During the process of drilling oil and gas wells, drill bit cuttings are produced by the drill bit as it bores the well bore. The well bore fluid or mud carries the cuttings to the well surface. Some of the cuttings are separated at the surface, but some remain in the mud, which is re-circulated down the work string in the well bore. The mud being re-circulated down hole may also pick up scale from the work string. Debris entrained within the mud is problematic. The debris can cause bottom-hole assemblies such as drill bits, drill motors, measurement while drilling tools, and other components to malfunction. Down hole mud screens have been developed to filter the mud before the fluid is introduced to the bottom-hole assemblies.
Applicant's U.S. Pat. No. 7,549,486 (which is incorporated herein by reference) is titled “Screen Apparatus and Method.” The patent discloses a mud screen having either a uniform outer diameter or a mud screen having two discrete sections, each section having a different outer diameter. The patent discloses a series of longitudinal openings for passage of the filtered fluid through the mud screen to the drill pipe.
Although down hole mud screens reduce the frequency at which bottom-hole assemblies malfunction, bottom-hole assemblies must still be removed from time to time. For example, the bottom-hole assembly may require repair or maintenance. Also, the need for certain bottom-hole assemblies may end before the drilling of the well bore is complete. To facilitate the removal of bottom-hole assemblies positioned below mud screens, conventional down hole mud screens must be removed from the well bore. This additional step of removing the entire down hole mud screen is time consuming and expensive, especially when the removal of the mud screen is not necessary for any other purpose. There is a need for a device that can be used to effectively filter debris from a well bore and that can facilitate the removal of a bottom-hole assembly positioned below the device while the device remains in the well bore.
A down hole apparatus for filtering debris from a debris-containing fluid in a well bore is disclosed. The apparatus includes a screen sub, a diverter assembly operatively connected to the screen sub, and a screen section extending from the diverter assembly. The screen section is also operatively connected to the screen sub. The screen section includes a plurality of openings for filtering debris from the fluid. The diverter assembly includes a detachable plug capable of being detached from the diverter assembly to open a central passage through the diverter assembly and the screen section to permit retrieval of a bottom-hole assembly. The diverter apparatus may also include one or more bypass openings. The central passage through the diverter assembly and the screen section formed by the removal of the detachable plug may be dimensioned to allow passage of a fishing tool therethrough.
The detachable plug may include a fishing portion and one or more dog members. The fishing portion of the detachable plug may be capable of engaging a receiving portion of a fishing tool for removal of the detachable plug from the diverter assembly. The fishing portion of the detachable plug may include a fishing shoulder capable of engaging the receiving portion of the fishing tool.
The diverter assembly may also include an outer body, an inner body disposed within the outer body, and one or more passages between the inner body and the outer body. An o-ring may position the outer body within the screen sub, and the inner body may be dimensioned to receive a portion of the detachable plug. Each of the one or more dog members may include a restricted surface, and the inner body may include a protruding section that is dimensioned to selectively engage the restricted surface of the one or more dog members.
A lower end of the screen section may engage a radial shoulder of the screen sub. Alternatively, the apparatus may further include a base member disposed around a lower end of the screen section, and engaging a radial shoulder of the screen sub. The screen sub may include two or more screen sections, each having a plurality of openings for filtering debris from the fluid. Each of the two or more screen sections may have a different diameter, and the plurality of openings of the two or more screen sections may have differing sizes.
In another embodiment, the down hole apparatus for filtering debris from a debris-containing fluid in a well bore includes a screen sub, a diverter assembly, a screen section, and a base member. The screen sub may include a radial shoulder. The diverter assembly may include an outer body capable of engaging the screen sub, an inner body disposed within the outer body, one or more passages between the inner body and the outer body, and a detachable plug dimensioned to selectively engage the inner body. The screen section extends from the diverter assembly, and includes a plurality of openings for filtering debris from the fluid. The base member is disposed around a lower end of the screen section, and is operatively connected to the radial shoulder of the screen sub. The detachable plug is capable of being detached from the diverter assembly to open a central passage through the diverter assembly and the screen section to permit retrieval of a bottom-hole assembly.
The detachable plug may include a fishing portion and one or more dog members. The dog members may be dimensioned to selectively engage the inner body. Each of the dog members may include a restricted surface dimensioned to selectively engage a protruding surface of the inner body. The fishing portion of the detachable plug may be capable of engaging a receiving portion of a fishing tool for removal of the detachable plug from the diverter assembly. The fishing portion of the detachable plug may include a fishing shoulder capable of engaging the receiving portion of the fishing tool. The inner body of the diverter assembly may include one or more bypass openings.
A method of filtering debris from a debris-containing fluid in a well bore is also disclosed. The method includes providing a filtering apparatus having a screen sub with a radial shoulder, a diverter assembly disposed within the screen sub and having a detachable plug, and a screen section extending from the diverter assembly within the screen sub and operatively connected to the radial shoulder of the screen sub. The screen section includes a plurality of openings. The method also includes deploying the screen sub down the well bore as part of a work string. The method further includes causing the fluid to flow through the work string, the screen sub, the diverter assembly, and the plurality of opening of the screen section, thereby filtering an amount of debris from the fluid. The debris collects in an annulus between the screen section and the screen sub. The method further includes removing the detachable plug from the filtering apparatus thereby opening a central passage through the diverter assembly and the screen section to permit retrieval of a bottom-hole assembly.
The step of removing the detachable plug from the filtering apparatus may include running a fishing tool down the work string to the detachable plug of the diverter assembly, engaging a fishing portion of the detachable plug with a receiving portion of the fishing tool, and removing the detachable plug from the diverter assembly by pulling the fishing tool up through the work string. The fishing tool may be run down the work string with wireline or coiled tubing.
The method of filtering debris from a fluid in a well bore may further include running the fishing tool down the work string, through the screen sub, the diverter assembly, and the screen section to reach the bottom-hole assembly. The bottom-hole assembly may be engaged with the fishing tool, and removed from the well bore by pulling the fishing tool up through the screen section, the diverter assembly, the screen sub, and the work string.
Alternatively, the method of filtering debris from a fluid in a well bore may further include running a second fishing tool down the work string, through the screen sub, the diverter assembly, and the screen section to reach the bottom-hole assembly. The bottom-hole assembly may be engaged with the second fishing tool, and removed from the well bore by pulling the second fishing tool up through the screen section, the diverter assembly, the screen sub, and the work string. The second fishing tool may be run down the work string with wireline or coiled tubing.
The screen sub may be a tubular member including a threaded upper end and a threaded lower end. The step of deploying the screen sub down the well bore may include threadedly connecting the threaded lower end of the screen sub to a lower tubular member and threadedly connecting the upper end of the screen sub to an upper tubular member. A tubular string containing the upper tubular member, the screen sub, and the lower tubular member may then be run down the well bore.
With reference to
First screen section 6 may include upper end 12, lower end 14, and plurality of openings 16 to allow the separation of debris from drilling mud by allowing only drilling mud to flow from annulus 18 through openings 16 into the internal space (not labeled) of first screen section 6. Upper end 12 of first screen section 6 may be operatively connected to diverter assembly 20. Second screen section 8 may include upper end 22, lower end 24, and plurality of openings 26 for filtering debris from drilling mud. Upper end 22 of second screen section 8 may be operatively connected to lower end 14 of first screen section 6.
Third screen section 10 may include upper end 28, lower end 30, and plurality of openings 32 for filtering debris from drilling mud. Upper end 28 of third screen section 10 may be operatively connected to lower end 24 of second screen section 8. Lower end 30 of third screen section 10 may be operatively connected to base member 34 by abutting radial shoulder 36 such that base member 34 supports third screen section 10. Base member 34 may in turn be operatively connected to screen sub 4 such that lower end 38 of base member 34 abuts radial shoulder 40 of screen sub 4. O-ring 41 may seal the connection between base member 34 and screen sub 4. Radial shoulder 40 of screen sub 4 may support base member 34 and third screen section 10. First screen section 6 may have the smallest diameter and the largest openings 16 of the three screen sections. Third screen section 10 may have the largest diameter and the smallest openings 32 of the three screen sections.
Referring now to
Diverter assembly 20 also includes detachable plug 64 which may have fishing portion 66, fishing shoulder 68, and one or more dog members 70. Each dog member 70 may contain restricted surface 72 and beveled end 74. In the engaged position as shown in
Returning to
As shown in
With reference to
Referring now to
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With reference to
After removing bottom-hole assembly 94, detachable plug 64 may again be attached to fishing tool 86 by engaging fishing portion 66 of detachable plug 64 with receiving portion 90 of fishing tool 86. Fishing tool 86 and attached detachable plug 64 may be lowered into the tubular string by wireline 88 or any other known method (e.g., by coiled tubing). Upon reaching diverter assembly 20, the one or more dog members 70 of detachable plug 64 may again engage inner body 48.
While preferred embodiments of the present invention 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.