TRANSITION TOOL AND METHOD

Abstract

A throttling valve formed by introducing an elongate tubular body into a tubular member through which fluid is flowing. The tubular body is provided with first and second ends, the first end being adapted for engaging a flow control device and the second end having a beveled end that enables fluid communication between the tubular member and the tubular body. The tubular body is provided with a tapered stem, the outside diameter of the stem proximate the first end of the tubular body being greater than the outside diameter of the stem proximate the second end, for seating against the opening in the end of the tubular member and effecting a seal between the outside surface of the stem and the margin of the opening in the tubular member. An elastomeric or other seal may be mounted on the outside surface of the stem for this same purpose.

Claims

1. Apparatus for transitioning an open end of a tubular member having fluid flowing therethrough to a flow control device, said apparatus comprising an elongate tubular insertion body, a first end of said tubular insertion body being adapted for engaging a flow control device, a second end of said tubular insertion body having a beveled end for insertion into the fluid flowing through the tubular member, a seal cup having a seal integral therewith for engaging the tubular member when said tubular insertion member is lowered into the tubular member, said seal cup being mounted on the outside diameter of the first end of said tubular insertion body and tapering from a first outside diameter to a smaller outside diameter toward the second end of said tubular insertion body, and a lock movable relative to said seal cup for energizing the seal of said seal cup.

2. The apparatus of claim 1 is tapered from a first outside diameter to a second, smaller outside diameter toward the second end of said tubular insertion body.

3. The apparatus of claim 1 wherein said tubular insertion body is provided with one or more perforations near the second end thereof for promoting fluid flow through said tubular insertion body as said tubular insertion body is introduced into the tubular member.

4. The apparatus of claim 1 additionally comprising means for forcing the second end of said tubular body into the tubular member.

5. The apparatus of claim 1 wherein the first end of said tubular insertion body forms a flange that is adapted for engaging the flow control device.

6. The apparatus of claim 1 wherein the second end said tubular body is beveled.

7. A method for regaining control of the pressure of an underground hydrocarbon reservoir after a loss of pressure control that causes damage to the wellhead comprising the steps of: lowering the stem of an insertion tool into the wellhead; moving a lock along the outside surface of the stem of the insertion tool to energize a seal located in a seal cup located on the outside surface of the insertion tool for contacting the margins of the opening into the wellhead while maintaining the flow of fluid from the underground hydrocarbon reservoir through the insertion tool; mounting a flow control device to the insertion tool; and closing a valve in the flow control device.

8. The method of claim 7 additionally comprising drilling a relief well into the underground hydrocarbon reservoir.

9. The method of claim 8 wherein the valve in the flow control device is closed after the relief well is drilled into the underground hydrocarbon reservoir.

10. The method of claim 7 additionally comprising equalizing the flow of fluid from the underground hydrocarbon reservoir around the stem of the insertion tool while lowering the stem into the wellhead.

11. The method of claim 10 wherein the flow of fluid around the stem of the insertion tool is equalized by routing the flow of fluid from the outside of the stem to the inside of the stem through perforations located in the portion of the stem that extends into the wellhead when the seal contacts the margins of the opening into the wellhead.

12. The method of claim 7 additionally comprising minimizing turbulence in the flow of fluid from the underground hydrocarbon reservoir into the insertion tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Referring now to the figures, FIG. 1 shows a schematic view of one embodiment of an adaptive transition tool constructed in accordance with the teachings of the present invention for use in mounting a flow control device to a well head.

[0013] FIG. 2 is a detail view of a portion of the transition tool of FIG. 1 showing a seal mounted on the outer surface of the tool.

[0014] FIG. 3 is a perspective view of a second embodiment of the adaptive transition tool of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

[0015] In more detail, a first embodiment of the transition tool of the present invention is shown schematically in FIG. 1. The transition tool, indicated generally at reference numeral 10, includes an elongate tubular insertion body 12 having a first end 16 adapted for engaging a flow control device (not shown) in the form of a flange 14 integral with first end 16 and a tapered stem 18 terminating in a beveled second end 20 of insertion body 12. Although a flange is shown in this particular embodiment as being the structure to which a flow control device is mounted, those skilled in the art who have the benefit of this disclosure will recognize that structure other than a flange may also be used to advantage for this purpose. Twist-lock connectors, compression fittings, threaded connectors, and many other types of structure in addition to flanges are contemplated by references to the adapting of the first end 16 for engaging a flow control device. The beveled end facilitates insertion of tubular insertion body 12 into the open end 26 of tubular member 24 in the event of an obstruction caused by, for instance, damage to the tubular member 24 or debris. A plurality of perforations 22 through the wall of insertion body 12 are spaced along the portion of stem 18 that extends into tubular member 24 for maintaining the flow of fluid passing through tubular member 24 as the stem 18 is lowered into the open end 26 of tubular member 24. Stem 18 is tapered from first end 16 to second end 20, the outside diameter near first end 16 being greater than the outside diameter proximate second end 20, so that as insertion body 12 is lowered into the open end 26 of tubular member 24, the outside surface of stem 18 contacts the margin of the opening in the open end 26 of tubular member 24. Although not visible because of the perspective nature of FIG. 1, a seal is positioned on the outside surface of stem 18 at the point of contact with the margin of the opening in the open end 26 of tubular member 24.

[0016] In the particular embodiment shown in FIG. 1, the tubular member 24 is the riser or well head of a subsea oil well, for instance, a subsea well head in which pressure control has been lost as a result of, for instance, failure of the tubing or cement in the well or damage or loss of function of the well head equipment, and the flange 14 of transition tool 10 is adapted for engaging a flow control device (not shown) such as a choke or valve stack. Those skilled in the art who have the benefit of this disclosure will recognize, however, that a well head is but one application for the apparatus of the present invention and that the invention can be exemplified by use in, for instance, a geothermal well. Similarly, the tubular member into which the tapered stem 18 of insertion body 12 is introduced need not be vertical; the taper in stem 18 enables the insertion tool 10 of the present invention to achieve the desired seal with the margin of the opening at the open end of a tubular member that is horizontal such as refinery piping and/or a high pressure steam or refrigeration line.

[0017] In the application shown in FIG. 1, however, the insertion tool 10 of the present invention provides certain additional advantages and functions. For instance, if fluid is flowing from the opening in tubular member 24 at high pressure, the taper of stem 18 minimizes the surface area of insertion tool 10 that is exposed to the high pressure fluid and equalizes the pressure around the tool, thereby minimizing any tendency of the stem 18 to be deflected by fluid impinging upon the surface of stem 18 and facilitating introduction of the tool into the open end of the tubular member 24. The bevel at the second end 20 of insertion body 12 functions to decrease turbulence in the flow of fluid that is maintained as the body 12 is lowered into tubular member 24. Further, the weight of a flow control device (which may be 25, or even 150, tons in the case of a valve stack for a subsea wellhead and depending upon the particular application) functions to increase the likelihood of a fluid tight seal between the outside diameter of the stem 18 of insertion body 12 and the opening at the open end 26 of tubular member 24 by effectively forcing the second end of tubular member down into the open end 26 of tubular member 24. As a result of the taper in stem 18, movement of the second end 20 further into the interior of tubular member 24 tightens the seal against the open end 26 of tubular member 24.

[0018] Even in applications in which the tubular member 24 is horizontal, movement of the second end 20 of insertion body 12 further into tubular member 24 is utilized to advantage. For instance, as a result of damage to the tubular member, the tubular member might not be round, in which case, the taper on stem 18 acts to both center stem 18 as it is introduced into the tubular member 24 so as to seat the surface of stem 18 on the margins of the open end 26 of tubular member 24 but also as a swaging tool to open up and to restore the shape of the opening, effecting a better seal between the outside diameter of stem 18 and the margins of the open end 26 of tubular member 24. This latter function is of such advantage that in one embodiment (not shown), hydraulic or screw jacks, or hydraulic rams, are provided for forcing the second end 20 of insertion tool 10 into tubular member 24. Alternatively, the second end 20 of tool 10 can be forced into tubular member 24 simply by pounding, for instance, with a sledge hammer or air-powered jack hammer against a plate that is mounted to the flange at the first end 16 of insertion body 12. Because there are so many ways to force the second end 20 of tool 10 into the open end 26 of tubular member 24, reference is made herein to means for forcing the second end 20 of tool 10 into the open end 26 of tubular member 24.

[0019] Referring now to FIG. 2, the seal on the outside surface of stem 18 is shown in more detail. It is generally preferred that seal 28 be comprised of a resilient material that deforms when seal 28 is compressed, for instance when the outside surface of insertion body 12 contacts the margins of the open end 26 of tubular member 24, but the particular material or materials is/are selected in accordance with the particular application; similarly, the type of seal and the cross-sectional shape of the seal is chosen depending upon the particular application, all in accordance with factors known to those skilled in the art. Seal 28 resides in an annular groove 30 in the outside surface of insertion body 12; again, the configuration of groove 30 depends upon the particular application and the seal that is selected for the application, all as known to those skilled in the art, the shape and configuration of seal 28 and groove 30 being shown in FIG. 2 for purposes of exemplification. Although not a requirement of the present invention, in the embodiment shown, seal 28 extends along the outside surface of insertion body 12 for sufficient distance to maintain a seal as the first end 16 of insertion body 12 as the insertion body 12 moves downwardly as a result of being forced into tubular member 24.

[0020] A second embodiment of the insertion tool of the present invention is indicated generally at reference numeral 110 in FIG. 3. As with the insertion tool 10 shown in FIGS. 1-2, insertion tool 110 comprises a tubular insertion body 112 having a first end 116 adapted for engaging a flow control device (not shown), and a second end 120 having a beveled end. As with insertion tool 10, the first end 116 of insertion tool 112 is adapted for engaging a flow control device and, in the embodiment shown, the first end 116 os provided with a flange 114 to which the similarly shaped and sized flange of the flow control device is mounted. Unlike the insertion tube 12 shown in FIGS. 1-2, the tubular insertion body 112 of insertion tool 110 is not tapered along stem 118. Instead of tapering the stem, the outside diameter of a seal cup 140 that rides on the outside surface of insertion body 112 is tapered from the portion proximate the first end 116 toward the second end 120 of insertion body 112. Seal cup 140 is provided with internal seals (not visible in FIG. 3) as described below. An internally-threaded locking ring 142 is carried on a set of threads (not visible) on the outside surface of insertion body 112 for rotation upwardly on insertion body 112 to energize the seals in seal cup 140. Again, the outside surface of locking ring 142 is tapered from a larger diameter at the end of locking ring 142 proximate the first end 116 of insertion body 112 to the end proximate the second end 120 of insertion body 112. Because the seal cup 140 and locking ring 142 are, in effect, integral with insertion body 112, it is intended that the references to the taper of the insertion body set out herein should include the structure shown in FIG. 3 in which the taper, rather than being located on the stem of the insertion body 112, is located on the outside surface of the seal cup 140 and/or locking ring 142. A locking, or set, screw 144 is provided for retaining the locking ring 142 in the position on the insertion body 112 in which the seals are energized.

[0021] The particular configuration and composition of the seals carried in seal cup 140 depends, as described above in connection with the embodiment shown in FIGS. 1-2, on the particular application in which insertion tool 110 is utilized and the selection of the configuration and composition of the seals is accomplished in accordance with information known to those skilled in the art. As set out above, it is generally preferred that the seals be comprised of a resilient elastomeric material or other formable or other application-specific material so that, when energized and after insertion into the open end of a tubular member (not shown in FIG. 3), the seals expand radially outwardly into engagement with the margins of the open end of the tubular member so as to effect a seal with the tubular member.

[0022] A method of regaining control of the pressure of an underground hydrocarbon reservoir after a loss of pressure control that causes damage to the wellhead will now be described with reference to the structure of the insertion tool of the present invention. After the wellhead has been cleared of debris, the tapered stem of the insertion tool of the present invention, for instance, the insertion tool 10, is lowered into the wellhead. Because of the taper of the stem 18, insertion tool 10 can be lowered into the wellhead even if the riser was bent and/or is not vertical as a result of damage caused by the loss of pressure control and even if the riser has been deformed such that the margin of the opening at the top of the tubular riser is not round. The tapered outside surface of the stem 18 of insertion tool 10 is then seated on the margins of the opening into the riser, the beveled end of stem 18 functioning to maintain the flow of fluid from the underground hydrocarbon reservoir through the insertion body 12 of insertion tool 10 while the tool 10 is seated. Any tendency of the insertion body 12 to be deflected out of alignment with the axis of the wellhead riser by impingement of the fluid escaping from the riser on the insertion body 12 is reduced by the taper on the outside surface of stem 18 and equalizes the flow of fluid around stem 18 as insertion tool 10 is lowered into the riser by routing the flow through the perforations 22 in stem 18.

[0023] Again, if the wellhead riser is out of round, the taper in stem 18 functions in a manner similar to a swaging tool to re-shape the margins of the opening into the riser; if the need arises, the insertion body 12 can even be rocked back and forth and/or driven down into the opening in the riser (see the discussion of the forcing means, above) so as to obtain a more effective seal between the seal 28 mounted in groove 30 on the outside surface of insertion body 12 and the margins of the opening into the riser. A flow control device is then mounted to the insertion tool, for instance, by mounting to flange 14, and a valve on the flow control device is then closed.

[0024] In another preferred embodiment of a method of regaining pressure control in accordance with the present invention, one or more relief wells are drilled into the same underground hydrocarbon reservoir from which fluids are escaping. In this second embodiment of the method of the present invention, the insertion tool 10 provides temporary pressure control while the relief well(s) is being drilled. Alternatively, the valve on the flow control device mounted to insertion tool 10 is not closed until after the relief well(s) are completed such that the insertion tool 10 and the relief well(s) together provide a permanent solution to the problem of regaining pressure control.

[0025] Those skilled in the art who have the benefit of this disclosure will recognize that certain changes can be made to the component parts of the apparatus of the present invention without changing the manner in which those parts function and/or interact to achieve their intended result. All such changes, and others that will be clear to those skilled in the art from this description of the preferred embodiments of the invention, are intended to fall within the scope of the following, non-limiting claims.