BACKGROUND OF THE INVENTION

1. Field of Invention

[0001] The present disclosure relates to a system for navigating past obstacles in a wellbore. More specifically, the present disclosure relates to selectively reorienting a shaped guide member to negotiate past irregular sections in a wellbore.

2. Description of Prior Art

[0002] Downhole operations in a hydrocarbon producing wellbore often involve deploying a tool or a string in the wellbore to a designated depth. Advances in hydrocarbon exploration and production have led to wells with more deviations, thereby introducing curves and bends in the wellbores that introduce obstacles to navigating tools or strings through the wellbore. Further, wellbore systems have been developed that include lateral wellbores that branch from a primary wellbore. Negotiating a tool or string across the angle between a primary wellbore and a lateral wellbore introduces additional difficulties. Further, a tool or string sometimes becomes lodged against washouts or other discontinuities in the wellbore wall when being lowered in an uncased wellbore.

SUMMARY OF THE INVENTION

[0003] Disclosed herein is an example of a downhole system for use in a wellbore and which includes a downhole tool having an axis, and that is deployed on wireline and a guide assembly. Here the guide assembly is made up of a connector coupled to the downhole tool, a sleeve with an end coupled to the connector and another end distal from the connector so that a portion of the circumference of the another end lies in a plane substantially perpendicular with the axis, and another portion that lies in a plane that is oblique with the axis, a pedestal having an outer periphery, and a ledge on the outer periphery that faces the sleeve, and that is profiled generally complementarily with the another end of the sleeve, so that when the ledge is axially urged against the another end of the sleeve, the pedestal rotates relative to the sleeve, a tip member having a curved surface and that is coupled to the pedestal. The downhole system can also a spring in the sleeve that is coupled to the sleeve and to the pedestal, and becomes rotationally tensioned with relative rotation of the sleeve and pedestal. In one example the tip member is an elongated member, and having a curved surface along an elongate lateral side. Optionally, the tip member can have a substantially planar surface along an elongate lateral side that is angularly spaced away from the curved surface. In an embodiment, the planar surface projects along a path that is oblique with the axis. The portions each optionally extend about 180 degrees around a circumference of the end of the sleeve. A standoff can be included on the sleeve.

[0004] Another example of a downhole system for use in a wellbore is described herein and which includes downhole tool that is selectively disposed in the wellbore, a wireline connected to an end of the downhole tool, and a guide assembly connected to an end of the downhole tool opposite the wireline, and that includes a downwardly projecting tip member and a means for orienting the tip member in a designated orientation for navigating past obstacles in the wellbore. The means for orienting the tip member can include a sleeve having an end that terminates at varying axial positions along a circumference of the sleeve, and a pedestal having a ledge on an outer periphery of the pedestal, where the ledge faces the sleeve and is profiled complementarily with the end of the sleeve, so that the pedestal rotates with respect to the sleeve when the ledge is put into abutting contact with the end of the sleeve. In an embodiment, the sleeve is coupled to the downhole tool, and the pedestal is coupled to the tip member, so that relative rotation of the pedestal and sleeve rotates the tip member with respect to the downhole tool. The tip member can be an elongate member having a curved elongate surface, and a planar elongate surface on a side opposite the curved elongate surface, and wherein the planar elongate surface is oblique to an axis of the guide system.

[0005] Also described herein is an example of a method of wellbore operations and which includes deploying a downhole string in a wellbore and on a wireline, where the downhole string includes a downhole tool equipped with a guide assembly having an obliquely angled tip member, landing the tip member on an obstacle in the wellbore, lifting the downhole string from the obstacle, reorienting the tip member along a path directed away from the obstacle, and lowering the downhole string so that the tip member slides past the obstacle. The obstacle can be a discontinuity along a sidewall of the wellbore, such as a washout, a ledge, a curved portion of the wellbore, or an entrance to a lateral wellbore. The method can include repeating the steps of lifting the downhole string and reorienting the tip member. In an alternative, the tip member is reoriented at an angle of around 120 degrees. The method can also include sensing when the tip member lands on the obstacle in the wellbore and lifting the downhole string from the obstacle in response to the step of sensing. An optional step of sensing can include receiving a signal with a controller on surface from a proximity sensor disposed in the guide assembly.

BRIEF DESCRIPTION OF DRAWINGS

[0006] Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which: [0007] FIG. 1 is a side sectional view of a tool string landing on an obstruction in a wellbore, where an example of a guide system is mounted to the tool string.

[0008] FIG. 2 is a side sectional view of the tool string of FIG. 1 being raised upward from the obstruction, and where the guide system is reorienting a tip member.

[0009] FIG. 3 is a side sectional view of the tool string of FIG. 2 being lowered in the wellbore for navigating past the obstacle.

[0010] FIGS. 4A and 4B are side perspective views of examples of the guide system of FIG. 1.

[0011] While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF INVENTION

[0012] The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. In an embodiment, usage of the term "about" includes +/- 5% of the cited magnitude. In an embodiment, usage of the term "substantially" includes +/- 5% of the cited magnitude. [0013] It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.

[0014] Shown in side sectional view in Figure 1 is an example of a downhole system 10 being lowered within a wellbore 12, wherein wellbore 12 is formed through a formation 14. As shown, the downhole system 10 is approaching a deviated section 16 of wellbore 12 while being lowered on wireline 18. The downhole system 10 includes a downhole tool 20, which can be for example a perforating gun, an imaging or logging tool, or other tubular being set downhole. A guide system 22 is shown mounted to a lower end of downhole tool 20 opposite its connection to wireline 18. The guide system 22 includes an orientation assembly 24 with a tip member 26 that depends downward from orientation assembly 24 and is a generally elongate member. One elongate side of tip member 26 is shown having a curved surface 28, wherein an opposite side of tip member 26 has a generally planar surface 29. Further illustrated in Figure 1 is a surface truck 30 shown mounted on surface 32. Wireline 18 connects to a reel (not shown) within surface truck 30 and spools over sheaves and into a wellhead assembly 34, shown mounted over an opening of wellbore 12. Further shown in Figure 1 is a controller 36, shown in dashed outline within surface truck 30, can be used for sending and receiving data and control signals to and from downhole system 10.

[0015] Tip member 26 of Figure 1 is shown having landed against an obstacle 38 on the sidewall of wellbore 12. In the example, the obstacle 38 is the angled sidewall of the wellbore 12 in the deviated section 16. Other examples of obstacles include washouts, ledges, and entrances into lateral wellbores from a primary wellbore. Referring now to Figure 2, one example of navigating past the obstacle 38 is demonstrated by lifting the downhole system 10 upwards within wellbore 12 and from obstacle 38. As will be described in more detail below, the guide system 22 automatically reorients tip member 26 as shown so that the curved surface 28 is now facing the direction of obstacle in wellbore 12. Shown in Figure 3 is a subsequent step of an example of navigating past the obstacle 38 where the downhole system 10 is lowered on wireline so that tip member 26 is proximate obstacle 38. As shown, the strategic positioning of tip member 26 orients the curved surface 28 so it faces obstacle 38, which enables the downhole system 10 to slide past obstacle 38 and make its way deeper into wellbore 12 and past the deviated section 16.

[0016] In side perspective views in Figures 4A and 4B are example embodiments of the guide system 22. A connector 40 is shown on one end of guide system 22 which is a generally annular member with an open end revealing a hollow portion, inside of hollow portion is an inner surface. Threads 42 are depicted formed within the inner surface of connector 40 and for connecting to the downhole tool 20 (Figure 1). An end of connector 40 opposite its open end connects to an annular sleeve 44, shown having an axial bore 45 extending therethrough. Sleeve 44 has an end 46 distal from its connection to connector 40, and wherein end 46 has a beveled profile such that the end 46 terminates at different axial locations with respect to a circumference of sleeve 44. More specifically, a portion 48 of the circumference of end 46 lies in a plane that is substantially perpendicular with an axis A _y of guide assembly 22. Another portion 50 of the circumference of end 46 projects along a varying axial location and thus lies in a plane that is substantially oblique with axis A _y . The portions 48, 50 define a shape that is sometimes referred to "mule shoe". Also included with guide assembly 22 is a standoff 52, which is made up of a collar 54 that is shown circumscribing a portion of sleeve 44. Ridges 56 are mounted on collar 54 at angular locations around collar 54, and are elongate members that project along the axial length of collar 54.

[0017] A generally cylindrical pedestal 58 is shown disposed adjacent end 46 of sleeve 44. The diameter of pedestal 58 transitions radially outward proximate to sleeve 44, and which defines a ledge 62 that faces sleeve 44. Similar to the end 46, ledge 62 has a portion 64 that extends along a part of the circumference of ledge 62, and which is lies in a plane generally perpendicular with axis A _y . Another portion 66 of ledge 62 extends along another part of the circumference of ledge 62, and which is complementarily formed to portion 50. Thus portion 66 extends along a plane that is generally oblique with axis A _y . Examples exist wherein each of the portions 48, 50, 64, 66 extend about 180 degrees around the respective circumferences of the end 46 and the ledge 62. Optionally, multiple portions 48, 50, 64, 66 can be formed on the end 46 and ledge 62, wherein the angular lengths of each of the portions 48, 50, 64, 66 is less than 180 degrees. Optionally, embodiments having multiple portions 48, 50, 64, 66 can give the end 46 and ledge 62 a generally castellated appearance. When assembled, the smaller diameter section of pedestal 58 between ledge 62 and sleeve 44 inserts into bore 45 of sleeve 44. As shown in Figure 4A, a bore 68 is formed within pedestal 58 and sized to receive a post 70 mounted on an end of tip member 26. As depicted in Figures 4A and 4B, an axis A™ of tip member 26 is generally oblique with axis A _y .

[0018] In one example of operation of the guide system 22, applying a force F against end of tip member 26 as shown in Figure 4A, urges pedestal 58 against sleeve 44 so that ledge 62 is in close contact with end 46 of sleeve 44. An example of force F can occur when tip member 26 lands on obstacle 38 (Figure 1). As the ledge 62 is profiled complementary to end 46, the pedestal 58 will rotate with respect to sleeve 44 until the portions 48, 64 are aligned, and portions 50, 66 are aligned. A spring 72 which is coupled to both the pedestal 58 and sleeve 44 is torqued into compression and stores energy while the sleeve 44 and pedestal 58 are abutted against one another. When the force F is removed, such as the step illustrated in Figure 2 so that the tip member 26 is freely suspended and not landed on a solid surface, the compressed torsion in spring 72 is released and causes rotation of pedestal 58 and tip member 26 relative to sleeve 44 and downhole tool 20 (Figure 1). As such, the curved surface 28 can be strategically reoriented so that when the downhole system 10 of Figure 1 is relowered, the curved surface 28 (and thus smoother surface) of the tip member 26 can engage obstacle 38 with less resistance than when in other orientations, so that the downhole system 10 can be urged further within wellbore 12. Moreover, orientating tip member 26 so that its axis A _M is oblique to the axis A _y provides an increased offset angle with respect to obstacle 38 thereby enhancing the ability of the guide system 22 to direct the downhole system 10 past the obstacle 38.

[0019] Referring back to Figure 1, a proximity sensor 74 is shown within guide system 22 and which can sense when the pedestal 58 and sleeve 44 are in close contact, thereby indicating the tip member 26 has landed on an obstacle 38 or other solid mass that blocks passage of downhole system 10. Sensor 74 can be in contact with controller 36 via wireline, so that operations personnel on surface 32 can detect when the downhole system 10 lands on an obstacle 38. Upon detection of landing, operations personnel can commence the actions of lifting the downhole system 10 and then relowering as illustrated in Figures 2 and 3. Other ways of sensing may be included, such as monitoring tension in the wireline 18.

[0020] The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While a presently preferred embodiment of the invention has been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These and other similar modifications will readily suggest themselves to those skilled in the art, and are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.