Abstract:
This invention relates to an elongated wireline entry device ( 10 ) which allows a wirelein tool or coiled tubing with a tool attached to be inserted in a well bore without disconneciton form the drill string appended thereto without introducing bending moments into the threaded connectiosn ( 101, 106, 202 ) attached to the drill string because the pin and box connectiosn of the tool are in axial, longitudinal alignment. The absence of these bending moments is required to suspend long pendular, and therefore heavy, drill strings forr htthis device without failure. The angle between the longitudinal ayes of the longitudinal passage and the wireline passage in the wireline entry device is at most 4.0°.

Description:
RELATED APPLICATION  
       [0001]    The present application claims priority from U.S. Provisional Application 60/269,395 filed Feb. 16, 2001, which is hereby incorporated by reference. 
     
    
     
       BACKGROUND OF INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to an improved top entry sub for use in drilling operations; specifically, to an apparatus of rated high tensile strength permitting the introduction of wireline or coiled tubing into the annulus of either a long and heavy string of drill pipe or of a drill string which can experience significant tensile loading from the movement of a drilling platform, such as by wave action, without disconnecting the sub from the drill string connected.  
           [0004]    2. Background  
           [0005]    Prior art devices include the U.S. Pat. No. Re. 33,150 to Boyd that discloses a side-entry sub that permits the connection within a drill string maintaining the drill string member above the tool to remain in axial alignment with the drill string member below the tool. This side entry sub has a longitudinal passage and a wireline passage, wherein the longitudinal axes of each intersect at an angle of about 6.5°. This device, while permitting significant tensile loading, does not permit the introduction of wireline tools into the annulus without disconnecting the drill string below the sub after the insertion of the wireline. A connection to the tubular string below this Boyd device must be disconnected and the wireline threaded through the side entry and thereafter connected to the longer wireline tools that make up the normal wireline assembly.  
           [0006]    Other prior art devices include U.S. Pat. No. 5,284,210 to Helms that discloses a top-entry sub permitting the introduction of wireline into the annulus of a drill string without the need to disconnect the sub from the well string. In the embodiment disclosed in FIGS. 1 and 4, the longitudinal axis of the drill pipe above and below the top-entry sub are substantially aligned. The Helms patent also discloses a wear sleeve for use with a double pin sub connected to the bottom of the top entry sub to avoid wear in the double pin sub by the wireline. The sleeve can be rotated periodically so the wear is more evenly distributed to increase the useful life of the sleeve.  
           [0007]    Boyd also has an elongated wireline entry sub referred to as the Long Boy. This tool has a main passage portion extending from the lower end of the tool body to an upper point of the tool body. This main passage then extends into a principal passage that would be threaded onto a pipe or upper sub member so as to support the tool as it is positioned within the drill string above the rig floor. There is formed a second passage wherein a wireline extends therethrough downward into the main passage of the tool. The longitudinal axes of these three passages form a somewhat Y-shape. The angle between the axes of the main passage and the principal passage is about 2°. The angle between the axes of the main passage and the wireline passage is about 2.25°. Therefore, the total angle between the axes of the principal and wireline passages is about 4.25°.  
           [0008]    U.S. Pat. No. 6,269,879 to Boyd discloses a wireline entry sub, like the Boyd Long Boy, but also having a wear resistant sleeve (Rockwell hardness of around 50) in the bottom end of the sub and/or in a sub saver attached to the bottom thereof. When worn by the wireline, the sleeve in the bottom of the wireline entry sub can be rotated by removing a screw so that fresh unworn surface can be used. The axes of the main passage (referred to therein as the principal passage), the principal passage (referred to therein as the first principal passage) and the wireline passage (referred to therein as the second passage) also form a Y-shape.  
           [0009]    The embodiment disclosed in FIG. 3 of the Helms patent, the Boyd Long Boy, and the elongated wireline entry sub disclosed in U.S. Pat. No. 6,269,879, however, introduce a bending moment into the drill string because of the offset between the longitudinal axis of the drill string above the wireline entry sub with the longitudinal axis of the drill string below the sub. As more and more tension is placed on such tools as from the use of long strings of drill pipe on offshore floating platforms, which can drill in up to 10,000 feet of water, the alignment of the upper drill string member with the lower drill string members becomes critical. The bending moment can overstress the threads on the string and cause failure of the system.  
           [0010]    Thus, there is a need to improve and provide such a wireline device that minimizes the bending moment of prior art devices, provides axial alignment of the wireline or coiled tubing pathway over the drill pipe annulus, and provides the entry of wireline or coiled tubing devices without having to disconnect the drill string therefrom.  
         BRIEF SUMMARY OF THE INVENTION  
         [0011]    The apparatus of the present invention has an annular tubular member constructed of pipe strength steel permitting extraordinary tension loading of a tool and also permitting the introduction of a flexible member with wireline or coil tubing tools attached thereto into the annulus under pressure and without having to disconnect below the tubular member to connect wireline or coil tubing tools to the introduced flexible member.  
           [0012]    An apparatus according to the present invention has at least an elongate tubular member having two ports at the upper end portion of the tool and one port at the bottom end portion of the tool. One of the two ports on the upper end portion and the port at the bottom end portion are connected by a longitudinal bore or passage, wherein the longitudinal axis thereof is co-axial with that of the drill string above and below the tool. This avoids or minimizes the introduction of a bending moment into the drill string due to the presence of the apparatus according to the present invention.  
           [0013]    In a preferred embodiment, the apparatus also has a wireline passage, wherein the longitudinal axes of the longitudinal passage and the wireline passage intersect at an angle of at most 4.0°, preferably at most 3.5°, and more preferably at most 3.0°.  
           [0014]    In one embodiment of the invention, the apparatus of the present invention is further comprised of a saver sub which carries on its inner annular surface an insert ring or bushing between it and the upper tubular member which holds the wireline or coil tubing off of the connecting surfaces of the upper tubular member and the saver sub.  
           [0015]    In another embodiment or in conjunction with the foregoing embodiment, the invention also contemplates that a wear bushing or ring can be also positioned in a recess adjacent the wireline or coiled tubing entry port of the wireline passage.  
           [0016]    The present invention allows the line wear insert ring or bushing in either or both locations to be periodically rotated as wear develops from the abrasion of the wireline or coil tubing rubbing across it. The line wear insert ring or bushing can be formed from any hardened material that resists the abrasion of the wireline or coil tubing. Such hardened materials preferably having a Rockwell rating of 60 or harder. Suitable examples of such hardened materials include tungsten carbide, ceramics, and various hardened steels. In one embodiment, the inner wear ring or bushing is a generally circular member having a key slot formed in it. In an alternate embodiment, the inner wear ring is formed with a polygonal, for example, hexagonal, profile to seat in either a lower saver sub profile or a recess adjacent the wireline or coiled tubing entry port of the wireline passage. Whether the use of the key/keyseat or the polygonal form is adopted, the wear ring is seated and its rotation prevented as the tool is in use.  
           [0017]    The overall length of the tool permits the introduction of wireline tools through the wireline or coil tubing entry portal, which is generally provided with a Bowen fitting. In the embodiments shown, the Bowen fitting includes a 10,000 psi collar or union that is seated with a 4 inch Acme stub, on an O-ring assembly to seal the wireline entry device. All other seats are typically metal to metal in accordance with standard drill string specifications and are capable of supporting heavy weight pipe up to 2 million pounds.  
           [0018]    The apparatus of the present invention is particularly useful in deep water drilling operations from either a drilling platform or a drill ship where the heaving of seas causes the rise and fall of the drilling rig floor relative to the drill string. Such drilling operations can be performed in waters as deep as 10,000 feet deep. The suspension of 10,000 feet of drill pipe from the rig floor in a heavy sea causes tremendous tensile loading of the drill string and the apparatus of the present invention is intended to permit the apparatus to be used and connected within the drill string.  
           [0019]    Since there are no offsets between the annulus of the drill string and the longitudinal axis of the longitudinal passage or bore therethrough, no bending moments are introduced into the pin or box connections at either end of the apparatus.  
           [0020]    It is therefore an object of the present invention to provide a high tensile load wireline or coiled tubing entry device for use in deep water.  
           [0021]    It is a further object of the present invention to provide a wireline or coiled tubing entry device which permits wireline tools connected to a wireline or coil tubing to be introduced into the annulus of the drill string without disconnection of the lower connection of the wireline entry apparatus from the drill string so that the full weight of the drill string can be supported by the elevators throughout the operation and thereby permitting the introduction of wireline tools under pressure through the tool.  
           [0022]    A still further object of the invention to minimize the damage to the wireline entry apparatus when used with a wireline from the abrasion that a wireline or coiled tubing can cause to the threaded ends of the apparatus by providing a means of having a line wear insert ring or bushing at one or both ends of the apparatus which holds the wireline or coiled tubing off of the surface of the end of the tool, thereby preventing cutting of the tool inner surface from the abrasive movement of the wireline or tubing. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    [0023]FIG. 1 is a cross sectional elevation view of an embodiment of the tool of this invention.  
         [0024]    [0024]FIG. 2 is a cross sectional plan view through line to  2 - 2 .  
         [0025]    [0025]FIG. 3 is a cross sectional plan view of the tool through the line  3 - 3 .  
         [0026]    [0026]FIG. 4 is a cross-sectional plan view of the tool through the line  4 - 4 .  
         [0027]    [0027]FIG. 5 a  is a cross sectional plan view through the line  5 A- 5 A.  
         [0028]    [0028]FIG. 5 b  is an alternative embodiment cross-sectional plan view of the tool through a line of equivalent location as the line  5 A- 5 A of FIG. 5.  
         [0029]    [0029]FIG. 6 is a cross-sectional view of the inner diameter of the tool showing the details of the wear bushing, key, lower sub and upper sub.  
         [0030]    [0030]FIG. 7 is a schematic drawing of the tool of the present invention rigged to the drill string above a rig floor.  
         [0031]    [0031]FIG. 8 is a cross sectional view of an alternative embodiment of the tool of this invention.  
         [0032]    [0032]FIG. 9 is a side cross sectional view of the alternative embodiment of FIG. 8 showing the wear shoulder engagement mechanism in greater detail.  
         [0033]    [0033]FIG. 10 is a top cross sectional view of the alternative embodiment of FIG. 8 showing a view of the wear shoulder through the line  10 - 10  of FIG. 9.  
         [0034]    [0034]FIG. 11 is a top cross sectional view of the alternative embodiment of FIG. 8 through the line  11 - 11 .  
         [0035]    [0035]FIG. 12 is a side cross sectional view of another embodiment of the tool of this invention.  
         [0036]    [0036]FIG. 13 is a top cross sectional view of the embodiment of FIG. 12 disclosing the upper wear bushing connection through the line  13 - 13  of said FIG. 12. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0037]    Referring now to the Figures where like numerals indicate similar elements, and in particular FIG. 1, there is shown an embodiment of a wireline entry sub  100  according to the present invention. Wireline entry sub  100  has a long upper annular tubular member generally referred to as  10  and a saver sub assembly shown at  20 . The tubular member  10  is provided with threaded box connection  101  to provide connection to the tubular members forming the upper portion of the drill string in the embodiment shown. These threads can be API 6⅝ full hole threads, but other thread types can be substituted therefor without departing from the spirit of the disclosure made herein. The tool  100  in a preferred embodiment provides a 4.375 inch diameter entry into the top of the body  10  for fluid entry, which allows full circulation through the tool  100 . Adjacent the top box end  101  of the tool  100  has a wireline entry side, which can be used to introduce either wireline or coiled tubing into the annular space formed within the main body of the tool  100 . This is generally referred to as a Bowen-type fitting  30  which has a Bowen union or nut (collar) which has a standard 10K fitting 4¾ inch on its upper end and has a 4 inch Acme threaded stub on its lower end as well as an O-ring (not shown) to seal the wireline entry union in a manner well known to those in the field. The inner diameter in the preferred embodiment shown on the wireline entry side is 3 inches on its inner diameter. This design permits the introduction of wireline tools sizes up to, and including, 2⅞ inches by approximately 25-foot long tools or assemblies. As shown in FIG. 2, showing a cross sectional of the tool through the line  2 - 2  of FIG. 1, discloses there is no communication between the wireline entry device and the fluid entry passage at the upper end of the tool  100 . The annular space  104  formed in the upper body  10  to permit entry of the wireline devices, extends into the body and joins the annular space  103  formed in the body at  102  at the main course of the body  105  as more clearly shown in FIG. 3, a cross sectional plan view of the upper tubular sub  10  through the line  3 - 3  of FIG. 1.  
         [0038]    Upper body  10 , preferably formed from a 4340 steel tubular blank, is also provided with threaded connections  106  in the form of a pin which, in the embodiment shown, are 7⅝ regular API thread. Saver sub  20  is preferably formed by machining 4340 steel tubular blank having thickened walls  201  providing an annular space therethrough. Referring to FIGS. 1, 5A and  6 , saver sub  20  has a counter bore which forms a shoulder  203  and a hardened insert or wear bushing  208 , preferably formed from D2 tool steel to resist cutting, that is inserted in the lower sub  20 . Bushing  208  is held in place by key  210 , which prevents rotation of the hardened wear bushing  208  and the bottom edge of pin  106 . The wear bushing  208  provides longitudinal key grooves throughout the exterior of its body to fit key  210  to prevent rotation of the wear bushing  208  in operation. After significant wear appears on the wear bushing, the lower sub  20  can be removed and the wear bushing  208  rotated. Additionally, the wear bushing  208  can be turned over (that is, up side down) and reinserted into the lower sub  20  for further service. The wear pattern on the bushing  208  caused by its continued contact with the wireline is thereby evenly distributed over the entire inner periphery of the wear bushing.  
         [0039]    Wear bushing  208  preferably has a plurality of grooves on its exterior surface, and thereby be capable of being rotated as needed to provide through each of the positions of wear corresponding to one of the grooves, for example, if there are 12 grooves, then there would be 12 positions of wear. Since wear is generally only on the upper portion of the bushing, the bushing can be flipped to provide, for example, 12 more wear positions, thereby providing as many as 24 wear positions.  
         [0040]    Alternatively, as shown in FIG. 5B, the wear bushing  208  could be formed in a polygonal shape, for example, a hexagonal shape, and rotated as wear developed in each face. It can be readily appreciated that a variety of geometric shapes or methods can be used to prevent rotation of the wear ring or bushing in the body without departing from the spirit of the invention disclosed herein.  
         [0041]    [0041]FIG. 6 more clearly shows the relationship between the lower edge or shoulder formed on threaded pin  106  holding the hardened wear ring or bushing  208  against lower shoulder  203 , which is the counter bore shoulder in the saver sub body  201 . Pin  210  is inserted before completing connection or makeup of the upper body  102  with the saver sub  201  and locks the wear bushing in place. Pin  210  can be readily removed after threaded connection  106  is disconnected. In one embodiment, the overall length of the tool  10  is approximately 13 feet and the angle between the longitudinal axes of the longitudinal passage and the wireline passage is approximately 3 degrees. This angle of separation permits the Bowen collar or union to be at the appropriate height, yet provide clearance with the upper end of the tool  100 .  
         [0042]    The angle of separation also permits the introduction of wireline entry tools of up to 25 feet in length into the annular drill string with sufficient clearance to minimize rubbing or abrasion on the interior surfaces of the tool  100  or the exterior surfaces of the wireline tools or entry devices. Since the upper pin  101  is in axial alignment with the lower pin  202 , there are no bending moments introduced that have marked prior art devices, such as that shown in FIG. 3 of U.S. Pat. No. 5,284,210, the Boyd Long Boy, and the elongated wireline entry sub disclosed in U.S. Pat. No. 6,269,879. Accordingly, much higher tensile loads can be imposed on the threaded connections without overstressing these links. The tool  100  will hold as much tensile load as the tubular members above and below it near the surface or drilling rig floor. As previously indicated, the present tool is particularly suitable for use in very deep offshore wells in which up to 10,000 feet of pipe can be suspended below the drilling rig platform in water before it enters the seabed. These tremendous tensile loads have imposed new and previously unexperienced design needs on wireline tool operators and those who supply equipment to wireline tool companies.  
         [0043]    Other connections can be made as needed above and below the top entry sub, but the strength of the tool and the length of the tool suggest that it can be used for all known deep-water high tensile loading applications currently pending in the world and will perform as well as the drill pipe designed for these deep water applications perform.  
         [0044]    In such operations, the wireline contractor or pipe recovery contractor can connect the assembled tool onto the drill pipe by connecting the upper box  101  to the drill string tubular members shown symbolically in FIG. 7 as  72 , descending from the elevators E in the derrick or rig D. This tool would also work with a top-drive rig setup in place of the conventional elevator rig set up shown. The saver sub  20  would be connected to an inline swivel  73  to which is connected a TIW valve  74 . Thereafter, the operator would connect Bowen wireline entry lubricator to the Bowen stub shown in FIG. 1 as  301  which would be fitted with a grease seal system (not shown) in a manner well known to those in the industry. The lubricator that permits the introduction of the wireline tools into the well string can be assembled off line and transported to the rig floor for connection to the top entry sub. Oftentimes primer cord, used for exploding inside and dislodging stuck pipe from the shock and vibration of the explosion, must be inserted into the well bore on the wireline. This and other types of explosive or dangerous tools can be safely introduced into the well string without having to expose the workers on the rig floor to the risk of premature detonation, outside of a containment tubular member.  
         [0045]    [0045]FIG. 8 discloses an alternative embodiment of the tool  100 ′ of the present invention. The main body  102 ′ is formed from an integral steel tubular blank to provide the pin and box connections described in the same manner as those described in connection with FIG. 1 above. The wireline tools and wireline are introduced into the body in the same manner as those described in connection with FIG. 1. Once the tools are below the wear shoulder device shown generally at  900  in FIG. 8, the shoulder  900  is adjusted and moved into a centralizing position of the well bore to hold the wireline off the interior surface  105 ′ of the tool  102 ′ to minimize the cutting of the interior surface of the tool from the manipulation of the wireline.  
         [0046]    The wear shoulder support body and pad mechanism are more fully disclosed in FIGS. 9 and 10, which is enlarged side and top cross sectional view of the device  900  respectively. The support body  903  is affixed to the exterior surface of the tool  102 ′ by setting bolts  901  and nuts  902  in a manner well known to those in this art. The wear shoulder pad  905  carried by body  907  which provides removable attachment of the wear shoulder  905  to the body, by mounting screws  906 , is moved into and out of engagement with the wireline in the bore  105 ′ by one or more cap head screws show at  904 .  
         [0047]    The wear pad  905  can be readily replaced in the field by removing the support body  903  from the tool  102 ′ and removing the screws  906  which hold the pad  905  to the moveable body  907 .  
         [0048]    [0048]FIG. 11 is a top cross sectional view of the tool  102 ′ through the line  11 - 11  in FIG. 8 which shows that this tool has the similar cross sectional passage as that shown in FIG. 3 above. The tool  102 ′ is formed from an integral piece of tubular steel and does not require the use of a bottom saver sub, like the one shown in FIG. 1 above, but in all other respects would function in the same manner as the tool described in FIG. 1.  
         [0049]    As can be readily appreciated from the review of the alternative embodiment shown in FIG. 8, the lower saver sub  201  of FIG. 1 is not attached to this form.  
         [0050]    [0050]FIG. 12 is another embodiment of the tool  100  of the present invention. The primary difference between the embodiment shown in FIG. 1 and the embodiment shown in FIG. 12 is the addition of a wear bushing  318  adjacent the proximal terminus of the Bowen fitted lubricator joint  30 , which is threaded into the body  10  with threads  312 . The wear bushing  318  fabricated from a material that resists cutting by the passage of the wireline past it, for example, D2 tool steel, is stopped from rotation by key  319  (see FIG. 13) in key seat formed on the inner surface of the passage  104  in a manner exactly like that described above for the lower key and key seat of FIG. 1.  
         [0051]    [0051]FIG. 13 is a top cross sectional view of the tool shown in FIG. 12 through the line  13 - 13 . As can be readily appreciated, the wireline entry port with the wear bushing  318  inserted provides a bore  104  substantially equivalent to the central bore of the tool  103 . Providing this wireline tool entry port to the drill string permits full sized downhole tools to be inserted in the drill string without disconnecting the drill string below the sub thereby eliminating unnecessary rig idle time in deep water projects, while providing a tool which supports as much tensile loading as the drill pipe to which it is attached.  
         [0052]    The high tensile loading top entry sub shown in FIG. 12 provides two wear bushings or rings  318  and  208  to hold the wireline or coiled tubing off the interior wall of the sub while still allowing the introduction of wireline tools and coiled tubing tools through the Bowen fitting while the drill string is suspended from the box connection on the tool. The internal wear surfaces provided by the one or more bushings, along with the axial alignment of the tool over the longitudinal axis of the drill string which prevents the introduction of bending moments which can unduly stress the tubular connections either above or below the tool, provides the benefits of the prior art side entry sub with the benefits of the prior art top entry sub.  
         [0053]    Since the apparatus of the present invention provides an axially aligned tool which is designed to be stronger than the weakest drill pipe connection in the entire drill string, which also permits wireline tools to be inserted in the well bore without disconnecting the drill string below the top entry sub to connect the tool after the wireline has been fed through the entry port on the top of the tool, this tool provides an improvement over all known tools currently used in the oil drilling industry, particularly for deep water projects. The tool provides an insert that can be readily rotated through a number of positions to allow long wear before needing replacement. This inner wear bushing ( 208 ,  905 ,  318 ) by holding the line off the interior surface of the tool permits the tool to have a long and trouble free service life.  
         [0054]    The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.