Rotatable flange adapter
Rotatable flange adaptor or rotatable flange is provided, such that bolt holes may be aligned for joining of flanges. A sealing device may be added to the hub of the adaptor, such that the sealing surfaces are not rotated. Keys are placed in races to provide for transmittal of force along the axis of the device while allowing rotary motion of a flange or flange adaptor.
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1. Field of the Invention
Apparatus for providing a rotatable pipe flange is provided. More particularly, a rotatable flange adapter or rotatable flange is provided that may be used, for example, on land drilling rigs between a blowout preventer and a flanged connector and for other applications.
2. Description of Related Art
Normal practice in drilling of wells for hydrocarbon production is to place a blowout preventer (BOP) at the surface of the earth. This is a device designed to prevent flow outside the drill pipe should excess pressure be encountered during drilling of a well. When drilling a well that may encounter high pressure, a ram-type BOP is employed, along with an annular BOP and related equipment to form a “BOP stack.” The combined devices may weigh as much as 85,000 pounds or more. The rams may extend several feet in a vertical plane in each direction from the axis of the BOP.
During drilling of wells, the BOP stack is connected to casing that has been previously placed in the well. The BOP stack may be installed and removed several times during drilling of the well as additional casing strings are placed and cemented in the well. The first casing string placed in the well is called the “conductor casing.” It may be driven into the earth or placed and cemented in a drilled hole. Conductor casing is often 20 inches in outside diameter. After it is placed, the well is drilled to a selected depth and the next smaller casing string is placed in the well. In land wells, this is often a casing string having a diameter of 13- 5/8 inches. It is called the “surface casing.”
A conventional BOP flange, having a diameter of 13- 5/8 inch, is suited for use on the surface casing head, which normally has a 13- 5/8-inch flange. However, after the first spool is attached, as shown in
To understand the need on a drilling rig for the invention disclosed here, the procedure for attaching a BOP stack to flange 19 or flange adaptor 20 must be understood. Referring to
Other instances arise where rotatable pipe flange adaptors or rotatable flanges are needed. The need may arise when flanges are used for structural applications. In this instance there is no requirement for a pressure seal between flanges, and the flanges then are used to transfer mechanical forces. A rotatable flange can provide adjustable positions of structural parts. When pressure is to be confined in tubulars attached to the flanges, a seal is required, but rotatable flanges may still be needed to allow infinite adjustment of the angle of one flange with respect to another flange. A rotatable flange will not be limited to aligning flanges only by rotating to another bolt hole in the flanges.
A swivel ring flange is known in the art. Such devices are available from the HydroTech division of Oil States, for example. This device, although it facilitates bolt hole alignment, requires external retaining means for keeping a rotating flange ring integral to the hub of the device. “Rotating Joint” devices are also known and available from FMC and others. Typical rotating joints are designed to allow for one segment of a pressure-containing pipe to rotate relative to another segment. The joint also includes a pressure seal between the rotating segments.
What is needed is apparatus and method that eliminate the need to rotate a BOP stack in order to match bolt holes in flanges or to avoid interference from rig structure with a BOP. Also, apparatus and method are needed to provide adjustment of the angular position of one flange with respect to another flange and transmitting force between the flanges, with or without pressure sealing between the flanges.
SUMMARY OF INVENTIONIn one embodiment, rotatable flange adaptor is provided that can be used to align a blowout preventer (BOP) flange and a flange on a well structure without rotating the BOP during installation. This is accomplished by providing a device comprised of two parts, called a hub and a ring, that are rotatable around their common axis. The hub and the ring each have a flange of a selected size and hole-pattern. The hub provides a pressure seal inside the contact between the hub and ring, so no moving pressure seal is necessary. The hub and ring are joined mechanically by keys inserted in matching races in each of the moving parts. In an alternate embodiment, the hub is made an integral part of a blowout preventer or other apparatus and a rotatable flange is mechanically joined thereto. In yet another embodiment, rotatable flange or flange adaptor without a pressure seal is provided for structural applications.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring to
Referring to
To assemble the adapter flange, hub 30 may be placed on a bench and supported with its axis in the horizontal direction. Ring 38 may then be lifted with an overhead hoist and its internal diameter placed over hub 30 in a concentric location. Port 40 would preferably be in a vertical or 12 o'clock position. Rollers would then be inserted through port 40 and allowed to find the bottom of races 32A and 32B, which are preferably filled with cylinders. Once all of the cylinders are placed, plug 42 is inserted and fastened into place with screw 42A.
Referring to
The rotatable flange adapters illustrated in the figures above are provided as separate apparatus that may be attached to well equipment such as shown in
Referring to
By using an integral hub to a BOP, as shown in
Although the present disclosure has been described in detail, it should be understood that various changes, substitutions and alterations can be made thereto without departing from the scope and spirit of the invention as defined by the appended claims.
Claims
1. A rotatable flange adaptor having an axis, comprising:
- a hub, the hub having an upper face, a lower face having bolt holes, and a first convex race between the upper face and the lower face;
- a ring adapted to rotate on the hub, the ring having bolt holes, and a second concave race matched to the first race; and
- at least one key, the key being adapted to fit in the first convex race and the second concave race so as to transmit force between the hub and the ring.
2. The rotatable flange adaptor of claim 1 further comprising a first pressure-sealing device on the upper face and a second pressure-sealing device on the lower face.
3. The rotatable flange adaptor of claim 1 wherein the ring further comprises a port and the key is comprised of a cylinder.
4. The rotatable flange adaptor of claim 1 wherein the ring further comprises a port and the key is comprised of a ball.
5. The rotatable flange adaptor of claim 1 wherein the ring further comprises adjustable screws and the key is comprised of a split ring.
6. The rotatable flange adaptor of claim 2 wherein at least one of the first pressure-sealing device or the second pressure-sealing device is comprised of a ring groove and ring gasket.
7. The rotatable flange adaptor of claim 1 wherein the ring further comprises holes adapted to receive a device for turning the ring.
8. A blowout preventer having a rotatable flange connector, comprising:
- a blowout preventer having a bore therethrough;
- a hub pressure-connected to the bore, the hub having an axis, a lower face having a pressure-sealing device and a first convex race between the blowout preventer and the lower face;
- a ring adapted to rotate on the hub, the ring having bolt holes and a second concave race matched to the first race; and
- a key, the key being adapted to fit in the first convex race and the second concave race so as to transmit force between the hub and the ring along the axis of the hub.
9. The rotatable flange connector of claim 8 wherein the ring further comprises a port and the key is comprised of a cylinder.
10. The rotatable flange connector of claim 8 wherein the ring further comprises a port and the key is comprised of a ball.
11. The rotatable flange connector of claim 8 wherein the ring further comprises adjustable screws and the key is comprised of a split ring.
12. The rotatable flange connector of claim 8 wherein at least one of the first pressure-sealing device or the second pressure-sealing device is comprised of a ring groove and ring gasket.
13. The rotatable flange adaptor of claim 8 wherein bolt holes of the hub are adapted to match the bolt holes of an 11-inch flange.
14. The rotatable flange adaptor of claim 8 wherein the ring further comprises holes adapted to receive a device for turning the ring.
15. A method for placing a blowout preventer on a well, comprising:
- providing the rotatable flange adaptor of claim 2;
- bolting the hub side of the adaptor to the bottom flange of a BOP with the first sealing device in place;
- moving the BOP over the wellhead mating flange;
- rotating the ring of the adapter flange to mate the bolt holes or align the BOP in a preferred direction; and
- placing the second sealing device, lowering the BOP and installing bolts.
Type: Application
Filed: Nov 21, 2005
Publication Date: May 24, 2007
Applicant:
Inventors: Miles Hobdy (Richmond, TX), Thomas Hill (Conroe, TX)
Application Number: 11/283,935
International Classification: E21B 33/06 (20060101);