The present disclosure relates generally to multilateral wellbores and, more particularly, to an expandable bullnose assembly that works with a wellbore deflector to allow entry into more than one lateral wellbore of a multilateral wellbore.
Hydrocarbons can be produced through relatively complex wellbores traversing a subterranean formation. Some wellbores include one or more lateral wellbores that extend at an angle from a parent or main wellbore. Such wellbores are commonly called multilateral wellbores. Various devices and downhole tools can be installed in a multilateral wellbore in order to direct assemblies toward a particular lateral wellbore. A deflector, for example, is a device that can be positioned in the main wellbore at a junction and configured to direct a bullnose assembly conveyed downhole toward a lateral wellbore. Depending on various parameters of the bullnose assembly, some deflectors also allow the bullnose assembly to remain within the main wellbore and otherwise bypass the junction without being directed into the lateral wellbore.
Accurately directing the bullnose assembly into the main wellbore or the lateral wellbore can often be a difficult undertaking. For instance, accurate selection between wellbores commonly requires that both the deflector and the bullnose assembly be correctly oriented within the well and otherwise requires assistance from known gravitational forces. Moreover, conventional bullnose assemblies are typically only able to enter a lateral wellbore at a junction where the design parameters of the deflector correspond to the design parameters of the bullnose assembly. In order to enter another lateral wellbore at a junction having a differently designed deflector, the bullnose assembly must be returned to the surface and replaced with a bullnose assembly exhibiting design parameters corresponding to the differently designed deflector. This process can be time consuming and costly.
The following figures are included to illustrate certain aspects of the present disclosure, and should not be viewed as exclusive embodiments. The subject matter disclosed is capable of considerable modifications, alterations, combinations, and equivalents in form and function, without departing from the scope of this disclosure.
The present disclosure relates generally to multilateral wellbores and, more particularly, to an expandable bullnose assembly that works with a wellbore deflector to allow entry into more than one lateral wellbore of a multilateral wellbore.
Disclosed is a bullnose assembly that is able to expand its diameter while downhole such that it is able to be accurately deflected into either a main wellbore or a lateral wellbore using a deflector. The deflector has a first channel that communicates to lower portions of the main wellbore, and a second channel that communicates with the lateral wellbore. If the diameter of the bullnose assembly is smaller than the diameter of the first channel, the bullnose assembly will be directed into the lower portions of the main wellbore. Alternatively, if the diameter of the bullnose assembly is larger than the diameter of the first channel, the bullnose assembly will be directed into the lateral wellbore. The variable nature of the disclosed bullnose assemblies allows for selective and repeat re-entry of any number of stacked multilateral wells having multiple junctions that are each equipped with the deflector.
Referring to
In some embodiments, the main bore 102 may be lined with a casing string 108 or the like, as illustrated. The lateral bore 104 may also be lined with casing string 108. In other embodiments, however, the casing string 108 may be omitted from the lateral bore 104 such that the lateral bore 104 may be formed as an “open hole” section, without departing from the scope of the disclosure.
In some embodiments, a tubular string 110 may be extended within the main bore 102 and a deflector 112 may be arranged within or otherwise form an integral part of the tubular string 110 at or near the junction 106. The tubular string 110 may be a work string extended downhole within the main bore 102 from the surface location and may define or otherwise provide a window 114 therein such that downhole tools or the like may exit the tubular string 110 into the lateral bore 104. In other embodiments, the tubular string 110 may be omitted and the deflector 112 may instead be arranged within the casing string 108, without departing from the scope of the disclosure.
As discussed in greater detail below, the deflector 112 may be used to direct or otherwise guide a bullnose assembly (not shown) either further downhole within the main bore 102, or into the lateral bore 104. To accomplish this, the deflector 112 may include a first channel 116a and a second channel 116b. The first channel 116a may exhibit a predetermined width or diameter 118. Any bullnose assemblies that are smaller than the predetermined diameter 118 may be directed into the first channel 116a and subsequently to lower portions of the main bore 102. In contrast, bullnose assemblies that are greater than the predetermined diameter 118 may slidingly engage a ramped surface 120 that forms an integral part or extension of the second channel 116b and otherwise serves to guide or direct a bullnose assembly into the lateral bore 104.
Referring now to
As illustrated, the deflector 112 may provide the first channel 116a and the second channel 116b, as generally described above. The deflector 112 may further provide or otherwise define the ramped surface 120 (not shown in
Referring now to
To accomplish this, the bullnose assembly 300 may include a body 302 and a bullnose tip 304 coupled or otherwise attached to the distal end of the body 302. In some embodiments, the bullnose tip 304 may form an integral part of the body 302 as an integral extension thereof. As illustrated, the bullnose tip 304 may be rounded off at its end or otherwise angled or arcuate such that it does not present sharp corners or angled edges that might catch on portions of the main bore 102 or the deflector 112 (
The bullnose assembly 300 is shown in
In some embodiments, the bullnose assembly 300 may include a piston 308 movably arranged within a piston chamber 310 defined within the bullnose tip 304. The piston 308 may be operatively coupled to a wedge member 312 disposed about the body 302 such that movement of the piston 308 correspondingly moves the wedge member 312. In the illustrated embodiment, one or more coupling pins 314 (two shown) may operatively couple the piston 308 to the wedge member 312. More particularly, the coupling pins 314 may extend between the piston 308 and the wedge member 312 through corresponding longitudinal grooves 316 defined in the body 302.
In other embodiments, however, the piston 308 may be operatively coupled to the wedge member 312 using any other device or coupling method known to those skilled in the art. For example, in at least one embodiment, the piston 308 and the wedge member 312 may be operatively coupled together using magnets (not shown). In such embodiments, one magnet may be installed in one of the piston 308 and the wedge member 312, and another corresponding magnet may be installed in the other of the piston 308 and the wedge member 312. The magnetic attraction between the two magnets may be such that movement of one urges or otherwise causes corresponding movement of the other.
The bullnose tip 304 may include a sleeve 318 and an end ring 319, where the sleeve 318 and the end ring 319 may form part of or otherwise may be characterized as an integral part of the bullnose tip 304. Accordingly, the bullnose tip 304, the sleeve 318, and the end ring 319 may cooperatively define the “bullnose tip.” As illustrated, the sleeve 318 generally interposes the end rig 319 and the bullnose tip 304. The wedge member 312 may be secured about the body 302 between the sleeve 318 and the bullnose tip 304. More particularly, the wedge member 312 may be movably arranged within a wedge chamber 320 defined at least partially between the sleeve 318 and the bullnose tip 304 and the outer surface of the body 302. In operation, the wedge member 312 may be configured to move axially within the wedge chamber 320.
The bullnose assembly 300 may further include a coil 322 wrapped about the bullnose tip 304. More particularly, the coil 322 may be arranged within a gap 324 defined between the sleeve 318 and the bullnose tip 304 and otherwise sitting on or engaging a portion of the wedge member 312. The coil 322 may be, for example, a helical coil or a helical spring that is wrapped around the bullnose tip 304 one or more times. In other embodiments, however, the coil 322 may be a series of snap rings or the like. In the illustrated embodiment, two wraps or revolutions of the coil 322 are shown, but it will be appreciated that more than two wraps (or a single wrap) may be employed, without departing from the scope of the disclosure. In the default configuration (
In some embodiments, the outer radial surface 326a of each wrap of the coil 322 may be generally planar, as illustrated. The inner radial surface 326b and the axial sides 326c of each wrap of the coil 322 may also be generally planar, as also illustrated. As will be appreciated, the generally planar nature of the coil 322, and the close axial alignment of the sleeve 318 and the bullnose tip 304 with respect to the coil 322, may prove advantageous in preventing the influx of sand or debris into the interior of the bullnose tip 304.
Referring now to
As the piston 308 translates axially within the piston chamber 310, it engages a biasing device 332 arranged within the piston chamber 310. In some embodiments, the biasing device 332 may be a helical spring or the like. In other embodiments, the biasing device 332 may be a series of Belleville washers, an air shock, or the like, without departing from the scope of the disclosure. In some embodiments, the piston 308 may define a cavity 334 that receives at least a portion of the biasing device 332 therein. Moreover, the bullnose tip 304 may also define or otherwise provide a stem 336 that extends axially from the distal end of the bullnose tip 304 in the uphole direction (i.e., to the left in
Moreover, as the piston 308 translates axially within the piston chamber 310, the wedge member 312 correspondingly moves axially since it is operatively coupled thereto. In the illustrated embodiment, as the piston 308 moves, the coupling pins 314 translate axially within the corresponding longitudinal grooves 316 and thereby move the wedge member 312 in the same direction. As the wedge member 312 axially advances within the wedge chamber 320, the wedge member 312 engages the coil 322 at a beveled surface 338 that forces the coil 322 radially outward to the second diameter 306b.
Once it is desired to return the bullnose assembly 300 to its default configuration, the hydraulic pressure on the bullnose assembly 300 may be released. Upon releasing the hydraulic pressure, the spring force built up in the biasing device 332 may force the piston 308 back to its default position, thereby correspondingly moving the wedge member 312 and allowing the coil 322 to radially contract to the position shown in
Those skilled in the art, however, will readily recognize that several other methods may equally be used to actuate the wedge member 312, and thereby move the bullnose assembly 300 between the default configuration (
In yet other embodiments, the present disclosure further contemplates actuating the wedge member 312 by using fluid flow around or flowing past the bullnose assembly 300. In such embodiments, one or more ports (not shown) may be defined through the bullnose tip 304 such that the piston chamber 310 is placed in fluid communication with the fluids outside the bullnose assembly 300. A fluid restricting nozzle may be arranged in one or more of the ports such that a pressure drop is created across the bullnose assembly 300. Such a pressure drop may be configured to force the piston 308 toward the actuated configuration (
While the bullnose assembly 300 described above depicts the bullnose tip 304 as moving between the first and second diameters 306a,b, where the first diameter is less than the predetermined diameter 118 and the second diameter is greater than the predetermined diameter 118, the present disclosure further contemplates embodiments where the dimensions of the first and second diameters 306a,b are reversed. More particularly, the present disclosure further contemplates embodiments where the bullnose tip 304 in the default configuration may exhibit a diameter greater than the predetermined diameter 118 and may exhibit a diameter less than the predetermined diameter 118 in the actuated configuration, without departing from the scope of the disclosure. Accordingly, actuating the bullnose assembly 300 may entail a reduction in the diameter of the bullnose tip 304, without departing from the scope of the disclosure.
Referring now to
Referring now to
Referring now to
More particularly, the bullnose assembly 700 is shown in
In contrast, the bullnose assembly 700 is shown in
In order to move between the default and actuated configurations, the bullnose assembly 700 may include a piston 704 arranged within a piston chamber 706. The piston chamber 706 may be defined within a collet body 708 coupled to or otherwise forming an integral part of the bullnose tip 304. The collet body 708 may define a plurality of axially extending fingers 710 (best seen in
The piston 704 may include a piston rod 714. The piston rod 714 may be actuated axially in order to correspondingly move the piston 704 within the piston chamber 706 such that the wedge member 713 is able to interact with the radial protrusion 712. In some embodiments, similar to the piston 308 of
As the piston 704 moves axially within the piston chamber 706, it compresses a biasing device 716 arranged within the piston chamber 706. Similar to the biasing device 332 of
Moreover, as the piston 704 moves axially within the piston chamber 706, the wedge member 713 engages the radial protrusion 712 and forces the axially extending fingers 710 radially outward. This is seen in
Referring again to
Accordingly, which bore (e.g., the main bore 102 or the lateral bore 104) a bullnose assembly 300, 700 enters is primarily determined by the relationship between the diameter of the bullnose tip 304 and the predetermined diameter 118 of the first channel 116a. As a result, it becomes possible to “stack” multiple junctions 106 (
Referring to
At each junction 106a,b, a lateral bore 104 (shown as first and second lateral bores 104a and 104b, respectively) extends from the main bore 102. The deflector 112 of
In exemplary operation, an expandable bullnose assembly, such as the bullnose assemblies 300, 700 described herein, may be introduced downhole and actuated in order to enter the first and second lateral bores 104a,b at each junction 106a,b, respectively. For instance, if it is desired to enter the first lateral bore 104a, the bullnose assembly 300, 700 may be actuated prior to reaching the deflector 112 at the first junction 106a. As a result, the bullnose assembly 300, 700 will exhibit the second diameter 306b, 702b and thereby be directed into the second channel 116b since the second diameter 306b, 702b is greater than the predetermined diameter 118 of the first channel 116a. Otherwise, the bullnose assembly 300, 700 may remain in its default configuration with the first diameter 306a, 702a and pass through the first channel 116a of the deflector 112 at the first junction 106a.
Once past the first junction 106a, the bullnose assembly 300, 700 may enter the second lateral bore 104b by being actuated prior to reaching the deflector 112 at the second junction 106b. As a result, the bullnose assembly 300, 700 will again exhibit the second diameter 306b, 702b and thereby be directed into the second channel 116b at the deflector 112 of the second junction 106b since the second diameter 306b, 702b is greater than the predetermined diameter 118 of the first channel 116a. If it is desired to pass through the deflector 112 of the second junction 106b and into the lower portions of the main bore 102, the bullnose assembly 300, 700 may remain in its default configuration with the first diameter 306a, 702a and pass through the first channel 116a of the deflector 112 at the second junction 106b.
Embodiments disclosed herein include:
A. A well system that includes a deflector arranged within a main bore of a wellbore and defining a first channel that exhibits a predetermined diameter and communicates with a lower portion of the main bore, and a second channel that communicates with a lateral bore, and a bullnose assembly including a body and a bullnose tip arranged at a distal end of the body, the bullnose tip being actuatable between a default configuration, where the bullnose tip exhibits a first diameter, and an actuated configuration, where the bullnose tip exhibits a second diameter different than the first diameter, wherein the deflector is configured to direct the bullnose assembly into one of the lateral bore and the lower portion of the main bore based on a diameter of the bullnose tip as compared to the predetermined diameter.
B. A bullnose assembly that includes a body, and a bullnose tip arranged at a distal end of the body, the bullnose tip being configured to move between a default configuration, where the bullnose tip exhibits a first diameter, and an actuated configuration, where the bullnose tip exhibits a second diameter that is different than the first diameter.
C. A multilateral wellbore system that includes a main bore having a first junction and a second junction spaced downhole from the first junction, a first deflector arranged at the first junction and defining a first channel that exhibits a predetermined diameter and communicates with a first lower portion of the main bore, and a second channel that communicates with a first lateral bore, a second deflector arranged at the second junction and defining a third channel that exhibits the predetermined diameter and communicates with a second lower portion of the main bore, and a fourth channel that communicates with a second lateral bore, and a bullnose assembly including a body and a bullnose tip arranged at a distal end of the body, the bullnose assembly being configured to move between a default configuration, where the bullnose tip exhibits a first diameter, and an actuated configuration, where the bullnose tip exhibits a second diameter that is different than the predetermined diameter, wherein the first and second deflectors are configured to direct the bullnose assembly into one of the first and second lateral bores and the first and second lower portions of the main bore based on a diameter of the bullnose tip as compared to the predetermined diameter.
Each of embodiments A, B, and C may have one or more of the following additional elements in any combination: Element 1: wherein the deflector further includes a ramped surface that guides the bullnose assembly to the second channel when the diameter of the bullnose tip is greater than the predetermined diameter. Element 2: wherein the first diameter is less than the predetermined diameter and the second diameter is greater than both the first diameter and the predetermined diameter, and wherein, when the bullnose tip exhibits the first diameter, the bullnose assembly is directed into the first channel and the lower portion of the main bore, and wherein, when the bullnose tip exhibits the second diameter, the bullnose assembly is directed into the second channel and the lateral bore. Element 3: wherein the bullnose assembly further includes a piston movably arranged within a piston chamber defined within the bullnose tip, a wedge member operatively coupled to the piston such that movement of the piston correspondingly moves the wedge member, and a coil arranged about the bullnose tip and in contact with the wedge member, the piston being actuatable such that the wedge member is moved to radially expand the coil, wherein, when the coil is radially expanded, the diameter of the bullnose tip exceeds the predetermined diameter. Element 4: wherein the piston is actuatable using at least one of hydraulic pressure acting on the piston, an actuating device operatively coupled to the piston, and a pressure drop created across the bullnose assembly that forces the piston to move within the piston chamber. Element 5: wherein the bullnose assembly further includes a collet body forming at least part of the bullnose tip and defining a plurality of axially extending fingers, a radial protrusion defined on an inner surface of the collet body and extending radially inward from each axially extending finger, and a piston movably arranged within a piston chamber defined within the collet body and having a wedge member defined on an outer surface thereof, the piston being actuatable such that the wedge member engages the radial protrusion and forces the plurality of axially extending fingers radially outward, wherein, when the plurality of axially extending fingers is forced radially outward, the diameter of the bullnose tip exceeds the predetermined diameter. Element 6: wherein the piston is actuatable using at least one of hydraulic pressure acting on the piston, an actuating device operatively coupled to the piston, and a pressure drop created across the bullnose assembly that forces the piston to move within the piston chamber. Element 7: wherein the first diameter is greater than the predetermined diameter and the second diameter is less than both the first diameter and the predetermined diameter, and wherein, when the bullnose tip exhibits the first diameter, the bullnose assembly is directed into the second channel and the lateral bore, and wherein, when the bullnose tip exhibits the second diameter, the bullnose assembly is directed into the first channel and the lower portion of the main bore.
Element 8: wherein the first diameter is less than the predetermined diameter and the second diameter is greater than both the first diameter and the predetermined diameter, and wherein when the bullnose assembly is in the default configuration it is able to be directed into the first and third channels and the first and second lower portions of the main bore, respectively, and wherein, when the bullnose assembly is in the actuated configuration it is able to be directed into the second and fourth channels and the first and second lateral bores, respectively. Element 9: wherein the first diameter is greater than the predetermined diameter and the second diameter is less than both the first diameter and the predetermined diameter, and wherein when the bullnose assembly is in the default configuration it is able to be directed into the second and fourth channels and the first and second lateral bores, respectively, and wherein, when the bullnose assembly is in the actuated configuration it is able to be directed into the first and third channels and the first and second lower portions of the main bore. Element 10: wherein the first and second deflectors each include a ramped surface that guides the bullnose assembly to the second and fourth channels, respectively, when the bullnose assembly is in the actuated configuration.
Therefore, the disclosed systems and methods are well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the teachings of the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope of the present disclosure. The systems and methods illustratively disclosed herein may suitably be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein. While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces. If there is any conflict in the usages of a word or term in this specification and one or more patent or other documents that may be incorporated herein by reference, the definitions that are consistent with this specification should be adopted.
Filing Document | Filing Date | Country | Kind |
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PCT/US13/52087 | 7/25/2013 | WO | 00 |