Patent ID: 12203350

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

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.

A detonator is provided that is capable of being positioned or placed into a perforating gun assembly with minimal effort by means of placement/positioning within a detonator positioning device according to an aspect. In an embodiment, the detonator positioning device includes a detonator positioned within the detonator positioning device, wherein the detonator electrically contactably forms an electrical connection with minimal need to manually and physically connect, cut or crimp multiple wires as required in a fully wired electrical connection. Such a wireless detonator has been generally described in commonly assigned DE Application No. 102013109227.6 filed Aug. 26, 2013, which is incorporated herein by reference in its entirety. In other words, the electrical connection is made only by making electrical contact with electrically contactable components as described in greater detail hereinbelow . . . that is by merely physically touching. Thus, as used herein, the term “wireless” means that the detonator itself is not manually, physically connected within the perforating gun assembly as has been traditionally done with wired connections, but rather merely makes electrical contact through various components as described herein to form the electrical connections. Thus, the signal is not being wirelessly transmitted, but is rather being relayed through electrical cables/wiring within the perforating gun assembly through the electrical contacts. In particular, the electrical connection is made through contact between a line-in contact-initiating pin38and a line-in portion20as described in greater detail below.

Now referring toFIGS.2and3such a detonator10incudes a detonator shell12and a detonator head18and is configured for being electrically contactably received within a perforating gun assembly40(see, for instance,FIG.4) without using a wired electrical connection directly to the detonator. Rather, a single line-out wire (not shown) is connected to the detonator positioning assembly as described in more detail hereinbelow.

Only a portion of the perforating gun assembly40is depicted herein, including a perforating gun body or barrel or carrier or housing42for housing the various components of the assembly. Also shown is a distal end of a typical tandem seal adapter or tandem sub44, in which a bulkhead assembly46is shown assembled within the perforating gun assembly40. The tandem sub44is configured to seal inner components within the perforating gun housing42from the outside environment using sealing means. The tandem seal adapter44seals adjacent perforating gun assemblies (not shown) from each other, and houses the bulkhead assembly46.

The bulkhead assembly46functions to relay a line-in contact-initiating pin38for wirelessly electrically contacting a line-in portion20of the detonator head18as described in greater detail hereinbelow. As shown inFIG.4, for instance, bulkhead wires48are depicted with a coating or insulating member, typically using heat shrinking, over the wires48for supplying current to the bulkhead assembly46. With reference toFIGS.4and10, a bulkhead retaining mechanism49is provided to secure the bulkhead assembly46within the tandem sub44. In the embodiment ofFIG.4, the retaining mechanism49abuts the end of the bulkhead assembly46from which the line-in contact-initiating pin38extends, while in the embodiment depicted inFIG.10, the retaining mechanism49abuts the opposite end of the bulkhead assembly46.

The detonator shell12of the detonator10useful herein is configured as a housing or casing11, typically a metallic housing, which houses at least a detonator head plug14, a fuse head15, an electronic circuit board16and explosive components. The fuse head15could be any device capable of converting an electric signal into an explosion. As shown inFIG.2, the detonator shell12is shaped as a hollow cylinder. The electronic circuit board16is connected to the fuse head15and is configured to allow for selective detonation of the detonator10. The electronic circuit board16is configured to wirelessly and selectively receive an ignition signal I, (typically a digital code uniquely configured for a specific detonator), to fire the perforating gun assembly40. By “selective” what is meant is that the detonator10is configured to receive one or more specific digital sequence(s), which differs from a digital sequence that might be used to arm and/or detonate another detonator in a different, adjacent perforating gun assembly, for instance, a train of perforating gun assemblies. So, detonation of the various assemblies does not necessarily have to occur in a specified sequence. Any specific assembly can be selectively detonated. In an embodiment, the detonation occurs in a bottom-up sequence.

The detonator head18extends from one end of the detonator shell12, and includes more than one electrical contacting component including an electrically contactable line-in portion20and an electrically contactable line-out portion22. According to one embodiment, the detonator head18may also include an electrically contactable ground portion13(not shown). In an embodiment, the detonator head18may be disk-shaped. In another embodiment, at least a portion of the detonator housing11is configured as the ground portion13. The line-in portion20, the line-out portion22and the ground portion13are configured to replace the wired connection of the prior art wired detonator60and to complete the electrical connection merely by contact with other electrical contacting components. In this way, the line-in portion20of the detonator10replaces the signal-in wire61of the wired detonator60, the line-out portion22replaces the signal-out wire60and the ground portion13replaces the ground wire63. Thus, when placed into a detonator positioning device100(see, for instance,FIG.4) as discussed in greater detail below, the line-in portion20, the line-out portion22and the ground portion13make an electrical connection by merely making contact with corresponding electrical contacting components (also as discussed in greater detail below). That is, the detonator10is wirelessly connectable only by making and maintaining electrical contact of the electrical contacting components to replace the wired electrical connection and without using a wired electrical connection.

The detonator head18also includes an insulator24, which is positioned between the line-in portion20and the line-out portion22. The insulator24functions to electrically isolate the line-in portion20from the line-out portion22. Insulation may also be positioned between other lines of the detonator head. As discussed above and in an embodiment, it is possible for all of the contacts to be configured as part of the detonator head18(not shown), as found, for instance, in a banana connector used in a headphone wire assembly in which the contacts are stacked longitudinally along a central axis of the connector, with the insulating portion situated between them.

In an embodiment, a capacitor17is positioned or otherwise assembled as part of the electronic circuit board16. The capacitor17is configured to be discharged to initiate the detonator10upon receipt of a digital firing sequence via the ignition signal I, the ignition signal being electrically relayed directly through the line-in portion20and the line-out portion22of the detonator head18. In a typical arrangement, a first digital code is transmitted down-hole to and received by the electronic circuit board. Once it is confirmed that the first digital code is the correct code for that specific detonator, an electronic gate is closed and the capacitor is charged. Then, as a safety feature, a second digital code is transmitted to and received by the electronic circuit board. The second digital code, which is also confirmed as the proper code for the particular detonator, closes a second gate, which in turn discharges the capacitor via the fuse head to initiate the detonation.

In an embodiment, the detonator10may be fluid disabled. “Fluid disabled” means that if the perforating gun has a leak and fluid enters the gun system then the detonator is disabled by the presence of the fluid and hence the explosive train is broken. This prevents a perforating gun from splitting open inside a well if it has a leak and plugging the wellbore, as the hardware would burst open. In an embodiment, the detonator10is a selective fluid disabled electronic (SFDE) detonator.

The detonator10according to an embodiment can be either an electric or an electronic detonator. In an electric detonator, a direct wire from the surface is electrically contactingly connected to the detonator and power is increased to directly initiate the fuse head. In an electronic detonator, circuitry of the electronic circuit board within the detonator is used to initiate the fuse head.

The detonator10may be immune to stray current or voltage and/or radiofrequency (RF) signals to avoid inadvertent firing of the perforating gun. Thus, the assembly is provided with means for ensuring immunity to stray current or voltage and/or RF signals, such that the detonator10is not initiated through random radio frequency signals, stray voltage or stray current. In other words, the detonator10is configured to avoid unintended initiation.

The detonator10is configured to be electrically contactingly received within the detonator positioning device100, which is seated or positioned within the perforating gun assembly40, without using a wired electrical connection to the detonator10itself, as shown inFIGS.4,5,7-9and10.

In an embodiment and as shown inFIGS.4,6and7, the detonator positioning device100includes a cylindrical body110′ depicted as a multi-part member, that is a body that is formed using a plurality of parts or sections, which may facilitate ease of assembly. With reference to the embodiment ofFIG.5, the cylindrical body110may also be provided as a unitary body, one that is formed as a whole, for instance by machining or molding processes known by those of ordinary skill in the art. As used herein, the prime symbol ′ in the various figures designates the difference between embodiments of the unitary body (no prime used) as compared to features of the multi-part body (prime used), and will not generally be used in the description. As an example, with reference to a central bore130, the central bore will be depicted as central bore130′ in the embodiment wherein multiple parts are used to form the body110′, while the central bore130(without the prime) will be used to depict the bore of the unitary body100. In an embodiment and with reference to, for instance,FIG.7, one or more passages102are provided in the closed end of the cylindrical body110to accommodate passage of a detonating cord (not shown) positioned within the detonator positioning device100.

With reference again in particular toFIGS.4-9, the cylindrical body110includes an open end113, a closed end114, and a central bore130adapted for receiving the detonator10. The cylindrical body110also includes a plurality of portions, including at least a first portion120and a second portion122, and in an embodiment a third portion124, which will be discussed in greater detail below. The central bore130extends along at least some of a length of the cylindrical body110, and typically includes an enlarged bore portion132adjacent the open end113of the cylindrical body110. The enlarged bore portion132is adapted to receive the head18portion of the detonator10, while the central bore130is adapted to receive the housing11portion of the detonator10. In an embodiment, the enlarged bore portion132is positioned within the first portion120of the cylindrical body110and the central bore130extends along a majority of the length of the cylindrical body110. In an embodiment, the enlarged bore portion132and the detonator head18are complementarily sized and shaped to receive and seat/be received and seated, respectively, in at least a semi-fixed position within the detonator positioning device100.

In an embodiment, a plurality of arms150extend toward the open end113of the cylindrical body110and at least partially enclose the enlarged bore portion132of the central bore130. In this way, each of the plurality of arms150is adapted to retain, hold or otherwise embrace the detonator head18portion of the detonator10when the detonator10is positioned within the enlarged bore portion132of the central bore130. Typically, the arms150are made of a flexible and resilient material that is capable of being bent or otherwise moved circumferentially outward, yet return to their original position once the movement force has been removed, (e.g. once the detonator is positioned within the detonator positioning device100). Thus, the arms150will enclose and typically contact at least a peripheral surface of the head18of the detonator10. Although the plurality of arms150are depicted as having four arms, it would be understood that more or less arms may be sufficient to perform the stated function, i.e., to retain the detonator head. For instance, the plurality of arms150could include 2, 3, 4, 5, 6, 7, 8 or more arms. As shown inFIGS.4-9and in an embodiment, the arms may include a retainer152positioned at a distal end of the arms to assist in retaining and maintaining the head18of the detonator10within the detonator positioning device100. As shown herein, the detonator head18is slidably received within the enlarged bore portion132, meaning the detonator head18is capable of sliding along at least a portion of the length of the enlarged bore portion132created by the arms150. In an embodiment, the plurality of arms150form at least a portion of a forward end121of the first portion120of the cylindrical body110.

Although not shown, it is possible to provide a window or opening in the cylindrical body110of the detonator positioning device100to facilitate visual verification of proper seating of the detonating cord (not shown), once the detonating cord has been connected to the assembly through the passage102.

Turning to the other end of the detonator positioning device100, a plurality of legs140are adapted to assist in positioning the device100within the perforating gun assembly40. In the embodiment shown inFIGS.4-8, the plurality of legs140extend from the cylindrical body110toward the closed end114of the cylindrical body110. Similar to the arms150, the legs140may be made from a resilient material, and typically include protrusions142at the distal ends thereof adapted for positioning and holding the device100in place. In an embodiment, each protrusion142extends away from the cylindrical body110.

Although the plurality of legs140are depicted as having four legs, it would be understood that more or less legs may be sufficient to perform the stated function, i.e., to position the detonator positioning device within a perforating gun assembly. For instance, the plurality of legs140could comprise 3, 4, 5, 6, 7, 8 or more legs. Having more legs (or arms as referenced above) means each individual leg/arm is ultimately thinner than if fewer legs/arms are used. Similarly, thinner legs/arms means the individual legs/arms are less rigid, so there will ultimately be a trade-off in number of legs/arms selected between rigidity and/or flexibility of the detonator positioning device and the ability to stabilize the detonator positioning device within the perforating gun assembly and/or retain the detonator head, as the case may be.

Further, in an embodiment, each of the plurality of arms150and the plurality of legs140are adapted to provide a snap fit upon insertion of the detonator10within the central bore130and insertion of the cylindrical body110within the perforating gun assembly40.

As mentioned above, a third portion124may also be formed as a portion of the cylindrical body110. As shown inFIGS.4-9and in an embodiment, the third portion124is formed integrally as part of the second portion122, while it is contemplated that the third portion124could be formed as a separate unit that is attached to the cylindrically body110. The third portion124has a forward face125and a rearward face126, and as shown in this embodiment, the plurality of legs140extend from the rearward face126of the third portion124. As depicted herein, the third portion124, extends circumferentially from an outer surface123of the second portion122and the third portion124is discontinuous about the outer surface123of the second portion122of the cylindrical body110, thus forming a plurality of sections127. Such an arrangement typically minimized overall weight and associated costs with fabricating the unit, while maintaining sufficient structural integrity to perform the stated functions. Further as depicted in this embodiment, the third portion124includes a circumferentially-extending lip128at a distal end129of the third portion124. In this arrangement, the distal end129is positioned opposite the plurality of legs140. The lip128is further adapted for positioning the detonator positioning device100by working in concert with the plurality of legs140to hold the detonator positioning device100in place within the perforating gun assembly40.

As stated above, the central bore130is adapted to receive and retain the detonator10, wherein the central bore130extends from the open end113to the closed end114of the cylindrical body110, and the enlarged bore portion132is positioned adjacent the open end113. Thus, when the detonator10is positioned within the central bore110of the detonator positioning device100, the detonator housing11extends along a length of the central bore130, while the detonator head18is received within the enlarged bore portion132.

In an embodiment, a line-out connector biasing member25is positioned or otherwise situated within the central bore130of the cylindrical body110, at a base134of the enlarged bore portion132, while a ground connector biasing member28is positioned or otherwise situated within the central bore130of the cylindrical body110, at a base136of the central bore130. Thus, the ground connector biasing member28is positioned within the central bore130between the detonator housing11of the detonator10and the closed end114of the cylindrical body110. In addition, a terminal26is typically positioned adjacent the line-out connector biasing member25.

In an embodiment, the terminal26is formed as a semi-round metallic material, with a slotted nipple27extending from an outer circumferential surface of the terminal26. The slotted nipple27is adapted for connection to the single electrical line-out wire needed to complete the electrical connection for this assembly (not shown). Although a slotted nipple27is depicted, it will be understood by those of ordinary skill in the art that other mechanisms may be provided to create the electrical connection between the single wire and the terminal26.

The line-out connector biasing member25and the ground connector biasing member28may be formed from a spring-like material for assisting in maintenance of physical and electrical contact between the line-in contact-initiating pin38extending from the bulkhead assembly46, and may also be formed of materials suitable to facilitate electrical connectivity. Typically, these components are also metallic, that is to say they are formed from an electrically conductive metal material.

Once received within the central bore130, therefore, the detonator10is electrically contactingly connected to the terminal26that is positioned between the line-out portion22of the detonating head18of the detonator10and the line-out connector biasing member25. Thus, once the detonator10is positioned within the central bore130, and the line-in contact-initiating pin38of the bulkhead assembly46makes contact with, and thus electrically contactably connects to the line-in portion20of the detonator head18. The line-out connector biasing member25will thus compress, causing the line-out portion22of the detonator head18to electrically contactably connect with the terminal26. The grounding connection will be discussed in more detail hereinbelow.

With reference to the closed end114of the detonator positioning device100and in an embodiment, a grounding strip or wire29is provided for completing the electrical connection and is also typically formed from an electrically conductive metal material. In an embodiment, the grounding strip29is embedded in the closed end114of the cylindrical body110. As shown in the embodiment ofFIGS.4-7, the grounding strip29extends from one side of the cylindrical body110through to the opposite side of the cylindrical body110in a way that a central portion of the grounding strip29is positioned adjacent one end of the ground connector biasing member28, opposite from the housing11of the detonator10. Thus, the ends of the grounding strip29extend beyond the outer surface of the cylindrical body110. When the detonator10is positioned within the central bore130of the detonator positioning device100, and the detonator10is compressed by the contact of the bulkhead assembly44, the ground connector biasing member28compresses and electrically contactably connects the ground portion13of the housing11with the ground connector biasing member28and the grounding strip29, which completes a ground loop via connection with the perforating gun housing42. As shown inFIG.4, the grounding strip is deformed upon insertion of the detonator positioning device100into an end plate180, the entire assembly of which is inserted within the perforating gun body42, thus completing the ground loop/connection.

As mentioned above, and with particular reference toFIGS.4,6and7, the cylindrical body110may be formed as a multi-part cylindrical body110′ including at least a first part111and a second part112. As shown herein, the first part111of the cylindrical body110can be removably connected, (or otherwise joined, fastened, united) to the second part112of the cylindrical body110′ to form an assembled cylindrical body109. In this way, each of the first part111and the second part112include at least a first portion120′ and a second portion122′, the assembled cylindrical body109comprising an open end113′, a closed end114′, and a central bore130′ adapted for receiving the detonator10, the central bore130′ extending along at least some of a length of the assembled cylindrical body109, the central bore130′ including an enlarged bore portion132′ adjacent the open end113′ of the assembled cylindrical body109. In this embodiment, a plurality of arms150′ extend toward the open end113′ of the assembled cylindrical body109and at least partially enclose the enlarged bore portion132′ of the central bore130′. Further, each of the plurality of arms150′ include a retainer152′ adapted to retain the detonator head18of the detonator10positioned within the enlarged bore portion132′ of the central bore130′. In an embodiment, a plurality of legs140′ extend from the assembled cylindrical body109and toward the closed end114′ of the assembled cylindrical body109, and each of the plurality of legs140′ include a protrusion142′ extending away from the assembled cylindrical body109and adapted for positioning the assembled cylindrical body109in the perforating gun assembly40.

Since the assembled cylindrical body109according to this embodiment requires assembly in the field, a plurality of couplers170are provided that are adapted for attaching the first part111of the assembled cylindrical body109to the second part112of the assembled cylindrical body109. It would be understood by one of ordinary skill in the art that it is possible to attach the first part111to the second part112by any number of fasteners172, including screws, bolts/nuts and the like that may be received in a socket or cavity174through threading, frictional fit and the like. As shown best inFIG.7and in an embodiment, the fastener172is a protrusion including a distal nob extending from the first part111, which is matingly inserted into an oppositely positioned cavity174of the second part112(not shown). In an embodiment, the fastener172snap fits into the cavity174.

In an embodiment, the first part111and the second part112may be configured as symmetrical or non-symmetrical halves.

According to an aspect the perforating gun assembly40and a method for assembling the perforating gun assembly40including a wireless detonator10and detonator positioning device100as described hereinabove is provided.

In an aspect, the method of assembling the perforating gun assembly40while using a semi-wired electrical connection includes at least the following steps: positioning the detonator positioning device100within the perforating gun assembly40, the detonator positioning device100including the central bore130; positioning the ground connector biasing member28at the base136of the central bore130; positioning the line-out connector biasing member25at the base134of the enlarged portion132of the central bore130; positioning the terminal26for receiving the single line-out wire adjacent the line-out connector biasing member25; positioning the wireless detonator10within the central bore130such that the housing11of the detonator10extends along at least a portion of the central bore130and the ground portion13of the housing11electrically contacts the ground connector biasing member28, and positioning the head18of the detonator10within the enlarged portion132of central bore130such that the line-out portion22of the detonator10electrically contacts the terminal26, and the line-in contact-initiating pin38electrically contacts the line-in portion20of the detonator10.

According to an aspect, the step of positioning the detonator positioning device100within the perforating gun assembly40includes positioning the detonator positioning device within a support member or end plate180, as seen, for instance,FIGS.4,5and7-10, and as discussed briefly above. As shown herein the end plate180has an inner cavity that is sufficiently sized to receive the closed end114of the cylindrical body110, and in particular to receive at least the second portion122(and/or the third portion124) by interlocking and/or snap-fit action with the plurality of legs140at a rearward end of the endplate180(seeFIGS.4,5and7) and by abutting the circumferentially-extending lip against the outer surface of the end plate180(see in particularFIGS.8and9) at the opposite end of the end plate180. Similarly, the outer dimension or exterior surface of the end plate180is sufficiently sized to be received within the perforating gun barrel42. Although not specifically shown, it will be understood by one of ordinary skill in the art that it is possible to form various members and components described herein as integrated units.

Turning to the embodiment found inFIG.10, a separate component is provided to facilitate the ground loop discussed hereinabove. As shown herein, a grounding rib182is attached to the exterior surface of the end plate180to complete the ground loop upon positioning of the detonator positioning device100within the perforating gun assembly40. In an embodiment, the grounding rib182is formed as a long, narrow, thin, semi-curved, flexible and resilient, metallic member, as seen best inFIG.11. As shown herein, a securing mechanism184is provided for attaching the grounding rib182to the exterior surface of the end plate180. Thus, when the assembly is inserted into the perforating gun barrel42, the grounding rib182is flexed circumferentially inwardly to complete the ground loop.

As used herein, “hold” means to enclose within bounds, to limit or hold back from movement or to keep in a certain position. The detonator positioning device100is positioned within the perforating gun assembly40and functions to receive and hold in place the detonator10according to an embodiment. In addition, the detonator positioning device100also functions to provide electrical contacting components for wirelessly-connectably electrically receiving the detonator10, while providing for a single wired connection to the detonator positioning device100itself.

The components and methods illustrated are not limited to the specific embodiments described herein, but rather, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the device and method include such modifications and variations. Further, steps described in the method may be utilized independently and separately from other steps described herein.

While the device and method have been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope contemplated. In addition, many modifications may be made to adapt a particular situation or material to the teachings found herein without departing from the essential scope thereof.

In this specification and the claims that follow, reference will be made to a number of terms that have the following meanings. The singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. 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. Terms such as “first,” “second,” “forward,” “rearward,” 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 herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur—this distinction is captured by the terms “may” and “may be.”

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.”

Advances in science and technology may make equivalents and substitutions possible that are not now contemplated by reason of the imprecision of language; these variations should be covered by the appended claims. This written description uses examples to disclose the device and method, including the best mode, and also to enable any person of ordinary skill in the art to practice the device and method, including making and using any devices or systems and performing any incorporated methods. The patentable scope thereof is defined by the claims, and may include other examples that occur to those of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.