1. Field of the Invention
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.
2. Background
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.
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.
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°.
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.
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.
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.
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.
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.
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°.
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.
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.
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.
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.
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.
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.
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.
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.
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.
a is a cross sectional plan view through the line 5A—5A.
b is an alternative embodiment cross-sectional plan view of the tool through a line of equivalent location as the line 5A—5A of
Referring now to the Figures where like numerals indicate similar elements, and in particular
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
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.
Alternatively, as shown in
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.
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.
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
The wear shoulder support body and pad mechanism are more fully disclosed in
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.
As can be readily appreciated from the review of the alternative embodiment shown in
The high tensile loading top entry sub shown in
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.
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.
The present application claims priority from U.S. Provisional Application 60/269,395 filed Feb. 16, 2001, which is hereby incorporated by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/US02/04518 | 2/19/2002 | WO | 00 | 4/14/2004 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO02/066792 | 8/29/2002 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4685516 | Smith et al. | Aug 1987 | A |
4886115 | Leggett et al. | Dec 1989 | A |
RE33150 | Boyd | Jan 1990 | E |
5284210 | Helms | Feb 1994 | A |
6202764 | Ables et al. | Mar 2001 | B1 |
6269879 | Boyd | Aug 2001 | B1 |
Number | Date | Country | |
---|---|---|---|
20040177973 A1 | Sep 2004 | US |
Number | Date | Country | |
---|---|---|---|
60269395 | Feb 2001 | US |