Wellbores are sometimes drilled into subterranean formations that contain hydrocarbons to allow recovery of the hydrocarbons. Some wellbore servicing methods employ wellbore tubulars that are lowered into the wellbore for various purposes throughout the life of the wellbore. Since wellbores are not generally perfectly vertical, stabilizers are used to maintain the wellbore tubulars aligned within the wellbore. Alignment may help prevent any friction between the wellbore tubular and the side of the wellbore wall or casing, potentially reducing any damage that may occur.
Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
In the drawings and descriptions that follow, like parts are typically marked throughout the specification and drawings with the same reference numerals, respectively. The drawn figures are not necessarily, but may be, to scale. Certain features of the disclosure may be shown exaggerated in scale or in somewhat schematic form and some details of certain elements may not be shown in the interest of clarity and conciseness.
The present disclosure may be implemented in embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings, with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure, and is not intended to limit the disclosure to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed herein may be employed separately or in any suitable combination to produce desired results. Moreover, all statements herein reciting principles and aspects of the disclosure, as well as specific examples thereof, are intended to encompass equivalents thereof. Additionally, the term, “or,” as used herein, refers to a non-exclusive or, unless otherwise indicated.
Unless otherwise specified, use of the terms “connect,” “engage,” “couple,” “attach,” or any other like term describing an interaction between elements is not meant to limit the interaction to direct interaction between the elements and may also include indirect interaction between the elements described.
Unless otherwise specified, use of the terms “up,” “upper,” “upward,” “uphole,” “upstream,” or other like terms shall be construed as generally toward the surface of the well; likewise, use of the terms “down,” “lower,” “downward,” “downhole,” or other like terms shall be construed as generally toward the bottom, terminal end of a well, regardless of the wellbore orientation. Use of any one or more of the foregoing terms shall not be construed as denoting positions along a perfectly vertical or horizontal axis. Unless otherwise specified, use of the term “subterranean formation” shall be construed as encompassing both areas below exposed earth and areas below earth covered by water, such as ocean or fresh water.
In certain situations, stabilizers are used throughout a downhole conveyance to centralize the downhole conveyance within a wellbore. The downhole conveyance will often be discussed herein as a drill string, but it should be known that the present disclosure is not so limited, and thus may be applied to any conveyance located within a wellbore. It is known that certain design parameters of stabilizers contribute to drill string dynamic behavior, including vibration, and whirl. The present disclosure recognizes, however, that the design of stabilizers must balance many conflicting parameters. Design parameters include but are not limited to taper (approach) angles, helical wellbore stabilizing element length (L), straight or spiral helical wellbore stabilizing elements, wrap angles, helical wellbore stabilizing element area, bypass area, base materials and coatings.
The present disclosure has further recognized that it is beneficial for the helical wellbore stabilizing elements to be shaped such that an annular flow area between leading edges of adjacent helical wellbore stabilizing elements and trailing edges of adjacent helical wellbore stabilizing elements is variable along at least a portion of the length (L) of the two or more helical wellbore stabilizing elements. In at least one embodiment, an unobstructed axial flow path exists between the adjacent helical wellbore stabilizing elements along the length (L). In at least one other embodiment, the helical wellbore stabilizing elements have a downhole longitudinal load line having a width (WD1) greater than 1 mm located at a downhole leading edge of one of the two or more helical wellbore stabilizers, and an uphole longitudinal load line having a width (WU1) greater than 1 mm located at an uphole trailing edge of another of the two or more helical wellbore stabilizers.
Referring to
The well system 100 illustrated in
The downhole tool assembly 180, in the illustrated embodiment, includes a downhole tool 185 and a stabilizer 190. The downhole tool 185 may comprise any downhole tool that could be positioned within a wellbore. Certain downhole tools 185 that may find particular use in the well system 100 include, without limitation, drilling and logging tools, rotary steerable tools, inline stabilizer tools, measurement or logging while drilling (MLWD) tools, mud motors and drill string stabilizers (e.g., collars with stabilizer blades), drill bits, bottom hole assemblies (BHAs), sealing packers, elastomeric sealing packers, non-elastomeric sealing packers (e.g., including plastics such as PEEK, metal packers such as inflatable metal packers, as well as other related packers), liners, an entire lower completion, one or more tubing strings, one or more screens, one or more production sleeves, etc.
The stabilizer 190, in accordance with one embodiment of the disclosure, includes a downhole component coupleable to the downhole conveyance 170. The downhole component may be a downhole tubular, a solid downhole stock, or a solid downhole stock having one or more fluid passageways extending along a length (L) thereof, among others, and remain within the scope of the present disclosure. The stabilizer 190, in accordance with this embodiment, additionally includes two or more helical wellbore stabilizing elements radially extending from the downhole component. In at least one embodiment, the stabilizer 190 includes four helical wellbore stabilizing elements radially extending from the downhole component. In at least one embodiment, the two or more helical wellbore stabilizing elements are shaped such that an annular flow area between leading edges of adjacent helical wellbore stabilizing elements and trailing edges of adjacent helical wellbore stabilizing elements is variable along at least a portion of a length (L) of the two or more helical wellbore stabilizing elements. In at least one embodiment, this is combined with the stabilizer having an unobstructed axial flow path between the adjacent helical wellbore stabilizing elements along the length (L), and in yet another embodiment, the stabilizer having a downhole longitudinal load line having a width (w1) greater than 1 mm located at a downhole leading edge of one of the two or more helical wellbore stabilizers and an uphole longitudinal load line having a width (w2) greater than 1 mm located at an uphole trailing edge of another of the two or more helical wellbore stabilizers, as well as combinations of the foregoing.
Compared to straight wellbore stabilizing element stabilizers 200 (e.g., as shown in
The present disclosure has recognized that the localized contact pressure at the minimum contact length across the helical wellbore stabilizing elements in different angular orientations is reduced if four helical wellbore stabilizing elements are used compared to an equivalent stabilizer employing only three helical wellbore stabilizing elements. The reduced (e.g., localized) contact pressure is important to reduce friction, and prevent the stabilizer from penetrating into the wellbore, which in turn improves the wellbore, reduces vibration, and reduces stabilizer wear/damage. However, it is noted that stabilizers employing four helical wellbore stabilizing elements for hole sizes less than about 156 mm (e.g., about 6.125 inches) might not meet the flow area requirements, while maintaining sufficient helical wellbore stabilizing element thickness. In such scenarios, a stabilizer employing three helical wellbore stabilizing elements may be used. For larger stabilizers, a greater number of helical wellbore stabilizing elements may also be used to reduce contact pressure. Nevertheless, the present disclosure has recognized that certain designs of helical wellbore stabilizing elements can increase pressure losses in the annulus (required to move cuttings away from the blades) and may even trap cuttings resulting in increased erosion of the drill string and stabilizers.
A spiral stabilizer design would ideally balance the requirement for coverage or wrap angle with the requirement to ensure that there is an unobstructed axial flow path that exists between adjacent helical wellbore stabilizing elements along the length (L) of the spiral stabilizer design. This unobstructed axial flow path (e.g., also known as line of sight and shown by the arrows 210, 260 in
One novel design of the stabilizer shape maximizes the wrap angle, thereby reducing drill string vibrations and providing nearly full support for all rotational positions. Such a shape also, in certain embodiments, provides locations for clamping for installation. The stabilizer shape, in one embodiment, provides an annular flow area between leading edges of adjacent helical wellbore stabilizing elements and trailing edges of adjacent helical wellbore stabilizing elements that is variable along at least a portion of a length (L) of the two or more helical wellbore stabilizing elements, and further provides an unobstructed axial flow path between the adjacent helical wellbore stabilizing elements along the length (L).
The present disclosure has recognized, in least in one embodiment, instead of a standard helical spiral, the helical wellbore stabilizing element shape is a modified “Z” or “S” shape. In one embodiment, this is done by removing additional helical wellbore stabilizing element areas during machining of the helical wellbore stabilizing elements so that the unobstructed axial flow path (e.g., line of sight) can be maintained while having a high wrap angle (e.g., >350 degrees but less than 360 degrees).
Turning to
Turning to
Turning to
The stabilizer 500 of
Furthermore, the downhole longitudinal load line 530 and uphole longitudinal load line 535 need not be axially aligned with one another. In certain embodiments, the downhole longitudinal load line 530 and uphole longitudinal load line 535 are axially aligned with one another, in certain other embodiments the downhole longitudinal load line 530 and uphole longitudinal load line 535 are not axially aligned but overlap one another (e.g., such that an unobstructed axial flow path does not exist), and in yet other embodiments the downhole longitudinal load line 530 and uphole longitudinal load line 535 are not axially aligned but do not overlap one another (e.g., such that an unobstructed axial flow path does exist).
In accordance with one embodiment, the downhole longitudinal load line 530 and uphole longitudinal load line 535 create a distributed load area on the downhole leading edge of one of the two or more helical wellbore stabilizers and on the uphole trailing edge of another of the two or more helical wellbore stabilizers, respectively.
The stabilizer 500 illustrated in
The use of a stabilizer shape according to the disclosure could also address an issue related to the engaging and clamping of helical sleeve stabilizers. Helical sleeve stabilizers are typically used on motor assisted rotary steerable system (MARSS) motors and certain ILS or other stabilizers where it is desirable to change the gauge (outer diameter) size at the rig site. Because of the hard materials used on the helical wellbore stabilizing element faces, it is difficult to get rig tongs on the stabilizers without slipping or damaging the coating on the helical wellbore stabilizing element faces.
As shown in
Traditional stabilizers are milled from billets or forgings by programming a helical area for the machinist to mill away to create the helical wellbore stabilizing elements 420 (e.g., see outlined area 810 in
Turning to
Alternative methods of manufacture include additive manufacturing methods to directly generate (print) the helical wellbore stabilizing elements onto the downhole tubular (e.g., cylindrical base). Since in additive manufacturing methods, material is deposited in the exact locations defined by the part, it would be relatively simple to modify the printing (additive) program to not deposit material in the shaded areas 820 of
In many embodiments, the shape of the modified helix areas are straight and aligned with the axis of the tool. It is conceivable that these could also be curved (splined) or profiled so that the profile is more of an “S-shaped” flow path centerline instead of the elongated Z-shape flow path centerline shown.
Although stabilizers have been predominantly mentioned here in this disclosure, this modification to the helical wellbore stabilizing element profile could also be applied to reamers as well. Reamers are used to enlarge bore holes and this modification could be used in those applications as well to facilitate debris removal. Similarly, it should be noted that the term stabilizer as used herein is intended to encompass all types of stabilizers and centralizers as might be used in an oil/gas wellbore. Those skilled in the art to which this application relates will appreciate that other and further additions, deletions, substitutions and modifications may be made to the described embodiments.
Aspects disclosed herein include:
A. A stabilizer for use in a wellbore, the stabilizer including: 1) a downhole component coupleable to a downhole conveyance in a wellbore; and 2) two or more helical wellbore stabilizing elements extending radially outward from the downhole component, the two or more helical wellbore stabilizing elements shaped such that an annular flow area between leading edges of adjacent helical wellbore stabilizing elements and between trailing edges of adjacent helical wellbore stabilizing elements is variable along at least a portion of a length (L) of the two or more helical wellbore stabilizing elements, and such that an unobstructed axial flow path exists between the adjacent helical wellbore stabilizing elements along the length (L).
B. A well system, the well system including: 1) a wellbore; 2) a downhole conveyance located within the wellbore; and 3) a stabilizer coupled to the downhole conveyance, the stabilizer including: a) a downhole component coupled to the downhole conveyance in a wellbore; and b) two or more helical wellbore stabilizing elements extending radially outward from the downhole component, the two or more helical wellbore stabilizing elements shaped such that an annular flow area between leading edges of adjacent helical wellbore stabilizing elements and between trailing edges of adjacent helical wellbore stabilizing elements is variable along at least a portion of a length (L) of the two or more helical wellbore stabilizing elements, and such that an unobstructed axial flow path exists between the adjacent helical wellbore stabilizing elements along the length (L).
C. A stabilizer for use in a wellbore, the stabilizer including: 1) a downhole component coupleable to a downhole conveyance in a wellbore; and 2) two or more helical wellbore stabilizing elements extending radially outward from the downhole component, the two or more helical wellbore stabilizing elements shaped such that an annular flow area between leading edges of adjacent helical wellbore stabilizing elements and between trailing edges of adjacent helical wellbore stabilizing elements is variable along at least a portion of a length (L) of the two or more helical wellbore stabilizing elements, and such that a downhole longitudinal load line having a width (WD1) greater than 1 mm is located at a downhole leading edge of one of the two or more helical wellbore stabilizers, and an uphole longitudinal load line having a width (WU1) greater than 1 mm is located at an uphole trailing edge of another of the two or more helical wellbore stabilizers.
D. A well system, the well system including: 1) a wellbore; 2) a downhole conveyance located within the wellbore; and 3) a stabilizer coupled to the downhole conveyance, the stabilizer including: a) a downhole component coupled to the downhole conveyance in a wellbore; and two or more helical wellbore stabilizing elements extending radially outward from the downhole component, the two or more helical wellbore stabilizing elements shaped such that an annular flow area between leading edges of adjacent helical wellbore stabilizing elements and between trailing edges of adjacent helical wellbore stabilizing elements is variable along at least a portion of a length (L) of the two or more helical wellbore stabilizing elements, and such that a downhole longitudinal load line having a width (WD1) greater than 1 mm is located at a downhole leading edge of one of the two or more helical wellbore stabilizers, and an uphole longitudinal load line having a width (WU1) greater than 1 mm is located at an uphole trailing edge of another of the two or more helical wellbore stabilizers.
Aspects A, B, C and D may have one or more of the following additional elements in combination: Element 1: wherein the downhole component is a downhole tubular. Element 2: wherein adjacent helical wellbore stabilizing elements define a flow path centerline, and furthermore wherein the flow path centerline is non-linear. Element 3: wherein the flow path centerline is a modified z-shape or modified s-shape. Element 4: wherein each of the two or more helical wellbore stabilizing elements includes a minimum downhole contact width (WD2), a downhole ramp width (WD3), a minimum uphole contact width (WU2), and an uphole ramp width (WU3). Element 5: wherein the minimum downhole contact width (WD2) and the minimum uphole contact width (WU2) are less than the downhole ramp width (WD3) and uphole ramp width (WU3), respectively. Element 6: wherein a leading face and a trailing face of the two or more helical wellbore stabilizing elements are not parallel with any plane formed through a centerline of the stabilizer. Element 7: wherein the leading face and the trailing face are a flat leading face and a flat trailing face that are each angled relative all planes formed through the centerline of the stabilizer. Element 8: wherein the leading face and the trailing face are an arced leading face and an arced trailing face that are not parallel with any plane formed through a centerline of the stabilizer. Element 9: wherein the two or more helical wellbore stabilizing elements have a wrap angle greater than 350 degrees but less than 360 degrees. Element 10: wherein the downhole longitudinal load line has a width (WD1) greater than 2 mm and the uphole longitudinal load line has a width (WU1) greater than 2 mm. Element 11: wherein the downhole longitudinal load line has a width (WD1) greater than 5 mm and the uphole longitudinal load line has a width (WU1) greater than 5 mm. Element 12: wherein the downhole longitudinal load line and the uphole longitudinal load line have different widths. Element 13: wherein the downhole longitudinal load line and the uphole longitudinal load line are a straight downhole longitudinal load line and a straight uphole longitudinal load line. Element 14: wherein the downhole longitudinal load line and the uphole longitudinal load line are a curved downhole longitudinal load line and a curved uphole longitudinal load line. Element 15: wherein the two or more helical wellbore stabilizing elements are shaped such that an unobstructed axial flow path exists between the adjacent helical wellbore stabilizing elements along the length (L). Element 16: wherein adjacent helical wellbore stabilizing elements define a flow path centerline, and furthermore wherein the flow path centerline is non-linear.
Those skilled in the art to which this application relates will appreciate that other and further additions, deletions, substitutions and modifications may be made to the described embodiments.
This application claims the benefit of U.S. Provisional Application Ser. No. 63/034,732, filed on Jun. 4, 2020, entitled “MODIFIED HELICAL BLADE STABILIZERS,” commonly assigned with this application and incorporated herein by reference in its entirety.
Number | Date | Country | |
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63034732 | Jun 2020 | US |