Milling systems for a subterranean borehole
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- WELLBORE INTEGRITY SOLUTIONS LLC
- Filing Date
- 2026-01-29
- Publication Date
- 2026-08-06
Smart Images
Figure US2026012985_06082026_PF_FP_ABST
Abstract
Description
PATENTAttorney Docket No.: WBRE / 0013PCMILLING SYSTEMS FOR A SUBTERRANEAN BOREHOLE CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S. provisional patent application serial number 63 / 752,320, filed on January 31, 2025, and entitled “Milling Systems For A Subterranean Borehole,” the contents of which are incorporated by reference in their entirety and for all purposes.BACKGROUND
[0002] A borehole may be drilled into a subterranean formation to access valuable resources, such as hydrocarbons, including oil and natural gas. To maintain structural integrity and prevent collapse, portions of the borehole are commonly lined with a casing pipe (“casing”), which provides a conduit for fluids, equipment, and other tubular components. When economically recoverable resources have been depleted, or under other operational circumstances, it may become necessary or desirable to plug and abandon the borehole. This process generally involves severing the casing and subsequently sealing the severed section with cement or another suitable sealing material.SUMMARY
[0003] One or more embodiments disclosed herein are directed to a section milling assembly for milling a casing of a borehole. The section milling assembly includes a body having a central axis and a mill block that is configured to be radially extended out of the body. The mill block includes a radially outer side, a radially inner side relative to the central axis, and a recess formed on the radially inner side. In addition, the section milling assembly includes a milling blade pivotably coupled to the mill block and a shield that is coupled to the mill block such that the shield is configured to at least partially cover the recess when the mill block is radially extended out of the body.
[0004] One or more embodiments disclosed herein are directed to a bottom hole assembly (BHA). The BHA includes a centralizer including one or more centralizing blades that are configured to engage with an inner surface of a casing in a borehole and a reamer including one or more reaming blades that are configured to ream out a section in the borehole. In addition, the BHA includes a section milling assembly coupled to the centralizer and the reamer that is configured to mill the casing. ThePATENTAttorney Docket No.: WBRE / 0013PCsection milling assembly includes a body having a central axis and a mill block that is configured to be radially extended out of the body. The mill block includes a radially outer side, a radially inner side relative to the central axis, and a recess formed on the radially inner side. In addition, the section milling assembly includes a milling blade pivotably coupled to the mill block and a shield that is coupled to the mill block such that the shield is configured to at least partially cover the recess when the mill block is radially extended out of the body.
[0005] One or more embodiments disclosed herein are directed to a method of milling a casing of a borehole. The method includes (a) introducing a section milling assembly into the borehole and (b) extending a mill block from a body of the section milling assembly. In addition, the method includes (c) pivotably extending a blade from the mill block and (d) extending a shield from the body to at least partially cover a recess on the mill block during (b). Further, the method includes (e) rotating the body to mill a casing in the borehole by use of the blade.BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For a detailed description of various exemplary embodiments, reference will now be made to the accompanying drawings in which:
[0007] FIGS. 1-5 are schematic views of a milling system and an associated milling and plugging operation for a borehole extending into a subterranean formation according to one or more embodiments, which may be combined with other embodiments;
[0008] FIG. 6 is a side view of a section milling assembly for use in the milling system of FIG. 1 according to one or more embodiments, which may be combined with other embodiments;
[0009] FIGs. 7 and 8 are side cross-sectional views of the section milling assembly of FIG. 6 in a retracted and extended position, respectively, according to one or more embodiments, which may be combined with other embodiments;
[0010] FIGs. 9 and 10 are enlarged, perspective views of the section milling assembly of FIG. 6 in the retracted and extended position, respectively, according to one or more embodiments;PATENTAttorney Docket No.: WBRE / 0013PC
[0011] FIG. 11 is a side view of a mill block of the section milling assembly of FIG.6 according to one or more embodiments, which may be combined with other embodiments;
[0012] FIGs. 12 and 13 are side views of a shield that may be used to cover a relief on the mill block of FIG. 11 according to one or more embodiments, which may be combined with other embodiments;
[0013] FIG. 14 is an enlarged perspective view of the mill block of FIG. 11 according to one or more embodiments, which may be combined with other embodiments;
[0014] FIGs. 15 and 16 are schematic side views illustrating the relative positions of the mill block of FIG. 11 and the shield of FIGs. 12 and 13 when the severing mill assembly is in the retracted and extended positions, respectively, according to one or more embodiments, which may be combined with other embodiments;
[0015] FIG. 17 is a perspective view of the shield of FIGs. 12 and 13 that illustrates a slot for limiting a movement according to one or more embodiments, which may be combined with other embodiments;
[0016] FIG. 18 is a cross-sectional view of a guide pin engaged within the slot illustrated in FIG. 17 according to one or more embodiments, which may be combined with other embodiments;
[0017] FIGs. 19 and 20 are schematic side views illustrating the relative position of the guide pin of FIG. 18 in the slot of FIG. 17 when the severing mill assembly is in the retracted and extended positions, respectively, according to one or more embodiments, which may be combined with other embodiments; and
[0018] FIG. 21 is a cross-sectional view taken along section A-A in FIG. 6 according to one or more embodiments, which may be combined with other embodiments.DETAILED DESCRIPTION
[0019] A borehole may be plugged and abandoned at the end of its production life or for other reasons. In some cases, a borehole may be plugged by introducing cement. It is often desirable to sever or mill a tubular in the section of the borehole to be plugged for introducing cement to contact and creating a seal or barrier against the exposed rock of the formation. Milling tools or bottom hole assemblies (BHA) forPATENTAttorney Docket No.: WBRE / 0013PCperforming the pre-cement milling operation may include one or more milling devices with expandable blades. However, cuttings or other debris can sometimes become lodged during operations in the blades or the receptacles for the blades. Lodged debris may may lead to a number of operationally negative outcomes, including a stuck tool due to an inability to fully withdrawal the deployed blades or a damaged tool. A stuck or damaged tool could cause the operator to trip in and out of the hole to replace the tool, fish for a stuck or damaged tool remaining in the wellbore that could not be withdrawn with the drill string, or, more severely, intervene in the wellbore bypassing the damaged tool, such as by drilling around the obstruction.
[0020] Accordingly, embodiments disclosed include milling systems for a subterranean borehole that are configured to reduce the risk of obstructions that may prevent the deployment or withdrawal of a milling blade or other deployable feature. In one or more embodiments, which may be combined with other embodiments, a milling assembly may include one or more shields that are configured to deploy with one or more milling blades to block the cuttings or other debris from entering the internal cavities of the milling system. Thus, through use of the embodiments disclosed, the risk of obstruction of the deployable milling blades in a downhole milling system may be reduced so that the efficiency and reliability of such an operation may be improved.
[0021] FIGs. 1-5 illustrate a milling system 10 and an associated sequence for milling and plugging a borehole 20 extending into a subterranean formation 12 (“formation 12”) by use of the milling system 10. The milling system 10 and the associated milling and plugging operation may be utilized to abandon the borehole 20.
[0022] Referring first to FIG. 1, the borehole 20 as defined may extend from the surface 5 through formation 12, where the borehole 20 has a centerline or axis 25 generally following the borehole 20. In the embodiment illustrated in FIG. 1, both the borehole 20 and the axis 25 are shown extending vertically, that is along the direction of gravity, so that the borehole 20 may be referred to as a vertical borehole. However, it should be appreciated by those of skill in the art that embodiments disclosed may be used in boreholes that are vertical; substantially vertical; deviated, such that the borehole is at least partially oriented in a both non-vertical and non-horizontal direction; substantially horizontal, such as a lateral direction that extends substantiallyPATENTAttorney Docket No.: WBRE / 0013PCnormal to the direction of gravity; and horizontal. Thus, the vertical orientation of axis 25 and borehole 20 shown in FIG. 1 is exemplary of one or more embodiments and is not limiting.
[0023] A casing pipe 30 (“casing 30”) is introduced within the borehole 20 to prevent a collapse of the borehole 20 and to provide a conduit for fluids and equipment into and out of the borehole 20. The casing 30 may be secured in some instances to the inner wall 26 of the borehole 20 with cement 32.
[0024] The casing 30 may extend along the entire axial length of the borehole 20 or may only extend along a portion of the borehole 20, such as a portion that extends from the surface 5. While only a single casing 30 is shown, it should be appreciated by those of skill in the art that the borehole 20 may include a plurality of casings or other tubulars which may be nested within one another.
[0025] The milling system 10 may include a bottom hole assembly (BHA) 100 that is introduced into the borehole 20 via the interior of casing 30. The BHA 100 may be more broadly referred to as a “tool assembly.” The BHA 100 may be suspended on the downhole end of a tool string 50 that extends from the surface 5 downhole. The tool string 50 may comprise a series of coupled elongate tubulars that in total extend downhole within borehole 20. For instance, the tool string 50 may comprise a plurality of tubular members that are coupled or connected, such as through threaded connections, end-to-end. As another example, the tool string 50 may comprise a single, continuous tubular member or conduit, such as coiled tubing, introduced downhole from a spool at the surface.
[0026] The BHA 100 may include a first or uphole end 100a where a coupling to the tool string 50 occurs, and a second or downhole end 100b that is opposite the uphole end 100a. In addition, the BHA 100 may include a plurality of components that are coupled end-to-end between the ends 100a, 100b. For instance, the BHA 100 may include a plug 110 positioned at or proximate to the downhole end 100b; a stabilizer or centralizer 120 that is positioned axially adjacent and uphole relative to the plug 110; a section milling assembly 130 that is positioned axially adjacent and uphole relative to the stabilizer 120; and a reamer 170 that is positioned at or proximate to the uphole end 100a that is positioned axially adjacent and uphole relative to the section milling assembly 130. A person of ordinary skill in the art appreciates that the specific axial positions or arrangements of these components ofPATENTAttorney Docket No.: WBRE / 0013PCthe BHA 100 relative to one another may be altered in other embodiments. In addition, while a particular component of the BHA 100 may be shown as being immediately adjacent to another component in an uphole or downhole manner, it should be appreciated by those of skill in the art that additional components or spacings may be positioned between components that are shown as being adjacent in the schematic representations of FIGs. 1-5. Further, in one or more embodiments, which may be combined with other embodiments, the relative positioning of the components of the BHA 100 between the ends 100a, 100b may be altered relative to the arrangement shown in FIG. 1.
[0027] Initially, as shown in FIGs. 1 and 2, the BHA 100 is introduced into the borehole 20 so that the plug 110 is positioned at a target depth. Thereafter, as shown in FIG. 2, one or more sealing assemblies 112 are actuated on the plug 110 to affix or secure the plug 110 to the inner surface of the casing 30 and to prevent or at least restrict fluid communication across the plug 110 within the casing 30, such as between portions of the interior of the casing 30 uphole and downhole of the plug 110.
[0028] Next, as shown in FIGs. 2 and 3, the BHA 100 without the plug 110 is tripped uphole of the actuated plug 110 to a milling position, where a milling operation within the borehole 20 may be initiated. Specifically, one or more centralizing blades 122 are actuated out of the stabilizer 120 to engage with an inner surface of the casing 30. In addition, one or more milling blades 132 (“blades 132”) are actuated radially outward from the section milling assembly 130. The BHA 100 is also rotated about the axis 25. In one or more embodiments, which may be combined with other embodiments, the BHA 100 may be rotated about axis 25 via suitable surface equipment 13 positioned at the surface 5, such as a kelly drive, power swivel, rotary table, top drive, or combinations thereof. In one or more embodiments, which may be combined with other embodiments, the BHA 100 may include or be coupled to one or more downhole systems or devices for rotating one or more components of the BHA 100, including stabilizer 120, section milling assembly 130, and reamer 170. For example, such downhole systems and devices may include a mud or drilling fluid motor, a positive displacement motor, a turbine motor, a rotary steerable system, a downhole electric motor, or combinations thereof. The actuation of the centralizing blades 122 and the blades 132 may be accomplished via any suitable mechanism orPATENTAttorney Docket No.: WBRE / 0013PCmethod, such as, for instance, hydraulic actuation, electrical actuation, tensile actuation, or combinations thereof.
[0029] As the BHA 100 is rotated about the axis 25, the drill string is advanced downhole. During this combined rotation and downhole advancement along the axis 25, the blades 132 engage with (“bite into”) the inner surface of the casing 30, as shown initiated in FIG. 2, and mill away an entire section of the casing 30, as shown progressed downhole in FIG. 3, defining a milled section. In some instances, along with a portion of the casing, potentially some of the cement 32 surrounding the casing 30 may be milled away as well, such as shown with milled section 21. During this process, the centralizing blades 122 may maintain contact with the inner surface of the casing 30, downhole of the blades 132 and the milled section 21 to centralize the BHA 100.
[0030] After the section milling assembly 130 mills away the casing 30 and defines the milled section 21 (see FIG. 3), the BHA 100 may then be raised uphole toward to the uphole end of the milled section 21 (not shown). The reamer 170 may then be actuated to deploy one or more reaming blades 172. The reamer blades 172 may be actuated via any suitable actuation mechanism or method, such as hydraulic actuation, electrical actuation, or tensile actuation, as previously described. The reamer blades 172 may expand radially outward to a greater diameter than the blades 132 of the section milling assembly 130. As shown in FIG. 4, rotating the BHA 100 about the axis 25 in conjunction with advancing the BHA 100 downhole while the reamer blades 172 are deployed may allow the reamer blades 172 to remove the cement 32 and some of the rock of the formation 12 along the milled section 21, converting at least a portion of the milled section 21 into a new, open section 22 within the formation 12, as shown in FIG. 4. The newly exposed portion of the formation 12 defining the open section 22 may be positioned axially between a first or uphole section 20a of the borehole 20 that extends from the surface 5 to the open section 22 and a second or downhole section 20b of the borehole 20 that extends downhole from the open section 22 along axis 25 to the face of the borehole. As shown in FIG. 4, the radius, as determined form the centerline or axis 25 to the outer edge of the open section 22 is greater than the radius from the centerline 25 to the outer edge of the milled section 21, as shown previously in FIG. 3.PATENTAttorney Docket No.: WBRE / 0013PC
[0031] In one or more embodiments, which may be combined with other embodiments, the blades 132 of the section milling assembly 130 may mill the casing 30 to define a milled section, such as milled section 21 of FIG. 3, and the reamer blades 172 may further ream out at least a portion of the milled section 21 to define an open section, such as open section 22 of FIG. 4, during a single downhole translation of the BHA 100.
[0032] After the open section 22 has been formed in formation 12 via work performed in borehole 20, the BHA 100 and tool string 50 may be pulled or “tripped” to the surface 5. Thereafter, as shown in FIG. 5, a cement 24 or other plugging material may be introduced into the borehole 20 so that the open section 22 and portions of the lower section 20b extending axially from open section 22 to the plug 110 are filled within cement 24. The contact between the cement 24 and the exposed rock of the formation in the open section 22 may provide an enhanced seal that is configured to prevent the migration of fluids into the upper section 20a of borehole 20 thereafter either through the interior of the casing or through the casing-borehole annulus, as the milling, reaming, and cementing mitigates both potential fluid pathways.
[0033] Referring now to FIG. 6, an embodiment section milling assembly, such as the section milling assembly 130 of the BHA 100 of FIG. 1 , is shown according to one or more embodiments, which may be combined with other embodiments. The section milling assembly 130 may include a tubular body 134 having a central or longitudinal axis 135 (“axis 135”), a first or uphole end 130a, and a second or downhole end 130b opposite the uphole end 130a along the axis 135. The axis may be substantially aligned with the axis of a borehole, such as the axis of borehole 20 of FIG. 1, when the BHA 100 is introduced.
[0034] The section milling assembly 130 may include a pair of blades 132. The blades 132 may be positioned radially opposite one another about the axis 135. Each blade 132 may be pivotably coupled to a mill block 136, such as via a pinned connection (see pinned connections 141 in FIGs. 7 and 8). During operations, the mill blocks 136 may be radially extended from the body 134, and the blades 132 may be further radially extended by pivoting radially outward from the mill blocks 136, such as shown in FIG. 6.PATENTAttorney Docket No.: WBRE / 0013PC
[0035] Specifically, reference is now made to FIGs. 7-10. FIGs. 7 and 8 show side cross-sectional views of the section milling assembly 130 of FIG. 6, according to one or more embodiments, which may be combined with other embodiments. FIG. 7 shows the section milling assembly 130 in a retracted position, with the mill blocks 136 and blades 132 radially retracted into the tubular body 134. Conversely, FIG. 8 shows the section milling assembly 130 in an extended position, with the mill blocks 136 and blades 132 extended radially outward from the tubular body 134.
[0036] Similarly, FIGs. 9 and 10 show enlarged perspective views of the section milling assembly 130 of FIG. 6. FIG. 9 shows the section milling assembly 130 in the retracted position of FIG. 7, and FIG. 10 shows the section milling assembly 130 in the extended position of FIG. 8.
[0037] Referring to FIG. 7, the tubular body 134 may define a throughbore 138 that extends axially between the ends 130a, 130b. A first or uphole connector 140 and a second or downhole connector 142 may be defined in the throughbore 138 at or proximate to the uphole end 130a and downhole end 130b, respectively. In one or more embodiments, which may be combined with other embodiments, the connectors may each comprise threaded connectors, such as box threaded connectors, that are configured to couple or connect to adjacent components, such as stabilizer 120 and reamer 170, of the BHA 100 as shown in FIGs. 1 -4.
[0038] A radially extending slot 139 defined by body 134 to extend radially through the body 134, across the axis 135, and the throughbore 138. When the section milling assembly 130 is in the retracted position of FIG. 7, the mill blocks 136 and blades 132 may be recessed radially into the slot 139.
[0039] A first or uphole mounting collar 144 may be engaged, such as threadably engaged, within the throughbore 138 axially between the slot 139 and the uphole end 130a. A second or downhole mounting collar 146 may be engaged, such as threadably engaged, within the throughbore 138 axially between the slot 139 and the downhole end 130b. A piston 148 may be at least partially positioned in the throughbore 138 axially between the mill blocks 136 and the downhole mounting collar 146. The piston 148 may be coupled to an engagement block 149 that is further engaged with the mill blocks 136.
[0040] A central flow tube 150 is coupled to or connected to the uphole mounting collar 144 and extends axially downhole from the mounting collar 144, across the slotPATENTAttorney Docket No.: WBRE / 0013PC139, and at least partially through the piston 148. The flow tube 150 may allow fluid communication between the uphole end 130a and the downhole end 130b across the slot 139 during operations.
[0041] A biasing member 152 may be positioned axially between the uphole mounting collar 144 and the mill blocks 136. The biasing member 152 may comprise one or more coiled springs, such as shown in FIGs 7-8, but it is appreciated that any suitable axial biasing member or assembly may be utilized. The biasing member 152 may be received into a retention housing 154 that is coupled or connected, such as threadedly secured, within the throughbore 138, positioned axially adjacent to the uphole mounting collar 144. The biasing member 152 may also abut an actuation block 156 that is engaged with the mill blocks 136. The biasing member 152 may axially bias the engagement block 156, mill blocks 136, engagement block 149, and piston 148 axially toward the downhole end 130b until the piston 148 is engaged with the downhole mounting collar 146.
[0042] As shown in the sequence from FIG. 7 to FIG. 8, to radially expand the mill blocks 136 and blades 132 relative to the axis 135, either or both the pressure of the fluid in throughbore 138 or the flow rate of the fluid through the throughbore 138 may be increased. The increased fluid pressure or flow rate is communicated through the flow tube 150 and into the piston 148. The increased fluid pressure or flow rate or flow rate may communicate an increase in pressure against the piston 148. When the pressure applied to the piston 148 is greater than the biasing force applied by the biasing member 152, the piston 148 may translate axially uphole and away from the downhole mounting collar 146. The axial movement of the piston 148 compresses the engagement block 149 against the mill blocks 136. Compression of the engagement block 149 against the mill blocks 136 forces the mill blocks 136 to move axially uphole within the slot 139 and press against the biasing member 152, countering the bias of the biasing member 152.
[0043] Referring now to FIGs. 9 and 10, each of the mill blocks 136 may include a plurality of splines or ribs 137. As is illustrated in FIGs. 6 and FIG. 11, the splines 137 may each be oriented at a non-zero angle 6 relative to the central axis 135 such that the splines 137 generally slant in an uphole direction when moving radially outward along the mill blocks 136. In one or more embodiments, which may be combined withPATENTAttorney Docket No.: WBRE / 0013PCother embodiments, the angle 0 may be an acute angle having a range that is greater than 0°and less than 90°.
[0044] Referring to FIGs. 9 and 10, the edges 133 of the slot 139 defined by both 134 may have a profile that includes a groves or waves that correspond to and intermesh with the splines 137. Thus, when the mill blocks 136 are translated axially uphole, the splines 137 may slidingly engage the corresponding edges 133 of the slot 139 as the mill blocks 136 project radially outward.
[0045] Referring to FIGs. 7 and 8, each of the blades 132 may be coupled to a corresponding mechanical link 158 (or “link 158”) that is pinned to both the blade 132 and either to the tubular body 134 or another component of section milling assembly 130. As the mill blocks 136 are moved axially uphole and expanded radially outward, as previously described, the links 158 may each rotate such that the blades 132 pivot and project radially outward relative to the mill blocks 136 about the pinned connections 141.
[0046] When the fluid pressure or flow rate of the fluid traversing the throughbore 138 is reduced, the biasing member 152 may axially translate the assembly of engagement block 156, mill blocks 136, engagement block 149, and piston 148, axially toward the downhole end 130b. As shown in FIGs. 9 and 10, the sliding engagement between the splines 137 and edges 133 of the slot 139 may cause the mill blocks 136 to radially retract into the slot 139 as the mill block 136 translates axially downhole. As shown in FIGs. 7 and 8, as the mill blocks 136 move axially downhole and radially into the slot 139, the links 158 may rotate to pivot the blades 132 radially inward about the pinned connections 141.
[0047] Referring now to FIG. 11, one of the mill blocks 136 of the section milling assembly 130 is shown in more detail according to one or more embodiments, which may be combined with other embodiments. The axis 135 of the section milling assembly, such as section milling assembly 130 of FIGs 6-9, is provided to show the general orientation of the mill block 136 relative to the axis 135. While only one of the mill blocks 136 of the section milling assembly 130 is shown, it should be appreciated by those of skill in the art that each of the mill blocks 136 may be similarly configured.
[0048] The mill block 136 generally includes a first or uphole end 136a and a second ordownhole end 136b. In addition, the mill block 136 includes a radially inner side 136c and a radially outer side 136d that both extend, such as axially extend,PATENTAttorney Docket No.: WBRE / 0013PCbetween the ends 136a, 136b. When the mill block 136 is coupled to the section milling assembly 130 of FIGS. 6-10, the radially inner side 136c may face radially inward toward the axis 135, and the radially outer side 136d may face radially outward from the axis 135.
[0049] Along the radially inner side 136c of mill block 136 is defined a radially extending relief or recess 160. The recesses 160 may be configured to provide sufficient clearance for internal components in the slot 139 so that the mill blocks 136 may be fully radially withdrawn during operations, such as seen in FIGs. 7 and 9. For instance, the recess 160 in each mill block 136 may be configured to provide clearance for the corresponding link 158 when the mill block 136 is fully radially withdrawn into the slot 139, such as shown in FIG. 7. However, when the mill blocks 136 are radially extended outward from the slot 139, such as shown in FIGs. 8 and 10, the recesses 160 may be at least partially exposed radially outside of the tubular body 134. Thus, during a milling operation, cuttings or other debris flowing along the borehole 20 may become lodged in the exposed recesses 160 so that subsequent withdrawal of the mill blocks 136 into the slot 139 may be prevented. Such an obstruction may cause the section milling assembly 130 to become stuck in the borehole or may cause damage the section milling assembly 130.
[0050] As shown in FIGs. 6, 9, and 10, the mill blocks 136 may include shields 200 that are configured to at least partially occlude the recesses 160 when the blades 132 and mill blocks 136 are radially extended outward from the slot 139 in the tubular body 134, such as seen in FIGs. 6 and 10. Specifically, as shown in FIGs. 6 and 10, as the mill blocks 136 are radially expanded out of the slot 139, the shields 200 may also be radially extended along with the mill blocks 136 to at least partially cover the recesses 160. The edges 133 of the slots 139 may be configured to define corresponding notches 131 that accommodate the shields 200. As will be described in more detail, the shields 200 may be passively actuated by the radial movement of the mill blocks 136 so that additional and independent actuation mechanisms for actively actuating the shields 200 may be avoided.
[0051] Referring to FIGs. 12 and 13, one of the shields 200 of the section milling assembly 130 is shown according to one or more embodiments, which may be combined with other embodiments. While only one of the shields 200 is shown in FIGs. 12 and 13, it should be appreciated by those of skill in the art that each of thePATENTAttorney Docket No.: WBRE / 0013PCshields 200 may be similarly configured. The shield 200 may comprise a flat plate having a first or outer side 201 and a second or inner side 203 opposite the outer side 201. The inner side 203 may be referred to as an “inner” side because it may face generally inward toward the corresponding mill block 136 when installed into the section milling assembly 130, such as seen in FIG. 10. The outer side 201 may be referred to as an “outer side” because it may face generally away from the corresponding mill block 136 when installed into the section milling assembly 130.
[0052] The shield 200 includes a first or radially inner edge 200a, a second or radially outer edge 200b opposite the radially inner edge 200a. The radially inner edge 200a may be positioned radially inward from the radially outer edge 200b relative to the axis 135 when the shield 200 is installed into the section milling assembly 130 as shown in FIGs. 9 and 10. The radially outer edge 200b may include a chamfer 208 that slopes upward when moving from the outer side 201 to the inner side 203. As may be appreciated in FIGs. 9 and 10, the chamfer 208 may deflect debris away from the mill block 136 and edge 133 of the slot 139 during operations.
[0053] FIGs. 12 and 13 show that the shield 200 may include a first lateral edge 200c and a second lateral edge 200d opposite the first lateral edge 200c. The first lateral edge 200c may be positioned generally uphole relative to the second lateral edge 200d when the shield 200 is installed into the section milling assembly 130 and the section milling assembly 130 is introduced into a borehole. Thus, the first lateral edge 200c may be referred to as an “uphole” edge and the second lateral edge 200d may be referred to as a “downhole” edge.
[0054] In one or more embodiments, which may be combined with other embodiments, the shield 200 may have a generally rhomboid shape. In some instances, the radially inner edge 200a and radially outer edge 200b may be parallel to one another, and the uphole edge 200c and downhole edge 200d may be parallel to one another. However, the uphole edge 200c and downhole edge 200d may not extend perpendicularly or orthogonally relative to the radially inner edge 200a and radially outer edge 200b. In one or more embodiments, which may be combined with other embodiments, when the shield 200 is installed into the section milling assembly 130 as shown in FIGs. 9 and 10, the radially inner edge 200a and radially outer edge 200b may extend axially or parallel to axis 135. In one or more embodiments, which may be combined with other embodiments, when the shield 200 is installed into thePATENTAttorney Docket No.: WBRE / 0013PCsection milling assembly 130 as shown in FIGs. 9 and 10, the uphole lateral edge 200c and downhole lateral edge 200d may extend along the same orientation as the splines 137 on the corresponding mill block 136, relative to axis 135, such as the angle 9 shown in FIGs. 6 and 11 and as previously described.
[0055] A notch or recess 206 defined along the radially inner edge 200a may at least partially correspond with the recess 160 as defined on the corresponding mill block, such as mill block 136 of FIGs. 6 and 11. The recess 206 may have a similar configuration, such as size and shape, to the recess 160 on the corresponding mill block 136. In addition, one or both of the sides 201 , 203 of the shield 200 may include a plurality of splines or ribs 205 that are configured to correspond with the splines 137 on the mill blocks 136. Like the splines 137 on mill block 136, the splines 205 on the outer side 201 of the shield 200 may engage or mesh with the notches 131 as defined as part of the profile on the edge 133 to guide the radial expansion or retraction of the shield 200 when the shield 200 and mill block 136 translate axially along axis 135. In addition, the splines 205 on the inner side 203 of the shield 200 may engage or mesh with the splines 137 on the corresponding mill block 136 to facilitate sliding engagement between the mill block 136 and shield 200 during operations.
[0056] The splines 205 may be oriented parallel to the lateral edges 200c, 200d between the radially inner edge 200a and radially outer edge 200b. Additional splines 202, 204 may be defined on the inner side 203 that are also parallel with the lateral edges 200c, 200d and the other splines 205. These additional splines 202, 204 may be used to radially actuate the shield 200 along with the corresponding mill block, such as mill block 136 of FIGs. 9 and 10, during operations. These additional splines 202, 204 may be referred to as “actuation splines.”
[0057] In one or more embodiments, which may be combined with other embodiments, the actuation splines 202, 204 may be configured to terminate part-way between the radially inner edge 200a and radially outer edge 200b. Specifically, a first actuation spline 202 may extend from the radially inner edge 200a to a terminal end 202a that is positioned between the edges 200a, 200b, and a second actuation spline 204 may extend from the radially outer edge 200b to a terminal end 204a that is positioned between the edges 200a, 200b.
[0058] In one or more embodiments, which may be combined with other embodiments, the first actuation spline 202 may be positioned at or proximate to thePATENTAttorney Docket No.: WBRE / 0013PCdownhole lateral edge 200d, and the second actuation spline 204 may be positioned at or proximate to the uphole lateral edge 200c. In some instances, the first actuation spline 202 may be positioned closer to the downhole lateral edge 200d than the uphole lateral edge 200c, and the second actuation spline 204 may be positioned closer to the uphole lateral edge 200c than the downhole lateral edge 200d.
[0059] FIG. 14 shows an enlarged perspective view of one of the mill blocks 136. The axis 135 of the section milling assembly 130 (not shown for the sake of clarity) is illustrated in FIG. 14 to show the relative orientation of the mill block 136 to the axis 135 in position.
[0060] The mill block 136 of FIG. 14 may define a plurality of slots 210, 212 that are configured to receive and slidingly engage with the actuation splines 202, 204, respectively and as shown in FIGs. 12 and 13, of the shields 200 during operations. Specifically, the mill block 136 defines a first or uphole slot 210 and a second or downhole slot 212. The slots 210, 212 as defined may be axially spaced from one another along the axis 135, where the uphole slot 210 is positioned uphole of the recess 160 and the downhole slot 212 is positioned downhole of the recess 160.
[0061] The slots 210, 212 may be defined to extend parallel with the splines 137. In addition, the slots 210, 212 may be defined to extend part-way between the radially inner side 136c and radially outer side 136d. Specifically, the uphole slot 210 may be defined to extend from the radially outer side 136d to a terminal end 210a that is positioned part way between the sides 136c, 136d, and the downhole slot 212 may be defined to extend from the radially inner side 136c to a terminal end 212a that is positioned part way between the sides 136c, 136d. The shape and orientation of the slots 210, 212 may be defined to correspond with the configuration, such as shape and orientation, of the actuation splines 202, 204 on the shield 200.
[0062] With reference to FIGs. 12-14, during operations, the shield 200 is positioned on a side of the mill block 136 so that the actuation splines 204, 202 are engaged in the slots 210, 212, respectively. The other splines 205 defined on the inner side 203 of the shield 200 may also engage or mesh with the corresponding splines 137 on the mill block 136.
[0063] FIGs. 15 and 16 are sequential, schematic side views of one of the mill blocks 136 and one of the corresponding shields 200 when the section milling assembly 130 is in the retracted position (FIG. 15) and the extended position (FIG.PATENTAttorney Docket No.: WBRE / 0013PC16), respectively. FIGs. 15-16 provide a schematic representation of the engagement and interaction between the actuation splines 202, 204 and slots 212, 210, respectively, to drive passive radial extension and retraction of the shield 200 with the mill block 136 during operations. However, FIGs. 15-16 do not illustrate other details, such as the other splines 137, 205 of the mill block 136 and shield 200 (see FIGs. 12-14) for the sake of clarity. In addition, FIGs. 15 and 16 show the approximate location of the edge 133 of the slot 139 in the body 134 (see FIGs. 9 and 10) for the sake of clarity.
[0064] In describing the transition in relative position shown from FIG. 15 to FIG.16, when the mill block 136 extends radially outward, the mill block 136 slides along the corresponding actuation splines 202, 204, utilizing the slots 212, 210, respectively, defined on the mill block 136. Specifically, as the mill block 136 extends radially outward, the mill block 136 slides using slot 210 along the second actuation spline 204 so that the terminal end 210a of the slot 210 is brought into contact with the terminal end 204a of the second actuation spline 204. In addition, as the mill block 136 extends radially outward, the mill block 136 slides using slot 212 along the first actuation spline 202 so that the terminal end 212a of the slot 212 is moved away from the terminal end 202a of the first actuation spline 202. Once the terminal end 210a of the slot 210 is engaged with the terminal end 204a of the second actuation spline 204, further radial extension of the mill block 136 may also drive a radial extension of the shield 200 relative to the edge 133.
[0065] Conversely, as shown in the sequence from FIG. 16 to FIG. 15, when the mill block 136 retracts radially inward, the mill block 136 utilizes the slot 212 to slide along the first actuation spline 202 so that the terminal end 212a of the slot 212 is brought into contact with the terminal end 202a of the first actuation spline 202. In addition, as the mill block 136 retracts radially inward, the mill block 136 utilizes the slot 210 to slide along the second actuation spline 204 so that the terminal end 210a of the slot 210 is moved away from the terminal end 204a of the second actuation spline 204. Once the terminal end 212a of the slot 212 is engaged with the terminal end 202a of the first actuation spline 202, further radial retraction of the mill block 136 may also drive a radial retraction of the shield 200.
[0066] The length of the slots 210, 212 and splines 202, 204 may be defined or configured, respectively, so that when the section milling assembly 130 is in thePATENTAttorney Docket No.: WBRE / 0013PCretracted position, such as shown in FIG. 15, the recesses 160, 206 of the mill block 136 and shield 200, respectively, may be at least partially overlapped or aligned. Without being limited to this or any other theory, alignment of the recesses 160, 260 when the mill block 136 and shield 200 are in a radially retracted position, such as shown in FIG. 15, may provide clearance for other components in the slot 139 of the tubular body 134, such as the link(s) 158, such as shown in FIGs. 7.
[0067] In addition, the length of the slots 210, 212 of mill block 136 and splines 202, 204 of shield 200, respectively, may be selected so that when the section milling assembly 130 is in extended position, such as shown in FIG. 16, the recess 160 of the shield 200 may be positioned radially inside the tubular body 134 via the edge 133. In this position, the shield 200 may cover or occlude the portion of the recess 160 of the mill block 136 that are extended radially beyond the edge 133.
[0068] As illustrated in FIGs. 15 and 16, the shields 200 may be passively actuated with the mill blocks 136 as the mill blocks 136 slidingly engage the actuation splines 202, 204 of the shield 200 by utilizing the corresponding slots 212, 210, defined by the mill block 136, respectively. As a result, additional actuation assemblies for actively extending and retracting the shields 200 may be avoided.
[0069] In one or more embodiments, which may be combined with other embodiments, additional features may be included on the shields 200 to prevent an overextension of the shields 200 during operations. For instance, FIG. 17 illustrates an embodiment of the shield 200 that defines an elongate slot 220 defined on the outer side 201. As with other portions of the Drawing, like number reference the same or similar features between and among the Figures and their associated descriptions, such as between the shield 200 of FIG. 17 and the shield shown in FIGs. 12 and 13 and as previously described.
[0070] The slot 220 of shield 200 as shown in FIG. 17 may be defined to extend part way into the shield 200 from the outer side 201 but not fully through the depth or thickness of the shield 200 to the inner side 203. In such instances, a person of skill in the art may refer to slot 220 as a recess rather than a void or space. However, according to one or more embodiments, which may be combined with other embodiments, the slot 220 may be defined to extend fully through the shield 200 and be accessible between the sides 201 , 203, defining a void or space.PATENTAttorney Docket No.: WBRE / 0013PC
[0071] The slot 220 may also be defined to extend from a first end 220a to a second end 220b along the outer side 201. The first end 220a may be defined to be positioned closer or more proximate to the radially inner edge 200a of the shield than the second end 220b, and the second end 220b may be defined to be positioned closer or more proximate to the radially outer edge 200b than the first end 220a. Thus, the first end 220a may be referred to as a “radially inner end” and the second end 220b may be referred to as a “radially outer end.” The slot 220 may generally be defined to be oriented parallel with the splines 205 on the outer side 201. In one or more embodiments, which may be combined with other embodiments, the slot 220 may be defined to be positioned between the recess 206 and the downhole edge 200d. However, a person of ordinary skill in the art may appreciate that other positions for such slots may be defined and are contemplated.
[0072] With brief reference again to FIGs. 9 and 10, one or more a guide pins 230 may be engaged within corresponding ports 240 in the tubular body 104. The guide pin(s) 230 may each be introduced into the slot 220 of a corresponding one of the shields 200 to limit a radial movement of the shield 200 during operations. Specifically, FIG. 18 illustrates a cross-sectional view of one of the guide pins 230 extending through the corresponding port 240 in the tubular body 104 and introduced into the slot 220 of the corresponding shield 200 along a radially-oriented crosssection relative to the axis 135 (FIGs. 6-8).
[0073] As illustrated in FIG. 18, the guide pin 230 includes a first or inner end 230a and a second or outer end 230b opposite the inner end 230a. In addition, the guide pin 230 includes an engagement head 232, a threaded section 234, and a guide post 236. When the pin 230 is introduced into and engaged with tubular body 104 and slot 220 of shield 200, the engagement head 232 may be positioned at and proximate to the outer end 230b, the guide post 236 may be positioned at and proximate to the inner end 230a, and the threaded section 234 may be positioned between the engagement head 232 and the guide post 236.
[0074] Likewise, the port 240 defined by tubular body 104 includes a counterbore 242 that extends from an outer surface and into the tubular body 104, a threaded section 244 that extends along the counterbore 242, and a smooth bore 246 that extends from the threaded section 244 further away from the outer surface. The threaded section 244 may have an inner diameter that is less than an inner diameterPATENTAttorney Docket No.: WBRE / 0013PCof the counterbore 242. Thus, a radially extending shoulder 243 is defined in the counterbore 242 adjacent to the threaded section 244.
[0075] As shown in FIG. 18, the threaded section 234 of the previously introduced guide pin 230 may be threadably engaged with the threaded section 244 of the port 240. The guide pin 230 is introduced into port 240 until the engagement head 232 is compressed against the radially extending shoulder 243 and the guide post 236 is positioned within the smooth bore 246 and protrudes into the slot 220 of the shield 200. The counterbore 242 may be sized so that the engagement head 232 is recessed radially inward from the outer surface of the tubular body 104.
[0076] During operations, the guide post 236 of the guide pin 230 slides along the slot 220 as the shield 200 and mill block 136 are radially expanded or retracted. As the guide post 236 is repositioned during radial expansion or retraction, the motion of the shield 200 is limited by the guide post 236. For instance, the engagement between the guide pin 230 and slot 220 may prevent an overextension of the shield 200 from the tubular body 134.
[0077] Similar to FIGs. 15-16, FIGs. 19-20 offer a sequential, schematic side views of one of the mill blocks 136 and one of the corresponding shields 200 when the section milling assembly 130 is in the retracted position, such as seen in FIG. 19, and the extended position, such as seen in FIG. 20, respectively. FIGs. 19 and 20 provide a schematic representation of the engagement and interaction between the guide pin 230 and slot 220 that limits radial extension and retraction of the shield 200 during operations. As similarly described previously in FIGs. 15 and 16, FIGs. 19 and 20 reference the approximate location of the edge 133 of the slot 139 in the body 134 for the sake of clarity (see also FIGs. 9 and 10).
[0078] As shown in FIG. 19, when the shield 200 is fully retracted, that is positioned within the slot 139 defined by the tubular body 104, the guide post 236 of the pin 230 may be engaged with the radially outer end 220b of the slot 220. Thus, further radial retraction of the shield 200 relative to the position illustrated in FIG. 19 may be prevented by the guide pin 230. Conversely, as shown in FIG. 20, when the shield 200 is fully extended, that is positioned beyond the edge 133 of the slot 139, the guide post 236 of the pin 230 may be engaged with the radially inner end 220a of the slot 220, preventing further radial extension of the shield 200.PATENTAttorney Docket No.: WBRE / 0013PC
[0079] Reference is now made to FIG. 21, which shows a cross-section of the section milling assembly 130 along section A-A in FIG. 6 according to one or more embodiments, which may be combined with other embodiments. Each mill block 136 may be coupled to a pair of shields 200 that are passively actuated with the mill block 136 as previously described. Specifically, each mill block 136 may include a first side 250a and a second side 250b that is opposite the first side 250a across a radius extending from the axis 135. A shield 200 may be coupled to each side 250a, 250b of the mill blocks 136. Thus, when the section milling assembly 130 includes 2 sets of mill blocks 136 and blades 132 such as shown in FIG. 21 and described throughout the specification, there may be a total of four (4) shields 200 covering the recesses 160, such as shown in FIG. 11, in each of the mill blocks 136 along both sides 250a, 250b.
[0080] Although for the purposes of the description of embodiment apparatuses, systems, and methods and processes, that two sets of mill blocks 136 and blades 132 were presented, especially in the Drawings, one of ordinary skill in the art may envision the utilization of more than two sets of mill blocks 136 and blades 132 on a single section milling assembly 130. For example, three sets or four sets of mill blocks 136 and blades 132 may be configured in a tri- or cross-pattern of mill blocks 136 and blades 132 in a common position axially along the length of the section milling assembly 130. As well, one may envision that pairs of sets of mill blocks 136 and blades 132 on a single section milling assembly 130 may be paired in separate sets along the axial length of the milling assembly, such as a first pair positioned in opposition to one another along a uphole position of the section milling assembly 130 and a second pair positioned in opposition in a downhole position of the same section milling assembly 130. In such instances, one may also envision that such pairings may either be in positioned to be in relative alignment with one another, such as the uphole and downhole are positioned along the same sides of the milling tool as viewed from a downhole position uphole, or that such pairings may be offset from one another, such as appearing to have a 90° or “cross” configuration such as when viewed from a downhole position uphole. Other configurations of sets of mill blocks 136 and blades 132 relative to one another are envisioned.
[0081] As explained above and reiterated below, the present disclosure includes, without limitation, the following Examples.PATENTAttorney Docket No.: WBRE / 0013PC
[0082] Example 1: A section milling assembly for milling a casing of a borehole, the section milling assembly comprising: a body having a central axis; a mill block that is configured to be radially extended out of the body, where the mill block includes a radially outer side, a radially inner side relative to the central axis, and a recess formed on the radially inner side; a milling blade pivotably coupled to the mill block; and a shield that is coupled to the mill block such that the shield is configured to at least partially cover the recess when the mill block is radially extended out of the body.
[0083] Example 2: The section milling assembly of any of the Examples, where the shield is configured to be passively extended from the body by the mill block when the mill block is radially extended out of the body.
[0084] Example 3: The section milling assembly of any of the Examples, where the shield is configured to be passively retracted into the body by the mill block when the mill block is radially retracted into the body.
[0085] Example 4: The section milling assembly of any of the Examples, where the mill block includes one or more slots, where the shield includes one or more actuation splines, and where the actuation splines are engaged within the slots of the mill block such that: when the mill block is radially extended out of the body, the one or more actuation splines engage with the one or more slots to drive a radial extension of the shield, and when the mill block is radially retracted into the body, the one or more actuation splines engage with the one or more slots to drive a radial retraction of the shield.
[0086] Example 5: The section milling assembly of any of the Examples, where the shield includes a slot, and where the section milling assembly further comprises a guide pin that is threadably engaged within the body, where the guide pin includes a post that is introduced into the slot to limit a movable range of the shield.
[0087] Example 6: The section milling assembly of any of the Examples, where the mill block includes a plurality of splines that are oriented in an uphole direction when moving radially outward along the mill block, and where the shield includes a plurality of splines that are configured to mesh with the plurality of splines of the mill block.
[0088] Example 7: The section milling assembly of any of the Examples, where the shield comprises: a radially inner edge; a radially outer edge; an uphole edge; and a downhole edge, where the shield has a rhomboid shape so that the uphole edgePATENTAttorney Docket No.: WBRE / 0013PCand downhole edge do not extend perpendicularly to the radially outer edge and the radially inner edge.
[0089] Example 8: The section milling assembly of any of the Examples, where the uphole edge and the downhole edge extend parallel to the plurality of splines on the mill block.
[0090] Example 9: The section milling assembly of any of the Examples, where the radially inner edge includes a recess that is at least partially aligned with the recess of the mill block.
[0091] Example 10: A bottom hole assembly (BHA) comprising: a centralizer including one or more centralizing blades that are configured to engage with an inner surface of a casing in a borehole; a reamer including one or more reaming blades that are configured to ream out a section in the borehole; and a section milling assembly coupled to the centralizer and the reamer that is configured to mill the casing, where the section milling assembly comprises: a body having a central axis; a mill block that is configured to be radially extended out of the body, where the mill block includes a radially outer side, a radially inner side relative to the central axis, and a recess formed on the radially inner side; a milling blade pivotably coupled to the mill block; and a shield that is coupled to the mill block such that the shield is configured to at least partially cover the recess when the mill block is radially extended out of the body.
[0092] Example 11 : The BHA of any of the Examples, where the section milling assembly is coupled between the reamer and the centralizer.
[0093] Example 12: The BHA of any of the Examples, where the shield is configured to be passively extended from the body by the mill block when the mill block is radially extended out of the body.
[0094] Example 13: The BHA of any of the Examples, where the shield is configured to be passively retracted into the body by the mill block when the mill block is radially retracted into the body.
[0095] Example 14: The BHAof any ofthe Examples, where the mill block includes one or more slots, where the shield includes one or more actuation splines, and where the actuation splines are engaged within the slots of the mill block such that: when the mill block is radially extended out of the body, the one or more actuation splines engage with the one or more slots to drive a radial extension of the shield, and whenPATENTAttorney Docket No.: WBRE / 0013PCthe mill block is radially retracted into the body, the one or more actuation splines engage with the one or more slots to drive a radial retraction of the shield.
[0096] Example 15: The BHA of any of the Examples, where the shield includes a slot, and where the section milling assembly further comprises a guide pin that is threadably engaged within the body, where the guide pin includes a post that is introduced into the slot to limit a movable range of the shield.
[0097] Example 16: The BHAof any ofthe Examples, where the mill block includes a plurality of splines that are oriented in an uphole direction when moving radially outward along the mill block, and where the shield includes a plurality of splines that are configured to mesh with the plurality of splines of the mill block.
[0098] Example 17: The BHA of any of the Examples, where the shield comprises: a radially inner edge; a radially outer edge; an uphole edge; and a downhole edge, where the shield has a rhomboid shape so that the uphole edge and downhole edge do not extend perpendicularly to the radially outer edge and the radially inner edge.
[0099] Example 18: The BHA of any of the Examples, where the uphole edge and the downhole edge extend parallel to the plurality of splines on the mill block.
[0100] Example 19: The BHA of any of the Examples, where the radially inner edge includes a recess that is at least partially aligned with the recess ofthe mill block.
[0101] Example 20: A method of milling a casing of a borehole, the method comprising: (a) introducing a section milling assembly into the borehole; (b) extending a mill block from a body of the section milling assembly; (c) pivotably extending a blade from the mill block; and (d) extending a shield from the body to at least partially cover a recess on the mill block during (b); (e) rotating the body to mill a casing in the borehole by use of the blade.
[0102] Example 21: The method of any of the Examples, where (d) comprises passively extending the shield with the extension of the mill block during (b).
[0103] Example 22: The method of any of the Examples, further comprising: (f) retracting the mill block into the body; and (g) passively retracting the shield into the body with the retraction of the mill block during (f).
[0104] Example 23: The method of any of the Examples, where (d) comprises engaging a terminal end of a first actuation spline on the shield with a terminal end of a first slot on the mill block, and where (f) further comprises engaging a terminal endPATENTAttorney Docket No.: WBRE / 0013PCof a second actuation spline on the shield with a terminal end of a second slot on the mill block.
[0105] Example 24: The method of any of the Examples, where (d) comprises slidingly engaging one or more splines on the shield with one or more splines on the mill block, where the one or more splines on the shield and the one or more splines on the mill block extend at an acute angle relative to a central axis of the body.
[0106] Example 25: The method of any of the Examples, further comprising sliding a guide pin coupled to the body within a slot defined in the shield to limit an extension of the shield during (d).
[0107] Embodiments disclosed include milling systems for a subterranean borehole that are configured to reduce the risk of obstructions that may prevent the deployment or withdrawal of a milling blade (or other deployable feature). In one or more embodiments, which may be combined with other embodiments, a milling assembly may include one or more shields that are configured to deploy with one or more of the milling blades to block the cuttings or other debris from entering the internal cavities of the milling system. Thus, through use of the embodiments disclosed, the risk of obstruction of the deployable milling blades in a downhole milling system may be reduced so that the efficiency and reliability of such an operation may be improved.
[0108] The preceding description is directed to various embodiments. However, one of ordinary skill in the art will understand that the examples disclosed have broad application, and that the description of any embodiment is meant only to be exemplary of that embodiment and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.
[0109] The drawing figures are not necessarily to scale. Certain features and components may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.
[0110] In the preceding description and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices,PATENTAttorney Docket No.: WBRE / 0013PCor through an indirect connection that is established via other devices, components, nodes, and connections. In addition, as used, the terms “axial” and “axially” generally mean along or parallel to a given axis (for example, central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the given axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. Further, when used (including in the claims), the words “about,” “generally,” “substantially,” “approximately,” and the like, when used to refer to a stated value, mean within a range of ±10% of the stated value.
[0111] While one or more embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings. The embodiments described are examples and are not limiting to the full scope of the disclosed concept. Many variations and modifications of the systems, apparatus, and processes described are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the embodiments described but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the operations in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before operations in a method claim are not intended to and do not specify a particular order to the operations but rather are used to simplify subsequent reference to such operations.
Claims
PATENTAttorney Docket No.: WBRE / 0013PCWhat is claimed is:
1. A section milling assembly for milling a casing of a borehole, the section milling assembly comprising:a body having a central axis;a mill block that is configured to be radially extended out of the body, where the mill block includes a radially outer side, a radially inner side relative to the central axis, and a recess formed on the radially inner side;a milling blade pivotably coupled to the mill block; anda shield that is coupled to the mill block such that the shield is configured to at least partially cover the recess when the mill block is radially extended out of the body.
2. The section milling assembly of claim 1, where the shield is configured to be passively extended from the body by the mill block when the mill block is radially extended out of the body.
3. The section milling assembly of claim 2, where the shield is configured to be passively retracted into the body by the mill block when the mill block is radially retracted into the body.
4. The section milling assembly of claim 3,where the mill block includes one or more slots,where the shield includes one or more actuation splines, andwhere the actuation splines are engaged within the slots of the mill block such that:when the mill block is radially extended out of the body, the one or more actuation splines engage with the one or more slots to drive a radial extension of the shield, andwhen the mill block is radially retracted into the body, the one or more actuation splines engage with the one or more slots to drive a radial retraction of the shield.PATENTAttorney Docket No.: WBRE / 0013PC5. The section milling assembly of claim 1, where the shield includes a slot, and where the section milling assembly further comprises a guide pin that is threadably engaged within the body, where the guide pin includes a post that is introduced into the slot to limit a movable range of the shield.
6. The section milling assembly of claim 1 , where the mill block includes a plurality of splines that are oriented in an uphole direction when moving radially outward along the mill block, and where the shield includes a plurality of splines that are configured to mesh with the plurality of splines of the mill block.
7. The section milling assembly of claim 6,where the shield comprises:a radially inner edge;a radially outer edge;an uphole edge; anda downhole edge,where the shield has a rhomboid shape so that the uphole edge and downhole edge do not extend perpendicularly to the radially outer edge and the radially inner edge.
8. The section milling assembly of claim 7, where the uphole edge and the downhole edge extend parallel to the plurality of splines on the mill block.
9. The section milling assembly of claim 7, where the radially inner edge includes a recess that is at least partially aligned with the recess of the mill block.
10. A bottom hole assembly (BHA) comprising:a centralizer including one or more centralizing blades that are configured to engage with an inner surface of a casing in a borehole;a reamer including one or more reaming blades that are configured to ream out a section in the borehole; andPATENTAttorney Docket No.: WBRE / 0013PCa section milling assembly coupled to the centralizer and the reamer that is configured to mill the casing, where the section milling assembly comprises:a body having a central axis;a mill block that is configured to be radially extended out of the body, where the mill block includes a radially outer side, a radially inner side relative to the central axis, and a recess formed on the radially inner side;a milling blade pivotably coupled to the mill block; anda shield that is coupled to the mill block such that the shield is configured to at least partially cover the recess when the mill block is radially extended out of the body.
11. The BHA of claim 10,where the mill block includes one or more slots,where the shield includes one or more actuation splines, andwhere the actuation splines are engaged within the slots of the mill block such that:when the mill block is radially extended out of the body, the one or more actuation splines engage with the one or more slots to drive a radial extension of the shield, andwhen the mill block is radially retracted into the body, the one or more actuation splines engage with the one or more slots to drive a radial retraction of the shield.
12. The BHA of claim 10, where the shield includes a slot, and where the section milling assembly further comprises a guide pin that is threadably engaged within the body, where the guide pin includes a post that is introduced into the slot to limit a movable range of the shield.
13. The BHA of claim 10,where the mill block includes a plurality of splines that are oriented in an uphole direction when moving radially outward along the mill block,PATENTAttorney Docket No.: WBRE / 0013PCwhere the shield includes a plurality of splines that are configured to mesh with the plurality of splines of the mill block,where the shield comprises:a radially inner edge;a radially outer edge;an uphole edge; anda downhole edge, andwhere the shield has a rhomboid shape so that the uphole edge and downhole edge do not extend perpendicularly to the radially outer edge and the radially inner edge.
14. The BHA of claim 13, where the uphole edge and the downhole edge extend parallel to the plurality of splines on the mill block, and where the radially inner edge includes a recess that is at least partially aligned with the recess of the mill block.
15. A method of milling a casing of a borehole, the method comprising:(a) introducing a section milling assembly into the borehole;(b) extending a mill block from a body of the section milling assembly;(c) pivotably extending a blade from the mill block;(d) extending a shield from the body to at least partially cover a recess on the mill block during (b); and(e) rotating the body to mill a casing in the borehole by use of the blade.
16. The method of claim 15, where (d) comprises passively extending the shield with the extension of the mill block during (b).
17. The method of claim 15, further comprising:(f) retracting the mill block into the body; and(g) passively retracting the shield into the body with the retraction of the mill block during (f).
18. The method of claim 17, where (d) comprises engaging a terminal end of a first actuation spline on the shield with a terminal end of a first slot on the mill block, andPATENTAttorney Docket No.: WBRE / 0013PCwhere (f) further comprises engaging a terminal end of a second actuation spline on the shield with a terminal end of a second slot on the mill block.
19. The method of claim 15, where (d) comprises slidingly engaging one or more splines on the shield with one or more splines on the mill block, where the one or more splines on the shield and the one or more splines on the mill block extend at an acute angle relative to a central axis of the body.
20. The method of claim 15, further comprising sliding a guide pin coupled to the body within a slot defined in the shield to limit an extension of the shield during (d).