Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
DOWNHOLE WHIPSTOCK AND METHOD OF MANUFACTURE
Document Type and Number:
WIPO Patent Application WO/2019/194800
Kind Code:
A1
Abstract:
A whipstock is manufactured for a downhole assembly. A preform of the whipstock defines a face in an outer surface angling from a distal end of the preform toward a proximal end of the preform. A tubing blank disposed on the preform is formed about the outer surface of the preform using differential pressure, and the formed tubing blank is incorporated as at least part of the whipstock of the downhole assembly, which can include at least one of an anchor and a packer. The formed tubing blank can constitute the entire length of the whipstock, or may constitute a section thereof to be connected to other sections. The integrity of the formed tubing blank can be strengthened using hard banding, cold working, filling a hollow of the formed blank, or preconfiguring longitudinal ridges on the formed blank.

Inventors:
TEALE DAVID (US)
Application Number:
PCT/US2018/026040
Publication Date:
October 10, 2019
Filing Date:
April 04, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
WEATHERFORD TECH HOLDINGS LLC (US)
International Classes:
E21B7/06; B21D22/02; B21D51/10; B21D26/033
Domestic Patent References:
WO2002048503A12002-06-20
Foreign References:
US20070240876A12007-10-18
FR2348763A11977-11-18
US20130098129A12013-04-25
US6464002B12002-10-15
US6464002B12002-10-15
US7963341B22011-06-21
Attorney, Agent or Firm:
MCDERMOTT, Sean P. (US)
Download PDF:
Claims:
CLAIMS:

1. A method of manufacturing a whipstock for a downhole assembly, the method comprising not necessarily in sequence:

creating a preform of at least a portion of the whipstock by defining a face in an outer surface of the preform angling from a distal end of the preform toward a proximal end of the preform;

positioning a surrounding blank of deformable material onto the preform;

forming the surrounding blank about the outer surface of the preform using applied pressure; and

incorporating the formed blank as at least part of the whipstock of the downhole assembly.

2. The method of claim 1, further comprising strengthening integrity of the formed blank.

3. The method of claim 2, wherein strengthening the integrity comprises hard banding at least a portion of the formed blank.

4. The method of claim 3, wherein hard banding at least the portion of the formed blank comprises hard banding at least the face on the formed blank.

5. The method of claim 2, 3 or 4, wherein strengthening the integrity comprises cold working at least a portion of the face on the formed blank.

6. The method of any one of claims 2 to 5, wherein strengthening the integrity comprises filling a hollow of the formed blank at least partially with a filler material.

7. The method of claim 6, wherein the filler material is selected from the group consisting of a concrete, a composite, a fiberglass, a plastic, an aggregate, and at least a portion of the preform.

8. The method of any one of claims 2 to 7, wherein strengthening the integrity comprises creating the preform with one or more surface features defined on the outer surface of the preform against which the surrounding blank forms.

9. The method of claim 8, wherein creating the preform with the one or more surface features defined on the outer surface of the preform against which the surrounding blank forms comprises creating the preform with one or more ridges defined longitudinally along the outer surface of the preform against which the surrounding blank forms.

10. The method of any one of claims 1 to 9, wherein forming the surrounding blank about the outer surface of the preform using the applied pressure comprises hydroforming the surrounding blank about the outer surface of the preforming using differential pressure between a greater pressure outside the surrounding blank and a lesser pressure inside the surrounding blank as the applied pressure.

11. The method of any one of claims 1 to 10, wherein forming the surrounding blank about the outer surface of the preform using the applied pressure comprises forming each of two or more sections of the surrounding blank respectively about the outer surfaces of two or more parts of the preform using the applied pressure and affixing the two or more formed blank sections together.

12. The method of claim 11, wherein affixing the two or more formed blank sections together comprises welding the two or more formed blank sections end to end.

13. The method of any one of claims 1 to 12, further comprising forming at least one of a coupling element and a pulling element on the face of the formed blank.

14. The method of any one of claims 1 to 13, wherein incorporating the formed blank as at least part of the whipstock of the downhole assembly comprises separating the preform from a hollow of the formed blank.

15. The method of any one of claims 1 to 14, wherein incorporating the formed blank as at least part of the whipstock of the downhole assembly comprises connecting at least one of a packer and an anchor toward the proximal end of the formed blank.

16. A downhole assembly for use in a borehole, the assembly comprising a whipstock manufactured according to the method of any one of claims 1 to 15.

17. A downhole assembly for use in a borehole, the assembly comprising a whipstock having a longitudinal length from a distal end to a proximal end and defining a ramp angling from the distal end toward the proximal end, the whipstock comprising:

a tubular component disposed along the longitudinal length, the tubular component having a tubular wall composed of a first material and defining a hollow therein; and

one or more surface features defined in the tubular wall of the tubular component at least partially on the whipstock and strengthening the whipstock along the longitudinal length thereof.

18. The assembly of claim 17, wherein the one or more surface features comprise one or more ribs defined in the tubular wall of the tubular component at least partially along the longitudinal length of the whipstock.

19. The assembly of claim 17 or 18, further comprising a filler composed of a second material and disposed at least partially inside the hollow.

20. The assembly of claim 17, 18 or 19, further comprising a banding composed of a second material and formed on at least a portion of the ramp.

21. The assembly of any one of claims 17 to 20, further comprising an anchor disposed toward the proximal end of the whipstock and operable to anchor the downhole assembly in the borehole.

22. The assembly of claim 21, wherein the anchor defines a throughbore

communicating with the hollow of the whipstock.

23. The assembly of any one of claims 17 to 22, further comprising a packer disposed toward the proximal end of the whipstock and operable to seal the downhole assembly in the borehole.

24. The assembly of claim 23, wherein the packer defines a throughbore communicating with the hollow of the whipstock.

25. The assembly of any one of claims 17 to 24, wherein the tubular component comprises a plurality of tubular sections connected together end to end.

Description:
DOWNHOLE WHIPSTOCK AND METHOD OF MANUFACTURE

BACKGROUND OF THE DISCLOSURE

[0001] For various reasons, operators may want to cut into the side of casing in an existing wellbore so a new sidetracked or lateral wellbore can be drilled. For example, the formation adjacent the original wellbore may become depleted or damaged, or a tool or pipe may have become stuck and may have blocked further use of the original wellbore.

For whatever reason, the sidetracked wellbore can be drilled and then lined with pipe for additional operational uses.

[0002] A whipstock assembly is used downhole so operators can drill a casing exit in a wellbore, such as when drilling a sidetrack or lateral wellbore. As illustrated in Figure 1, a whipstock assembly 20 according to the prior art is used for diverting a milling tool 40 to create a sidetracked wellbore. Operators run the whipstock assembly 20 down the original wellbore’s casing 12 to the desired location. The whipstock assembly 20 has a wedge- shaped member or whipstock 22 with a concave face 24 that can steer a mill or cutter 42 and the tool 40 to the side of the casing 12 where a window will be formed. Whipstock assemblies and their use are known, and an example is shown in U.S. Pat. No. 6,464,002, which is incorporated by reference herein in its entirety.

[0003] The whipstock assembly 20 may be run in by itself on a setting tool, and the mill 42 on the tool 40 can be run in after the whipstock assembly 20 has been set. Alternatively, to save a trip, the whipstock assembly 20 can be run in with tool 40 by having the mill 42 temporarily attached to the whipstock’s upper edge ln either case, the whipstock assembly 20 uses an anchor 30 on its end so the whipstock assembly 20 can be anchored in the wellbore 10 at the desired location. The anchor 30 sets in the casing 12 and keeps the whipstock assembly 20 in place to resist the downward force placed upon it as the mill 42 moves along its length to cut through the wall of the casing 12.

[0004] As noted above, the ramp’s face 24 has a geometry to create a guiding for the mill 42 and tool 40 to achieve a proper casing exit. This face 24 is usually defined at a very shallow angle ranging between 2 to 4 degrees to properly guide the mill 42 and tool 40. Such a shallow angle inherently means that the length of the whipstock 22 is considerably greater than the whipstock’s diameter.

[0005] Currently, the whipstock 22 is manufactured from a large diameter, solid bar stock of material. The ramped, concave face 24 is milled in the blank stock using conventional machining techniques. Although the machining provides an accurate geometry to the face 24, the manufacture comes at great costs for material and required machining time.

[0006] Large machines are needed to machine, support, move, and handle the whipstock blank to produce the wedge 22. Section length and weight limitations of these machines typically limit how the whipstock blanks can be handled and machined. Additionally, transportation requirements also limit the manufacture of the whipstock 22. For a larger diameter whipstock 22, for example, the length of the whipstock 22 can often exceed 25- feet, and some sizes can reach 30-feet in overall length. Manufacturing such a long whipstock 22 typically requires dividing the ramp’s length into two or more manageable sub-sections or pieces, which are separately machined and then welded together on site or at a suitable location to produce the overall whipstock 22 and to reduce shipping costs.

[0007] The subject matter of the present disclosure is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.

SUMMARY OF THE DISCLOSURE

[0008] As disclosed herein, a method manufacturing a whipstock for a downhole assembly comprises not necessarily in sequence: creating a preform of at least a portion of the whipstock by defining a face in an outer surface of the preform angling from a distal end of the preform toward a proximal end of the preform; positioning a surrounding blank of deformable material onto the preform; forming the surrounding blank about the outer surface of the preform using applied pressure; and incorporating the formed blank as at least part of the whipstock of the downhole assembly.

[0009] The method can further comprise strengthening integrity of the formed blank. For example, the strengthening can involve one or more of hard banding at least a portion of the formed blank, cold working at least a portion of the face on the formed blank, filling a hollow of the formed blank at least partially with a filler material, and creating the preform with one or more features defined on the outer surface of the preform against which the surrounding blank forms.

[0010] For example, hard banding can be performed on at least the face on the formed blank. The filler material can be selected from the group consisting of a concrete, a composite, a fiberglass, a plastic, an aggregate, at least a portion of the preform, or any other suitable material to strengthen/support structure or control casing exit operation by preserving the face structure. [0011] Creating the preform with the one or more features can include creating the preform with one or more ridges defined longitudinally along the outer surface of the preform against which the surrounding blank forms. Other features can be used, such as ribs, valleys, scallops, slots, splines or the like, and they can be defined in any suitable manner.

[0012] To form the surrounding blank about the outer surface of the preform using the applied pressure, a hydroforming process can use differential pressure between a greater pressure outside the surrounding blank and a lesser pressure inside the surrounding blank as the applied pressure. Other processes can be used to apply the forming pressure.

[0013] ln forming the surrounding blank, each of two or more sections of the surrounding blank can be respectively formed about the outer surfaces of two or more parts of the preform using the applied pressure. Then, the two or more formed blank sections can be affixed together by welding the two or more formed blank sections end to end.

[0014] To incorporate the formed blank as at least part of the whipstock of the downhole assembly, the preform from a hollow of the formed blank. At least one of a coupling element and a pulling element can be formed on the face of the formed blank, and at least one of a packer and an anchor can be connected toward the proximal end of the formed blank.

[0015] A downhole assembly is disclosed herein for use in a borehole, wherein the assembly comprises a whipstock manufactured according to the method disclosed above. The assembly can include an anchor disposed toward a proximal end of the whipstock and operable to anchor the downhole assembly in the borehole. The assembly can include a packer disposed toward a proximal end of the whipstock and operable to seal the downhole assembly in the borehole.

[0016] A downhole assembly is disclosed herein for use in a borehole. The assembly comprises a whipstock having a longitudinal length from a distal end to a proximal end and defining a ramp angling from the distal end toward the proximal end. The whipstock comprises: a tubular component disposed along the longitudinal length, the tubular component having a tubular wall composed of a first material and defining a hollow therein; and one or more features defined in the tubular wall of the tubular component at least partially on the whipstock and strengthening the whipstock along the longitudinal length thereof. The tubular component can include a plurality of tubular sections connected together end to end. [0017] The one or more features can include one or more ribs defined in the tubular wall of the tubular component at least partially along the longitudinal length of the whipstock.

A filler composed of a second material can be disposed at least partially inside the hollow. A banding composed of a second material can be formed on at least a portion of the ramp.

[0018] The assembly can include an anchor disposed toward the proximal end of the whipstock and operable to anchor the downhole assembly in the borehole. The anchor can define a throughbore communicating with the hollow of the whipstock.

[0019] The assembly can include a packer disposed toward the proximal end of the whipstock and operable to seal the downhole assembly in the borehole. The packer can define a throughbore communicating with the hollow of the whipstock.

[0020] The foregoing summary is not intended to summarize each potential embodiment or every aspect of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Fig. 1 illustrates a whipstock assembly according to the prior art for diverting a milling tool to create a sidetrack wellbore.

[0022] Fig. 2A illustrates an elevational view of a whipstock assembly according to the present disclosure.

[0023] Fig. 2B illustrates an elevational view of another whipstock assembly according to the present disclosure.

[0024] Fig. 2C illustrates a perspective view of the whipstock of the disclosed assembly.

[0025] Fig. 3 is a flowchart of a manufacturing method of a whipstock according to the present disclosure.

[0026] Figs. 4A-4D illustrate components during a hydroforming process to manufacture the whipstock.

[0027] Figs. 5A-5D illustrate various view of a whipstock component from the disclosed manufacture.

[0028] Figs. 6A-6D illustrate combined elevational and opposing end views of different manufactured sections for a whipstock.

[0029] Fig. 7 illustrates components during another forming process to manufacture the whipstock.

[0030] Figs. 8A-8B illustrate two sides of a formed tubing blank having various strengthening features. [0031] Fig. 9 illustrates a whipstock assembly according to the present disclosure used in one embodiment of a completion.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0032] Figures 2A-2B illustrate embodiments of a whipstock assembly 50 according to the present disclosure. The whipstock assembly 50 includes a whipstock 60, which is a wedge-shaped, ramped-shaped body with a face or ramp 62. As noted previously, the ramp 62 can steer a mill or a cutter (not shown) to the side of casing where a window can be formed. The face 62 can be concave in shape and angling from a distal uphole end to a proximal downhole end of the whipstock 60. The face 62 can usually be defined at a shallow angle ranging between 2 to 4 degrees.

[0033] The whipstock assembly 50 can be used in open and cased holes. Depending on how it is used, the assembly 50 can have a packer 80 and anchor 90 connected downhole from the whipstock 50. An adapter 70 can affix the whipstock 50 to the packer 80 and anchor 90.

[0034] Various types of anchors 90 can be used for the whipstock assembly 50 and only two examples are provided here ln general, the anchor 90 can be set mechanically or hydraulically. A mechanically-set anchor 90 requires a compressive force to shear a pin so the anchor 90 can be set. Such a mechanical anchor 90 works well when the anchor 90 is to be set at the bottom of a wellbore or when there is some type of restriction that has been placed in the wellbore, like a bridge plug, against which the anchor 90 can rest ln other instances, the anchor 90 may be positioned at some point along the wellbore where there is no surface against which to create a compressive force ln these instances, the anchor 90 can be set with pressurized fluid and requires a hydraulic mechanism.

[0035] As shown in Fig. 2A, the anchor 90 for the whipstock assembly 50 has slip elements 91 to engage in casing. These slip elements 91 can be set mechanically or hydraulically.

[0036] As shown in Fig. 2B, the anchor 90 for the whipstock assembly 50 can be a hydraulically-set anchor, which can be similar to that disclosed in U.S. Pat. No. 7,963,341, which is incorporated herein by reference in its entirety. The anchor 90 has first and second inclined bodies 92 and 94 with a cavity formed between their inclined surfaces.

The bodies 92 and 94 can slidably move relative to each other along a portion of their inclined surfaces to increase an outer diameter of the anchor 90 to a set position. A biasing member (96) disposed in the cavity can move the anchor’s bodies 92, 94 from a run-in position to the set position with the increased outer diameter. A triggering mechanism (98) initiates movement of at least one of the bodies 92 or 94 to the set position. The triggering mechanism (98) includes a shearable connection and a releasable locking connection that releases the biasing member (96).

[0037] Sometimes, the whipstock assembly 50 has a packer that can isolate the lower portion of the wellbore when set. Other times, isolation may not be necessary. Various types of packer 80 can be used for the whipstock assembly 50, and only two examples are provided here. For instance, the packer 80 can be a permanent, compression-set packer that is run below the whipstock 60 and above the anchor 90 on the assembly 50. Other types of packers can be used ln general, the packer 80 can be set before or after the anchor 90 has been set depending on the type of packer 80 and anchor used. As shown here, the anchor 90 can be disposed below the packer 80, but an opposite configuration could also be used.

[0038] As shown here in Fig. 2A, the assembly 50 includes a compression-set packer 80, which can be set with the same setting procedures to set the anchor slip elements 91. ln the example of Fig. 2B, the adapter 70 connects the packer 80 to the lower end of the whipstock 60. This packer 80 can be set mechanically once the anchor 90 is hydraulically set by hydraulic communication 75.

[0039] Regardless of the specific types and configurations of packer 80 and anchor 90 used, the whipstock assembly 50 can be run in casing in a manner similar to that discussed previously so operators can drill a casing exit in a wellbore, such as when drilling a sidetrack or lateral wellbore. To run in the whipstock assembly 50, the ramp’s distal end may have a coupling element 66 (Fig. 2C), which can couple to a setting tool or to the milling tool. Once run in, the whipstock assembly 50 can be set in the casing at a desired location in a manner similar to that discussed previously. The casing exit can then be milled, and the sidetrack can be formed.

[0040] Once the sidetrack is completed [i.e., drilled, lined with pipe, perforated, etc.), the whipstock assembly 50 can left in the wellbore or can be removed entirely from the wellbore. Alternatively, at least part of the assembly 50 may left in place. For example, the whipstock 60 can be removed from the assembly 50, leaving the packer 80 and the anchor 90 in place. To do this, operators can engage the whipstock 60 with a pulling tool (not shown) at a profile (e.g., 64: Fig. 2C) and pull up on the whipstock 60 against the packer 80 and the anchor 90 set in the casing so that the whipstock 60 separates from the packer 80 at the adapter 70.

[0041] Having an understanding of the whipstock assembly 50 and its use, discussion now turns to steps for manufacturing the whipstock 60 for the assembly 50. According to manufacturing steps disclosed herein, the whipstock 60 can be manufactured as one complete component, or the whipstock 60 can be assembled from separately manufactured components ( e.g ., three components 61a-c shown here) and assembled together to make the complete body of the whipstock 60. Additionally, the whipstock 60 can be a solid body in the form of a shell having a filler material therein, or the whipstock 60 can be a hollow body in the form of a shell without a filler material therein, according to manufacturing steps disclosed herein.

[0042] Fig. 3 discloses a process 100 of manufacturing a whipstock (60) according to the present disclosure, while Figs. 4A-4D illustrate components used during the manufacture of the whipstock (60). lnstead of using bar stock to create the whipstock (60), the manufacturing process 100 uses a preform 120 and a surrounding blank 130 of deformable material so the machining requirements from the disclosed process 100 are greatly reduced. Transportation costs can also be reduced due to the reduced weight of the whipstock (60).

[0043] To manufacture the whipstock (60), the preform 120 of the whipstock (60) is created by defining a face or ramp 122 in an outer surface of the preform 120 angling from a distal end of the whipstock (60) toward a proximal end of the whipstock (60) (Block 102). As noted, the face 122 is typically concave in shape. The preform 120 can be composed of any suitable material.

[0044] As noted herein, the preform 120 can be for the entire whipstock (60) or for one of several sections of the whipstock (60) to be assembled with other sections. Either way, the surrounding blank 130 (for the entire whipstock (60) or for a section thereof) is disposed onto the preform 120. ln general, the surrounding blank 130 may be in the form of an outer tubular member, tubing, or a tube of deformable material, although the blank 130 need not be cylindrical and other surrounding shapes could be used. For the purposes of discussion, reference may be made to the blank 130 as being a“tubing” blank for convenience.

[0045] The material of the tubing blank 130 can be of an annealed metal, which can then be shaped in a forming process and later strengthened with cold working and other manufacturing steps disclosed herein. As some examples, the tubing blank 130 can be composed of a 300-series stainless steel, a low carbon steel, such as 1018 to 1040-low carbon steel, or other metal.

[0046] To manufacture the whipstock, a forming process is conducted to form the tubing blank 130 about the outer surface of the preform 120 using applied pressure. As discussed below with reference to Figs. 4A-4D, for example, the forming process can use the differential pressure from hydroforming to collapse the outer tubing blank 130 onto the preform 120. Pressure can be applied in other ways, such as by mechanically pressing, by inflating a bladder, etc. As shown briefly in Fig. 7, for example, one or more bladders or diaphragms 145 filled with pressurized fluid, oil, or the like can be used to exert pressure/force to shape the surrounding deformable material of the blank 130 against the preform 120.

[0047] For the hydroforming process, end caps 142 are sealed onto the ends of the tubing blank 130 with the preform 120 held inside the blank’s hollow 134. The entire assembly 120, 130, 142 is disposed in a chamber 144 of a pressure vessel 140 (Block 104). ln this configuration, the two sealing end caps 142 creates a seal between the outer tubing blank 130 and the outside environment of the chamber 144 and traps atmospheric pressure inside the blank’s hollow 134.

[0048] The hydroforming process is then conducted, and the tubing blank 130 is formed about the outer surface of the preform 120 using differential pressure between a greater pressure outside the tubing blank 130 and a lesser pressure inside the tubing blank 130 (Block 106). For example, the assembly 120, 130, 142 is submerged in water in the pressure vessel 140. External pressure is applied and increased until the tubing blank 130 is collapsed sufficiently onto the machined preform 120, which has the representative geometry of the concave ramp 122. The outer pressure to internal pressure differential acts to collapse the tubing blank 130 uniformly so that the collapsed blank 130 has the complimentary ramp 132 and other features noted herein.

[0049] As one consideration for the forming process, the solid preform 120 can be machined with a geometry adjusted to compensate for expected material spring-back resulting from the hydroforming of the outer tubing blank 130 onto the preform 120. As another consideration, the tubing blank 130 can be formed with a uniform sidewall thickness around its circumference, or certain sections, such as a longitudinal strip of the blank 130 intended to form the face of the whipstock (60), may be preconfigured with a thicker sidewall. These and other variations are possible.

[0050] During the forming process, the circumferential perimeter/area of the tubing blank 130 is collapsed about the external perimeter/area of the preform 120. Because the external perimeter/area of the preform 120 would typically be less than the original perimeter/area of the tubing blank 130, surface features 156 ( e.g ., ribs, ridges, valleys, scallops, slots, splines or the like) can be configured to accommodate the differences and can prevent undesired buckling and wrinkling of the material of the tubing blank 130.

[0051] After forming the whipstock shape, the preform 120 is separated from the hollow 132 of the formed tubing blank 130. For example, the assembly 120, 130, 142 is removed from pressure vessel 140; the end caps 142 are removed; and the preform 120 is extracted on a press from the formed tubing blank 130.

[0052] With the preform 120 extracted, the finished whipstock shape of the collapsed tubing blank 130 is a tubular form of the whipstock (60) (or section thereof) for

incorporation into the downhole whipstock assembly (50) (Block 108). The preform 120 can then be reused if desired ln embodiments where the tubular form of the whipstock (60) has a filler material, either an additional filler material can be added inside the hollow of the formed tubing blank 130 once extracted from the preform 120, or if feasible, the preform 120 itself may remain inside the formed tubing blank 130 of the whipstock (60) to act at least partially as filler material.

[0053] As noted, the preform 120 and the formed tubing blank 130 can constitute the entire whipstock (60) or can be constitute a section of the whipstock (60) for connection to other sections to complete the whipstock (60). Accordingly, the entire ramp (62) of the whipstock (60) can be created from two or more separate preforms 120 of the whipstock (60). Separate tubing blanks 130 are formed onto these separate preforms 120, and the whipstock (60) is constructed by affixing the formed blanks 130 together (Block 110). For example, the formed blanks 130 can be affixed together by welding them end to end so that the ramp (62) angles from the distal end to the proximal end. Hydroforming the individual blanks 130 of each concave design and then joining the pieces with conventional welding techniques can reduce machining time and raw material costs. A side benefit of reduced shipping costs can also be realized.

[0054] With the whipstock (60) formed, ancillary features can be added by machining, welding, and the like (Block 112). For example, a coupling element (66) and/or a pull profile (68) can be added to the whipstock (60). At this point, certain manufacturing steps can preferably strengthen the integrity of the formed whipstock (60) for incorporation into the downhole whipstock assembly (50) (Block 114). ln particular, one technical challenge to creating a casing exit is to prevent or limit the lead mill from plunging into the upper surface of the concave ramp (62) of the whipstock (60) during the casing exit. Because the tubular concave of the disclosed whipstock (60) is thin walled relative to a conventional bar manufactured version, it can be beneficial to strengthen the concave ramp (62) as well as other portions of the whipstock (60) to limit mill plunge and help preserve the top running surface of the concave ramp (62).

[0055] ln the end, some final manufacturing steps can be performed (Block 116). For example, the whipstock (60) can be assembled or constructed by attaching separately formed sections together. Various techniques can be used for the attachment between sections for the whipstock (60). For example, the sections can be welded together with tack welds; threads can be formed or added to the ends for threading the sections together; press fit features on the sections can be press-fit together; or other attachment could be used.

[0056] During the manufacturing process 100, additional manufacturing steps can strengthen the integrity of the formed whipstock (60), and additional features can be added to the formed whipstock (60). For example, the welded sections of the whipstock (60) can be cold worked, hard surfaced, filled with material, or the like. End components can be affixed to the whipstock (60) so it can be connected to other components of the whipstock assembly (50).

[0057] A number of strengthening techniques can be used alone or in combination with one another in preparing the whipstock (60) for use. For the purposes of discussion, Figs. 5A-5D illustrate various views of a whipstock component 150 manufactured from the disclosed process and strengthened according to one or more techniques ln general, the component 150 can be a formed blank of the entire whipstock, a formed blank of one section of the whipstock, or several formed sections already connected end to end.

[0058] ln one technique, strengthening the integrity involves cold working at least a portion of the formed tubing blank 150 for the disclosed whipstock (60). Structural integrity is preferably maintained as close to an original component made from bar stock as possible. This can be achieved on the disclosed whipstock component 150 by cold working the material in key areas (due to the collapsing method) to produce elevated strength levels in selected zones. These cold worked areas can be considered equivalent to a heat treated bar stock counterpart and provide structural integrity. For example, the ramp 152 of the component 150 can be cold worked.

[0059] ln another technique, strengthening the integrity involves hard banding at least a portion of the formed whipstock component 150. For example, the ramp 152 on the component 150 can have banding applied in the form of one or more raised nodes, rails, bands, plates, or the like. One technique is to lace or coat the top surface of the concave ramp 152 with a harder material, such as hard banding. This can be applied with a weld- type process or other form of application ln general, the banding can run longitudinally or non-longitudinally along the ramp 152 or other surface. For example, Fig. 8A shows the ramp 152 of a component 150 having different types of banding 153 formed thereon.

[0060] ln yet another technique, strengthening the integrity involves creating the preform (120) with one or more surface features ( e.g ., ribs, ridges, corrugations, scallops, slots, splines, or the like) defined on, along, or around the outer surface of the preform (120) against which the tubing blank for the component 150 forms complementary surface features 156 [e.g., ribs, ridges, scallops, slots, splines or the like) defined on, along, or around the component 150. For example, the surface features 156 in Fig. 5C include three longitudinal slots 157 in the outer circumference opposite the ramp 152 to produce at least two longitudinal ribs 158 strengthening the component 150. ln general, the surface features 156 can run longitudinally along the component 150, as shown. However, the surface features 156 of ribs, ridges, valleys, corrugations, scallops, slots, splines, or the like can be defined on the component 150 randomly, non-longitudinally, laterally, in a linear or non-linear pattern, or any other way to provide strengthening. For example, the surface features 156 can be defined as ridges and valleys in any direction and shape on any of the various surfaces of the component 150 to provide strengthening. As another example shown in Fig. 8B, the surface features 156 can be defined as scallops 159 at various locations along the length of the component 150, such as on the side opposite the ramp 152.

[0061] ln yet another technique, strengthening the integrity involves filling the hollow 154 of the whipstock componentl50 at least partially with a filler or support material 160. For example, Fig. 5D illustrates the hollow 154 of the component 150 filed completely with a material 160. The filler material 160 can include a concrete, a composite, fiberglass, plastic, an aggregate material, or the suitable material to reinforce the sidewall of the component 150 and prevent mill plunge. This filler material 160 resists any lateral movement of the mill as it progresses down the surface of the concave ramp 152 in creating a casing exit. As opposed to filling the hollow 150 completely, only portion can be filled; rods, plates, or the like can be installed in the hollow; or other reinforcement can be applied. The filler material 160 may also be at least part of the preform used in producing the component 150 and left inside the hollow 154.

[0062] Ultimately, the final manufacturing step (Block 116) involves attaching the whipstock (60) to the packer (80) and/or anchor (90) depending on the arrangement of the whipstock assembly (50). For example, an adapter plug (70) can be affixed (welded, threaded, press-fit, or the like) to the proximal end of the whipstock (60), and the adapter plug (70) can affix (welded, threaded, press-fit, or the like) to the packer (80) and/or anchor (90). ln fact, the adapter plug (70) could even be affixed to the proximal end of the whipstock (60) during the hydroforming process described above.

[0063] Overall, the whipstock (60) can be manufactured with a number of variations as desired. Figs. 6A-6D illustrate combined elevational and opposing end views of different manufactured whipstock components 150, which again can be for the entire whipstock, a section of thereof, or several sections already connected ln Fig. 6A, the outer

circumference of the component 150 opposite the ramp 152 includes surface features 156 in the form of two longitudinal channels 157, which essentially produces a central longitudinal rib 158 to strengthen the component 150. The surface features 156 in Fig. 6B include three longitudinal channels 157 that essentially produces two longitudinal ribs 158 to strengthen the component 150, and the surface features 156 in Fig. 6C include four longitudinal channels 157 that essentially produce three longitudinal ribs 158 to strengthen the component 150. ln Fig. 6D, the outer circumference of the component 150 opposite the ramp 152 includes surface features 156 in the form of three longitudinal channels 157 that are more deeply defined to form thinner ribs 158. As will be

appreciated, these and other surface features 156 can be used.

[0064] The whipstock assembly 50 of the present disclosure can be used in a completion to produce a casing exit for a sidetrack similar to what has been disclosed previously with respect to Fig. 1, for example. Because the whipstock 60 of the assembly 50 is hollow, at least partially hollow, or filled with an aggregate material, the whipstock assembly 50 can be used in other forms of completions. [0065] As one example, Fig. 9 illustrates a whipstock assembly 250 according to the present disclosure used in a multilateral completion 200. A main wellbore 10 is lined with casing 12 from which a first lateral sections 14 has been formed. This first lateral section 14 is lined with a liner 210, which is set by a liner hanger 212 and is cemented in place. Perforations 15 are defined in the liner 210 for production.

[0066] The whipstock assembly 250 has been run and set in the casing 12 uphole of the first lateral section 14. As shown, the assembly 250 includes a whipstock 260, an adapter 270, a packer 280, and an anchor 290. The whipstock 260 is formed according to the manufacturing process disclosed herein and defines a hollow 265. The packer 280 and anchor 290 can be any suitable type used. However, the adapter 270, packer 280, and anchor 290 define a central throughbore communicating the whipstock’s hollow 265 with the downhole lateral section 14.

[0067] A sidetrack lateral section 16 has also been formed through the casing 12 uphole of the whipstock assembly 250. This sidetrack section 16 has been lined with a liner 220, which is set by a liner hanger 212 and is cemented in place. Perforations 15 are defined in the liner 210 for production from the formation.

[0068] Additional perforations 18 have been defined in the liner 220 and through the disclosed whipstock 260 of the assembly 250 to provide fluid communication from the liner 220 with the hollow 265, which already communicates through the adapter 270, the packer 280, and the anchor 290 with the downhole lateral section 14.

[0069] As can be seen, the sidetrack 16 can communicate with the main wellbore 10. Additionally, the tubular whipstock 260 of the present disclosure along with the

throughbore the assembly 50 allows the lower lateral section 14 to also communicate with the main wellbore 10. The tubular nature and hollow 265 of the whipstock 260 of the present disclosure makes it particularly suited for this type of multilateral completion 200.

[0070] The whipstock 260 may have been installed without its hollow 265 filled with filler material for strengthening, although other strengthening techniques can be used. Alternatively, the whipstock 260 may have been installed with its hollow 265 filled with filler material for strengthening. Yet, this filler material in the hollow 265 may be degradable, may be removed by treatment ( e.g ., acid), may be porous and allowing flow, or the like so that fluid communication is possible between the second perforations 28 and the lower lateral section 14. [0071] The foregoing description of preferred and other embodiments is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants lt will be appreciated with the benefit of the present disclosure that features described above in accordance with any embodiment or aspect of the disclosed subject matter can be utilized, either alone or in combination, with any other described feature, in any other embodiment or aspect of the disclosed subject matter.

[0072] ln exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.