Stabilizer Assembly and Method
A stabilizer assembly for a tubular member includes a stabilizing body dimensioned to fit around the tubular member, a central portion having a radial projection, and a first end having a first threaded outer surface and a set of integral first elastic members. A first nut member includes a proximal end with a threaded inner surface configured to engage the first threaded outer surface of the stabilizing body and a central portion with a first tapered inner surface configured to engage the first elastic members of the stabilizing body. Threading the first nut member onto the first end of the stabilizing body forces the first elastic members to engage the first tapered inner surface of the first nut member thereby radially flexing the first elastic members to engage the tubular member. An inner surface of a distal end of each first elastic member may include a grip section.
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In the drilling of oil and gas wells, downhole drilling motors may be connected to a drill string to rotate and steer a drill bit. Conventional drilling motors typically include a power assembly, a transmission assembly, and a bearing assembly. Rotation is provided by the power assembly. The transmission assembly transmits torque and speed from the power assembly to a drill bit disposed at a lower end of the drilling motor. The bearing assembly takes up the axial and radial loads imparted on the drill string during drilling.
A releasable drilling stabilizer may be attached to a portion of a drill string or a drilling motor in order to stabilize the drill string or drilling motor within the wellbore. The releasable drilling stabilizer prevents unintentional key seating and reduces vibrations. Conventional releasable stabilizers include a central stiff stabilizing member having projections configured to engage an inner surface of the wellbore; slips, wedges, or flexible members disposed within the central stabilizing member for gripping an outer surface of the drill string; and end caps threadedly connected to the ends of the central stabilizing member. The end caps force the slips, wedges, or flexible members to grip the drill string as the end caps are threaded onto the central stabilizing member. Similar releasable stabilizers are disclosed in U.S. Pat. No. 3,916,998 to Bass, Jr. et al. and U.S. Pat. No. 4,258,804 to Richey et al. These conventional arrangements include at least two sets of contacting surfaces between the stabilizing member and the drill string, i.e., a first contact between the stabilizing member and the slip, wedge, or flexible member and a second contact between the slip, wedge, or flexible member and the outer surface of the drill string. Because the releasable stabilizer must transmit torque and axial load through frictional forces at the contact points, each set of contacting surfaces increases the chance of the releasable stabilizer not transmitting torque during use (i.e., failing, slipping, or otherwise becoming disconnected from the drill string).
With reference to
Referring still to
Inner diameter 40 of central portion 17 of stabilizing body 12 may be dimensioned to fit over a tubular member, such as a portion of a drill string or a drill motor. Elastic members 20 and 24 on first and second ends 22 and 26, respectively, may be configured to be contracted or flexed to selectively provide first and second ends 22 and 26 with an inner diameter that is less than inner diameter 40 of central portion 17 in order to engage the tubular member over which it is positioned. Longitudinal slots 28 and 30 and thinned sections 36 and 38 may allow each elastic member 20 and 24 to flex relative to central portion 17 thus changing its radial position relative to the tubular member.
First end 22 of stabilizing body 12 may include threaded outer surface 42, and second end 26 may include threaded outer surface 44. Proximal end 46 of first nut member 14 may include threaded inner surface 48 configured to engage threaded outer surface 42 of first end 22 of stabilizing body 12. Proximal end 50 of second nut member 16 may include threaded inner surface 52 configured to engage threaded outer surface 44 of second end 26 of stabilizing body 12. First and second nut members 14 and 16 may be detachably connected to first and second ends 22 and 26 of stabilizing body 12 through these threaded connections.
First nut member 14 may include tapered inner surface 54 configured to engage first elastic members 20. As first nut member 14 is threadedly connected to first end 22 of stabilizing body 12, first elastic members 20 may engage with and be contracted or flexed by tapered inner surface 54 of first nut member 14. Second nut member 16 may include tapered inner surface 56 configured to engage second elastic members 24. As second nut member 16 is threadedly connected to second end 26 of stabilizing body 12, second elastic members 24 may engage with and be contracted or flexed by tapered inner surface 56 of second nut member 16. In an alternate embodiment, first and second elastic members 20 and 24 may be contracted or flexed by clamping.
Referring now to
In one embodiment, all threaded surfaces of stabilizer assembly 10 are oriented in the same direction (i.e., all right-hand threads or all left-hand threads). In this embodiment, if radial projections 18 are worn down and nut member 14 or 16 contacts an inner surface of a wellbore, one threaded connection will be loosened but the other threaded connection will be tightened. In other words, the threaded connection between nut member 14 and stabilizing body 12 may be loosened while the threaded connection between nut member 16 and stabilizing body 12 may be tightened. Alternatively, the threaded connection between nut member 16 and stabilizing body 12 may be loosened while the threaded connection between nut member 14 and stabilizing body 12 may be tightened. In this way, stabilizer assembly 10 will remain secured to the tubular member instead of both threaded connections being loosened.
In an alternate embodiment, stabilizing body 12 may include elastic members at only one end and stabilizer assembly 10 may include only one nut member.
Referring still to
In one embodiment, first and second wedge members 118 and 120 may be formed of a different material than the remainder of stabilizer assembly 100. For example, first and second wedge members 118 and 120 may be formed of a harder material than the remainder of stabilizer assembly 100 in order to provide stronger tapered inner surfaces 122 and 124 and to provide a stronger grip between contact surfaces 60 and 62 and outer surface 64 of tubular member 58.
In another embodiment, all threaded surfaces of stabilizer assembly 100 are oriented in the same direction (i.e., all right-hand threads or all left-hand threads). In this embodiment, if radial projections 18 are worn down and nut member 102 or 104 contacts an inner surface of a wellbore, one threaded connection will be loosened but the other threaded connection will be tightened. In other words, the threaded connection between nut member 102 and stabilizing body 12 may be loosened while the threaded connection between nut member 104 and stabilizing body 12 may be tightened. Alternatively, the threaded connection between nut member 104 and stabilizing body 12 may be loosened while the threaded connection between nut member 102 and stabilizing body 12 may be tightened. In this way, stabilizer assembly 100 will remain secured to the tubular member instead of both threaded connections being loosened.
In an alternate embodiment, stabilizing body 12 may include elastic members at only one end and stabilizer assembly 100 may include only one nut member.
Grip sections 70 and 72 may include any combination of grooves and/or projections to improve the resistance to movement of stabilizer assembly 10 or 100 on a tubular member. For example, grip sections 70 and 72 may include longitudinal grooves 130 as shown in
Referring now to
Drilling motor 144 may be lowered from well surface 146 into wellbore 148 with stabilizer assembly 10 secured to the outer surface of bearing section 142. Drill string 140 and drilling motor 144 may be rotated in order rotate drill bit 150. Radial projections 18 of stabilizer assembly 10 may contact the inner surface of wellbore 148 in order to stabilizing drill string 140 and drilling motor 144 within wellbore 148 as the components are rotated.
When drilling motor 144 is removed from wellbore 148, stabilizer assembly 10 may be detached from bearing section 142. Unthreading first and second nut members 14 and 16 from first and second ends 22 and 26 of stabilizing body 12 allows first and second elastic members 20 and 24 to expand, thereby releasing contact surfaces 60 and 62 (or grip sections 70 and 72) from the outer surface of bearing section 142. Finally, a user may slide first and second nut members 14 and 16, along with stabilizing body 12, off of bearing section 142.
In the same way, stabilizer assembly 100 may also be detachably secured to drill string 140 in order to stabilize drill string 140 within wellbore 148. Threading first and second nut members 102 and 104 onto first and second ends 22 and 26 of stabilizing body 12 contracts or flexes first and second elastic members 20 and 24 to grip drill string 140 with contact surfaces 60 and 62 (or grip sections 70 and 72) of first and second elastic members 20 and 24. Unthreading first and second nut members 102 and 104 from first and second ends 22 and 26 of stabilizing body 12 allows first and second elastic members 20 and 24 to expand, thereby releasing contact surfaces 60 and 62 (or grip sections 70 and 72) from the outer surface of drill string 140.
Stabilizer assemblies 10 and 100 both include stabilizing body 12 that directly contacts and grips a tubular member over which it is positioned; neither stabilizer assembly includes a separate member (such as a slip or a wedge) for gripping the tubular member. Because the stabilizing body 12 directly contacts both the tubular member and the inner surface of the wellbore, stabilizing body 12 is capable of transmitting torque and axial load to prevent rotation and sliding of stabilizing body 12 relative to the tubular member.
Because stabilizing body 12 includes integral elastic members, stabilizing body 12 includes only one set of contacting surfaces between stabilizing body 12 and the tubular member. The single contacting surface arrangement of stabilizing body 12 reduces the chance of failure due to not transmitting torque during use over conventional stabilizers including at least two contacting surfaces between the stabilizing member and the tubular member.
While preferred embodiments have been described, it is to be understood that the embodiments are illustrative only and that the scope of the invention is to be defined solely by the appended claims when accorded a full range of equivalents, many variations and modifications naturally occurring to those skilled in the art from a review hereof.
Claims
1. A stabilizer assembly for a tubular member, comprising:
- a stabilizing body dimensioned to fit around the tubular member, a central portion of the stabilizing body including a radial projection, and a first end of the stabilizing body including a first threaded outer surface and a set of integral first elastic members;
- a first nut member including a proximal end with a threaded inner surface configured to engage the first threaded outer surface of the stabilizing body, a central portion of the first nut member including a first tapered inner surface configured to engage the first elastic members of the stabilizing body;
- wherein threading the first nut member onto the first end of the stabilizing body forces the first elastic members to engage the first tapered inner surface of the first nut member thereby radially flexing the first elastic members to engage the tubular member.
2. The stabilizer assembly of claim 1, wherein the first elastic members are fingers formed by a set of longitudinal slots in the first end of the stabilizing body.
3. The stabilizer assembly of claim 2, wherein each longitudinal slot includes a rounded proximal end.
4. The stabilizer assembly of claim 2, wherein an inner surface of a distal end of each finger includes a grip section configured to grip the tubular member.
5. The stabilizer assembly of claim 4, wherein each grip section includes longitudinal grooves, circumferential grooves, or a combination of longitudinal grooves and circumferential grooves.
6. The stabilizer assembly of claim 4, wherein each grip section includes a plurality of projections formed by overlapping longitudinal grooves and circumferential grooves.
7. The stabilizer assembly of claim 4, wherein each finger includes a thinned section between a proximal end and the grip section at the distal end.
8. The stabilizer assembly of claim 1, wherein the radial projection extends only partially around the central portion of the stabilizing body.
9. The stabilizer assembly of claim 8, wherein the stabilizing body further includes a set of radial projections spaced around the central portion of the stabilizing body.
10. The stabilizer assembly of claim 1, wherein a second end of the stabilizing body includes a second threaded outer surface and a set of integral second elastic members, the stabilizer assembly further comprising:
- a second nut member including a proximal end with a threaded inner surface configured to engage the second threaded outer surface of the stabilizing body, a central portion of the second nut member including a second tapered inner surface configured to engage the second elastic members of the stabilizing body, wherein threading the second nut member onto the second end of the stabilizing body forces the second elastic members to engage the second tapered inner surface of the second nut member thereby radially flexing the second elastic members to engage the tubular member.
11. The stabilizer assembly of claim 10, wherein the first elastic members are first fingers formed by a set of first longitudinal slots in the first end of the stabilizing body, and wherein the second elastic members are second fingers formed by a set of second longitudinal slots in the second end of the stabilizing body.
12. The stabilizer assembly of claim 11, wherein an inner surface of a distal end of each of the first and second fingers includes a grip section configured to grip the tubular member.
13. A stabilizer assembly for a tubular member, comprising:
- a stabilizing body dimensioned to fit around the tubular member, a central portion of the stabilizing body including a radial projection, and a first end of the stabilizing body including a first threaded outer surface and a set of integral first elastic members;
- a first nut member including a proximal end with a threaded inner surface configured to engage the first threaded outer surface of the stabilizing body, a distal portion of the first nut member including a radial shoulder;
- a first wedge member dimensioned to fit within the distal portion of the first nut member such that a distal end of the first wedge member engages the radial shoulder of the first nut member, wherein the first wedge member includes a first tapered inner surface configured to engage the first elastic members of the stabilizing body;
- wherein threading the first nut member onto the first end of the stabilizing body forces the first elastic members to engage the first tapered inner surface of the first wedge member thereby radially flexing the first elastic members to engage the tubular member.
14. The stabilizer assembly of claim 13, wherein the first elastic members are fingers formed by a set of longitudinal slots in the first end of the stabilizing body.
15. The stabilizer assembly of claim 14, wherein each longitudinal slot includes a rounded proximal end.
16. The stabilizer assembly of claim 14, wherein an inner surface of a distal end of each finger includes a grip section configured to grip the tubular member.
17. The stabilizer assembly of claim 13, wherein the radial projection extends only partially around the central portion of the stabilizing body.
18. The stabilizer assembly of claim 17, wherein the stabilizing body includes a set of radial projections spaced around the central portion of the stabilizing body.
19. The stabilizer assembly of claim 13, wherein a second end of the stabilizing body includes a second threaded outer surface and a set of integral second elastic members, the stabilizer assembly further comprising:
- a second nut member including a proximal end with a threaded inner surface configured to engage the second threaded outer surface of the stabilizing body, a distal portion of the second nut member including a radial shoulder;
- a second wedge member dimensioned to fit within the distal portion of the second nut member such that a distal end of the second wedge member engages the radial shoulder of the second nut member, wherein the second wedge member includes a second tapered inner surface configured to engage the second elastic members of the stabilizing body, wherein threading the second nut member onto the second end of the stabilizing body forces the second elastic members to engage the second tapered inner surface of the second wedge member thereby radially flexing the second elastic members to engage the tubular member.
20. The stabilizer assembly of claim 19, wherein the first elastic members are first fingers formed by a set of first longitudinal slots in the first end of the stabilizing body, and wherein the second elastic members are second fingers formed by a set of second longitudinal slots in the second end of the stabilizing body.
21. The stabilizer assembly of claim 20, wherein each of the first and second longitudinal slots includes a rounded proximal end.
22. The stabilizer assembly of claim 20, wherein an inner surface of a distal end of each of the first and second fingers includes a grip section configured to grip the tubular member.
23. A method of stabilizing a tubular member within a wellbore, comprising the steps of:
- a) providing a stabilizer assembly comprising: a stabilizing body dimensioned to fit around the tubular member, a central portion of the stabilizing body including a radial projection, and a first end of the stabilizing body including a first threaded outer surface and a set of integral first elastic members; and a first nut member including a proximal end with a threaded inner surface configured to engage the first threaded outer surface of the stabilizing body, a central portion of the first nut member including a first tapered inner surface configured to engage the first elastic members of the stabilizing body;
- b) sliding the first nut member and the stabilizing body over the tubular member;
- c) sliding the first nut member over the first end of the stabilizing body;
- d) rotating the first nut member to engage the first threaded outer surface of the stabilizing body with the threaded inner surface of the first nut member;
- e) securing the stabilizer assembly to the tubular member by further rotating the first nut member to further engage the first threaded outer surface of the stabilizing body with the threaded inner surface of the first nut member, engaging and flexing the first elastic members with the first tapered inner surface of the first nut member, thereby gripping the tubular member with the first elastic members;
- f) lowering the tubular member with the stabilizer assembly into the wellbore such that the radial projection of the stabilizing body engages an inner surface of the wellbore or an inner surface of a larger tubular member within the wellbore to stabilize the tubular member as the tubular member is rotated.
24. The method of claim 23, wherein an inner surface of a distal end of each first elastic member includes a grip section, and wherein step (e) further comprises gripping the tubular member with the grip section of each first elastic member.
25. The method of claim 23, wherein a second end of the stabilizing body includes a second threaded outer surface and a set of integral second elastic members; wherein the stabilizer assembly further comprises: a second nut member including a proximal end with a threaded inner surface configured to engage the second threaded outer surface of the stabilizing body, a central portion of the second nut member including a second tapered inner surface configured to engage the second elastic members of the stabilizing body;
- wherein step (c) further comprises: sliding the second nut member over the tubular member and over the second end of the stabilizing body;
- wherein step (d) further comprises: rotating the second nut member in order to engage the second threaded outer surface of the stabilizing body with the threaded inner surface of the second nut member; and
- wherein step (e) further comprises: securing the stabilizer assembly to the tubular member by further rotating the second nut member to further engage the second threaded outer surface of the stabilizing body with the threaded inner surface of the second nut member, engaging and flexing the second elastic members with the second tapered inner surface of the second nut member, thereby gripping the tubular member with the second elastic members.
26. The method of claim 23, wherein an inner surface of a distal end of each of the first and second elastic members includes a grip section; wherein step (e) further comprises gripping the tubular member with the grip section of each of the first and second elastic members.
27. A method of stabilizing a tubular member within a wellbore, comprising the steps of:
- a) providing a stabilizing body dimensioned to fit around an outer surface of the tubular member, the stabilizing body including a radial projection and a set of integral elastic members;
- b) sliding the stabilizing body over the tubular member; and
- c) flexing the integral elastic members of the stabilizing body to contact the outer surface of the tubular member.
Type: Application
Filed: Jun 26, 2015
Publication Date: Dec 29, 2016
Applicant:
Inventors: Gunther HH von Gynz-Rekowski (Montgomery, TX), Kevin J. Rudy (Conroe, TX), Mike V. Williams (Montgomery, TX)
Application Number: 14/751,723