Patent Application
20190162058
This disclosure generally relates to a firing head assembly. More specifically, a firing head assembly having a safety assembly, for use in conjunction with a perforating gun is described.
In the extraction of hydrocarbons, such as fossil fuels (e.g., oil) and natural gas, from underground wellbores extending deeply below the surface, complex machinery and explosive devices are utilized. It is common practice to facilitate the flow of production fluid by perforating a fluid bearing subterranean formation using a perforating gun, which is lowered into the wellbore to the depth of the formation and then detonated to form perforations in the formation surrounding the perforating gun. A firing head assembly is coupled to the gun and initiated/activated to fire the gun. While the firing head assembly may be coupled to the perforating gun before the gun is lowered into the wellbore, it is often preferred for safety and other reasons, to allow initiation of the firing head only after the gun is positioned in the wellbore. An initiator is designed to fire the explosive train in the perforating gun after the initiator sees/receives an appropriate command from the surface.
It is very important that the firing head used to initiate explosives in a perforating gun be reliable and safe in operation. There have been numerous accidents resulting in severe injury or death where an explosive well tool, such as a perforating gun, fires prematurely at the surface of a wellbore while personnel are rigging the tool in preparation for running it into the wellbore.
There may be countless reasons for an operator or personnel to decide not to fire a perforating gun that has been run into the wellbore. Such reasons may include problems with running the perforating gun into the wellbore (i.e., running in hole), problems with other completion equipment or problems with the perforating gun assembly or its related components. In addition, one potential risk is that after the firing procedure is performed, there may be no positive indication that the perforating gun actually fired, which may mean that there are live explosives/shaped charges returning to the surface of the wellbore. This may endanger all personnel and equipment present at the surface when the perforating guns are retrieved to the surface.
In view of continually increasing safety requirements and the problems described hereinabove, there is a need for a firing head assembly that facilitates safe initiation of shaped charges in a perforating gun. There is also a need for a firing head assembly for use in a perforating gun that reduces the risk of property damage and bodily harm, including death, in a firing condition. Furthermore, there is a need for a firing head assembly having a safety feature, which will not allow the perforating gun to fire unless an operator selects the option to fire the perforating gun. Additionally, there is a need for a firing head assembly that allows an operator to abort a firing operation in a manner that prevents firing of the perforating gun.
According to an aspect, the present embodiments may be associated with a firing head assembly. The firing head assembly includes a tubular housing having a first end, a second end, and a lumen that extends between the first and second ends. An upper piston is slidably disposed proximate to the first end of the tubular housing, and a lower piston is slidably disposed proximate to the second end of the tubular housing. Each piston at least partially extends into the lumen of the tubular housing. The firing assembly may further include a compressible member within the tubular housing. The compressible member has a first end portion that is coupled to the upper piston, and a second end portion that is coupled to the lower piston. The firing head assembly includes a safety assembly having a sleeve and a key. In an embodiment, the sleeve includes a substantially zigzag-shaped slot having a plurality of stop points. The key may radially extend from an external surface of the upper piston through the zigzag-shaped slot in such a manner that slides through the slot and engages with at least one of the plurality of stop points of the slot. The firing head assembly may further include a first securing element positioned along the second end of the tubular housing. The upper piston operatively adjusts the arrangement of the key within the zigzag-shaped slot to activate the firing head assembly.
According to an aspect, the present embodiments may also be associated with a well completion apparatus. The well completion apparatus includes a perforating gun, and a firing head assembly operably associated with the perforating gun. Similar to the firing head assembly described hereinabove, the well completion apparatus includes a tubular housing, upper and lower pistons positioned proximate to the first and second ends of the tubular housing, respectively, and slidably moveable within a lumen of the tubular housing. A compressible member is positioned within the lumen, and is adjustable between a relaxed state, a compressed state and a partially compressed state. The compressible member has a first end portion that abuts the upper piston, and a second end portion that abuts the lower piston. The pressure activated firing assembly further includes a safety assembly, which may be configured as described hereinabove.
Further embodiments of the disclosure are associated with a method of using a pressure activated firing head assembly in both a firing condition and a non-firing condition. In an embodiment, the method includes positioning a perforating gun at a desired location. The perforating gun includes a firing head assembly configured substantially as described hereinabove. The firing head assembly includes a tubular housing having a first end, a second end, an inner diameter, and a lumen extending between the first and second ends of the tubular housing. In an embodiment, the firing head assembly includes an upper piston and a lower piston. The upper piston and the tubular housing at least partially define an upper chamber of the lumen above the upper piston, while the lower piston and the tubular housing at least partially define a lower chamber of the lumen below the lower piston. The compressible member is in an intermediate chamber between the upper and lower chambers. The upper, intermediate, and lower chambers each have a respective pressure. According to an aspect, the method further includes adjusting the first pressure and the second pressure to initiate an event. The event may be one of triggering an explosive reaction in the firing condition, and canceling an explosive reaction in the non-firing condition.
A more particular description will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments thereof and are not therefore to be considered to be limiting of its scope, exemplary embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
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 some embodiments.
The headings used herein are for organizational purposes only and are not meant to limit the scope of the description or the claims. To facilitate understanding, reference numerals have been used, where possible, to designate like elements common to the figures.
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.
As used herein, the term “underbalanced” refers to a procedure where before perforating a wellbore, the pressure in the wellbore is lower than the static pressure inside the adjacent formation. Once the wellbore has been perforated, fluid (e.g., oil and gas) in the formation flows into the wellbore.
For purposes of illustrating features of the embodiments, reference will be made to various figures.
Turning now to the figures,
According to an aspect, the tubular housing 20 includes a first end 22 and a second end 24. The second end 24 may be spaced apart from the first end 22 by the housing body, with a lumen (i.e., interior space) 26 extending therebetween. The lumen 26 has an inner diameter ID, which in some embodiments, is constant along a length L of the tubular housing 20.
The upper and lower pistons or driving members 32, 34 are illustrated as being spaced apart from each other. According to an aspect, the upper piston 32 is slidably disposed proximate to the first end 22 of the tubular housing 20, while the lower piston 34 is slidably disposed proximate to the second end 24 of the tubular housing 20. Each of the upper and lower pistons 32, 34 at least partially extends into the lumen 26 of the tubular housing 20, and may be longitudinally movable therein. According to an aspect, the upper piston 32 move towards and/or away from the lower piston 34. As will be discussed further below, movement of the upper piston 32 within the lumen 26 operatively adjusts the arrangement of a key 54 of a safety assembly 50 within the zigzag-shaped slot 53 in order to activate the firing head assembly 10. The lower piston 34 is configured to move away from the upper piston 32 when the firing head assembly is activated, as will be described in further detail hereinbelow. According to an aspect, at least one of the upper piston 32 and the lower piston 34 is compressively fitted and partially arranged within the lumen 26 of the tubular body 20. In this configuration, movement of the pistons 32, 34 is facilitated by the application or removal of a force, i.e. a change in the wellbore pressure, onto the pistons 32, 34, thereby causing them to slide within the lumen 26.
A compressible member 40 is illustrated in
While
Movement of the upper and lower pistons 32, 34 adjust the compressible member 40 between a compressed state, in which the compressible member 40 has a minimum length Lmin (
According to an aspect, the lumen 26 includes an upper chamber 28a having a first pressure P1 and a lower chamber 28b having a second pressure P2. The upper chamber 28a is disposed above the upper piston 32, and is defined by the upper piston 32 and the tubular housing 20. The lower chamber 28b is disposed below the lower piston 34, and is defined by the lower piston 34 and the tubular housing 20. The lumen further includes an intermediate chamber 28c having a third pressure P3. The intermediate chamber 28c houses the compressible member 40, and is disposed between the upper and lower chambers 28a, 28b. According to an aspect, the third pressure P3 is either atmospheric pressure or predetermined pressure supplied by the pressurized gas 48 (
One or more ports 27 may be disposed in the housing 20 (i.e., the housing 20 may include one or more ports 27). When the firing head assembly 10 is positioned in a wellbore, the ports 27, when positioned above the upper piston 32 and below the lower piston 34, facilitate communication of a wellbore fluid with at least one of the upper chamber 28a and the lower chamber 28b. The wellbore fluid has a wellbore pressure, and the ports 27 may communicate the wellbore pressure to the lumen 26 (i.e., such that the pressure of the fluid in the wellbore would be the same as the pressure in the lumen 26). According to an aspect, the lower chamber 28b includes a port/opening 27b in the tubular housing 20 that fluidly connects the wellbore to the lower chamber 28b, so that the second pressure P2 is the same as the wellbore pressure. In this configuration, the second pressure P2 of the lower chamber 28b may be different from the first pressure P1 of the upper chamber 28a. According to an aspect, the upper and lower chambers 28a, 28b each comprise a respective port 27a, 27b that fluidly connects the wellbore to the upper and lower chambers 28a, 28b. This arrangement facilitates the first and second pressures P1, P2 being the same as the wellbore pressure, because the respective ports 27a, 27b are both open to the wellbore environment.
According to an aspect, the first and second pressures P1, P2 may be adjusted by moving the firing head assembly 10 downwardly or upwardly in the wellbore, or by adding or removing some wellbore fluid from the wellbore. As would be understood by one of ordinary skill in the art, an operator of the firing head assembly 10 may adjust the pressure of the wellbore by either adding or removing a selected fluid to the wellbore. The selected fluid may include nitrogen, an industry standard, or any other fluid with a lower density than the wellbore fluid.
According to an aspect, the firing head assembly 10 includes a plurality of sealing members/pressure seals 90. The sealing members 90 may include one or more O-rings that extend around the upper piston 32 and the lower piston 34. It is contemplated that the sealing members 90 may help to secure the upper and lower pistons 32, 34 within the lumen 26. In an embodiment, at least one of the sealing members 90 is positioned between the upper piston 32 and the lumen 26 of the tubular housing 20, while at least one other of the sealing members 90 is positioned between the lower piston 34 and the lumen 26 of the tubular housing 20. The sealing members 90 help isolate the compressible member 40, and the third pressure P3 in the intermediate chamber 28c, from the wellbore fluid and/or the wellbore pressure as well as from the first and second pressures P1, P2. The sealing members 90 additionally isolate the third pressure P3 of the intermediate chamber 28c from the first pressure P1 of the upper chamber 28a, and the third pressure P3 of the intermediate chamber 28c from the second pressure P2 of the lower chamber 28b. In an embodiment, since the first and second pressures P1, P2 may be different from the third pressure P3 in the intermediate chamber 28c, as described hereinabove, the sealing members 90 maintain the individual pressures P1, P2, P3, as well as maintain a pressure differential between the third pressure P3 of the intermediate chamber 28c, and the first and second pressures P1, P2 of the upper and lower chambers 28a, 28b, respectively.
In an embodiment, the firing head assembly 10 includes a safety assembly 50. The safety assembly 50 facilitates use of the firing head assembly 10 in an underbalanced condition in such a manner that an associated perforating gun (
When two of more of the openings 55 are joined together in an alternating angled configuration, the openings 55 form the zigzag shaped slot 53. The openings 55 terminate at stop points (i.e., abutments, or notches) S. While
According to an aspect, the safety assembly 50 includes a key 54. The key 54 radially extends from (i.e., extends outwardly from) an external surface 33 of the upper piston 32. As best seen in
As illustrated in
Securing elements, such as those depicted in
According to an aspect, the firing head assembly 10 includes a first securing element 60 positioned along the second end 24 of the tubular housing 20 to maintain the lower piston 34, and a second securing element 72 to maintain the firing pin 70 in the spaced apart configuration from the percussion initiator 80. The first securing element 60 at least temporarily retains the lower piston 34 in a spaced apart configuration from the firing pin 70. The first securing element 60 retains the lower piston 34 in this configuration, so long as its maximum strength is not exceeded. As illustrated in
According to an aspect and as shown in
The perforating gun 120 is operably associated with a firing head assembly 10′. In this embodiment, the firing head assembly 10′ is substantially similar to the firing head assembly 10 illustrated in
As described hereinabove, the firing head assembly 10′ includes a safety assembly 50 having a sleeve 52 and a key 54. The sleeve 52 includes a substantially zigzag-shaped slot 53, having a plurality of stop points S, within with the key 54 slides to adjust the compressible member 40 between relaxed, compressed, and partially-compressed states. According to an aspect, the stop points S include two or more distal stop points S1, S5 spaced at a substantial distance from the compressible member 40. When the key 54 is oriented at the distal stop points S1, S5, as illustrated in
Embodiments of the present disclosure further related to a method 200 of using a firing head assembly in both a firing condition 222 and a non-firing condition 224. The firing head assembly is operably associated with a perforating gun, both of which are components of a well completion apparatus. In this embodiment, the perforating gun and firing head assembly are substantially similar to the perforating gun and firing head assembly illustrated in
According to an aspect, the method 200 includes positioning 210 a well completion apparatus, including the perforating gun and the firing head assembly in a wellbore. The first pressure and second pressures are adjusted 220 to initiate an event. According to an aspect, the adjusting step 220 includes adding 221 a fluid (i.e., a liquid or gas) to the wellbore or increasing the wellbore pressure by means of a compressed gas, or removing 223 a fluid from the wellbore or decreasing the pressure of the previously injected a compressed gas. According to an aspect, the step of adding 221 the fluid to the wellbore increases the wellbore pressure, which in turn increases the first and second pressures and charges the compressible member (such as, a spring or a compressed gas, as described hereinabove) to generate a compressive force within the intermediate chamber. Alternatively, the step of removing 223 the fluid from the wellbore decreases the wellbore pressure, which decreases the first and second pressures and at least partially reduces the compressive force of the compressible member. In an embodiment, the adjusting 220 step may include moving the perforating gun downwardly 225 or upwardly 227 in the wellbore. When the perforating gun is moved downwardly 225 in the wellbore, the first and second pressures are increased, thereby charging the compressible member so that it generates the compressive force, while moving the perforating gun upwardly 227 decreases the first and second pressures and reduces any compressive force previously-generated by the compressible member.
The event initiated by the step of adjusting 220 the first pressure and the second pressure includes one of triggering an explosive reaction in the firing condition 222, and canceling an explosive reaction in the non-firing condition 224. In both the firing and non-firing conditions 222, 224, adjustment of the first pressure changes the length of the compressible member and adjusts the arrangement of the key in the zigzag shaped slot. According to an aspect, the length of the compressible member changes as it is compressed, partially-compressed or relaxed. Additionally, when the key is arranged at one of the stop points of the zigzag shaped slot, the length of the compressible member is at least temporarily fixed until the first pressure is adjusted.
According to an aspect, when the compressible member includes a pressurized gas, as illustrated in
In circumstances when the explosive reaction is not desired, the firing head assembly may be placed in a ‘safe mode’, whereby the perforating gun may be safely removed without triggering the explosive event. It may be desirable to retrieve the perforating gun from the perforation location when, for instance, the exposure time of the explosive is threatened to be exceeded or problems with other aspects of the completion have arisen. According to an aspect, when the key is arranged at distal stop points, the firing head assembly is in the safe mode, which allows safe retrieval of the perforating gun from the wellbore. In this safe mode, the compressible member is in a relaxed state and the firing pin is positioned away from the initiator and the perforating gun may be safely removed from the desired location without triggering the explosive reaction.
According to an aspect, when the compressible member includes the pressurized gas, the adjustment of the wellbore pressure in the non-firing condition 224 is similar to when the compressible member is a spring. When the wellbore pressure is increased, the pressurized gas is compressed and the key moves generally downwardly in the zigzag shaped slot to another proximal stop point (as seen for instance in
The present disclosure, in various embodiments, configurations and aspects, includes components, methods, processes, systems and/or apparatus substantially developed as depicted and described herein, including various embodiments, sub-combinations, and subsets thereof. Those of skill in the art will understand how to make and use the present disclosure after understanding the present disclosure. The present disclosure, in various embodiments, configurations and aspects, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments, configurations, or aspects hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and/or reducing cost of implementation.
The phrases “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
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 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.” Where necessary, ranges have been supplied, and those ranges are inclusive of all sub-ranges therebetween. It is to be expected that variations in these ranges will suggest themselves to a practitioner having ordinary skill in the art and, where not already dedicated to the public, the appended claims should cover those variations.
The foregoing discussion of the present disclosure has been presented for purposes of illustration and description. The foregoing is not intended to limit the present disclosure to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the present disclosure are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the embodiments, configurations, or aspects of the present disclosure may be combined in alternate embodiments, configurations, or aspects other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the present disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, the claimed features lie in less than all features of a single foregoing 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 the present disclosure.
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 method, machine and computer-readable medium, including the best mode, and also to enable any person of ordinary skill in the art to practice these, 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 language of the claims.
This application claims the benefit of U.S. Provisional Patent Application No. 62/591,818 filed Nov. 29, 2017, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62591818 | Nov 2017 | US |
