GUIDE TOOL FOR GUIDING DOWNHOLE TOOLS THROUGH WELLBORE RESTRICTIONS
A guide tool for mounting onto a downhole tool for use in a wellbore penetrating subsurface formations is provided. The guide tool has a bull nose. The bull nose has a first section with an end for sealing against and engaging a lower end of the downhole tool and a second section axially deflectably coupled to the first section.
Priority is claimed from U.S. Provisional Application No. 61/012,479, filed on Dec. 10, 2007.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot Applicable
BACKGROUND OF THE INVENTION1. Field of the Invention
The invention relates generally to well interventions. More specifically, the invention relates to apparatus and method for guiding a downhole tool through a wellbore having wellbore restrictions.
2. Background Art
In the extraction of oil and gas from underground reservoirs, it is frequently necessary to insert a downhole tool or an assembly of such tools, e.g., a tool “string”, into a wellbore drilled through the reservoir. It can be difficult to push tool strings, examples of which include well completion strings, workover strings, and logging tool systems to the full depth of the wellbore due to restrictions in the wellbore. Examples of such restrictions include ledges and washouts created during the drilling of the wellbore, during well stimulation, during injection of fluids into the reservoir from the Earth's surface, or while producing fluids from the underground reservoir to the surface. Ledges and washouts may also be created as a result of collapse of the formation in which the wellbore is drilled, where the flow of fluids from within the wellbore is insufficient to move debris from the collapsed formation to the Earth's surface.
When inserting a relatively stiff (“stiff” being defined in terms of bending moment) tool string, e.g., a tubular string or a stiff well logging tool string, into a wellbore, the lower end of the stiff tool string can be prevented from going further into the wellbore if it lands against a washout or ledge formed as explained above. A semi-stiff, spoolable rod, such as described in International Application Publication No. WO 2006/003477, and used to provide services under the service mark ZIPLOG, which is service mark of the assignee of the present invention, may face the same challenge as the stiff tool string when traversing a wellbore with such restrictions. Another challenge related to such spoolable rods is that the well equipment operator cannot visually or otherwise determine if the lower end of the rod is moving or not. Failure to determine such movement while the surface end of the rod is being inserted into the wellbore can cause the equipment operator to continue pushing the rod into the wellbore against a stopped lower end of the rod, causing damage to or failure of the rod.
SUMMARYIn one aspect, a guide tool for mounting onto a downhole tool for use in a wellbore penetrating subsurface formations is provided. The guide tool has a bull nose. The bull nose has a first section with an end for sealing against and engaging a lower end of the downhole tool and a second section axially deflectably coupled to the first section.
In another aspect, an apparatus for use in a wellbore penetrating subsurface formations is provided. The apparatus comprises a downhole tool and a guide tool having a bull nose. The bull nose has a first section with an end that seals against and engages a lower end of the downhole tool and a second section axially deflectably coupled to the first section.
Other features and advantages of the invention will be apparent from the following description and the appended claims.
The accompanying drawings, described below, illustrate typical examples of the invention and are not to be considered limiting of the scope of the invention, for the invention may admit to other equally effective examples. The figures are not necessarily to scale, and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.
The invention will now be described in detail with reference to a few examples, as illustrated in the accompanying drawings. In describing the examples, numerous specific details may be set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without some or all of these specific details. In other instances, well-known features and/or processes may not be described in detail so as not to unnecessarily obscure the invention and because they would be within the ambit of one of skill in the art. In addition, like or identical reference numerals may be used to identify common or similar elements.
In the example illustrated in
The guide tool 124 may include one or more sensors, shown generally at 132. In some examples, sensor 132a may be a vibration sensor for measuring vibration of the downhole tool 120. Vibration data from the vibration sensor 132a may be sent to the surface and can be interpreted to determine if the downhole tool 120 is moving in the wellbore or not, or to determine the depth of the downhole tool 120 in the wellbore. If the readout of the vibration sensor 132a at the surface indicates no vibration, the operator may conclude that the lower end of the downhole tool 120 is not moving and may stop insertion or retraction of the downhole tool 120 into or from the wellbore before physical damage to the downhole tool 120 or wellbore takes place. In other examples, sensor 132b may be a temperature sensor for measuring differential temperature in the wellbore. Such differential temperature may be correlated to the depth of the downhole tool 120 in the wellbore. In other examples, sensor 132c may be a pressure sensor for sensing pressure external to the guide tool 124 or downhole tool 120.
Sensor(s) 132 as described above may be fiber-optic or electrical. In some examples, the guide tool 124 may include a fiber splice, shown generally at 133, for making connections between an optical fiber(s) in the guide tool 124 and an optical fiber(s) in the downhole tool 120. In other examples, the guide tool 124 may include an electrical connector (not shown separately) for making electrical connections between electrical components in the guide tool 124 and electrical components in the downhole tool 120, e.g., where the sensor(s) 132 are electrical. The seal provided at the upper end 128 of the bull nose 126, as explained above, may function to prevent unwanted fluid from entering into an area where the fiber optic and/or electrical connections are made.
The bull nose 126 has an upper section 134 including the upper end 128 and a lower section 136 including the lower end 130. The lower section 136 may be coupled to the upper section 134 via an indexing system, identified generally at 138. The indexing system 138 provides indexed movement or deflection of the longitudinal axis of the lower section 136 with respect to the longitudinal axis of the upper section 134. The indexing system 138 can deflect the lower section 136 relative to the upper section 134 through a set of preset angles, e.g., 0°, 45°, 90°, 120°, without decoupling the lower section 136 from the upper section 134. Deflection is enabled by rotation about the connection area, generally indicated at 139, between the upper section 134 and the lower section 136. The indexing system 138 may be, for example, mechanically-activated, pressure-activated, or electrically-activated. In some examples, a mechanically-activated indexing system 138 may be a spring-loaded indexing system that can be activated by adjustment of applied axial load. Such indexing may take the form of a set of J-slots (not shown) such as shown in U.S. Pat. No. 5,433,276 issued to Martain et al. The lower section 136 functions as a “hole finder” that will ensure that the bull nose 126 is oriented toward the continued wellbore in case the bull nose 126 is lodged against a restriction in the wellbore. A restriction in the wellbore is essentially any structure or feature that can stop the downhole tool 120 from progressing along the wellbore.
Referring to
A guide tool according to the various aspects of the invention may provide a wellbore equipment operator to avoid tool damage, and to continue operations in a wellbore having obstructions with minimum delay.
While the invention has been described with respect to a limited number of examples, those skilled in the art, having benefit of this disclosure, will appreciate that other examples can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
Claims
1. A guide tool for use in a wellbore penetrating subsurface formations, the guide tool having a bull nose, said bull nose having a first section with an end for sealing against and engaging a lower end of a downhole tool and a second section coupled to the first section such that an axis of the second section is deflectable to an axis of the first section.
2. The guide tool of claim 1, wherein the second section is coupled to the first section by an indexing system that provides indexed deflection.
3. The guide tool of claim 2, wherein the indexing system is mechanically-activated.
4. The guide tool of claim 2, wherein the indexing system is pressure-activated.
5. The guide tool of claim 1, further comprising a pressure sensor disposed in the bull nose.
6. The guide tool of claim 1, further comprising a vibration sensor disposed in the bull nose.
7. The guide tool of claim 1, further comprising a temperature sensor disposed in the bull nose.
8. The guide tool of claim 1, further comprising a fiber splice coupled to the bull nose for making fiber connections.
9. The guide tool of claim 1, wherein the bull nose has a capsule shape when in a neutral position.
10. An apparatus for use in a wellbore penetrating subsurface formations, the apparatus comprising:
- a downhole tool; and
11. a guide tool having a bull nose, said bull nose having a first section with an end that seals against and engages a lower end of the downhole tool and a second section coupled to the first section such that an axis of the second section is deflectable relative to an axis of the first section.
12. The apparatus of claim 10, wherein the downhole tool comprises a spoolable rod.
13. The apparatus of claim 10, wherein the downhole tool comprises one or more wellbore tubulars.
14. The apparatus of claim 10, wherein the second section is coupled to the first section by an indexing system that provides indexed deflection.
15. The apparatus of claim 13, wherein the indexing system is mechanically-activatable.
16. The apparatus of claim 14, wherein the indexing system is activatable from a remote location by adjusting axial load on the downhole tool.
17. The apparatus of claim 13, wherein the indexing system is pressure-activated.
18. The apparatus of claim 16, wherein the indexing system is activatable from a remote location by adjusting pressure in the downhole tool.
19. The apparatus of claim 10, further comprising a pressure sensor disposed in the bull nose.
20. The apparatus of claim 10, further comprising a vibration sensor disposed in the bull nose.
21. The apparatus of claim 10, further comprising a temperature sensor disposed in the bull nose.
Type: Application
Filed: Dec 9, 2008
Publication Date: Jun 11, 2009
Inventors: Henning Hansen (Alicante), Geir Owe Egge (Stavanger), Terje Wilberg (Sandnes)
Application Number: 12/330,773
International Classification: E21B 23/00 (20060101); E21B 23/14 (20060101);