US20140360723A1 - Protective sheath through a casing window - Google Patents
Protective sheath through a casing window Download PDFInfo
- Publication number
- US20140360723A1 US20140360723A1 US14/297,212 US201414297212A US2014360723A1 US 20140360723 A1 US20140360723 A1 US 20140360723A1 US 201414297212 A US201414297212 A US 201414297212A US 2014360723 A1 US2014360723 A1 US 2014360723A1
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- United States
- Prior art keywords
- protective sheath
- casing
- bit
- drilling
- drill
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
- E21B7/046—Directional drilling horizontal drilling
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B41/00—Equipment or details not covered by groups E21B15/00 - E21B40/00
- E21B41/0035—Apparatus or methods for multilateral well technology, e.g. for the completion of or workover on wells with one or more lateral branches
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B29/00—Cutting or destroying pipes, packers, plugs, or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
- E21B29/002—Cutting, e.g. milling, a pipe with a cutter rotating along the circumference of the pipe
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B29/00—Cutting or destroying pipes, packers, plugs, or wire lines, located in boreholes or wells, e.g. cutting of damaged pipes, of windows; Deforming of pipes in boreholes or wells; Reconditioning of well casings while in the ground
- E21B29/06—Cutting windows, e.g. directional window cutters for whipstock operations
Definitions
- a vertical wellbore may be drilled into an earthen formation. If the wellbore comes into contact with a fluid reservoir, the fluid may then be extracted. If the wellbore doesn't contact the fluid reservoir, or as the resources in a reservoir are depleted, it may be useful to create additional wellbores to access additional resources. For instance, a new wellbore may be drilled at the site of an additional fluid reservoir.
- hydrocarbon-based fluids e.g., oil and natural gas
- directional drilling may be used in lieu of creating a new, vertical wellbore.
- a lateral or deviated borehole may be formed and may branch off an existing wellbore.
- the lateral borehole may extend laterally at a desired trajectory suitable for reaching a particular site.
- a whipstock may be employed in a method referred to as sidetracking.
- Whipstocks have a ramped surface providing a travel path for a bit coupled to a drill string.
- the whipstock can be set at a desired depth and the ramped surface oriented to provide a particular drilling trajectory.
- the whipstock may be located at an openhole or cased portion of a wellbore.
- a milling assembly may be used to mill through, and form a window in, the casing.
- the milling assembly may be removed and a drilling assembly may be tripped into the wellbore to extend the lateral borehole through the casing window.
- a method includes positioning a drilling assembly within a primary wellbore.
- the drilling assembly may include a casing bit coupled to a protective sheath.
- the casing bit may be used to mill a window in casing of the primary wellbore, and the protective sheath may be extended through the window.
- the drill string and drill bit may be guided through the protective sheath and through the window, and the drill bit may be used to drill a lateral borehole.
- a drilling assembly may include a casing bit coupled to a protective sheath.
- a drill string may also be coupled to, and inside, the protective sheath.
- the drill string may include drill bit.
- a drilling system may be used to form a window in a casing of a primary wellbore and to drill a lateral borehole off the primary wellbore.
- the drilling system may include a drillable casing bit configured to mail the window in the casing.
- a protective sheath may be coupled to the drillable casing bit.
- the drilling system may also include an anchor used to anchor the protective sheath and restrict the protective sheath from moving axially, rotationally, or both.
- a drill string may be coupled to an interior of the protective sheath.
- the drill string may include a drill bit configured to dill through the drillable casing bit and through formation around the primary wellbore.
- a fastener may releasably couple the drill string to the protective sheath.
- FIG. 1 schematically illustrates an example system for drilling a lateral borehole, the system including a casing bit for drilling a window into a casing of a primary wellbore to begin formation of the lateral borehole, in accordance with one embodiment of the present disclosure
- FIG. 2 schematically illustrates the system of FIG. 1 following commencement of drilling of the lateral borehole using the casing bit, and including extension of the lateral borehole using a drill bit drilling through the casing bit, in accordance with an embodiment of the present disclosure
- FIG. 3 illustrates a partial cross-sectional view of an example system for drilling a lateral borehole, the system including a casing bit for drilling a window in a wellbore casing, a drill string coupled to the casing bit, and an interior drill bit, in accordance with one embodiment of the present disclosure;
- FIG. 4 illustrates a partial cross-sectional view of the system of FIG. 3 , the casing bit and a portion of the drill string having passed through a window of the wellbore casing, in accordance with one embodiment of the present disclosure
- FIG. 5 schematically illustrates an example window formed in the wellbore casing of FIG. 4 ;
- FIG. 6 illustrates a partial cross-sectional view of the system of FIGS. 3 and 4 , the casing bit and drilling assembly being anchored to the earthen formation, in accordance with one embodiment of the present disclosure
- FIG. 7 illustrates a partial cross-sectional view of the system of FIGS. 3 , 4 and 6 , the interior drill bit having been detached and extended through the protective sheath towards the casing bit, in accordance with an embodiment of the present disclosure
- FIG. 8 illustrates a partial cross-sectional view of the system of FIG. 7 , with the interior drill bit extending the lateral borehole following drilling through the casing bit, in accordance with another embodiment of the present disclosure.
- FIG. 9 illustrates a partial cross-sectional view of another example system for drilling a lateral borehole, the system including an interior drill bit adjacent the casing bit, and including a deflection assembly coupled to the casing bit, in accordance with another embodiment of the present disclosure.
- embodiments herein relate to systems and assemblies for drilling a lateral borehole. More particularly, embodiments disclosed herein may relate to drilling systems, assemblies and methods for drilling a lateral borehole off a cased, primary wellbore.
- Example drilling systems and assemblies may include a casing bit and a drill bit.
- the casing bit may be coupled to a drill string element which may be coupled to, or may include, a protective sheath.
- the protective sheath can pass through the window.
- the drill bit may also pass through the window.
- the protective sheath may restrict and potentially prevent the drill bit from contacting the casing or a surrounding formation until the drill bit drills through or is otherwise removed from the casing bit.
- FIG. 1 shows an example primary wellbore 102 which is, in this embodiment, a cased wellbore.
- the cased wellbore shown in FIG. 1 includes a casing 104 which may extend along all or a portion of the length of the primary wellbore 102 .
- the casing 104 may be used for any number of reasons.
- the casing 104 may be production casing that is cemented or otherwise secured in place to isolate the primary wellbore 102 from the surrounding formation 106 , and/or to provide structural support along the length of the primary wellbore 102 .
- the casing 104 may include additional or other casing, including intermediate casing, surface casing, conductor casing, liner, or other component.
- the drilling system 100 may be provided and may include components to allow drilling of a lateral borehole (e.g., lateral borehole 110 of FIG. 2 ) which branches off the primary wellbore 102 .
- the lateral borehole may be drilled using a drill string 112 to rotate one or more drill bits.
- the drill string 112 may be coupled to a protective sheath 126 , which in turn may be coupled to a casing bit 116 .
- the casing bit 116 may a mill or otherwise configured to mill into the casing 104 , and to form a window or opening therein.
- the casing bit 116 may drill partially into the formation 106 to initiate a lateral borehole.
- the casing bit 116 may also be used after full formation of the window to continue drilling the lateral borehole.
- some embodiments of the present disclosure contemplate use of a drill string 112 that can transmit torque and axial loads, and which can transfer such forces to the protective sheath 126 .
- the protective sheath 126 may ultimately transfer such forces to the casing bit 116 .
- the drill string 112 may therefore include any number of structures to facilitate such use for the formation and/or extension of a lateral borehole.
- the drill string 112 may include a tubular member.
- the tubular member of the drill string 112 may include coiled tubing with a downhole motor, jointed/segmented tubing, a liner, casings (e.g., as part of a casing-while-drilling system), or other components, or some combination thereof, to be capable of carrying transmitted loads to the protective sheath 126 and ultimately to the casing bit 116 .
- the drill string 112 may include or be coupled to any number of different components or structures.
- the drill string 112 may include, or be coupled to, multiple sections of jointed pipe, a motor, stabilizers, or other components.
- An example motor may include a positive displacement motor (e.g., a mud motor or progressive cavity motor), a turbine or turbodrill motor, an electrical motor, some other type of motor, or a combination of the foregoing.
- the drill string 112 may also include directional drilling and/or measurement equipment.
- the drill string 112 may include a steerable drilling assembly to control the direction of drilling of the lateral borehole within the formation 106 .
- a steerable drilling assembly may include various types of directional control systems, including rotary steerable systems referred to as push-the-bit or point-the-bit systems, or any other type of rotary steerable or directional control system.
- components coupled to the drill string 112 may be part of a bottomhole assembly for drilling the lateral borehole into the formation 106 .
- the drilling system 100 may include, or be used with, a deflection member 118 .
- the deflection member 118 may include a whipstock or any other structure that may be used to facilitate formation of the window in the casing 102 or the lateral borehole.
- the deflection member 118 may include an inclined surface.
- the inclined surface may be generally planar, although in other embodiments the inclined surface may be concave (e.g., to accommodate a rounded casing bit 116 , drill string 112 , etc.), have multiple tiers of differing inclines, or be otherwise configured.
- the drill string 112 and casing bit 116 may be tripped into the wellbore until they engage with the deflection member 118 .
- the inclined surface of the deflection member 118 may direct the casing bit 116 towards the interior surface of the casing 104 .
- the deflection member 118 may be anchored or otherwise maintained at a desired position, depth, and orientation in order to deflect the casing bit 116 at a desired location and azimuthal orientation.
- the casing bit 116 may mill a window for drilling of a lateral borehole.
- a set of one or more anchors 120 , packers, or other components may be used to anchor the deflection member 118 at an axial position and azimuthal orientation within the primary wellbore 102 .
- the one or more anchors 120 and/or other components may define a setting assembly for engaging the sidewalls of the casing 104 in the primary wellbore 102 .
- the anchors 120 may be expandable. For instance, hydraulic fluid may be used to expand the anchors 120 from a retracted position to the expanded position shown in FIG. 1 .
- the anchors 120 that can be set in other manners.
- the anchors 120 may expand or be set mechanically, using spring-loaded components, through directed explosive charges, or in other manners.
- the anchors 120 optionally have a sufficient ratio of the expanded diameter relative to the retracted diameter, thereby facilitating engagement with a sidewall of a casing 104 or primary wellbore 102 , to potentially allow use in wellbores having any number of different sizes.
- the anchors 120 may be modified, or even eliminated and replaced by other suitable components usable to secure the deflection member 118 in place.
- the drilling system 100 may also include still other or additional components.
- the casing bit 116 may be used primarily for milling through the casing 104 . Upon milling through the casing 104 , and potentially through a portion of the formation 106 , the casing bit 116 may stop rotating and/or stop advancing. As shown in FIG. 2 , a drill bit 122 may then be used to extend the lateral borehole 110 .
- the drill bit 122 of FIG. 2 may be coupled to the drill string 112 of FIG. 1 .
- the drill string 112 may be used to rotate and advance the protective sheath 126 and the casing bit 116 to form the window in the casing 104 .
- the drill string 112 and drill bit 122 may be coupled to an interior of the protective sheath 126 using a fastener.
- the fastener may secure the drill string 112 and/or drill bit 122 relative to the protective sheath 126 , and allow axial and rotational loads to be transmitted between the drill string 112 and the protective sheath 126 .
- a casing bit 116 which may be drilled through by a drill bit 122 may be referred to as a “drillable casing bit”. After drilling through the casing bit 116 , which may be a drillable casing bit, the drill bit 122 can move into and potentially extend the lateral borehole 110 .
- the particular structure, components, and method of use of the drilling system 100 may be varied in any number of manners.
- the length of the protective sheath 126 may be varied.
- the length and size of the protective sheath 126 may be sized based on particular conditions within the primary wellbore 102 or based on components of the drilling system 100 .
- the protective sheath 126 may be coupled to the drill string 112 during a milling operation for forming a window in the casing 104 . Thereafter, however, the drill string 112 may be detached from the protective sheath 126 to allow a lateral borehole 110 to be formed or extended.
- the drill string 112 may be detached from the protective sheath 126 to allow a lateral borehole 110 to be formed or extended. According to at least some embodiments, including the embodiment shown in FIG.
- the length of the protective sheath 126 may allow the protective sheath 126 to extend at least from a top of the deflection member 118 to a position beyond the window milled in the casing 104 .
- the protective sheath 126 may restrict the drill bit 122 from contacting the deflection member 118 and/or the casing 104 .
- a protective sheath 126 extends from a top of the deflection member 118 and fully through the window in the casing 104 , the particular length of the protective sheath 126 may vary depending on a variety of factors. Example factors may include the length of an inclined surface of the deflection member 118 , a diameter of the primary wellbore 102 , a diameter of the casing bit 116 , and the like. In other embodiments, the length of the protective sheath 126 may be selected to give a tolerance to positioning of the protective sheath 126 .
- the length may be extended to allow the protective sheath 126 to start a few feet above the top of the deflection member 118 and extend fully to a position a few feet beyond the milled window in the casing 104 .
- an example protective sheath 126 may have a length of between 5 ft. (1.5 m) and 100 ft. (30.5 m).
- the length of the protective sheath 126 may be between 15 ft. (4.6 m) and 60 ft. (18.3 m).
- the length of the protective sheath 126 may be between 20 ft. (6.1 m) and 40 ft. (12.2 m).
- the protective sheath 126 may be 30 ft. (9.1 m) in some embodiments.
- the length of the protective sheath 126 may be greater than 100 ft. (305 m) or less than 5 ft. (1.5 m.).
- the length may of course also be varied if the location of the protective sheath 126 is varied. For instance, if the protective sheath 126 extends through the window in the casing 104 , but doesn't extend fully to the top of the deflection member 118 , the protective sheath 126 may be shortened.
- the protective sheath 126 When the protective sheath 126 extends from the top of the deflection member 118 fully through the casing 104 , and optionally an added distance in either or both directions, the protective sheath 126 may house the drill bit 122 and protect the drill bit 122 from damage that could otherwise result from the drill bit 122 contacting either the deflection member 118 or the casing 104 . Moreover, protecting the drill bit 122 in this manner may further allow a different bit (i.e., drill bit 122 ) to drill the lateral borehole 110 than the bit (i.e., casing bit 116 ) used to mill the window in the casing 104 .
- a different bit i.e., drill bit 122
- the drill bit 122 may not exhibit the wear caused to the casing bit 116 by the casing and/or may be designed for cutting into the formation 106 . Such factors, along with reduced damage to the drill bit 122 due to protection provided by the protective sheath 126 , may increase the drilling efficiency and life of the drill bit 122 .
- the drilling system 100 may include motors, stabilizers, or other components (e.g., as part of a bottomhole assembly). These additional components may also be protected against damage.
- the window may have jagged or uneven edges and the protective sheath 126 may protect against interference with the edges of the window.
- the lateral borehole 110 may be re-entered for performing additional operations.
- the protective sheath 126 may be left in place (and potentially anchored in place). As a result, components used to perform the additional operations may be tripped into the wellbore 102 and into the lateral borehole 110 while being guided by the protective sheath 126 . For instance, completion components (e.g., packers) may be run into the lateral borehole 110 , and may pass through the protective sheath 126 which protects the components from damage or interference.
- completion components e.g., packers
- FIGS. 3-8 various partial, cross-sectional views are provided to illustrate another example embodiment of a drilling system 200 in accordance with another aspect of the present disclosure.
- FIGS. 3-8 illustrate various stages of drilling a lateral borehole 210 off of a primary wellbore 202 , while also providing a protective sheath 226 for protecting and guiding a drill bit 222 used to form or extend the lateral borehole 210 .
- FIGS. 3-8 illustrate a primary wellbore 202 formed in a formation 206 .
- the primary wellbore 202 may be formed in any suitable manner.
- the primary wellbore 202 is shown as a cased wellbore and has a casing 204 therein.
- the casing 204 may generally be a tubular structure adjacent the interior, peripheral walls of the primary wellbore 202 .
- the casing 204 may be cemented or otherwise secured in place within the primary wellbore 202 .
- a lateral, deviated, or branched borehole (e.g., lateral borehole 210 in FIGS. 4 and 6 - 8 ) may be drilled.
- the lateral bore hole 210 may extend within the formation 206 and at an angle from the primary wellbore 202 .
- the primary wellbore 202 may be oriented generally vertically, and the lateral borehole 210 can be formed to extend therefrom at a particular trajectory.
- the primary wellbore 202 may also not be vertical, and that the degree of deviation of the lateral borehole 210 from the primary wellbore 202 can be varied in a number of manners.
- angles of the primary wellbore 202 and lateral borehole 210 may extend at any possible angle relative to each other and/or the surface.
- a lateral borehole 210 may be formed to extend in a generally horizontal direction, that direction may or may not be about perpendicular relative to the primary wellbore 202 or parallel relative to a surface of the formation 206 .
- other trajectories are obtained, and the lateral borehole 210 may curve along its path to obtain the desired end trajectory or desired target.
- a deflection member 218 may be tripped into the primary wellbore 202 .
- FIGS. 3-8 somewhat schematically illustrate a side view of the example deflection member 218 , which in this embodiment is shown as a whipstock.
- the deflection member 218 may include, or be coupled to, anchors 220 that may be used to set the deflection member 218 at a desired position and orientation.
- the anchors 220 When tripping the deflection member 218 into the primary wellbore 202 , the anchors 220 may be in a retracted state (not shown). With the anchors 220 retracted, the deflection member 218 may move axially and/or rotationally within the primary wellbore 202 .
- the deflection member 218 may be oriented and secured in place in the primary wellbore 202 using the anchors 220 .
- the anchors 220 are part of a setting assembly and may expand to engage against the interior wall of the casing 204 . Such engagement may create a frictional or interference fit to secure the deflection member 218 in place by resisting axial and/or rotational movement within the primary wellbore 202 .
- the anchors 220 may be expandable in any number of manners. For instance, in some embodiments the anchors 220 may by hydraulically actuated. In other embodiments the anchors 220 may be mechanically or otherwise expanded and/or retracted.
- the anchors 220 are shown as engaging the casing 204 , the anchors 220 optionally may be aligned with an uncased, or openhole, portion of the wellbore 202 . In such an embodiment, the anchors 220 may expand to engage the formation 206 directly, and potentially may cut into, or pierce, the formation 206 to secure the deflection member 218 in place.
- the deflection member 218 may be used to direct the path of a drilling assembly used to drill a lateral borehole off the primary wellbore 202 .
- the deflection member 218 may include a ramped surface 228 .
- the ramped surface 228 may be positioned at a desired orientation configured to guide the drilling assembly along a particular trajectory. As shown in FIG. 3 , due to the ramped surface 228 , a width of the deflection member 218 may increase from an upper end towards a lower end.
- the ramped surface 228 can urge the drilling assembly radially outwardly, away from a central axis of the primary wellbore 202 , and against the casing 204 , and ultimately into the formation 206 .
- the casing bit 216 can generally follow the incline of the ramped surface 228 and engage the casing 204 .
- the casing bit 216 can mill an opening therein.
- the opening which is referred to herein as a “window” 230
- the opening may be gradually formed as the casing bit 216 moves along the ramped surface 228 and through the casing 204 .
- the window 230 may have a generally elongated shape.
- FIG. 5 illustrates a side view of the exterior of the casing 204 with the window 230 formed therein.
- the window 230 may not have a perfectly smooth periphery, but instead may include one or more jagged or uneven edges.
- a drill bit, mill, or other cutting element may pass through the window 230 to form a lateral borehole 210 . If unprotected, the drill bit, mill, or other cutting element may catch on the jagged edges of the window 230 , or otherwise contact the edges of the window 230 .
- the edges of the window 230 could also interfere with other components of a drilling assembly (e.g., drill string, motor, stabilizer, etc.), or with completion or other components which re-enter the lateral borehole after removal of a drill string. Such engagement or interference can potentially damage the components, make entry into the lateral borehole 210 difficult, or reduce the effectiveness and/or useful life of a downhole system or bottomhole assembly.
- the properties of the casing 204 may significantly differ from that of the surrounding formation 206 .
- the casing 204 may be formed of a metal (e.g., steel), while the formation 206 may be formed of one or more types of rock or other materials.
- a cutting element or bit structure suited for cutting the formation 206 may not be as efficient at milling the window 230 , or may be more easily damaged by the casing 204 .
- Embodiments herein, including the drilling system 200 of FIGS. 3-8 relate to an example embodiment that may be used to effectively mill a window in a casing 204 , while also protecting a cutting element or bit that may be used to form or extend a lateral borehole 210 .
- the drilling system 200 may include two or more bits, each of which may have multiple cutting structures or elements.
- the drilling system 200 includes a casing bit 216 as a first bit, and a drill bit 222 as a second bit.
- the casing bit 216 may be primarily configured for use in milling a window 230 in the casing 204
- the drill bit 222 may be primarily configured for use in cutting, shearing, impacting, or otherwise extending the lateral borehole 210 in the formation 206 .
- the casing bit 216 is shown as being coupled to a protective sheath 226 which may in turn be coupled to, and optionally suspended from, a drill string 212 .
- the drill string 212 may include jointed pipe, casing-while-drilling (“CWD”), or other types of drill string elements, or any combination thereof.
- CWD casing-while-drilling
- Torque and axial thrust may be applied to the drill string 212 and transferred to the protective sheath 226 , which may in turn transfer such torque and motion to the casing bit 216 .
- the drill string 212 may optionally be used to convey drilling mud or another fluid. Such fluids may, for instance, pass through an interior of the drill string 212 .
- the fluid may be used in connection with a hydraulic motor or drive system (not shown) to rotate the drill string 212 , or a component thereof, as well as the protective sheath 226 and the casing bit 216 .
- the drilling mud or other fluid may enter the protective sheath 226 , and the casing bit 216 may include one or more openings therein to allow fluid to pass therethrough.
- Such a fluid may then also act as a coolant on an exterior of the casing bit 216 and/or a jet nozzle to flush cuttings away from the face of the casing bit 216 .
- the drilling fluid may facilitate cutting of the casing 204 and/or formation 206 , reduce wear of the casing bit 216 , and prolong the life or effectiveness of the casing bit 216 .
- the protective sheath 226 and casing bit 216 may be lowered toward the deflection member 218 by using the drill string 212 .
- the ramped surface 228 of the deflection member 218 may push the casing bit 216 into the casing 204 where the window 230 may be formed by rotation of the casing bit 216 as weight-on-bit is applied thereto.
- FIG. 3 illustrates the casing bit 216 prior to formation of the window 230
- FIG. 4 illustrates the casing bit 216 after milling of the window 230 .
- Also shown in FIG. 4 is the start of a lateral borehole 210 branching from the primary wellbore 202 .
- the casing bit 216 may be primarily used to mill the window 230 in the casing 204 , the casing bit 216 may also cut, to at least some extent, into the formation 206 . Indeed, in some embodiments, the casing bit 216 may partially cut into the formation 206 before the window 230 is at its full size. In at least some embodiments, the cutting of the formation 206 may stop at about the same time as completion of the window 230 . In other embodiments such as that shown in FIG. 4 , the casing bit 216 may continue to cut into the formation 206 even after the window 230 is fully formed. In such an embodiment, the amount of additional cutting performed using the casing bit 216 may vary. For instance, the length of the lateral borehole 210 may vary from a few inches or centimeters to many feet or meters by the time an operator ceases using the casing bit 216 to drill a portion of the lateral borehole 210 .
- the casing bit 216 may be removed. In other embodiments, however, the casing bit 216 may potentially be left within the lateral borehole 210 .
- the illustrated embodiment depicts an additional anchor 232 coupled to the protective sheath 226 .
- the anchor 232 When the anchor 232 is in a retracted state as shown in FIGS. 3 and 4 , the protective sheath 226 and the casing bit 216 may advance within the lateral borehole 210 .
- the anchor 232 may engage or grip the formation 206 and restrict, if not prevent, axial and/or rotational movement of the protective sheath 226 and/or casing bit 216 .
- FIG. 6 illustrates an example embodiment in which the anchor 232 has been expanded to engage the formation 206 and restrict movement of the casing bit 216 and protective sheath 226 .
- the particular manner in which the anchor 232 operates may vary. For instance, hydraulic fluid may be used to hydraulically expand the anchor 232 . In another embodiment, the anchors 232 may be mechanically, explosively, or otherwise activated.
- a controller e.g., a programmable or electronic controller
- a control signal may be provided in a wireless, physical, conductive, or other manner, or using some combination of the foregoing.
- the control signal may open a valve which can allow hydraulic fluid passing within the protective sheath 226 to then expand the anchor 232 .
- a control signal may activate a motor to mechanically expand the anchor 232 , release a spring-loaded element, ignite a directed explosive charge, or otherwise expand the anchor 232 .
- the anchor 232 may be controlled by an operator, in other embodiments the control may be automatic.
- a controller of the anchor 232 may be programmed to activate at a particular location, and one or more sensors (e.g., measurement-while-drilling tools, logging-while-drilling tools, smart drill collars, etc.) may provide positioning information to the controller to sense when the conditions for activating the anchor 232 are present.
- sensors e.g., measurement-while-drilling tools, logging-while-drilling tools, smart drill collars, etc.
- a second bit which is illustrated as a drill bit 222 in FIG. 6
- the drill bit 222 is also coupled to the drill string 212 .
- the drill bit 222 may be coupled to a distal end portion of the drill string 212 , and optionally be located inside the protective sheath 226 that is also coupled to the drill string 212 .
- the illustrated drilling system 200 may be intended for use as a single trip drilling assembly, so that milling of the window 230 and drilling of the lateral borehole 210 may occur in a single trip.
- the deflection member 218 and anchor 220 may also be set in a single trip so that setting of the anchor, milling of the window 230 , and drilling of the lateral borehole 210 may occur in a single trip.
- the drill bit 222 or drill string 212 may be fixed at a particular location within the protective sheath 226 in a manner that allows the drill bit 222 to advance within the primary wellbore 202 and/or lateral borehole 210 at about the same rate as the protective sheath 226 .
- a fastener 234 may selectively couple the drill string 212 at a particular axial location within the protective sheath 226 .
- the fastener 234 may directly couple the drill bit 222 to the protective sheath 226 .
- the fastener 234 may provide a connection that allows rotational and axial forces on the drill string 212 to be transferred to the protective sheath 226 .
- the drill string 212 or drill bit 222 may have a rotation that is about synchronous with the rotation of the casing bit 216 and/or protective sheath 226 .
- the fastener 234 may effectively lock the drill bit 222 to the drill string 212 .
- the fastener 234 may allow rotational movement (i.e., torque) and axial thrust (i.e., weight-on-bit) on the drill string 212 to be transmitted to the protective sheath 226 .
- the protective sheath 226 and drill string 212 may have about the same rotation and axial movement.
- the anchor 232 is activated to restrict rotation of the drill string 212 and/or the casing bit 216 , the rotation of both the casing bit 216 and drill bit 222 may stop.
- the drill bit 222 may rotate independently of the protective sheath 226 and/or casing bit 216 .
- the fastener 234 may be coupled to the drill string 212 .
- a motor or other element of a bottomhole assembly associated with the drill bit 222 may allow the drill bit 222 to rotate at a rate that is faster or slower relative to rotation of the drill string 212 , protective sheath 226 , or casing bit 216 .
- the drill string 212 may be allowed to rotate and move axially relative to the protective sheath 226 and the casing bit 216 .
- Such independent rotation and axial movement may occur using any number of mechanisms.
- the fastener 234 may be deactivated or selectively released.
- the fastener 234 may include a hydraulically activated release. Depending on the design of the release, when hydraulic pressure is supplied or cut-off, the fastener 234 may release, allowing the drill bit 222 and drill string 212 to move independently of the protective sheath 226 .
- a ball, dart, or other obstruction element may be inserted into the drill string 212 and may land on a seat. Pressure may build behind the seat and obstruction element to break one or more shear pins of the fastener 234 .
- a spring-loaded release, or other mechanical system may be activated to detach the drill string 212 and/or drill bit 222 relative to the protective sheath 226 . Any such deactivation or release may be controlled by an operator, or may be automatic. For instance, mud-pulse telemetry, pressure pulses, rotational speed signals, wired drill pipe connections, wireless signals, active or passive RFID tags, or other mechanisms may be used to convey a signal from an operator on the surface to a downhole controller.
- a controller may include a sensor that measures rotation of the protective sheath 226 . When the rotation stops or drops below a particular threshold, the fastener 234 may deactivate to release the drill string 212 or the drill bit 222 .
- the fastener 234 may include a sacrificial element.
- drilling mud or another fluid may be used to rotate the drill string 212 and/or the drill bit 222 .
- the drilling mud or other fluid can be supplied to a motor associated with the drill bit 222 anchoring the protective sheath 234 ; however, such rotation may also occur while the casing bit 216 is in use and un-anchored. If the rotations of the drill bit 222 and the casing bit 216 are synchronous (or the rotations of the corresponding drill string 212 and protective sheath 226 ), the sacrificial element of the fastener 234 may also rotate synchronously and remain in place.
- Restricting rotation of the protective sheath 226 may not stop the drill bit 222 or drill string 212 from rotating. Instead, a drive force may continue to be applied to the drill string 212 and/or drill bit 222 .
- the drive force may apply a torque that ultimately causes the sacrificial element to break and fail, thereby releasing the drill string 212 and drill bit 222 from the protective sheath 226 .
- the drill string 212 and drill bit 222 may then be able to rotate and move axially within the interior of the drill string 212 .
- the fastener 234 may be located at any suitable location, and the drill bit 222 may therefore be fastened at any suitable location along the length of the protective sheath 226 .
- the drill bit 222 is shown as being fixed at location that is in an upper end portion of the protective sheath 226 .
- the drill bit 222 may still be located within the primary wellbore 202 .
- Such an embodiment is, however, merely illustrative. In other embodiments (e.g., the embodiment shown in FIG.
- the drill bit 222 may be anchored at a location more proximate the casing bit 216 , such that as the casing bit 216 is anchored in place, the drill bit 222 may already be located at least partially within the lateral borehole 210 .
- the drill bit 222 may pass through the window 230 prior to drilling or extending a length of the lateral borehole 210 .
- the window 230 may be surrounded by edges of the casing 204 that can potentially damage the drill bit 222 , whether on account of the material of the casing 204 , the shape of the edges around the window 230 , or other factors.
- the protective sheath 226 may shield the drill bit 222 and the drill string 212 from contacting the edges of the window 230 or potentially any part of the casing 204 or deflection member 218 .
- the protective sheath 226 may be anchored in place and may extend from the interior of the primary wellbore 202 , through the window 230 , and into the lateral borehole 210 .
- the protective sheath 226 may, at its outer surface, potentially contact the deflection member 218 and/or casing 204 .
- the drill bit 222 and drill string 212 may be located within the protective sheath 226 .
- the drill bit 222 may be shielded from direct contact with the deflection member 218 and/or the edges of the window 230 .
- the protective sheath 226 may be formed in any number of different manners.
- the protective sheath 226 may include a tubular member coupled to (e.g., suspended from) a portion of the drill string 212 .
- the protective sheath 226 may have the same or different properties relative the drill string 212 , casing 204 , or other components of the drilling system 200 .
- the protective sheath 226 may be configured to bend or flex, may be jointed, or otherwise structured.
- the protective sheath 226 may also be part of a bottomhole assembly, or a separate component coupled to a bottomhole assembly associated with the drill bit 222 .
- An example protective sheath 226 may include CWD components to allow the protective sheath 226 to form a casing extending through the window 230 and into the lateral borehole 210 .
- the anchor 232 may cement or otherwise fix a casing within the lateral borehole 210 .
- the protective sheath 226 may include a joint to facilitate bending and assist in forming a channel to guide the drill bit 222 into the lateral borehole 210 .
- the protective sheath 226 may include expandable casing.
- the protective sheath 226 may provide other uses other than protecting the drill bit 222 as the drill bit 222 moves through the window 230 .
- a deflection member 218 may be used to orient the drill string 212 at a desired trajectory.
- the drill string 212 may also restrict the drill bit 222 and drill string 214 from contacting the deflection member 218 .
- the protective sheath 226 may, however, generally define the path from the primary wellbore 202 to the lateral borehole 210 , and can thus act as a guide to the drill bit 222 .
- the drill bit 222 and drill string 212 may be sized to allow the drill bit 222 to move within the protective sheath 226 , which may act as a slide through which the drill bit 222 may move towards the casing bit 216 and ultimately to the distal end of the lateral borehole 210 as shown in FIG. 7 .
- the protective sheath 226 may also remain in place during not only lateral drilling of the lateral borehole 210 using the drill bit 222 , but also potentially during re-entry of other components, including completion or other intervention components.
- the casing bit 216 may obstruct further movement of the drill bit 222 .
- the casing bit 216 and drill bit 222 may be coordinated to allow the drill bit 222 to drill through the casing bit 216 .
- the casing bit 216 may be a drillable casing bit and/or have an optional opening therein. When the opening is included, the opening may be used to center the drill bit 222 and/or to allow the drill bit 222 to more efficiently begin drilling through the casing bit 216 .
- the opening may have a size and/or length configured to allow the casing bit 216 to effectively mill the window 230 and start the lateral borehole 210 , while also minimizing or reducing the amount of material through which the drill bit 222 may drill through to reach the exterior of the casing bit 216 .
- the interior of the casing bit 216 may be formed of a material that is different than at least some materials on an exterior of the casing bit 216 .
- superhard or superabrasive materials may be located on the exterior of the casing bit 216 , while the interior of the casing bit 216 may have a different, and relatively softer, material (e.g., steel, iron, etc.).
- the drill bit 222 may be formed in any suitable manner for cutting through the interior of the casing bit 216 as well as through rock or other materials of the formation 206 .
- the interior of the casing bit 216 may be configured to allow the drill bit 222 to drill through the casing bit 216 at least nearly as efficiently as through the formation 206 .
- the drill bit 222 may then be at the distal end of the lateral borehole 210 .
- the lateral borehole 210 may be extended.
- the drill bit 222 may be used to form an extended length 211 of the lateral borehole 210 .
- the extended length 211 of the lateral borehole 210 may also have a reduced size (e.g., width or diameter).
- a drilling system 200 may include a protective sheath 226 and a casing bit 216 to mill a window in a casing 204 , but may not include a drill bit 222 . Instead, an entirely separate assembly may be tripped into the primary wellbore 202 and guided by the protective sheath 226 to extend a lateral borehole 210 .
- a deflection member 218 as described herein may have any number of other constructions.
- a ramped surface 228 or a portion thereof, may have an incline between 0.5° and 15° relative to a longitudinal axis of the primary wellbore 202 . More particularly, the ramped surface 228 may have an incline with lower and upper limits that include any of 0.5°, 1°, 1.5°, 2°, 2.5°, 3°, 3.5°, 4°, 5°, 7.5°, 10°, 12.5°, 15°, or any value therebetween.
- the ramped surface 228 may be inclined at an angle of between 2° and 5° relative to the longitudinal axis of the primary wellbore 202 .
- the ramped surface may be inclined at 3°.
- the ramped surface 228 , or a portion thereof may have an angle of less than 0.5°, or greater than 15°, relative to the longitudinal axis of the primary wellbore 202 .
- the angle of the ramped surface 228 may be an average angle of incline over multiple different stages having different inclines.
- the deflection member 218 may be tripped into the primary wellbore 202 separate from the drill string 212 . In other embodiments, however, the drill string 212 and deflection member 218 may be part of the same drilling assembly to allow for single trip setting of the deflection member 218 , milling of the window 230 , drilling of the lateral borehole 210 , or some combination thereof.
- FIG. 9 illustrates an example embodiment of a drilling system 300 that may be used for single trip drilling of a lateral borehole.
- the drilling system 300 may also be used to anchor a deflection member 318 and mill a window in a casing 304 in the same, single trip.
- drilling system 300 may be similar in various regards to components described in embodiments described elsewhere herein, or illustrated in FIGS. 1-8 . Accordingly, to avoid unnecessarily obscuring aspects of the disclosure, certain details will not be repeated relative to the drilling system 300 , but should instead be understood to be equally applicable to the embodiment shown in FIG. 9 . Indeed, each embodiment disclosed herein is intended to include components and features that may be interchanged with features and components of other embodiments disclosed herein.
- the drilling system 300 may be used to form a lateral borehole off of a primary wellbore 302 that includes a casing 304 therein.
- the drilling system 300 may itself include a deflection member 318 , a casing bit 316 , and a drill bit 322 coupled together using a drill string 312 , protective sheath 326 , fasteners 334 , connectors 336 , or other components that allow single trip installation and/or use.
- the deflection member 318 may include a whipstock or any other components suitable for deflecting the casing bit 316 against the casing 304 for formation of a window.
- the deflection member 318 includes a setting assembly having one or more expandable anchors 320 .
- the expandable anchors 320 are illustrated in a retracted state in which a width of the anchors 320 may be less than the interior diameter of the casing 304 , thereby allowing the deflection member 318 to be inserted into, or retracted from, the primary wellbore 302 .
- the deflection member 318 is further illustrated as including a connector 336 .
- the connector 336 may couple the deflection member 318 to the casing bit 316 .
- the connector 336 may have sufficient structural strength and integrity to maintain the deflection member 318 coupled to the casing bit 316 when tripped into the primary wellbore 302 , but may be structured to break or release at a desired time or location. For instance, when the anchors 320 are expanded, the casing bit 316 may begin to rotate. When the deflection member 318 is fixed at an axial and/or rotational position, the rotation of the casing bit 316 may generate a torque or other force causing the connector 336 to fail.
- the connector 336 may be used to decouple the deflection member 318 from the casing bit 316 or drill string 312 in any number of manners, and need not be or include a sacrificial element. Indeed, in some embodiments, the connector 336 may be selectively couplable to allow decoupling from, and re-coupling between, the deflection member 318 and the casing bit 316 .
- the drill string 312 may be used to advance the casing bit 316 within the primary wellbore 302 . Advancing the casing bit 316 may cause the casing bit 316 to move toward, and mill a window into, the casing 304 . As discussed herein, when the casing bit 316 has milled a window, and optionally cut at last a portion of the formation 306 to start a lateral borehole, use of the casing bit 316 may be discontinued.
- the casing bit 316 may also be secured at an axial and/or rotational position in using an anchor 332 or other securement device (either directly or, as shown in FIG.
- the drill bit 322 may be advanced within the protective sheath 326 towards the casing bit 316 .
- the drill bit 322 may drill through the casing bit 316 and then into the formation 306 to extend the lateral borehole.
- the protective sheath 326 may protect the drill bit 322 and/or the drill string 312 against contact with the casing 304 (e.g., at the edges of the window in the casing 304 ); however, the protective sheath 326 may also provide other uses.
- the protective sheath 326 may protect other components of the drilling system 300 .
- a bottomhole assembly including the drill bit 322 may include a stabilizer 333 or other components (e.g., mud motor, drill collars, sensors, jars, tractors, conveyors, vibration tools, etc.).
- the stabilizer 333 and other components may also pass through the protective sheath 326 to be protected from contact with the casing 304 or the deflection member 318 .
- completion or other components may enter the primary wellbore 302 following removal of the drill string 312 , and can pass through the protective sheath 326 to be protected against damage from the deflection member 318 and/or the casing 304 .
- the drill string 312 may be coupled to a protective sheath 326 .
- the protective sheath 326 may provide a slide or guide for the drill bit 322 to allow the drill bit 322 to move through a window in the casing 304 without directly contacting the casing 304 .
- the protective sheath 326 may be separable from the drill string 312 (e.g., using fasteners 334 ).
- the protective sheath 326 may include components of a CWD system.
- a joint 313 may couple components of the protective sheath 326 to each other.
- the joint 313 may be a CWD joint, and can be used to couple CWD or other component of the protective sheath 326 , to facilitate bending or flexure of the protective sheath 326 , or for any number of other purposes.
- the drill bit 322 may be directly or indirectly coupled to the drill string 312 , protective sheath 326 , or casing bit 316 so as to be part of the same drilling assembly, and to allow single trip drilling of the lateral borehole.
- the fastener 334 which is shown as coupling the drill string 312 to the protective sheath 326 , may be used to make such a connection.
- the fastener 334 may include a sacrificial element, hydraulic release, or other type of connector to allow selective decoupling of the drill bit 322 from the protective sheath 326 .
- the particular location of the fastener 334 and/or location of a connection of the drill bit 322 can be varied. Relative to the embodiment in FIGS. 3-8 , for instance, the drill bit 322 is shown as being fastened in a distal end portion near the casing bit 316 . In one embodiment, the drill bit 322 may be generally aligned in a longitudinal direction with the anchor 332 , or potentially nearer the casing bit 316 than the anchor 332 .
- the protective sheath 326 may guide and protect the drill bit 322 through the window even before the fastener 334 is selectively released to decouple the drill bit 322 or drill string 312 from the protective sheath 326 .
- the drill bit 322 may be used to independently drill within the lateral borehole, and can potentially drill through the casing bit 316 and/or into the formation 306 to form or extend the lateral borehole.
- the drill bit 332 may be a fixed cutter, roller cone, impregnated diamond, or other drilling bit.
- the drill bit 332 may have a fixed outer or gauge diameter.
- the drill bit 332 may be an expandable drill bit.
- the casing bit 316 may have a fixed diameter or may be expandable.
- Relational terms such as “bottom,” “below,” “top,” “above,” “back,” “front,” “left,” “right,” “rear,” “forward,” “up,” “down,” “horizontal,” “vertical,” “clockwise,” “counterclockwise,” “upper,” “lower,” “uphole,” “downhole,” and the like, may be used to describe various components, including their operation and/or illustrated position relative to one or more other components. Relational terms do not indicate a particular orientation for each embodiment within the scope of the description or claims.
- a component of a bottomhole assembly that is described as “below” another component may be further from the surface while within a vertical wellbore, but may have a different orientation during assembly, when removed from the wellbore, or in a deviated borehole.
- relational descriptions are intended solely for convenience in facilitating reference to various components, but such relational aspects may be reversed, flipped, rotated, moved in space, placed in a diagonal orientation or position, placed horizontally or vertically, or similarly modified.
- Certain descriptions or designations of components as “first,” “second,” “third,” and the like may also be used to differentiate between identical components or between components which are similar in use, structure, or operation. Such language is not intended to limit a component to a singular designation.
- a component referenced in the specification as the “first” component may be the same or different than a component that is referenced in the claims as a “first” component.
- Couple refers to “in direct connection with,” or “in connection with via one or more intermediate elements or members.”
- Components that are “integral” or “integrally” formed include components made from the same piece of material, or sets of materials, such as by being commonly molded or cast from the same material, or commonly machined from the same piece of material stock. Components that are “integral” should also be understood to be “coupled” together.
- While embodiments disclosed herein may be used in oil, gas, or other hydrocarbon exploration or production environments, such environments are merely illustrative. Systems, tools, assemblies, methods, milling systems, and other components of the present disclosure, or which would be appreciated in view of the disclosure herein, may be used in other applications and environments. In other embodiments, milling tools, deflection elements, methods of milling and drilling, or other embodiments discussed herein, or which would be appreciated in view of the disclosure herein, may be used outside of a downhole environment, including in connection with other systems, including within automotive, aquatic, aerospace, hydroelectric, manufacturing, other industries, or even in other downhole environments.
- well wellbore
- borehole and the like are therefore also not intended to limit embodiments of the present disclosure to a particular industry.
- a wellbore or borehole may, for instance, be used for oil and gas production and exploration, water production and exploration, mining, utility line placement, or myriad other applications.
- the stated values include at least experimental error and variations that would be expected by a person having ordinary skill in the art, as well as the variation to be expected in a suitable manufacturing or production process.
- a value that is about or approximately the stated value and is therefore encompassed by the stated value may further include values that are within 5%, within 1%, within 0.1%, or within 0.01% of a stated value.
Abstract
Systems, assemblies, and methods are described which relate to drilling a lateral borehole from a primary wellbore. A primary wellbore may have a casing therein. A window may be milled in the casing using a casing bit. The casing bit may pass through the window and into the surrounding formation. A protective sheath coupled to the casing bit may also extend through the window. The casing bit and protective sheath may remain in place while a drill bit slides through the protective sheath. The drill bit may drill through the casing bit and drill the formation to extend the lateral borehole. An anchor may be used to secure the protective sheath and/or casing bit in place. The drill bit may be included in a single trip assembly with the casing bit and protective sheath.
Description
- This application claims the benefit of, and priority to, U.S. Patent Application Ser. No. 61/832,564 filed on Jun. 7, 2013 and entitled “Protective Sheath Through a Casing Window,” which application is incorporated herein by this reference in its entirety.
- In exploration and production operations for natural resources such as hydrocarbon-based fluids (e.g., oil and natural gas), a vertical wellbore may be drilled into an earthen formation. If the wellbore comes into contact with a fluid reservoir, the fluid may then be extracted. If the wellbore doesn't contact the fluid reservoir, or as the resources in a reservoir are depleted, it may be useful to create additional wellbores to access additional resources. For instance, a new wellbore may be drilled at the site of an additional fluid reservoir.
- In some cases, however, directional drilling may be used in lieu of creating a new, vertical wellbore. In directional drilling, a lateral or deviated borehole may be formed and may branch off an existing wellbore. The lateral borehole may extend laterally at a desired trajectory suitable for reaching a particular site. In creating the lateral borehole, a whipstock may be employed in a method referred to as sidetracking.
- Whipstocks have a ramped surface providing a travel path for a bit coupled to a drill string. To create the lateral borehole, the whipstock can be set at a desired depth and the ramped surface oriented to provide a particular drilling trajectory. The whipstock may be located at an openhole or cased portion of a wellbore. When the wellbore is cased, a milling assembly may be used to mill through, and form a window in, the casing. Upon forming the window, the milling assembly may be removed and a drilling assembly may be tripped into the wellbore to extend the lateral borehole through the casing window.
- Assemblies, systems and methods of the present disclosure may relate to the drilling of a lateral borehole from a primary wellbore. In one example system, a method includes positioning a drilling assembly within a primary wellbore. The drilling assembly may include a casing bit coupled to a protective sheath. The casing bit may be used to mill a window in casing of the primary wellbore, and the protective sheath may be extended through the window. The drill string and drill bit may be guided through the protective sheath and through the window, and the drill bit may be used to drill a lateral borehole.
- In another example embodiment, a drilling assembly may include a casing bit coupled to a protective sheath. A drill string may also be coupled to, and inside, the protective sheath. The drill string may include drill bit.
- According to another example embodiment, a drilling system may be used to form a window in a casing of a primary wellbore and to drill a lateral borehole off the primary wellbore. The drilling system may include a drillable casing bit configured to mail the window in the casing. A protective sheath may be coupled to the drillable casing bit. The drilling system may also include an anchor used to anchor the protective sheath and restrict the protective sheath from moving axially, rotationally, or both. A drill string may be coupled to an interior of the protective sheath. The drill string may include a drill bit configured to dill through the drillable casing bit and through formation around the primary wellbore. A fastener may releasably couple the drill string to the protective sheath.
- This summary is provided solely to introduce some features and concepts that are further developed in the detailed description. Other features and aspects of the present disclosure will become apparent to those persons having ordinary skill in the an through consideration of the ensuing description, the accompanying drawings, and the appended claims. This summary is therefore not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claims.
- In order to describe various features and concepts of the present disclosure, a more particular description of certain subject matter will be rendered by reference to specific embodiments which are illustrated in the appended drawings. Understanding that these drawings depict only some example embodiments and are not to be considered to be limiting in scope, nor drawn to scale for all embodiments, various embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
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FIG. 1 schematically illustrates an example system for drilling a lateral borehole, the system including a casing bit for drilling a window into a casing of a primary wellbore to begin formation of the lateral borehole, in accordance with one embodiment of the present disclosure; -
FIG. 2 schematically illustrates the system ofFIG. 1 following commencement of drilling of the lateral borehole using the casing bit, and including extension of the lateral borehole using a drill bit drilling through the casing bit, in accordance with an embodiment of the present disclosure; -
FIG. 3 illustrates a partial cross-sectional view of an example system for drilling a lateral borehole, the system including a casing bit for drilling a window in a wellbore casing, a drill string coupled to the casing bit, and an interior drill bit, in accordance with one embodiment of the present disclosure; -
FIG. 4 illustrates a partial cross-sectional view of the system ofFIG. 3 , the casing bit and a portion of the drill string having passed through a window of the wellbore casing, in accordance with one embodiment of the present disclosure; -
FIG. 5 schematically illustrates an example window formed in the wellbore casing ofFIG. 4 ; -
FIG. 6 illustrates a partial cross-sectional view of the system ofFIGS. 3 and 4 , the casing bit and drilling assembly being anchored to the earthen formation, in accordance with one embodiment of the present disclosure; -
FIG. 7 illustrates a partial cross-sectional view of the system ofFIGS. 3 , 4 and 6, the interior drill bit having been detached and extended through the protective sheath towards the casing bit, in accordance with an embodiment of the present disclosure; -
FIG. 8 illustrates a partial cross-sectional view of the system ofFIG. 7 , with the interior drill bit extending the lateral borehole following drilling through the casing bit, in accordance with another embodiment of the present disclosure; and -
FIG. 9 illustrates a partial cross-sectional view of another example system for drilling a lateral borehole, the system including an interior drill bit adjacent the casing bit, and including a deflection assembly coupled to the casing bit, in accordance with another embodiment of the present disclosure. - In accordance with some aspects of the present disclosure, embodiments herein relate to systems and assemblies for drilling a lateral borehole. More particularly, embodiments disclosed herein may relate to drilling systems, assemblies and methods for drilling a lateral borehole off a cased, primary wellbore. Example drilling systems and assemblies may include a casing bit and a drill bit. The casing bit may be coupled to a drill string element which may be coupled to, or may include, a protective sheath. Upon milling a window in a casing of the cased, primary wellbore, the protective sheath can pass through the window. The drill bit may also pass through the window. As the drill bit passes through the window, the protective sheath may restrict and potentially prevent the drill bit from contacting the casing or a surrounding formation until the drill bit drills through or is otherwise removed from the casing bit.
- Referring now to
FIGS. 1 and 2 , schematic diagrams are provided of anexample drilling system 100 that may utilize systems, assemblies and methods in accordance with one or more embodiments of the present disclosure.FIG. 1 shows an exampleprimary wellbore 102 which is, in this embodiment, a cased wellbore. The cased wellbore shown inFIG. 1 includes acasing 104 which may extend along all or a portion of the length of theprimary wellbore 102. Thecasing 104 may be used for any number of reasons. For instance, thecasing 104 may be production casing that is cemented or otherwise secured in place to isolate theprimary wellbore 102 from the surroundingformation 106, and/or to provide structural support along the length of theprimary wellbore 102. In other embodiments, thecasing 104 may include additional or other casing, including intermediate casing, surface casing, conductor casing, liner, or other component. - In the particular embodiment illustrated in
FIG. 1 , thedrilling system 100 may be provided and may include components to allow drilling of a lateral borehole (e.g.,lateral borehole 110 ofFIG. 2 ) which branches off theprimary wellbore 102. The lateral borehole may be drilled using adrill string 112 to rotate one or more drill bits. In the particular example embodiment ofFIG. 1 , thedrill string 112 may be coupled to aprotective sheath 126, which in turn may be coupled to acasing bit 116. Thecasing bit 116 may a mill or otherwise configured to mill into thecasing 104, and to form a window or opening therein. During formation of the window, thecasing bit 116 may drill partially into theformation 106 to initiate a lateral borehole. In some embodiments, thecasing bit 116 may also be used after full formation of the window to continue drilling the lateral borehole. - More particularly, some embodiments of the present disclosure contemplate use of a
drill string 112 that can transmit torque and axial loads, and which can transfer such forces to theprotective sheath 126. Theprotective sheath 126 may ultimately transfer such forces to thecasing bit 116. Thedrill string 112 may therefore include any number of structures to facilitate such use for the formation and/or extension of a lateral borehole. For instance, thedrill string 112 may include a tubular member. As an example, the tubular member of thedrill string 112 may include coiled tubing with a downhole motor, jointed/segmented tubing, a liner, casings (e.g., as part of a casing-while-drilling system), or other components, or some combination thereof, to be capable of carrying transmitted loads to theprotective sheath 126 and ultimately to thecasing bit 116. Of course, thedrill string 112 may include or be coupled to any number of different components or structures. In some embodiments, thedrill string 112 may include, or be coupled to, multiple sections of jointed pipe, a motor, stabilizers, or other components. An example motor may include a positive displacement motor (e.g., a mud motor or progressive cavity motor), a turbine or turbodrill motor, an electrical motor, some other type of motor, or a combination of the foregoing. Thedrill string 112 may also include directional drilling and/or measurement equipment. As an example, thedrill string 112 may include a steerable drilling assembly to control the direction of drilling of the lateral borehole within theformation 106. A steerable drilling assembly may include various types of directional control systems, including rotary steerable systems referred to as push-the-bit or point-the-bit systems, or any other type of rotary steerable or directional control system. In some embodiments, components coupled to thedrill string 112 may be part of a bottomhole assembly for drilling the lateral borehole into theformation 106. - To further facilitate drilling of the lateral borehole, the
drilling system 100 may include, or be used with, adeflection member 118. Thedeflection member 118 may include a whipstock or any other structure that may be used to facilitate formation of the window in thecasing 102 or the lateral borehole. In this particular embodiment, thedeflection member 118 may include an inclined surface. The inclined surface may be generally planar, although in other embodiments the inclined surface may be concave (e.g., to accommodate arounded casing bit 116,drill string 112, etc.), have multiple tiers of differing inclines, or be otherwise configured. - In operation, the
drill string 112 andcasing bit 116 may be tripped into the wellbore until they engage with thedeflection member 118. The inclined surface of thedeflection member 118 may direct thecasing bit 116 towards the interior surface of thecasing 104. In some embodiments, thedeflection member 118 may be anchored or otherwise maintained at a desired position, depth, and orientation in order to deflect thecasing bit 116 at a desired location and azimuthal orientation. When at the desired location and azimuthal orientation, thecasing bit 116 may mill a window for drilling of a lateral borehole. - A set of one or
more anchors 120, packers, or other components may be used to anchor thedeflection member 118 at an axial position and azimuthal orientation within theprimary wellbore 102. The one ormore anchors 120 and/or other components may define a setting assembly for engaging the sidewalls of thecasing 104 in theprimary wellbore 102. In one embodiment, theanchors 120 may be expandable. For instance, hydraulic fluid may be used to expand theanchors 120 from a retracted position to the expanded position shown inFIG. 1 . In other embodiments, however, theanchors 120 that can be set in other manners. For instance, theanchors 120 may expand or be set mechanically, using spring-loaded components, through directed explosive charges, or in other manners. Regardless of the particular manner in which theanchors 120 operate, theanchors 120 optionally have a sufficient ratio of the expanded diameter relative to the retracted diameter, thereby facilitating engagement with a sidewall of acasing 104 orprimary wellbore 102, to potentially allow use in wellbores having any number of different sizes. In other embodiments, theanchors 120 may be modified, or even eliminated and replaced by other suitable components usable to secure thedeflection member 118 in place. - The
drilling system 100 may also include still other or additional components. By way of example, and as discussed in greater detail herein, thecasing bit 116 may be used primarily for milling through thecasing 104. Upon milling through thecasing 104, and potentially through a portion of theformation 106, thecasing bit 116 may stop rotating and/or stop advancing. As shown inFIG. 2 , adrill bit 122 may then be used to extend thelateral borehole 110. - More particularly, the
drill bit 122 ofFIG. 2 may be coupled to thedrill string 112 ofFIG. 1 . Thedrill string 112 may be used to rotate and advance theprotective sheath 126 and thecasing bit 116 to form the window in thecasing 104. InFIG. 1 , however, thedrill string 112 anddrill bit 122 may be coupled to an interior of theprotective sheath 126 using a fastener. The fastener may secure thedrill string 112 and/ordrill bit 122 relative to theprotective sheath 126, and allow axial and rotational loads to be transmitted between thedrill string 112 and theprotective sheath 126. Upon release of the fastener, however, the rotational and axial forces on thedrill bit 122 anddrill string 112 may allow movement independent of theprotective sheath 126. Consequently, thedrill string 112 anddrill bit 122 may be moved through theprotective sheath 126 and can potentially drill through thecasing bit 116. For purposes of this disclosure, acasing bit 116 which may be drilled through by adrill bit 122 may be referred to as a “drillable casing bit”. After drilling through thecasing bit 116, which may be a drillable casing bit, thedrill bit 122 can move into and potentially extend thelateral borehole 110. - The particular structure, components, and method of use of the
drilling system 100 may be varied in any number of manners. For instance, the length of theprotective sheath 126 may be varied. Optionally, the length and size of theprotective sheath 126 may be sized based on particular conditions within theprimary wellbore 102 or based on components of thedrilling system 100. For instance, as discussed herein, theprotective sheath 126 may be coupled to thedrill string 112 during a milling operation for forming a window in thecasing 104. Thereafter, however, thedrill string 112 may be detached from theprotective sheath 126 to allow alateral borehole 110 to be formed or extended. According to at least some embodiments, including the embodiment shown inFIG. 2 , the length of theprotective sheath 126 may allow theprotective sheath 126 to extend at least from a top of thedeflection member 118 to a position beyond the window milled in thecasing 104. As a result, when thedrill bit 122 passes through the interior of theprotective sheath 126, theprotective sheath 126 may restrict thedrill bit 122 from contacting thedeflection member 118 and/or thecasing 104. - If a
protective sheath 126 extends from a top of thedeflection member 118 and fully through the window in thecasing 104, the particular length of theprotective sheath 126 may vary depending on a variety of factors. Example factors may include the length of an inclined surface of thedeflection member 118, a diameter of theprimary wellbore 102, a diameter of thecasing bit 116, and the like. In other embodiments, the length of theprotective sheath 126 may be selected to give a tolerance to positioning of theprotective sheath 126. In such an embodiment, the length may be extended to allow theprotective sheath 126 to start a few feet above the top of thedeflection member 118 and extend fully to a position a few feet beyond the milled window in thecasing 104. In any such embodiments, and for illustration only, an exampleprotective sheath 126 may have a length of between 5 ft. (1.5 m) and 100 ft. (30.5 m). In another embodiment, the length of theprotective sheath 126 may be between 15 ft. (4.6 m) and 60 ft. (18.3 m). In still another embodiment, the length of theprotective sheath 126 may be between 20 ft. (6.1 m) and 40 ft. (12.2 m). For instance, theprotective sheath 126 may be 30 ft. (9.1 m) in some embodiments. Of course, in other embodiments, the length of theprotective sheath 126 may be greater than 100 ft. (305 m) or less than 5 ft. (1.5 m.). Further, the length may of course also be varied if the location of theprotective sheath 126 is varied. For instance, if theprotective sheath 126 extends through the window in thecasing 104, but doesn't extend fully to the top of thedeflection member 118, theprotective sheath 126 may be shortened. - When the
protective sheath 126 extends from the top of thedeflection member 118 fully through thecasing 104, and optionally an added distance in either or both directions, theprotective sheath 126 may house thedrill bit 122 and protect thedrill bit 122 from damage that could otherwise result from thedrill bit 122 contacting either thedeflection member 118 or thecasing 104. Moreover, protecting thedrill bit 122 in this manner may further allow a different bit (i.e., drill bit 122) to drill thelateral borehole 110 than the bit (i.e., casing bit 116) used to mill the window in thecasing 104. Thedrill bit 122 may not exhibit the wear caused to thecasing bit 116 by the casing and/or may be designed for cutting into theformation 106. Such factors, along with reduced damage to thedrill bit 122 due to protection provided by theprotective sheath 126, may increase the drilling efficiency and life of thedrill bit 122. - Protection of the
drill bit 122 from damage caused by thecasing 104 and/ordeflection member 118 are only some of the features of theprotective sheath 126. In other embodiments, for instance, thedrilling system 100 may include motors, stabilizers, or other components (e.g., as part of a bottomhole assembly). These additional components may also be protected against damage. Further, particularly for thecasing 104, the window may have jagged or uneven edges and theprotective sheath 126 may protect against interference with the edges of the window. Further still, upon removal of thedrill bit 122 anddrill string 112 from theprimary wellbore 112, thelateral borehole 110 may be re-entered for performing additional operations. Theprotective sheath 126 may be left in place (and potentially anchored in place). As a result, components used to perform the additional operations may be tripped into thewellbore 102 and into thelateral borehole 110 while being guided by theprotective sheath 126. For instance, completion components (e.g., packers) may be run into thelateral borehole 110, and may pass through theprotective sheath 126 which protects the components from damage or interference. - Turning now to
FIGS. 3-8 , various partial, cross-sectional views are provided to illustrate another example embodiment of adrilling system 200 in accordance with another aspect of the present disclosure. In particular,FIGS. 3-8 illustrate various stages of drilling alateral borehole 210 off of aprimary wellbore 202, while also providing aprotective sheath 226 for protecting and guiding adrill bit 222 used to form or extend thelateral borehole 210. - More particularly,
FIGS. 3-8 illustrate aprimary wellbore 202 formed in aformation 206. Theprimary wellbore 202 may be formed in any suitable manner. In this particular embodiment, for instance, theprimary wellbore 202 is shown as a cased wellbore and has acasing 204 therein. Thecasing 204 may generally be a tubular structure adjacent the interior, peripheral walls of theprimary wellbore 202. In some embodiments, thecasing 204 may be cemented or otherwise secured in place within theprimary wellbore 202. - Under some circumstances, a lateral, deviated, or branched borehole (e.g.,
lateral borehole 210 in FIGS. 4 and 6-8) may be drilled. The lateral borehole 210 may extend within theformation 206 and at an angle from theprimary wellbore 202. For instance, theprimary wellbore 202 may be oriented generally vertically, and thelateral borehole 210 can be formed to extend therefrom at a particular trajectory. Of course, it should be appreciated by a person having ordinary skill in the art in view of the disclosure herein that theprimary wellbore 202 may also not be vertical, and that the degree of deviation of thelateral borehole 210 from theprimary wellbore 202 can be varied in a number of manners. Indeed, the angles of theprimary wellbore 202 andlateral borehole 210 may extend at any possible angle relative to each other and/or the surface. Thus, while alateral borehole 210 may be formed to extend in a generally horizontal direction, that direction may or may not be about perpendicular relative to theprimary wellbore 202 or parallel relative to a surface of theformation 206. In other embodiments, other trajectories are obtained, and thelateral borehole 210 may curve along its path to obtain the desired end trajectory or desired target. - In order to drill and extend the
lateral borehole 210, adeflection member 218 may be tripped into theprimary wellbore 202.FIGS. 3-8 somewhat schematically illustrate a side view of theexample deflection member 218, which in this embodiment is shown as a whipstock. Generally speaking, thedeflection member 218 may include, or be coupled to, anchors 220 that may be used to set thedeflection member 218 at a desired position and orientation. When tripping thedeflection member 218 into theprimary wellbore 202, theanchors 220 may be in a retracted state (not shown). With theanchors 220 retracted, thedeflection member 218 may move axially and/or rotationally within theprimary wellbore 202. - Once the
deflection member 218 reaches a desired depth, the deflection member may be oriented and secured in place in theprimary wellbore 202 using theanchors 220. In some embodiments, theanchors 220 are part of a setting assembly and may expand to engage against the interior wall of thecasing 204. Such engagement may create a frictional or interference fit to secure thedeflection member 218 in place by resisting axial and/or rotational movement within theprimary wellbore 202. Theanchors 220 may be expandable in any number of manners. For instance, in some embodiments theanchors 220 may by hydraulically actuated. In other embodiments theanchors 220 may be mechanically or otherwise expanded and/or retracted. Additionally, while theanchors 220 are shown as engaging thecasing 204, theanchors 220 optionally may be aligned with an uncased, or openhole, portion of thewellbore 202. In such an embodiment, theanchors 220 may expand to engage theformation 206 directly, and potentially may cut into, or pierce, theformation 206 to secure thedeflection member 218 in place. - The
deflection member 218 may be used to direct the path of a drilling assembly used to drill a lateral borehole off theprimary wellbore 202. In one embodiment, such as where thedeflection member 218 is a whipstock, thedeflection member 218 may include a rampedsurface 228. When anchoring thedeflection member 218 in place, the rampedsurface 228 may be positioned at a desired orientation configured to guide the drilling assembly along a particular trajectory. As shown inFIG. 3 , due to the rampedsurface 228, a width of thedeflection member 218 may increase from an upper end towards a lower end. As a result, as a drilling assembly that includes thedrill string 212,protective sheath 226, andcasing bit 216 is moved downward into theprimary wellbore 202, the rampedsurface 228 can urge the drilling assembly radially outwardly, away from a central axis of theprimary wellbore 202, and against thecasing 204, and ultimately into theformation 206. As shown inFIG. 4 , for instance, thecasing bit 216 can generally follow the incline of the rampedsurface 228 and engage thecasing 204. Upon contacting thecasing 204, thecasing bit 216 can mill an opening therein. The opening, which is referred to herein as a “window” 230, may be gradually formed as thecasing bit 216 moves along the rampedsurface 228 and through thecasing 204. As a result, thewindow 230 may have a generally elongated shape.FIG. 5 , for instance, illustrates a side view of the exterior of thecasing 204 with thewindow 230 formed therein. - As shown in
FIG. 5 , when thewindow 230 is formed, thewindow 230 may not have a perfectly smooth periphery, but instead may include one or more jagged or uneven edges. As discussed herein, a drill bit, mill, or other cutting element may pass through thewindow 230 to form alateral borehole 210. If unprotected, the drill bit, mill, or other cutting element may catch on the jagged edges of thewindow 230, or otherwise contact the edges of thewindow 230. The edges of thewindow 230 could also interfere with other components of a drilling assembly (e.g., drill string, motor, stabilizer, etc.), or with completion or other components which re-enter the lateral borehole after removal of a drill string. Such engagement or interference can potentially damage the components, make entry into thelateral borehole 210 difficult, or reduce the effectiveness and/or useful life of a downhole system or bottomhole assembly. - Furthermore, the properties of the
casing 204 may significantly differ from that of the surroundingformation 206. For instance, thecasing 204 may be formed of a metal (e.g., steel), while theformation 206 may be formed of one or more types of rock or other materials. In some cases, a cutting element or bit structure suited for cutting theformation 206 may not be as efficient at milling thewindow 230, or may be more easily damaged by thecasing 204. Embodiments herein, including thedrilling system 200 ofFIGS. 3-8 , relate to an example embodiment that may be used to effectively mill a window in acasing 204, while also protecting a cutting element or bit that may be used to form or extend alateral borehole 210. - More particularly, and returning now to
FIGS. 3 and 4 , thedrilling system 200 may include two or more bits, each of which may have multiple cutting structures or elements. In this particular embodiment, thedrilling system 200 includes acasing bit 216 as a first bit, and adrill bit 222 as a second bit. Thecasing bit 216 may be primarily configured for use in milling awindow 230 in thecasing 204, while thedrill bit 222 may be primarily configured for use in cutting, shearing, impacting, or otherwise extending thelateral borehole 210 in theformation 206. - In this particular embodiment, the
casing bit 216 is shown as being coupled to aprotective sheath 226 which may in turn be coupled to, and optionally suspended from, adrill string 212. Thedrill string 212 may include jointed pipe, casing-while-drilling (“CWD”), or other types of drill string elements, or any combination thereof. Torque and axial thrust may be applied to thedrill string 212 and transferred to theprotective sheath 226, which may in turn transfer such torque and motion to thecasing bit 216. - The
drill string 212 may optionally be used to convey drilling mud or another fluid. Such fluids may, for instance, pass through an interior of thedrill string 212. The fluid may be used in connection with a hydraulic motor or drive system (not shown) to rotate thedrill string 212, or a component thereof, as well as theprotective sheath 226 and thecasing bit 216. In some embodiments, the drilling mud or other fluid may enter theprotective sheath 226, and thecasing bit 216 may include one or more openings therein to allow fluid to pass therethrough. Such a fluid may then also act as a coolant on an exterior of thecasing bit 216 and/or a jet nozzle to flush cuttings away from the face of thecasing bit 216. The drilling fluid may facilitate cutting of thecasing 204 and/orformation 206, reduce wear of thecasing bit 216, and prolong the life or effectiveness of thecasing bit 216. - As discussed herein, the
protective sheath 226 andcasing bit 216 may be lowered toward thedeflection member 218 by using thedrill string 212. The rampedsurface 228 of thedeflection member 218 may push thecasing bit 216 into thecasing 204 where thewindow 230 may be formed by rotation of thecasing bit 216 as weight-on-bit is applied thereto.FIG. 3 illustrates thecasing bit 216 prior to formation of thewindow 230, whileFIG. 4 illustrates thecasing bit 216 after milling of thewindow 230. Also shown inFIG. 4 is the start of alateral borehole 210 branching from theprimary wellbore 202. - While the
casing bit 216 may be primarily used to mill thewindow 230 in thecasing 204, thecasing bit 216 may also cut, to at least some extent, into theformation 206. Indeed, in some embodiments, thecasing bit 216 may partially cut into theformation 206 before thewindow 230 is at its full size. In at least some embodiments, the cutting of theformation 206 may stop at about the same time as completion of thewindow 230. In other embodiments such as that shown inFIG. 4 , thecasing bit 216 may continue to cut into theformation 206 even after thewindow 230 is fully formed. In such an embodiment, the amount of additional cutting performed using thecasing bit 216 may vary. For instance, the length of thelateral borehole 210 may vary from a few inches or centimeters to many feet or meters by the time an operator ceases using thecasing bit 216 to drill a portion of thelateral borehole 210. - When the drilling of the
formation 206 using thecasing bit 216 is stopped, thecasing bit 216 may be removed. In other embodiments, however, thecasing bit 216 may potentially be left within thelateral borehole 210. As an example, the illustrated embodiment depicts anadditional anchor 232 coupled to theprotective sheath 226. When theanchor 232 is in a retracted state as shown inFIGS. 3 and 4 , theprotective sheath 226 and thecasing bit 216 may advance within thelateral borehole 210. In contrast, by expanding or activating theanchor 232, theanchor 232 may engage or grip theformation 206 and restrict, if not prevent, axial and/or rotational movement of theprotective sheath 226 and/orcasing bit 216.FIG. 6 illustrates an example embodiment in which theanchor 232 has been expanded to engage theformation 206 and restrict movement of thecasing bit 216 andprotective sheath 226. The particular manner in which theanchor 232 operates may vary. For instance, hydraulic fluid may be used to hydraulically expand theanchor 232. In another embodiment, theanchors 232 may be mechanically, explosively, or otherwise activated. - Optionally, a controller (e.g., a programmable or electronic controller) may be used to facilitate activation. For instance, if an operator of the
drilling system 200 determines that thewindow 230 has been completed and the length of thelateral borehole 210 is sufficient to allow theanchor 232 to engage theformation 206, a control signal may be provided in a wireless, physical, conductive, or other manner, or using some combination of the foregoing. The control signal may open a valve which can allow hydraulic fluid passing within theprotective sheath 226 to then expand theanchor 232. Alternatively, a control signal may activate a motor to mechanically expand theanchor 232, release a spring-loaded element, ignite a directed explosive charge, or otherwise expand theanchor 232. Moreover, while theanchor 232 may be controlled by an operator, in other embodiments the control may be automatic. For instance, a controller of theanchor 232 may be programmed to activate at a particular location, and one or more sensors (e.g., measurement-while-drilling tools, logging-while-drilling tools, smart drill collars, etc.) may provide positioning information to the controller to sense when the conditions for activating theanchor 232 are present. - When the
casing bit 216 is secured in place within thelateral borehole 210, a second bit, which is illustrated as adrill bit 222 inFIG. 6 , may then be used to extend thelateral borehole 210. InFIG. 6 , for instance, thedrill bit 222 is also coupled to thedrill string 212. More particularly, thedrill bit 222 may be coupled to a distal end portion of thedrill string 212, and optionally be located inside theprotective sheath 226 that is also coupled to thedrill string 212. The illustrateddrilling system 200 may be intended for use as a single trip drilling assembly, so that milling of thewindow 230 and drilling of thelateral borehole 210 may occur in a single trip. In some embodiments, thedeflection member 218 andanchor 220 may also be set in a single trip so that setting of the anchor, milling of thewindow 230, and drilling of thelateral borehole 210 may occur in a single trip. - In at least some embodiments, the
drill bit 222 ordrill string 212 may be fixed at a particular location within theprotective sheath 226 in a manner that allows thedrill bit 222 to advance within theprimary wellbore 202 and/orlateral borehole 210 at about the same rate as theprotective sheath 226. In this particular embodiment, for instance, afastener 234 may selectively couple thedrill string 212 at a particular axial location within theprotective sheath 226. Of course, in other embodiments, thefastener 234 may directly couple thedrill bit 222 to theprotective sheath 226. - Regardless of how or where located, the
fastener 234 may provide a connection that allows rotational and axial forces on thedrill string 212 to be transferred to theprotective sheath 226. Indeed, as described herein, while fixed to theprotective sheath 226, thedrill string 212 ordrill bit 222 may have a rotation that is about synchronous with the rotation of thecasing bit 216 and/orprotective sheath 226. In the illustrated embodiment, for instance, thefastener 234 may effectively lock thedrill bit 222 to thedrill string 212. When locked, thefastener 234 may allow rotational movement (i.e., torque) and axial thrust (i.e., weight-on-bit) on thedrill string 212 to be transmitted to theprotective sheath 226. Thus, theprotective sheath 226 anddrill string 212 may have about the same rotation and axial movement. When theanchor 232 is activated to restrict rotation of thedrill string 212 and/or thecasing bit 216, the rotation of both thecasing bit 216 anddrill bit 222 may stop. In other embodiments, however, thedrill bit 222 may rotate independently of theprotective sheath 226 and/orcasing bit 216. For instance, thefastener 234 may be coupled to thedrill string 212. A motor or other element of a bottomhole assembly associated with thedrill bit 222 may allow thedrill bit 222 to rotate at a rate that is faster or slower relative to rotation of thedrill string 212,protective sheath 226, orcasing bit 216. - At about the time the
casing bit 216 is anchored in place, or sometime thereafter, thedrill string 212 may be allowed to rotate and move axially relative to theprotective sheath 226 and thecasing bit 216. Such independent rotation and axial movement may occur using any number of mechanisms. For instance, thefastener 234 may be deactivated or selectively released. As an example, thefastener 234 may include a hydraulically activated release. Depending on the design of the release, when hydraulic pressure is supplied or cut-off, thefastener 234 may release, allowing thedrill bit 222 anddrill string 212 to move independently of theprotective sheath 226. In another embodiment, a ball, dart, or other obstruction element may be inserted into thedrill string 212 and may land on a seat. Pressure may build behind the seat and obstruction element to break one or more shear pins of thefastener 234. In other embodiments, a spring-loaded release, or other mechanical system may be activated to detach thedrill string 212 and/ordrill bit 222 relative to theprotective sheath 226. Any such deactivation or release may be controlled by an operator, or may be automatic. For instance, mud-pulse telemetry, pressure pulses, rotational speed signals, wired drill pipe connections, wireless signals, active or passive RFID tags, or other mechanisms may be used to convey a signal from an operator on the surface to a downhole controller. In another embodiment, a controller may include a sensor that measures rotation of theprotective sheath 226. When the rotation stops or drops below a particular threshold, thefastener 234 may deactivate to release thedrill string 212 or thedrill bit 222. - In another embodiment, the
fastener 234 may include a sacrificial element. For a drive system using a motor, drilling mud or another fluid may be used to rotate thedrill string 212 and/or thedrill bit 222. Optionally, the drilling mud or other fluid can be supplied to a motor associated with thedrill bit 222 anchoring theprotective sheath 234; however, such rotation may also occur while thecasing bit 216 is in use and un-anchored. If the rotations of thedrill bit 222 and thecasing bit 216 are synchronous (or the rotations of thecorresponding drill string 212 and protective sheath 226), the sacrificial element of thefastener 234 may also rotate synchronously and remain in place. Restricting rotation of theprotective sheath 226, however, may not stop thedrill bit 222 ordrill string 212 from rotating. Instead, a drive force may continue to be applied to thedrill string 212 and/ordrill bit 222. The drive force may apply a torque that ultimately causes the sacrificial element to break and fail, thereby releasing thedrill string 212 anddrill bit 222 from theprotective sheath 226. Thedrill string 212 anddrill bit 222 may then be able to rotate and move axially within the interior of thedrill string 212. - The
fastener 234 may be located at any suitable location, and thedrill bit 222 may therefore be fastened at any suitable location along the length of theprotective sheath 226. In the embodiment illustrated inFIG. 6 , thedrill bit 222 is shown as being fixed at location that is in an upper end portion of theprotective sheath 226. In some embodiments, upon anchoring of theprotective sheath 226, thedrill bit 222 may still be located within theprimary wellbore 202. Such an embodiment is, however, merely illustrative. In other embodiments (e.g., the embodiment shown inFIG. 9 ), thedrill bit 222 may be anchored at a location more proximate thecasing bit 216, such that as thecasing bit 216 is anchored in place, thedrill bit 222 may already be located at least partially within thelateral borehole 210. - Regardless of the distance at which the
drill bit 222 is positioned relative to thecasing bit 216, when thefastener 234 is released and thedrill bit 222 can move axially along theprotective sheath 226, thedrill bit 222 may pass through thewindow 230 prior to drilling or extending a length of thelateral borehole 210. As discussed herein, thewindow 230 may be surrounded by edges of thecasing 204 that can potentially damage thedrill bit 222, whether on account of the material of thecasing 204, the shape of the edges around thewindow 230, or other factors. In accordance with some embodiments of the present disclosure, theprotective sheath 226 may shield thedrill bit 222 and thedrill string 212 from contacting the edges of thewindow 230 or potentially any part of thecasing 204 ordeflection member 218. - More particularly, as discussed herein, the
protective sheath 226 may be anchored in place and may extend from the interior of theprimary wellbore 202, through thewindow 230, and into thelateral borehole 210. Theprotective sheath 226 may, at its outer surface, potentially contact thedeflection member 218 and/orcasing 204. Thedrill bit 222 anddrill string 212, however, may be located within theprotective sheath 226. Thus, as thedrill bit 222 moves from a location within the primary wellbore 202 (FIG. 6 ) through thewindow 230 and to the lateral borehole 210 (FIG. 7 ), thedrill bit 222 may be shielded from direct contact with thedeflection member 218 and/or the edges of thewindow 230. - The
protective sheath 226 may be formed in any number of different manners. For instance, as discussed herein, theprotective sheath 226 may include a tubular member coupled to (e.g., suspended from) a portion of thedrill string 212. Optionally, theprotective sheath 226 may have the same or different properties relative thedrill string 212, casing 204, or other components of thedrilling system 200. In some embodiments, theprotective sheath 226 may be configured to bend or flex, may be jointed, or otherwise structured. Theprotective sheath 226 may also be part of a bottomhole assembly, or a separate component coupled to a bottomhole assembly associated with thedrill bit 222. An exampleprotective sheath 226 may include CWD components to allow theprotective sheath 226 to form a casing extending through thewindow 230 and into thelateral borehole 210. In such an embodiment, theanchor 232 may cement or otherwise fix a casing within thelateral borehole 210. In at least some embodiments, theprotective sheath 226 may include a joint to facilitate bending and assist in forming a channel to guide thedrill bit 222 into thelateral borehole 210. In some embodiments, theprotective sheath 226 may include expandable casing. - The
protective sheath 226 may provide other uses other than protecting thedrill bit 222 as thedrill bit 222 moves through thewindow 230. As discussed herein, adeflection member 218 may be used to orient thedrill string 212 at a desired trajectory. Thedrill string 212 may also restrict thedrill bit 222 and drill string 214 from contacting thedeflection member 218. Theprotective sheath 226 may, however, generally define the path from theprimary wellbore 202 to thelateral borehole 210, and can thus act as a guide to thedrill bit 222. In particular, thedrill bit 222 anddrill string 212 may be sized to allow thedrill bit 222 to move within theprotective sheath 226, which may act as a slide through which thedrill bit 222 may move towards thecasing bit 216 and ultimately to the distal end of thelateral borehole 210 as shown inFIG. 7 . When anchored, theprotective sheath 226 may also remain in place during not only lateral drilling of thelateral borehole 210 using thedrill bit 222, but also potentially during re-entry of other components, including completion or other intervention components. - When the
drill bit 222 reaches the end of theprotective sheath 226, thecasing bit 216 may obstruct further movement of thedrill bit 222. In some embodiments, however, thecasing bit 216 anddrill bit 222 may be coordinated to allow thedrill bit 222 to drill through thecasing bit 216. For instance, thecasing bit 216 may be a drillable casing bit and/or have an optional opening therein. When the opening is included, the opening may be used to center thedrill bit 222 and/or to allow thedrill bit 222 to more efficiently begin drilling through thecasing bit 216. In some embodiments, the opening may have a size and/or length configured to allow thecasing bit 216 to effectively mill thewindow 230 and start thelateral borehole 210, while also minimizing or reducing the amount of material through which thedrill bit 222 may drill through to reach the exterior of thecasing bit 216. In at least some embodiments, the interior of thecasing bit 216 may be formed of a material that is different than at least some materials on an exterior of thecasing bit 216. As an example, superhard or superabrasive materials (e.g., polycrystalline diamond, tungsten carbide, metal borides, etc.), or cutters having such materials, may be located on the exterior of thecasing bit 216, while the interior of thecasing bit 216 may have a different, and relatively softer, material (e.g., steel, iron, etc.). Thedrill bit 222 may be formed in any suitable manner for cutting through the interior of thecasing bit 216 as well as through rock or other materials of theformation 206. In some embodiments, the interior of thecasing bit 216 may be configured to allow thedrill bit 222 to drill through thecasing bit 216 at least nearly as efficiently as through theformation 206. - When the
drill bit 222 has drilled through thecasing bit 216, thedrill bit 222 may then be at the distal end of thelateral borehole 210. In such an embodiment, by continuing to drive thedrill bit 222 by applying weight-on-bit (e.g., using axial loading on the drill string 212), thelateral borehole 210 may be extended. As shown inFIG. 8 , for instance, thedrill bit 222 may be used to form anextended length 211 of thelateral borehole 210. In some embodiments, such as where thedrill bit 222 is smaller than thecasing bit 216, theextended length 211 of thelateral borehole 210 may also have a reduced size (e.g., width or diameter). - The above description of certain embodiments, including the embodiments illustrated in
FIGS. 3-8 , contains certain specific elements that are intended to be illustrative only, and may be varied in any number of manners. For instance, while thedrilling system 200 described herein has been described as enabling a single trip operation, such an embodiment is merely illustrative. In other embodiments, for instance, adrilling system 200 may include aprotective sheath 226 and acasing bit 216 to mill a window in acasing 204, but may not include adrill bit 222. Instead, an entirely separate assembly may be tripped into theprimary wellbore 202 and guided by theprotective sheath 226 to extend alateral borehole 210. - Further, a
deflection member 218 as described herein may have any number of other constructions. For instance, a rampedsurface 228, or a portion thereof, may have an incline between 0.5° and 15° relative to a longitudinal axis of theprimary wellbore 202. More particularly, the rampedsurface 228 may have an incline with lower and upper limits that include any of 0.5°, 1°, 1.5°, 2°, 2.5°, 3°, 3.5°, 4°, 5°, 7.5°, 10°, 12.5°, 15°, or any value therebetween. For instance, at least a portion of the rampedsurface 228 may be inclined at an angle of between 2° and 5° relative to the longitudinal axis of theprimary wellbore 202. In still another embodiment, the ramped surface may be inclined at 3°. In still other embodiments, the rampedsurface 228, or a portion thereof, may have an angle of less than 0.5°, or greater than 15°, relative to the longitudinal axis of theprimary wellbore 202. In some embodiments, the angle of the rampedsurface 228 may be an average angle of incline over multiple different stages having different inclines. - The
deflection member 218 may be tripped into theprimary wellbore 202 separate from thedrill string 212. In other embodiments, however, thedrill string 212 anddeflection member 218 may be part of the same drilling assembly to allow for single trip setting of thedeflection member 218, milling of thewindow 230, drilling of thelateral borehole 210, or some combination thereof. -
FIG. 9 , for instance, illustrates an example embodiment of adrilling system 300 that may be used for single trip drilling of a lateral borehole. In thedrilling system 300 ofFIG. 9 , thedrilling system 300 may also be used to anchor adeflection member 318 and mill a window in acasing 304 in the same, single trip. - Many of the components of the
drilling system 300 may be similar in various regards to components described in embodiments described elsewhere herein, or illustrated inFIGS. 1-8 . Accordingly, to avoid unnecessarily obscuring aspects of the disclosure, certain details will not be repeated relative to thedrilling system 300, but should instead be understood to be equally applicable to the embodiment shown inFIG. 9 . Indeed, each embodiment disclosed herein is intended to include components and features that may be interchanged with features and components of other embodiments disclosed herein. - In the embodiment shown in
FIG. 9 , thedrilling system 300 may be used to form a lateral borehole off of aprimary wellbore 302 that includes acasing 304 therein. Thedrilling system 300 may itself include adeflection member 318, acasing bit 316, and adrill bit 322 coupled together using adrill string 312,protective sheath 326,fasteners 334,connectors 336, or other components that allow single trip installation and/or use. - The
deflection member 318 may include a whipstock or any other components suitable for deflecting thecasing bit 316 against thecasing 304 for formation of a window. In this embodiment, thedeflection member 318 includes a setting assembly having one or more expandable anchors 320. The expandable anchors 320 are illustrated in a retracted state in which a width of theanchors 320 may be less than the interior diameter of thecasing 304, thereby allowing thedeflection member 318 to be inserted into, or retracted from, theprimary wellbore 302. - The
deflection member 318 is further illustrated as including aconnector 336. In general, theconnector 336 may couple thedeflection member 318 to thecasing bit 316. Theconnector 336 may have sufficient structural strength and integrity to maintain thedeflection member 318 coupled to thecasing bit 316 when tripped into theprimary wellbore 302, but may be structured to break or release at a desired time or location. For instance, when theanchors 320 are expanded, thecasing bit 316 may begin to rotate. When thedeflection member 318 is fixed at an axial and/or rotational position, the rotation of thecasing bit 316 may generate a torque or other force causing theconnector 336 to fail. When theconnector 336 fails, thedeflection member 318 may become detached from thecasing bit 316. It will be appreciated by a person having ordinary skill in the art, however, that theconnector 336 may be used to decouple thedeflection member 318 from thecasing bit 316 ordrill string 312 in any number of manners, and need not be or include a sacrificial element. Indeed, in some embodiments, theconnector 336 may be selectively couplable to allow decoupling from, and re-coupling between, thedeflection member 318 and thecasing bit 316. - Upon separation of the
deflection member 318 from thecasing bit 316, thedrill string 312 may be used to advance thecasing bit 316 within theprimary wellbore 302. Advancing thecasing bit 316 may cause thecasing bit 316 to move toward, and mill a window into, thecasing 304. As discussed herein, when thecasing bit 316 has milled a window, and optionally cut at last a portion of theformation 306 to start a lateral borehole, use of thecasing bit 316 may be discontinued. Thecasing bit 316 may also be secured at an axial and/or rotational position in using ananchor 332 or other securement device (either directly or, as shown inFIG. 9 , by coupling theanchor 332 to the protective sheath 326). Thereafter, thedrill bit 322 may be advanced within theprotective sheath 326 towards thecasing bit 316. Thedrill bit 322 may drill through thecasing bit 316 and then into theformation 306 to extend the lateral borehole. - The
protective sheath 326 may protect thedrill bit 322 and/or thedrill string 312 against contact with the casing 304 (e.g., at the edges of the window in the casing 304); however, theprotective sheath 326 may also provide other uses. For instance, theprotective sheath 326 may protect other components of thedrilling system 300. For instance, a bottomhole assembly including thedrill bit 322 may include astabilizer 333 or other components (e.g., mud motor, drill collars, sensors, jars, tractors, conveyors, vibration tools, etc.). Thestabilizer 333 and other components may also pass through theprotective sheath 326 to be protected from contact with thecasing 304 or thedeflection member 318. In other embodiments, completion or other components may enter theprimary wellbore 302 following removal of thedrill string 312, and can pass through theprotective sheath 326 to be protected against damage from thedeflection member 318 and/or thecasing 304. - As discussed herein, the
drill string 312 may be coupled to aprotective sheath 326. Theprotective sheath 326 may provide a slide or guide for thedrill bit 322 to allow thedrill bit 322 to move through a window in thecasing 304 without directly contacting thecasing 304. In another embodiment, theprotective sheath 326 may be separable from the drill string 312 (e.g., using fasteners 334). In one example embodiment, theprotective sheath 326 may include components of a CWD system. Optionally, a joint 313 may couple components of theprotective sheath 326 to each other. The joint 313 may be a CWD joint, and can be used to couple CWD or other component of theprotective sheath 326, to facilitate bending or flexure of theprotective sheath 326, or for any number of other purposes. - The
drill bit 322 may be directly or indirectly coupled to thedrill string 312,protective sheath 326, orcasing bit 316 so as to be part of the same drilling assembly, and to allow single trip drilling of the lateral borehole. Thefastener 334, which is shown as coupling thedrill string 312 to theprotective sheath 326, may be used to make such a connection. Optionally, thefastener 334 may include a sacrificial element, hydraulic release, or other type of connector to allow selective decoupling of thedrill bit 322 from theprotective sheath 326. - The particular location of the
fastener 334 and/or location of a connection of thedrill bit 322 can be varied. Relative to the embodiment inFIGS. 3-8 , for instance, thedrill bit 322 is shown as being fastened in a distal end portion near thecasing bit 316. In one embodiment, thedrill bit 322 may be generally aligned in a longitudinal direction with theanchor 332, or potentially nearer thecasing bit 316 than theanchor 332. In such an embodiment, as thecasing bit 316 mills a window in thecasing 304, and is anchored to theformation 306, theprotective sheath 326 may guide and protect thedrill bit 322 through the window even before thefastener 334 is selectively released to decouple thedrill bit 322 ordrill string 312 from theprotective sheath 326. When decoupled, thedrill bit 322 may be used to independently drill within the lateral borehole, and can potentially drill through thecasing bit 316 and/or into theformation 306 to form or extend the lateral borehole. In some embodiments, thedrill bit 332 may be a fixed cutter, roller cone, impregnated diamond, or other drilling bit. In some embodiments, thedrill bit 332 may have a fixed outer or gauge diameter. In other embodiments, thedrill bit 332 may be an expandable drill bit. Similarly, thecasing bit 316 may have a fixed diameter or may be expandable. - In the description herein, various relational terms are provided to facilitate an understanding of various aspects of some embodiments of the present disclosure. Relational terms such as “bottom,” “below,” “top,” “above,” “back,” “front,” “left,” “right,” “rear,” “forward,” “up,” “down,” “horizontal,” “vertical,” “clockwise,” “counterclockwise,” “upper,” “lower,” “uphole,” “downhole,” and the like, may be used to describe various components, including their operation and/or illustrated position relative to one or more other components. Relational terms do not indicate a particular orientation for each embodiment within the scope of the description or claims. For example, a component of a bottomhole assembly that is described as “below” another component may be further from the surface while within a vertical wellbore, but may have a different orientation during assembly, when removed from the wellbore, or in a deviated borehole. Accordingly, relational descriptions are intended solely for convenience in facilitating reference to various components, but such relational aspects may be reversed, flipped, rotated, moved in space, placed in a diagonal orientation or position, placed horizontally or vertically, or similarly modified. Certain descriptions or designations of components as “first,” “second,” “third,” and the like may also be used to differentiate between identical components or between components which are similar in use, structure, or operation. Such language is not intended to limit a component to a singular designation. As such, a component referenced in the specification as the “first” component may be the same or different than a component that is referenced in the claims as a “first” component.
- Furthermore, while the description or claims may refer to “an additional” or “other” element, feature, aspect, component, or the like, it does not preclude there being a single element, or more than one, of the additional element. Where the claims or description refer to “a” or “an” element, such reference is not be construed that there is just one of that element, but is instead to be inclusive of other components and understood as “at least one” of the element. It is to be understood that where the specification states that a component, feature, structure, function, or characteristic “may,” “might,” “can,” or “could” be included, that particular component, feature, structure, or characteristic is provided in some embodiments, but is optional for other embodiments of the present disclosure. The terms “couple,” “coupled,” “connect,” “connection,” “connected,” “in connection with,” and “connecting” refer to “in direct connection with,” or “in connection with via one or more intermediate elements or members.” Components that are “integral” or “integrally” formed include components made from the same piece of material, or sets of materials, such as by being commonly molded or cast from the same material, or commonly machined from the same piece of material stock. Components that are “integral” should also be understood to be “coupled” together.
- Although various example embodiments have been described in detail herein, those skilled in the art will readily appreciate in view of the present disclosure that many modifications are possible in the example embodiments without materially departing from the present disclosure. Accordingly, any such modifications are intended to be included in the scope of this disclosure. Likewise, while the disclosure herein contains many specifics, these specifics should not be construed as limiting the scope of the disclosure or of any of the appended claims, but merely as providing information pertinent to one or more specific embodiments that may fall within the scope of the disclosure and the appended claims. The various embodiments discussed herein may be used in combination, and various features disclosed in one embodiment are intended to be usable in connection with other embodiments disclosed herein.
- A person having ordinary skill in the art should realize in view of the present disclosure that equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made to embodiments disclosed herein without departing from the spirit and scope of the present disclosure. Equivalent constructions, including functional “means-plus-function” clauses are intended to cover the structures described herein as performing the recited function, including both structural equivalents that operate in the same manner, and equivalent structures that provide the same function. It is the express intention of the applicant not to invoke means-plus-function or other functional claiming for any claim except for those in which the words ‘means for’ appear together with an associated function. Each addition, deletion, and modification to the embodiments that falls within the meaning and scope of the claims is to be embraced by the claims.
- While embodiments disclosed herein may be used in oil, gas, or other hydrocarbon exploration or production environments, such environments are merely illustrative. Systems, tools, assemblies, methods, milling systems, and other components of the present disclosure, or which would be appreciated in view of the disclosure herein, may be used in other applications and environments. In other embodiments, milling tools, deflection elements, methods of milling and drilling, or other embodiments discussed herein, or which would be appreciated in view of the disclosure herein, may be used outside of a downhole environment, including in connection with other systems, including within automotive, aquatic, aerospace, hydroelectric, manufacturing, other industries, or even in other downhole environments. The terms “well,” “wellbore,” “borehole,” and the like are therefore also not intended to limit embodiments of the present disclosure to a particular industry. A wellbore or borehole may, for instance, be used for oil and gas production and exploration, water production and exploration, mining, utility line placement, or myriad other applications.
- Certain embodiments and features may have been described using a set of numerical values that may provide lower and upper limits. It should be appreciated that ranges including the combination of any two values are contemplated unless otherwise indicated, and that a particular value may be defined by a range having the same lower and upper limit. All numbers, percentages, ratios, measurements, or other values stated herein are intended to include not only the stated value, but also other values that are about or approximately the stated value, as would be appreciated by one of ordinary skill in the art encompassed by embodiments of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least experimental error and variations that would be expected by a person having ordinary skill in the art, as well as the variation to be expected in a suitable manufacturing or production process. A value that is about or approximately the stated value and is therefore encompassed by the stated value may further include values that are within 5%, within 1%, within 0.1%, or within 0.01% of a stated value.
- The Abstract at the end of this disclosure is provided to allow the reader to quickly ascertain the general nature of some embodiments of the present disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
Claims (20)
1. A method for drilling a lateral borehole from a cased, primary wellbore, comprising:
positioning a drilling assembly within a primary wellbore, the drilling assembly including a casing bit coupled to a protective sheath;
milling a window in a casing of the primary wellbore with the casing bit;
extending the protective sheath through the window;
guiding a drill string and drill bit through the protective sheath and through the window; and
drilling a lateral borehole using the drill bit.
2. The method recited in claim 1 , the casing bit being a drillable casing bit, wherein drilling the lateral borehole including:
drilling through the casing bit using the drill bit.
3. The method recited in claim 1 , further comprising:
anchoring the protective sheath following extending the protective sheath through the window.
4. The method recited in claim 3 , wherein anchoring the protective sheath includes anchoring the protective sheath to restrict at least one of axial or rotational movement of the protective sheath.
5. The method recited in claim 1 , wherein the protective sheath is a casing while drilling joint coupled to the drill string.
6. The method recited in claim 1 , wherein milling the window in the casing further includes using the casing bit to initiate drilling of the lateral borehole.
7. The method recited in claim 1 , wherein the drill string is coupled to an interior of the protective sheath.
8. The method recited in claim 7 , wherein drilling the lateral borehole includes releasing the drill string from the protective sheath.
9. The method recited in claim 1 , further comprising:
anchoring a deflection member within the primary wellbore; and
deflecting the casing bit into the casing using the deflection member.
10. The method recited in claim 1 , wherein extending the protective sheath includes positioning the protective sheath partially through the window.
11. A drilling assembly, comprising:
a casing bit;
a protective sheath coupled to the casing bit; and
a drill string coupled to an interior of the protective sheath, the drill string including a drill bit.
12. The drilling assembly recited in claim 11 , further comprising:
an anchor coupled to the protective sheath.
13. The drilling assembly recited in claim 11 , the casing bit being a drillable casing bit and configured to mill through casing of a wellbore.
14. The drilling assembly recited in claim 11 , further comprising:
a fastener selectively coupling the drill string to the protective sheath.
15. The drilling assembly recited in claim 14 , the fastener including a sacrificial element.
16. The drilling assembly recited in claim 11 , further comprising:
a deflection member releasably coupled to the casing bit.
17. The drilling assembly recited in claim 16 , further comprising:
an anchor coupled to the deflection member.
18. A drilling system for forming a window in a casing of a primary wellbore and drilling a lateral borehole off the primary wellbore, comprising:
a drillable casing bit configured to mill a window in casing of a primary wellbore;
a protective sheath coupled to the drillable casing bit;
an anchor configured to anchor the protective sheath and restricting at least one of axial or rotational motion of the protective sheath;
a drill string coupled to, and within the protective sheath, the drill string including a drill bit configured to drill through the drillable casing bit and through formation around the primary wellbore; and
a fastener releasably coupling the drill string to the protective sheath.
19. The drilling system recited in claim 18 , the anchor being selectively expandable to anchor the protective sheath within the formation.
20. The drilling system recited in claim 18 , further comprising:
a deflection member releasably coupled to at least one of the drillable casing bit or the protective sheath.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/297,212 US20140360723A1 (en) | 2013-06-07 | 2014-06-05 | Protective sheath through a casing window |
PCT/US2014/041235 WO2014197767A1 (en) | 2013-06-07 | 2014-06-06 | Protective sheath through a casing window |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US201361832564P | 2013-06-07 | 2013-06-07 | |
US14/297,212 US20140360723A1 (en) | 2013-06-07 | 2014-06-05 | Protective sheath through a casing window |
Publications (1)
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US20140360723A1 true US20140360723A1 (en) | 2014-12-11 |
Family
ID=52004477
Family Applications (1)
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US14/297,212 Abandoned US20140360723A1 (en) | 2013-06-07 | 2014-06-05 | Protective sheath through a casing window |
Country Status (2)
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US (1) | US20140360723A1 (en) |
WO (1) | WO2014197767A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
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US20190226306A1 (en) * | 2018-01-19 | 2019-07-25 | Saudi Arabian Oil Company | Method of producing from a hydrocarbon bearing zone with laterals extending from an inclined main bore |
US10781665B2 (en) | 2012-10-16 | 2020-09-22 | Weatherford Technology Holdings, Llc | Flow control assembly |
US11408277B2 (en) * | 2020-10-28 | 2022-08-09 | Saudi Arabian Oil Company | Assembly, indicating device, and method for indicating window milling in a well |
WO2022182444A1 (en) * | 2021-02-25 | 2022-09-01 | Weatherford Technology Holdings, Llc | Rfid actuated release of mill from whipstock |
US11519234B2 (en) | 2020-11-24 | 2022-12-06 | Weatherford Technology Holdings, Llc | Contingency release of mill from whipstock |
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US4007797A (en) * | 1974-06-04 | 1977-02-15 | Texas Dynamatics, Inc. | Device for drilling a hole in the side wall of a bore hole |
US5392858A (en) * | 1994-04-15 | 1995-02-28 | Penetrators, Inc. | Milling apparatus and method for well casing |
US20110011646A1 (en) * | 2000-04-13 | 2011-01-20 | Giroux Richard L | Apparatus and methods for drilling a wellbore using casing |
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US5435400B1 (en) * | 1994-05-25 | 1999-06-01 | Atlantic Richfield Co | Lateral well drilling |
BR0211345B1 (en) * | 2001-07-23 | 2011-11-29 | method for introducing a fluid into a drillhole formed in an underground earth formation, and system for drilling and for introducing a fluid into a drillhole in an underground earth formation. | |
GB0226725D0 (en) * | 2002-11-15 | 2002-12-24 | Bp Exploration Operating | method |
US8146683B2 (en) * | 2004-02-19 | 2012-04-03 | Baker Hughes Incorporated | Drilling out casing bits with other casing bits |
WO2009029800A1 (en) * | 2007-08-30 | 2009-03-05 | Baker Hughes Incorporated | Apparatus and method for drilling wellbores that utilize a detachable reamer |
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2014
- 2014-06-05 US US14/297,212 patent/US20140360723A1/en not_active Abandoned
- 2014-06-06 WO PCT/US2014/041235 patent/WO2014197767A1/en active Application Filing
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US4007797A (en) * | 1974-06-04 | 1977-02-15 | Texas Dynamatics, Inc. | Device for drilling a hole in the side wall of a bore hole |
US5392858A (en) * | 1994-04-15 | 1995-02-28 | Penetrators, Inc. | Milling apparatus and method for well casing |
US20110011646A1 (en) * | 2000-04-13 | 2011-01-20 | Giroux Richard L | Apparatus and methods for drilling a wellbore using casing |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10781665B2 (en) | 2012-10-16 | 2020-09-22 | Weatherford Technology Holdings, Llc | Flow control assembly |
US20190226306A1 (en) * | 2018-01-19 | 2019-07-25 | Saudi Arabian Oil Company | Method of producing from a hydrocarbon bearing zone with laterals extending from an inclined main bore |
US10774625B2 (en) * | 2018-01-19 | 2020-09-15 | Saudi Arabian Oil Company | Method of producing from a hydrocarbon bearing zone with laterals extending from an inclined main bore |
US11408277B2 (en) * | 2020-10-28 | 2022-08-09 | Saudi Arabian Oil Company | Assembly, indicating device, and method for indicating window milling in a well |
US11519234B2 (en) | 2020-11-24 | 2022-12-06 | Weatherford Technology Holdings, Llc | Contingency release of mill from whipstock |
WO2022182444A1 (en) * | 2021-02-25 | 2022-09-01 | Weatherford Technology Holdings, Llc | Rfid actuated release of mill from whipstock |
US11572739B2 (en) | 2021-02-25 | 2023-02-07 | Weatherford Technology Holdings Llc | RFID actuated release of mill from whipstock |
AU2022226072B2 (en) * | 2021-02-25 | 2023-10-26 | Weatherford Technology Holdings, Llc | Rfid actuated release of mill from whipstock |
Also Published As
Publication number | Publication date |
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WO2014197767A1 (en) | 2014-12-11 |
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