal214of the plurality of line-out terminals214may be directly connected to each other within the housing201or on the circuit board210. In other words, if one line-out terminal214is in electrical communication with the circuit board210, then each line-out terminal214of the plurality of line-out terminals214may be in electrical communication with the circuit board210. Similarly, if one line-out terminal214becomes in electrical communication with the line-in terminal212, then each line-out terminal214of the plurality of line-out terminals may be in electrical communication with the line-in terminal212. Similarly, if one ground terminal216is in electrical communication with the circuit board210, then each ground terminal216of the plurality of ground terminals216may be in electrical communication with the circuit board210.

As further seen inFIG.1andFIG.7, the circuit board210may be a printed circuit board and/or may include one or more surface mounted components270. The arrangement of the circuit board210and the shape of the initiator head200may provide sufficient space in the interior space202to accommodate a variety of surface mounted components270. In an exemplary embodiment, the surface mounted component270of the circuit board210may be an integrated circuit (IC) with a dedicated function, a programmable IC, or a microprocessor IC. The circuit board210may be configured to activate the fuse260in response to a control signal received at the line-in terminal212. For example, a user may send a firing signal via a firing panel. The firing signal may be received at the line-in terminal212, and the circuit board210, through ICs provided on the circuit board210, may process the firing signal and activate the fuse260. Additionally, the circuit board210may include a switch circuit configured to establish electrical communication between the line-out terminal214and the line-in terminal212in response to a predetermined switch signal. The line-out terminal214may be in electrical communication with subsequent initiator heads200provided downstream in a string of connected perforating guns, thereby allowing a user to send switch signals to toggle which initiator head is active to receive a firing command.

In an exemplary embodiment, one of the surface mounted components270may be one selected from a group consisting of a temperature sensor, an orientation sensor, a safety circuit, and a capacitor. Readings from one of these components may be used by a microprocessor on circuit board210to determine when it is appropriate to activate the fuse260. The temperature sensor may be configured to measure temperature of the wellbore environment and provide a signal corresponding to the temperature to the circuit board210. The orientation sensor may include, but is not limited to, an accelerometer, a gyroscope, and/or a magnetometer. The orientation sensor may be configured to determine an orientation of the initiator head200within the wellbore, which, if the orientation of the initiator head is fixed relative to a charge holder, can be used to determine an orientation of the charge(s) in the perforating gun. In an exemplary embodiment, the orientation sensor may determine an orientation of the initiator head200relative to gravity. Alternatively, the orientation sensor may determine an orientation of the initiator head relative an ambient magnetic field. The safety circuit may provide additional safety precautions to prevent unintentional activation of the initiator100. The capacitor may be used to store a voltage to activate the fuse260. The size of the interior space202may allow for a larger capacity capacitor to be used. This allows a larger discharge voltage for activating the fuse260, which may help to ensure more reliable activation of the fuse260.

FIG.1andFIGS.4-7further show an exemplary embodiment of the stem250. The stem250may extend in the axial direction302from the housing201. In an exemplary embodiment, the stem250may be formed of the same material as the second housing piece240and may be integrally and/or monolithically formed with the second plate242. Alternatively, the stem may be formed as a separate piece and mechanically connected to the second housing piece via clips or mated structures such as protrusions and recesses, or adhesively connected using an adhesive.

As seen inFIG.1, the stem250may include a stem outer peripheral wall252. The stem outer peripheral wall252may define a stem cavity254provided radially inward from the stem outer peripheral wall252. A first discharge channel256and a second discharge channel258may connect the stem cavity254and the interior space202of the housing201. The first discharge channel256may accommodate therein a first discharge terminal218in electrical communication with the circuit board210. In other words, the first discharge terminal218may extend from the circuit board210into the first discharge channel256. Similarly, the second discharge channel256may accommodate therein a second discharge terminal219in electrical communication with the circuit board210. In other words, the second discharge terminal219may extend from the circuit board210into the second discharge channel258.

FIG.1further shows that, in an exemplary embodiment, the fuse260may be provided within the stem cavity254. A first end of a first fuse terminal262may be in electrical communication with the first discharge terminal218within the first discharge channel256, and a second end of the first fuse terminal may be proximate to the fuse260. A first end of a second fuse terminal264may be in electrical communication with the second discharge terminal219within the second discharge channel258, and a second end of the second fuse terminal264may be proximate to the fuse260and the second end of the first fuse terminal262. The circuit board210may be configured to activate the fuse260in response to a control signal by discharging a stored voltage across the first fuse terminal262and the second fuse terminal264. The store voltage may be stored in a capacitor in electrical communication with the circuit board210. In an exemplary embodiment, the capacitor may be one of the surface mounted components270provided on the circuit board210. The proximity of the second end of the first fuse terminal262and the second end of the second fuse terminal264may allow for the generation of a spark when the stored voltage is discharged, thereby activating the fuse260. In an exemplary embodiment, activating the fuse260may include igniting or detonating the fuse260.

As seen inFIG.6, an exemplary embodiment of the stem250may include a window253cut through the stem outer peripheral wall252. The window253may allow access for a user to connect the first discharge terminal218to the first fuse terminal262and the second discharge terminal219to the second fuse terminal264, such as by soldering, during assembly of the initiator head200.

FIGS.14-19show exemplary embodiments in which the circuit board210is in electrical communication with the fuse260via direct physical contact, so as to streamline the manufacturing process by eliminating soldering between the circuit board210and the fuse260. For example,FIG.14shows an exemplary embodiment in which the circuit board210is in electrical communication with the fuse260via a fuse connector assembly600. The fuse connector assembly600may include a first discharge connector602configured to receive and make direct electrical contact with the first fuse terminal262and a second discharge connector604configured to receive and make direct electrical contact with the second fuse terminal264(not shown inFIG.14).

The fuse connector assembly600may include a mounting block606, the first discharge connector602extending through the mounting block606, and the second discharge connector604extending through the mounting block606. The mounting block606may be formed of an insulating material and may facilitate connection and/or fastening of the fuse connector assembly600to the circuit board210. Further, the mounting block606may provide mechanical strength and support for the fuse connector assembly600. When the fuse connector assembly600is connected to the circuit board210, the first discharge connector602and the second discharge connector604may extend from the circuit board210into the stem250.

FIG.15further shows an exemplary embodiment of the first discharge connector602. For simplicity, only the first discharge connector602is described in detail herein; it will be understood fromFIG.15that the second discharge connector604may be substantially similar to the first discharge connector602in terms of structure. The first discharge connector602may be formed of an electrically conductive material. The first discharge connector602may include a first body portion610, and a first board connector terminal612may be provided at a first end of the first body portion610. The first board connector terminal612may connect to the circuit board210.

The first discharge connector602may further include a first base portion620and a second base portion630extending from the first body portion610at a second end of the first body portion610. The first discharge connector602may further include a first arm portion622extending from the first base portion620and a second arm portion632extending from the second base portion630. The first arm portion622may be bent or inclined in a direction toward the second arm portion632. Similarly, the second arm portion632may be bent or inclined in a direction toward the first arm portion622. The first discharge connector602may further include a first tip portion624at an end of the first arm portion622and a second tip portion634at an end of the second arm portion632. The first tip portion624may be bent or inclined in a direction away from the second tip portion634. Similarly, the second tip portion634may be bent or inclined in a direction away from the first tip portion624.

A first contact portion626may be formed between the first arm portion622and the first tip portion624, and a second contact portion636may be formed between the second arm portion632and the second tip portion634. The first contact portion626may be resiliently biased toward the second contact portion636based on the connection between the first base portion620and the first arm portion622. Similarly, the second contact portion636may be resiliently biased toward the first contact portion626based on the connection between the second base portion630and the second arm portion632. The first contact portion626may be in contact with the second contact portion636. Alternatively, there may be a gap between the first contact portion626and the second contact portion636. In an exemplary embodiment, a size of the gap may be less than a thickness of the first fuse terminal262.

The first discharge connector602may be configured to receive, and make electrical contact with, the first fuse terminal262. Similarly, the second discharge connector604may be configured to receive, and make electrical contact with, the second fuse terminal264. For example, during assembly of the initiator head200, the circuit board210and the fuse260may be pushed together in the axial direction302, thereby bringing the first fuse terminal262into contact with the first tip portion624and the second tip portion634. Further relative motion between the fuse260and the circuit board210may cause the first fuse terminal262to deflect the first tip portion624and the second tip portion634away from each other. The first fuse terminal262may then be in contact with the first contact portion626and the second contact portion636, i.e., sandwiched between the first contact portion626and the second contact portion636. The resilient bias of the first contact portion626and the second contact portion636may help to maintain contact, and thus electrical communication, between the first contact portion626, the second contact portion636, and the first fuse terminal262. It will be understood that contact between the second discharge connector604and the second fuse terminal264may be achieved in a similar way. The window253may allow for visual confirmation of the connection between the first discharge connector602and the first fuse terminal262and between the second discharge connector604and the second fuse terminal264.

FIG.16shows an exemplary embodiment in which the circuit board210is in electrical communication with the fuse260via a fuse connector assembly700. The fuse connector assembly700may include a first discharge connector702configured to receive and make direct electrical contact with the first fuse terminal262and a second discharge connector704configured to receive and make direct electrical contact with the second fuse terminal264(not shown inFIG.16).

The fuse connector assembly700may include a mounting block706, the first discharge connector702extending through the mounting block706, and the second discharge connector704extending through the mounting block706. The mounting block706may be formed of an insulating material and may facilitate connection and/or fastening of the fuse connector assembly700to the circuit board210. Further, the mounting block706may provide mechanical strength and support for the fuse connector assembly700. When the fuse connector assembly700is connected to the circuit board210, the first discharge connector702and the second discharge connector704may extend from the circuit board210into the stem250.

FIG.17further shows an exemplary embodiment of the first discharge connector702. For simplicity, only the first discharge connector702is described in detail herein; it will be understood fromFIG.17that the second discharge connector704may be substantially similar to the first discharge connector702in terms of structure. The first discharge connector702may be formed of an electrically conductive material. The first discharge connector702may include a first body portion710, and a first board connector terminal712may be provided at a first end of the first body portion710. The first board connector terminal712may connect to the circuit board210.

The first discharge connector702may further include a first base portion720and a second base portion730extending from the first body portion710at a second end of the first body portion710. The first discharge connector702may further include a first arm portion722extending from the first base portion720and a second arm portion732extending from the second base portion730. The first arm portion722may be bent or inclined in a direction away from the second arm portion732. Similarly, the second arm portion732may be bent or inclined in a direction away from the first arm portion722. The first discharge connector702may further include a first tip portion724at an end of the first arm portion722and a second tip portion734at an end of the second arm portion732. The first tip portion724may be bent or inclined in a direction toward the second tip portion734and back toward the first body portion710. Similarly, the second tip portion734may be bent or inclined in a direction toward the first tip portion724and back toward the first body portion710.

A first contact portion726may be formed at an end of the first tip portion724, and a second contact portion736may be formed at an end of the second tip portion734. The first contact portion726may be resiliently biased toward the second contact portion736based on the connection between the first base portion720and the first arm portion722. Similarly, the second contact portion736may be resiliently biased toward the first contact portion726based on the connection between the second base portion730and the second arm portion732. The first contact portion726may be in contact with the second contact portion736. Alternatively, there may be a gap between the first contact portion726and the second contact portion736. In an exemplary embodiment, a size of the gap may be less than a thickness of the first fuse terminal262.

The first discharge connector702may be configured to receive, and make electrical contact with, the first fuse terminal262. Similarly, the second discharge connector704may be configured to receive, and make electrical contact with, the second fuse terminal264. For example, during assembly of the initiator head200, the circuit board210and the fuse260may be pushed together in the axial direction302, thereby bringing the first fuse terminal262into contact with the first tip portion724and the second tip portion734. Further relative motion between the fuse260and the circuit board210may cause the first fuse terminal262to deflect the first tip portion724and the second tip portion734away from each other. The first fuse terminal262may then be in contact with the first contact portion726and the second contact portion736, i.e., sandwiched between the first contact portion726and the second contact portion736. The resilient bias of the first contact portion726and the second contact portion736may help to maintain contact, and thus electrical communication, between the first contact portion726, the second contact portion736, and the first fuse terminal262. It will be understood that contact between the second discharge connector704and the second fuse terminal264may be achieved in a similar way. The window253may allow for visual confirmation of the connection between the first discharge connector702and the first fuse terminal262and between the second discharge connector704and the second fuse terminal264.

FIGS.18-19show an exemplary embodiment in which the circuit board210is in electrical communication with the fuse260via a fuse connector assembly800. The fuse connector assembly800is similar in many aspects to the fuse connector assembly700; similar structures will be indicated with the same reference numerals, and detailed descriptions of these similar structures will be omitted. In the fuse connector assembly800, the first arm portion822may include a first arm part822aextending from the first base portion720and a second arm part822bextending from the first arm part822a. The second arm portion832may include a third arm part832aextending from the first base portion730and a fourth arm part832bextending from the first arm part832a. Each of the first art part822aand the third arm part832amay be bent or inclined in a direction away from each other. Each of the second arm part822band the fourth arm part832bmay be bent or inclined in a direction toward each other.

FIGS.2-7shows an exemplary embodiment of an initiator100. The initiator100may include an initiator head200and an initiator shell300. The initiator head200may be similar in structure and function as described in detail above. The initiator shell300may be coaxial with the initiator head200. In an exemplary embodiment, a head dimension X1of the head200in a first direction perpendicular to the axial direction302may be larger than a shell dimension X2in the first direction. According to an aspect, the initiator may be configured as an ignitor or a detonator, depending on the needs of the application.

In an exemplary embodiment, the initiator shell300may include a shell wall310and a shell crimp312crimped around the stem250. The shell wall310may extend in the axial direction302and may be formed of a deep-drawn metal. Non-limiting examples of the metal used for the shell wall310may include aluminum, copper, steel, tin, or brass. Plastics may also be used a material for the shell wall310. The shell wall310may define a shell interior320. A primary explosive322may be provided within the shell interior320. In an exemplary embodiment, the circuit board210may be configured to activate the primary explosive322, and in some embodiments the primary explosive322and the secondary explosive324, in response to a control signal received at the line-in terminal212. For example, the primary explosive322may be arranged such that the fuse260is within an operable distance of the primary explosive322. Being within an operable distance means that the fuse260is provided close enough to the primary explosive322that the primary explosive322is ignited and/or detonated when the fuse260is activated. In other words, by activating the fuse260in response to a control signal, the circuit board210may activate the primary explosive322.

The secondary explosive324may abut the primary explosive322and seal the primary explosive322within a non-mass explosive (NME) body330. The primary explosive322and the secondary explosive324may have a total thickness of about 3 mm to about 30 mm in an exemplary embodiment. Alternatively, the total thickness may be about 3 mm to about 10 mm. The secondary explosive324may be configured as a layer of an explosive material. According to an exemplary embodiment, the primary explosive322may include at least one of lead azide, silver azide, lead styphnate, tetracene, nitrocellulose, BAX, and a lead azide free primary explosive as described in USPGP 2019/0256438, herein incorporated by reference.

Each of the primary explosive322and the secondary explosive324may have a safe temperature rating of above 150° C. (with the exception of PETN, which has a rating of approximately 120° C.). The secondary explosive324may include a material that is less sensitive to initiation, as compared to the primary explosive322. The secondary explosive324may include at least one of PETN, RDX, HMX, HNS and PYX. In an embodiment, the secondary explosive324may be less sensitive to initiation than PETN.

The primary explosive322and the secondary explosive324may be provided within the NME body330. The NME body330may help to avoid an unintentional initiation of the primary explosive322or the main load explosive332by an external mechanical force. The NME body330may be composed of an electrically conductive, electrically dissipative or electrostatic discharge (ESD) safe synthetic material. According to an exemplary embodiment, the non-mass-explosive body330may be formed of a metal, such as cast-iron, zinc, machinable steel or aluminum. Alternatively, the NME body330may be formed from a plastic material. While the NME body330may be made using various processes, the selected process utilized for making the NME body330is based, at least in part, by the type of material from which it is made. For instance, when the NME body330is made from a plastic material, the selected process may include an injection molding process. When the NME body330is made from a metallic material, the NME body330may be formed using any conventional CNC machining or metal casting processes.

The initiator shell300may further include a main load explosive332provided adjacent the primary explosive322, and in embodiment including a secondary explosive324, adjacent the secondary explosive324. The main load explosive332includes compressed secondary explosive materials. According to an aspect, the main load explosive332may include one or more of cyclotrimethylenetrinitramine (RDX), octogen/cyclotetramethylenetetranitramine (HMX), hexanitrostilbene (HNS), pentaerythritol tetranitrate (PETN), 2,6-Bis(picrylamino)-3,5-dinitropyridine (PYX), and 1,3,5-triaminio-2,4,6-trinitobenzene (TATB). The type of explosive material used may be based at least in part on the operational conditions in the wellbore and the temperature downhole to which the explosive may be exposed.

In an exemplary embodiment shown inFIGS.11-13, an exterior shape of the housing201may be rotationally asymmetric with respect to the axial direction302. In other words, when looking along the axial direction302, a periphery of the housing201may be shaped such that an orientation of the housing201is unique for each angle around the axial direction. For example,FIG.11shows that a key protrusion290or a key protrusion292may be formed on a periphery of the housing201, andFIG.13shows that a key recess294may be formed on a periphery of the housing201. As is clear fromFIG.11andFIG.13, there are no possible rotations of the housing201where the housing201has a matching profile. In other words, an exterior profile of housing201is unique for each possible rotation angle. It will be understood that the size, shape, and/or number of key protrusions and/or key recesses is not limited to what is shown inFIG.11andFIG.13, as long as they create a rotational asymmetry in the shape of housing201. Additionally, key protrusions and key recesses may be combined together on a single housing201.

FIGS.8-13illustrate an exemplary embodiments of an initiator system500. The initiator system500may include an initiator holder400(seeFIGS.10-13) and an initiator100received within the initiator holder400.

As seen inFIGS.8-10, an exemplary embodiment of the initiator holder400may include a holder ground terminal410. The holder ground terminal410may include a holder ground contact412. In an exemplary embodiment shown inFIGS.8-9, the holder ground contact412may be punched from the material of the holder ground terminal410and then bent to a side of the holder ground terminal410. This may help to impart a spring-loaded action to the holder ground contact412and bias the holder ground contact412in a direction toward the initiator head200, thereby helping to ensure a more secure electrical contact between the ground terminal216and the holder ground contact412. In other words, when the initiator100is positioned within the initiator holder400, the holder ground contact412may be in electrical communication with the ground terminal216(seeFIG.9) via contact.

FIGS.8-10, andFIG.12show that, in an exemplary embodiment of the holder ground terminal410, the holder ground contact412may be one of a plurality of holder ground contacts412. As seen inFIG.9, if the initiator head200includes a plurality of ground terminals216, then the plurality of holder ground contacts412provided a layer of redundancy for establishing a connection to ground. For example, even of one pair the ground terminals216and the holder ground contacts412fails to establish a secure electrical connection, a second pair of the ground terminals216and the holder ground contacts412may form a secure electrical connection.

As further seen inFIGS.10-13, the initiator holder400may further include a holder ground bar414extending from the holder ground terminal410. The holder ground bar414may contact a ground when the initiator holder400is received within a perforating gun. In other words, the holder ground terminal410may be in electrical communication with ground, for example through the holder ground bar414.

As further seen in the exemplary embodiment ofFIG.10, the initiator holder400may include a through-wire terminal420. The through-wire terminal420may include a through-wire contact422. In an exemplary embodiment shown inFIGS.8-9, the through wire contact422may be punched from the material of the through-wire terminal420and then bent to a side of the through-wire terminal420. This may help to impart a spring-loaded action to the through-wire contact422and bias the through-wire contact422in a direction toward the initiator head200, thereby helping to ensure a more secure electrical contact between the through-wire terminal214and the through-wire contact414. In other words, when the initiator100is positioned within the initiator holder400, the through-wire contact422may be in electrical communication with the through-wire terminal214via contact.

FIGS.8-9,FIG.10, andFIG.12show that, in an exemplary embodiment of the through-wire terminal420, the through-wire contact422may be one of a plurality of through-wire contacts422. As seen inFIG.9, if the initiator head200includes a plurality of through-wire terminals214, then the plurality of through-wire contacts422provided a layer of redundancy for establishing an electrical connection. For example, even of one pair the through-wire terminals214and the through-wire contacts422fails to establish a secure electrical connection, a second pair of the through-wire terminals214and the through-wire contacts412may form a secure electrical connection.

FIGS.10-13show exemplary embodiments of an initiator system500comprising a key system configured to ensure a correct alignment between the initiator100and the initiator holder400. For example, when an initiator100is received into holder hole402, the initiator100may rotate around the axial direction302. This could create a misalignment between the through-line terminal(s)214and the ground terminal(s)216of the initiator head200and the through-line contact(s)422and holder ground contact(s)412of the holder400. Accordingly, a key system may be configured to rotationally fix the initiator head200relative to the holder400, thereby helping to ensure a correct alignment between the initiator100and the initiator400. In this context, a correct alignment may be an alignment in which the through-line terminal(s)214and the ground terminal(s)216of the initiator head200are correspondingly aligned with the through-line contact(s)422and holder ground contact(s)412of the holder400.

FIGS.10-11show an exemplary embodiment in which recesses440,442may be formed in an outer peripheral wall430of the holder400. For example, a first holder recess440may be formed partially through the outer peripheral wall430. Alternatively or additionally, a second holder recess442may be formed through the entire thickness of the outer peripheral wall430. As seen inFIG.11, an exemplary embodiment of the housing201of the initiator head200may include a first key protrusion290formed on an outer periphery of housing201. The first key protrusion290may be shaped and sized to fit within the first holder recess440. Alternatively or additionally, a second key protrusion292may be formed on an outer periphery of the housing201. The second key protrusion292may be shaped and sized to fit within the second holder recess442.

FIGS.12-13show an exemplary embodiment in which protrusions may be formed in the outer peripheral wall430of the holder400. For example, a holder protrusion444may extend radially inwardly from the outer peripheral wall430. As seen inFIG.13, an exemplary embodiment of the housing201of the initiator head200may include a housing recess294corresponding to the holder protrusion444.

It will be understood from the exemplary embodiments shown inFIGS.10-13that the number, size, and shape of recesses and protrusions may be varied to achieve the same effect, as long as the recesses and their corresponding protrusions are rotationally asymmetric around the longitudinal axis. For example, a single recess and a single protrusion may be sufficient to achieve rotational asymmetry. Alternatively, a plurality of recesses of corresponding protrusions may be used. Further, it will be understood that recesses and protrusions may be mixed on a single piece. For example, an exemplary embodiment of the housing201may include both a protrusion and a recess, corresponding to a complementary recess and protrusion on the initiator holder400.

With reference now toFIGS.20-25, an exemplary embodiment of an orientable perforating gun assembly900incorporating an initiator assembly950according to the disclosure is shown. The initiator assembly950shown and described with respect toFIGS.20-25refers collectively to initiator components including, for example, the initiator head200, the stem250, and the shell300, and associated components including the circuit board210, the line-in terminal212, the line-out terminal214, and the ground terminal216, according to the exemplary embodiments of an initiator described above and throughout the disclosure.

The orientable perforating gun assembly900shown and described with respect toFIGS.20-25includes, in part and without limitation, a perforating gun assembly as shown and described in U.S. Publication No. 2020/0024935 published Jan. 23, 2020, which is commonly owned by DynaEnergetics Europe GmbH and incorporated by reference herein in its entirety. The features, configurations, and aspects of the orientable perforating gun assembly900shown and described with respect toFIGS.20-25may be similarly incorporated in any perforating gun assembly consistent with the disclosure.

As shown inFIG.20, the exemplary orientable perforating gun assembly900includes, among other things, a gun housing910having a first end912connected to an orientation alignment ring930, and a second end914opposite the first end. A locking ring940is positioned within a bore932of the orientation alignment ring930, as discussed further below. The locking ring940includes tool connectors942for connecting to a tool (e.g., purpose-made pliers, not shown) that is used to lock the locking ring940within the orientation alignment ring bore932. Locking structure holes934on the orientation alignment ring930receive locking structures, such as set screws or pins936(or the like), for locking the orientation alignment ring930to the gun housing first end912, in a fixed position, as discussed further below. A second pin connector end968of an electrical transfer assembly964, discussed further below, protrudes through an aperture944of the locking ring940.

With reference now toFIGS.21-24, various cross-sections taken at different depths through the exemplary perforating gun assembly900are shown, to more clearly illustrate the various components. For reference, like numerals refer to like components, even where a component may be shown only in part in a particular cross-section, due to the depth of the cross-section.

As shown in the exemplary embodiment(s), the gun housing910includes an interior space916between the first end912and the second end914, and a charge carrier920including a shaped charge927is positioned in the gun housing interior space916. The charge carrier920retains the shaped charge927in a shaped charge receptacle980. The charge carrier920and the shaped charge927are positioned in a fixed orientation relative to the gun housing910and, in the exemplary embodiment, aligned with a scallop915, i.e., an area of reduced thickness of the gun housing910through which the shaped charge927fires, for reducing damaging burrs as a result of the explosive penetration. The charge carrier920includes a first end921nearest to the gun housing first end912, and a second end922opposite the first end921and nearest to the gun housing second end914.

The orientation alignment ring930is connected to the gun housing first end912and surrounds both the gun housing first end912and the locking ring940which is connected to the gun housing first end912, within the bore932of the orientation alignment ring930. The locking ring940is connected to the gun housing first end912via a threaded connection between an external threaded portion913of the gun housing first end912and a threaded portion945of the locking ring940. Alternatively, the locking ring940may be integrally and/or monolithically formed as a unitary structure with the gun housing first end912. Accordingly, at least a portion of each of the locking ring940and the gun housing first end912is positioned within the bore932of the orientation alignment ring930.

Before the set screws936are inserted through the locking structure holes934to secure the orientation alignment ring930to the gun housing first end912, the orientation alignment ring930is in an unfixed connection state such that the orientation alignment ring930can be rotated an unlimited number of times about a longitudinal axis911, and thereby the gun housing910, of the perforating gun assembly900. In other words, the orientation alignment ring930and the gun housing910are rotatable relative to each other when the orientation alignment ring930is in the unfixed connection state. Thus, the gun housing910, the charge carrier920and the shaped charge927are rotatable to a desired orientation relative to the orientation alignment ring930and other perforating gun assemblies in a string of perforating gun assemblies. The orientation of the gun housing910, and thereby the charge carrier920and the shaped charge927, is fixed when, e.g., the set screws936are inserted into the locking structure holes934and lock the orientation alignment ring930to the gun housing first end912, in a fixed connection state. In the fixed connection state, the orientation alignment ring930and the gun housing910are not rotatable relative to each other. The orientation alignment ring930is in a sealing contact with the gun housing first end912via, e.g., o-rings969on an outside of the gun housing first end912, in sealing contact with, and between, the gun housing first end912and the orientation alignment ring930within the orientation alignment ring bore932.

The charge carrier920includes an initiator holder400, as discussed above and throughout the disclosure, positioned at the charge carrier second end922and dimensioned for receiving an initiator assembly950in a fixed orientation relative to the charge carrier920. With respect to the charge carrier920in the exemplary embodiment(s) of a perforating gun assembly shown inFIGS.21-25, the initiator holder400may include, e.g., an outer peripheral wall430according to the exemplary embodiments described above, along with a passage929within at least a portion of a body925of the charge carrier920. The charge carrier passage929is aligned with and open to a holder hole402of the initiator holder400, according to the exemplary embodiments, along the longitudinal axis911of the perforating gun assembly900. Accordingly, the charge carrier passage929may receive, e.g., the stem250and the shell300of the initiator assembly950, and the initiator holder outer peripheral wall430may receive the initiator head200. In addition, the charge carrier body925may include a detonating cord passage971for receiving a detonating cord970in a ballistic coupling proximity to the initiator shell300, such that initiation of the explosive components of the initiator will initiate the detonating cord970for then initiating the shaped charge927. In other embodiments, the charge carrier body925, including the charge carrier passage929and shaped charge receptacle980may be configured such that the initiator assembly950directly initiates the shaped charge927.

The initiator head200, as previously discussed, includes a line-in terminal212, a line-out terminal214and a ground terminal216(not shown inFIGS.21-25) according to the exemplary embodiments. With reference specifically toFIG.24, the exemplary perforating gun assembly includes a through-wire terminal420(according to the exemplary embodiments described above, throughout the disclosure) extending from a position within the initiator holder400to an outside of the initiator holder400. The through-wire terminal420, as previously discussed, is positioned on or within the initiator holder400to make contact with the line-out terminal214of the initiator head200. A through-wire962of the perforating gun assembly is in electrical communication with the through-wire terminal420, and thereby the line-out terminal214of the initiator head200.

The exemplary perforating gun assembly900further includes a pressure bulkhead960including an electrical transfer assembly964, and the electrical transfer assembly964is in electrical communication with the through-wire962which, in the exemplary embodiments, extends from the through-wire terminal420to the electrical transfer assembly964. The pressure bulkhead960is positioned within and seals a bulkhead channel966that extends through the gun housing first end912, from the gun housing interior space916to an outside of the gun housing910, and is open to each of the gun housing interior space916and the outside of the gun housing910. The bulkhead960may seal the bulkhead channel966via, e.g., o-rings969on an outside of the bulkhead960, that seal against the bulkhead channel966.

The electrical transfer assembly964, in the exemplary embodiments, includes a first pin connector end967and a second pin connector end968opposite the first pin connector end, wherein the first pin connector end967and the second pin connector end968are in electrical communication via conductive components that may include, e.g., conductive inserts963and conductive spring contacts965within the bulkhead960. Conductive components may be sealed within the bulkhead960via, e.g., o-rings969. The conductive spring contacts965may provide a bias to enhance electrical contact made by the first pin connector end967and the second pin connector end968, as discussed herein. The bulkhead960and electrical transfer assembly964may further be according to, without limitation, a bulkhead and electrical transfer assembly as shown and described in U.S. Pat. No. 10,844,697 issued Nov. 24, 2020, or U.S. Publication No. 2020/0217635 published Jul. 9, 2020, which are each commonly owned by DynaEnergetics Europe GmbH and incorporated herein by reference in their entirety.

With continuing reference toFIGS.21-24, the first pin connector end967is in electrical contact with the through-wire962or an electrical feedthrough contact924in electrical communication with the through-wire962, within a feedthrough connection portion923of the charge carrier first end921, and the second pin connector end968extends to the outside of the gun housing910.

In the exemplary embodiment(s), the gun housing first end912is a male end and the gun housing second end914is a female end. The orientation alignment ring930further includes an external threaded portion933and the external threaded portion933of the orientation alignment ring930is configured for connecting to a complementary internal threaded portion, i.e., internal threaded portion919of the gun housing second (female) end914, of a second (female) end of an adjacent, downstream perforating gun assembly in a perforating gun string. For purposes of this disclosure, “downstream” means further down into the wellbore while “upstream” means further towards the wellbore surface. However, depending on the direction in which a firing signal may be relayed through the perforating gun assemblies in the perforating gun assembly string, a relative direction, i.e., upstream or downstream, of the perforating gun assemblies and connections may be reversed without departing from the spirit and scope of the disclosure. The gun housing second (female) end914is similarly configured for connecting to an adjacent, upstream orientation alignment ring connected to a male end of an adjacent, upstream perforating gun assembly in the perforating gun string.

As previously discussed, the initiator assembly950includes, at the initiator head200, a line-in portion212. The gun housing first (male) end912and the electrical transfer assembly964, including, e.g., the second pin connector end968, are collectively dimensioned for the second pin connector end968to electrically contact a downstream line-in portion of the adjacent, downstream perforating gun assembly, when the orientation alignment ring930is connected to the female end of the downstream perforating gun assembly.

With continuing reference toFIGS.21-25, the charge carrier920in the exemplary perforating gun assembly900includes an orienting structure926extending away from the body925of the charge carrier920, in a direction towards an internal surface918of the gun housing. An engagement portion928of the orienting structure926is in contact with the gun housing internal surface918and fixes an orientation of the charge carrier920(and, thereby, the shaped charge927) relative to the gun housing910by, for example and without limitation, friction, contact force, and the like. The charge carrier920including the charge carrier body925, shaped charge receptacle980, initiator holder400, and orienting structure926, in the exemplary embodiment(s), may be integrally formed by, e.g., injection molding. However, any connections, configurations, and assembly of such components, consistent with this disclosure, may similarly be used. Further, relative designations of component “ends” or components or portions such as the initiator holder400, charge carrier body925, and the like, are for ease in describing the components and configurations and are not limited to any particular boundaries or delineations between components.

In an exemplary embodiment, the orienting structure926may divide the interior space916into a first interior space916ato a first side of the orienting structure926and a second interior space916bto a second side of the orienting structure926. The orienting structure926may include spaces931such that the first interior space916ais in pressure communication with the second interior space916b. This may significantly increase the free gun volume within the gun housing910, thereby allowing for a shorter overall gun housing910and/or a larger amount of explosives to be used within the shaped charge927while reducing the likelihood that the gun housing910ruptures or splits.

In an aspect, at least a portion of the charge carrier body925is aligned with the longitudinal axis911. Further to such aspect, the electrical transfer assembly964including the second pin connector end968, and the line-in terminal212of the initiator assembly950, are similarly aligned along the longitudinal axis911such that when adjacent perforating gun assemblies900are connected together, the electrical contact between, e.g., the second pin connector end968of the perforating gun assembly900and a line-in terminal of an initiator assembly in the adjacent, downstream perforating gun assembly will automatically make electrical contact when the perforating gun assembly900is connected to the adjacent, downstream perforating gun assembly.

With reference in particular now toFIG.25, the initiator assembly950is positioned within the initiator holder400in a fixed orientation relative to the charge carrier920. The initiator assembly950includes, among other things, an orientation sensor, e.g., mounted on the circuit board210inside the initiator head200as previously discussed. In the exemplary embodiment(s) shown inFIG.25, the initiator assembly includes a key protrusion290on a periphery of a housing201of the initiator assembly950(i.e., the initiator head200as previously discussed), for orienting the initiator assembly950within the initiator holder400and thereby the charge carrier920and the gun housing910. The initiator holder400includes a recess440on an outer peripheral wall430of the initiator holder400, and the key protrusion290is received within the recess440, to orient the initiator assembly950. Other configurations of key protrusions, as discussed above throughout this disclosure, and techniques for orienting the initiator assembly950with respect to the initiator holder400consistent with this disclosure, may similarly be used.

As previously discussed, the orientation sensor may include one of an accelerometer, in inclinometer, a gyroscope, and a magnetometer. The orientation sensor may be configured to determine an orientation of the initiator assembly950within the wellbore and thereby an orientation of the perforating gun assembly900, including the gun housing910, the charge carrier920, and the shaped charge927, which are in a known, fixed orientation relative to each other, according to the set orientation of the gun housing910as discussed with respect to the orientation of the gun housing910and the orientation alignment ring930in the fixed connection state. The initiator assembly line-in terminal212, as previously discussed, may be in electrical communication with a firing controller on a surface of the wellbore, and the orientation sensor may be configured for sending real-time orientation information to the firing controller, via the line-in terminal212. As such, each individual perforating gun assembly in a string of perforating gun assemblies may be selectively fired at the desired perforating location and orientation within the wellbore. The electrical communication between the line-out terminal214and the electrical transfer assembly964in each perforating gun assembly900, and the electrical communication between the electrical transfer assembly of each perforating gun and the line-in terminal of a corresponding adjacent, downstream perforating gun, allows each individual gun to communicate its real-time orientation information to the firing controller at the surface of the wellbore, and receive its unique firing signal from the controller. Accordingly, an operator may orient each individual perforating gun assembly in a preferred direction as required to perforate a PFP in a well completion design. The orientation, i.e., perforating direction, of each individual perforating gun assembly, may then be confirmed in a real-time (i.e., substantially concurrent with the orientation experienced by the perforating gun assembly) process while the perforating gun string is deployed in the wellbore, rather than retrieving the perforating gun string or running a camera down the wellbore (after retrieving the perforating gun string), each of which is time-consuming and does not ensure proper orientation before the operation.

In an aspect, the disclosure is directed to a method for orienting an individual perforating gun assembly relative to other perforating gun assemblies in a string. For example, an exemplary method includes providing a perforating gun assembly900such as in the exemplary embodiment(s) discussed above and, for brevity, not necessarily repeated in full. The perforating gun assembly900may include, among other things, the gun housing910including the first end912and the second end914opposite the first end, and the interior space916between the first end912and the second end914. The charge carrier920may be positioned in the gun housing interior space916, in a fixed orientation relative to the gun housing910. The orientation alignment ring930may be connected to the gun housing first end912in an unfixed connection state.

The gun housing910and orientation alignment ring930may be rotated relative to each other, to a desired orientation of the gun housing910relative to the orientation alignment ring930. The orientation alignment ring930may be fixed to the gun housing first end912by engaging the locking structure, such as set screws936, through the locking structure holes934, between the orientation alignment ring930and the gun housing first end912. Locking the orientation alignment ring930to the gun housing first end912fixes the orientation of the gun housing910(and internal components such as the charge carrier920, shaped charge927, and initiator assembly950) relative to the orientation alignment ring930, in the fixed connection state. The initiator assembly950including an orientation sensor may be connected to the charge carrier920by, e.g., inserting the initiator assembly950into the initiator holder400, including the charge carrier passage929. Inserting the initiator assembly950may, in some embodiments, be done before the orientation alignment ring930is fixed to the gun housing first end912, as safety and particular operations may allow. The gun housing second (female) end914may then be connected to, e.g., the adjacent, upstream orientation alignment ring connected to an adjacent, upstream perforating gun assembly. As the degree of the threaded connection, generally, between the orientation alignment ring and the gun housing second (female) end may be known, the fixed orientation of the gun housing910relative to the orientation alignment ring930may thereby provide a desired orientation of the gun housing910(and perforating gun assembly900, generally) relative to the adjacent, upstream perforating gun assembly and other perforating gun assemblies in the tool string.

The locking ring940may then be connected to the gun housing first end912, e.g., by a threaded connection as previously discussed, within the orientation alignment ring bore932. Threading the locking ring940onto the gun housing first end912places a shoulder portion991of the orientation alignment ring930in abutting contact with a shoulder portion992of the locking ring940such that retention and tensile strength of the orientation alignment ring930in the perforating gun string is increased.

The method may further include connecting the perforating gun assembly900to an adjacent, downstream perforating gun assembly, by connecting the orientation alignment ring930to a gun housing second (female) end of the adjacent, downstream perforating gun assembly. The orientation alignment ring930may include seals, such as o-rings969, for sealing, in part, the orientation alignment ring930to the gun housing of the adjacent, downstream perforating gun assembly. In an aspect, the step of connecting the orientation alignment ring930to the adjacent, downstream perforating gun assembly includes threadingly connecting the external threaded portion933of the orientation alignment ring930to the internal threaded portion of the gun housing second (female) end of the adjacent, downstream perforating gun.

In an aspect, the method may further include electrically contacting the electrical transfer assembly964, i.e., the second pin connector end968, and a line-in portion, such as the line-in terminal212of the initiator assembly950, of the adjacent, downstream perforating gun assembly, when the orientation alignment ring930is connected to the adjacent, downstream perforating gun assembly. While the exemplary embodiment(s) of the perforating gun assembly include the line-in terminal212on the initiator assembly, the line-in portion may, in other embodiments, be a separate electrical relay or contact consistent with this disclosure.

This disclosure, in various embodiments, configurations and aspects, includes components, methods, processes, systems, and/or apparatuses as depicted and described herein, including various embodiments, sub-combinations, and subsets thereof. This disclosure contemplates, in various embodiments, configurations and aspects, the actual or optional use or inclusion of, e.g., components or processes as may be well-known or understood in the art and consistent with this disclosure though not depicted and/or described herein.

In this specification and the claims that follow, reference will be made to a number of terms that have the following meanings. The terms “a” (or “an”) and “the” refer to one or more of that entity, thereby including plural referents unless the context clearly dictates otherwise. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. Furthermore, references to “one embodiment”, “some embodiments”, “an embodiment” and the like are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Terms such as “first,” “second,” “upper,” “lower,” etc. are used to identify one element from another, and unless otherwise specified are not meant to refer to a particular order or number of elements.

As used in the claims, the word “comprises” and its grammatical variants logically also subtend and include phrases of varying and differing extent such as for example, but not limited thereto, “consisting essentially of” and “consisting of.” Where necessary, ranges have been supplied, and those ranges are inclusive of all sub-ranges therebetween. It is to be expected that the appended claims should cover variations in the ranges except where this disclosure makes clear the use of a particular range in certain embodiments.

This disclosure is presented for purposes of illustration and description. This disclosure is not limited to the form or forms disclosed herein. In the Detailed Description of this disclosure, for example, various features of some exemplary embodiments are grouped together to representatively describe those and other contemplated embodiments, configurations, and aspects, to the extent that including in this disclosure a description of every potential embodiment, variant, and combination of features is not feasible. Thus, the features of the disclosed embodiments, configurations, and aspects may be combined in alternate embodiments, configurations, and aspects not expressly discussed above. For example, the features recited in the following claims lie in less than all features of a single disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this disclosure.

Advances in science and technology may provide variations that are not necessarily express in the terminology of this disclosure although the claims would not necessarily exclude these variations.