MXPA97007845A - P head unit - Google Patents

Abstract

The present invention relates to a well head unit in which an in-line shaft (10) is positioned within a well (3) housing of the well head. The in-line tree has a vertical through-hole of production (11), two in-line valves (13A, 13B) controllable in hydraulic or electric form in vertical production drilling and a lateral drilling that derives from vertical through-hole drilling. A horizontal tree (20) having a vertical through-hole (23) is positioned in the well (3) housing of the well head, so that the in-line tree (20) is within the vertical bore. The horizontal tree has a lateral perforation (24) that is aligned with the lateral perforation (16) of the in-line tree. The online tree (10) can be entered and retrieved through the horizontal tree (20). Alternatively, the horizontal shaft (20) can be removed from the housing (3) of the well head without a BOP if the valves are closed in lines (13A, 13

Description

CAMPQ WELL HEAD UNIT OF INVENTION The present invention relates to a development of the wellhead unit presented in our previous application, EP-A-572732.

BACKGROUND OF THE INVENTION This prior application has a horizontal tree having a comparatively large vertical bore without internal vertical valves in lines and which is at least large enough for the pipe support to be placed in the bore. A lateral outlet port of the production fluid derives from the vertical through-hole. The pipe support and the horizontal shaft are provided within complementary guide means for orienting the pipe support at a predetermined angular position, in which a lateral output port of the production fluid in the pipe support is in alignment with that of the horizontal tree. With this horizontal shaft, it is necessary to remove the anti-explosion shutter (BOP) from the well head unit to install the horizontal shaft and then reposition the BOP on the horizontal shaft before the pipe termination can be introduced. . When the termination of the pipe is introduced and before the BOP is removed, the production hole must be sealed with a plug attached by cable. In addition, for safety reasons, it is necessary to isolate any potential output of production fluid. In this way, during the operation, the well head unit requires at least one plug placed by cable in the vertical production bore, above the lateral bore of the borehole. 00270. 0080 production, and also requires at least one gate valve for the production fluid in the lateral production drilling.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a well head unit comprising a wellhead housing; an inline shaft within the well head housing, the in-line shaft comprises a housing having a vertical through-hole for production, an in-line valve in the vertical through-hole for production, and a side hole that derives from the vertical through-hole production beyond the tree housing online; and placed in the wellhead housing there is a horizontal shaft having a fairly vertical bore within which the in-line shaft is located and has a side bore which is aligned with the lateral bore of the in-line shaft; where the in-line tree can be introduced and retrieved through the vertical through-hole of the horizontal shaft without removing the horizontal shaft. This unit provides all the advantages associated with the wellhead unit of EP-A-572732 and, in particular, allows direct vertical access to the termination. Because the in-line shaft can be retrieved through the horizontal shaft without removing the horizontal shaft, the wellhead unit offers considerable flexibility. In this way, if it is necessary to extract the tree in line, this can be done by placing a BOP on the horizontal tree and pulling or pulling the tree in line through the horizontal tree and the BOP. Alternatively, the tree 00270. 0080 horizontal can be removed without protection from the BOP while leaving the tree in line in place, and the inline tree valve is closed to provide the necessary insulation for the production drilling. It is also possible to install the termination and the tree in line and then return the well head at a later date in order to install an appropriate horizontal tree. This is logistically good since the appropriate horizontal tree can be selected after a termination has been installed. If the output of the production fluid requires double-barrier insulation, two in-line valves can be provided in the vertical through-hole of tree production in line, below the lateral perforation. Because the in-line valves are below the lateral perforation, they can provide a double barrier for both vertical production drilling and lateral drilling, so that the in-line valves replace one of the plugs in the vertical drilling of production and composite valves for the production fluid in the lateral drilling. It is necessary to retain a stopper in the vertical production drilling in order to divert the flow towards the lateral perforations. This provides a simplification of the structure of the well head above the level of the mud. The wellhead unit also preferably includes a pipe support that is positioned within the wellhead unit below the in-line shaft and that can be removed from the wellhead through the horizontal shaft. The pipe support can be permanently attached to the tree in line. However, if the pipe support is attached or connected in a releasable manner with 00270. 0080 the tree in line, the tree in line and the support for pipe can be introduced together. The two can then be removed together or, if necessary, the in-line shaft can be released from the pipe support, so that only the tree is removed in line. The in-line shaft preferably comprises a one-piece housing containing the in-line valves, the vertical through-hole drilling and the lateral drilling. This avoids the need for any complex connection and the seal between the valves and the lateral perforation. The in-line valve or each in-line valve is preferably a balloon valve of the type well known in the art. The valve or each valve is preferably driven hydraulically or electrically, making the operation of the valve unnecessary by cable. The invention is readily applicable to a dual drilling arrangement, in which the in-line shaft has a second vertical through-hole with a lateral bore aligned with a corresponding lateral bore in the horizontal shaft. Additional drilling, which can be used to monitor the annular pressure or gas injection, can also be provided with at least one in-line valve such as a balloon valve. The wellhead unit of the present invention can be terminated or completed by two methods. Firstly, with the housing of the wellhead installed and the anti-explosion shutter installed in the well head housing, insert a pipe support through the explosion-proof stopper and the wellhead housing and place it inside the wellhead. 00270. 0080 wellhead housing; introduce the tree in line through the anti-explosion shutter and into the well head housing, above the pipe support; with the valve or each valve of the shaft in closed or closed line, remove the anti-explosion shutter; introducing the horizontal tree on the tree in line and placing it on the upper part of the housing in a position such that the lateral perforation in the horizontal tree is aligned with the lateral perforation of the tree in line; cover the vertical through hole of the tree in line above the lateral perforation; and open the valve or each in-line tree valve to allow the production fluid to flow through the wellhead unit. Second, the wellhead unit can be completed or terminated when the wellhead housing is installed, but is not yet exposed to all the production fluid pressure, by the steps of: placing the horizontal shaft directly on the wellhead. wellhead housing; install an anti-explosion shutter on the horizontal shaft; drilling and additionally tubing the well through the horizontal shaft and the anti-explosion shutter; insert the pipe support through the anti-explosion shutter and the horizontal shaft and place it inside the well head housing or the horizontal shaft; introduce the tree in line through the anti-explosion shutter and the horizontal tree and place it above the pipe support with the lateral perforation of the tree in line aligned with the lateral perforation of the horizontal tree; when the valve or valves of the tree are in closed or closed line, remove the explosion-proof plug; cover the vertical through hole of the tree in line above the lateral perforation; and open 00270. 0080 the valve or each valve in line to allow the production fluid to flow through the wellhead unit. With this method a removable protective sleeve can be placed on the horizontal shaft to protect the lateral perforations of the horizontal shaft during the drilling and tubing process. These two methods require only one BOP maneuver, thus saving a BOP maneuver in comparison with EP-A-572732. During a non-continuous drilling process, this saving is even more significant, since several wells can be completed or completed in a single BOP maneuver, with the BOP moving from tree to tree without being extracted to the surface. In addition, the availability of two separate methods to complete or terminate the wellhead unit using the same components, provides greater flexibility for the completion of the wellhead.

BRIEF DESCRIPTION OF THE DRAWINGS An example of a well head unit constructed in accordance with the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic view of the wellhead unit; and Figure 2 is a more detailed diagramatic cross section of the wellhead unit.

DETAILED DESCRIPTION OF THE PREFERRED MODE As shown in Figure 2, the unit comprises a guide base 1 of the well head, from which the first casing 2 is extended to support the 00270. 0080 unconsolidated formation of the seabed. As is well known in the art, other casings may be placed within the first casing 2. A casing 3 of the casing head from which an additional casing 4 is suspended is placed inside the first casing 2 and is locked by fingers 5. of the nozzle energized by spring. A pipe support 6 from which the pipe 7 is suspended or suspended is inserted into the well head unit 3 and is correctly oriented by means of a hydraulically extending pin on the BOP which engages a spiral of the Pipe support insertion tool. The pipe support seals are placed and tested in a conventional manner. The pipe support has a central vertical production bore 8 and an annular bore 9. A line tree 10 is inserted with the pipe support 6 and is placed inside the well head housing 3 above the pipe support 6. The in-line support 10 has a production bore 11, vertical and central, which is aligned with a production bore 8 in the support ß for pipe. In addition, the line shaft 10 has an annular bore 12 which is aligned with the annular bore 9 of the pipe support 6. Within the production drilling 11 there is a pair of balloon valves 13A, 13B which are controlled by means of a hydraulic or electrical line 14. The balloon valves 13A, 13B are conventional valves that can be selectively controlled to open and close the production perforation 11. An additional, similarly controlled globe valve 15 is provided in the annular perforation 12. A natural perforation 16 drifts radially outward from the vertical production perforation 11, above the perforations. 00270. 0080 globe valves 13A, 13B. The in-line shaft 10 is secured in the housing 3 by means of securing lugs 17 which are secured in a complementary recess 18 in a conventional manner. A horizontal shaft 20 is placed and secured in the housing 3 of the well head by means of securing lugs 21, which engage with a complementary recess 22 in the housing 3 of the wellhead. The horizontal shaft has a central vertical through hole 23 that is large enough to allow the line tree 10 and the pipe support 6 to pass therethrough. A lateral perforation 24 derives from the vertical through-hole 23 and the in-line shaft 10 and the horizontal shaft 20 are oriented with respect to each other, in such a way that the lateral perforation 16 of the in-line shaft is aligned with the lateral perforation 24 of the shaft. horizontal tree This alignment is achieved using a helix and pin arrangement similar to that used to align support 6 for tubing. The interface between the two lateral perforations 16, 24 is sealed by a pair of metal-metal annular seals 25, 26. The vertical through-hole 11 is capped with a cap 27 and covered with a cover 28. The flow through the lateral production perforation 24 is controlled by a master valve 29, while the flow through the annular perforation 12 is controlled by the valves 30 and 31. Although not shown in Figure 1, the annular perforation 12 is a perforation. which is plugged with a plug 32 as shown in Figure 2. A side bore 33 derives from the annular bore and is aligned with a corresponding side bore 34 in the horizontal tree 20. A line00270. 0080 of crossover 35 derives from the annular perforation 12 to the line for the production fluid in order to allow the annular production to be monitored by the production fluid. Once the well head unit is completed or completed, the well can be brought online by opening the balloon valves 13A, 13B, 15. If access to a termination is required, the balloon valves 13A, 13B, 15 will be they close to allow the lid 28 and the plug 27 to be removed, thus providing a double barrier protection and allowing a BOP to be installed on the horizontal shaft 20. Alternatively, if it is necessary to extract the horizontal shaft 20, the valves of balloon 13A, 13B are closed again and cap 28 and plug 27 are removed. The horizontal shaft 20 can then be removed without the need for a BOP. 00270. 0080

Claims (11)

1. CLAIMS: 1. A well head unit characterized in that it comprises a wellhead housing; an inline shaft within the well head housing, the in-line shaft comprises a housing having a vertical through-hole for production, an in-line valve in the vertical through-hole for production, and a side hole that derives from the vertical through-hole production beyond the tree housing online; a horizontal shaft having a vertical through-hole, within which the in-line shaft is located, is landed in the wellhead housing and has a side bore which is aligned with the lateral bore of the in-line shaft; wherein the in-line tree can be introduced and retrieved through the vertical through-hole of the horizontal shaft without requiring removal of the horizontal shaft.
2. 2. A well head unit according to claim 1, characterized in that two in-line valves are provided in the vertical through-hole for production of the in-line shaft, below the lateral bore. A well head unit according to claim 1 or 2, characterized in that it further comprises a pipe support which is placed inside the well head unit below the in-line shaft and which can be removed from the well head through the horizontal tree. 4. A well head unit according to claim 3, characterized in that the pipe support is releasably connected to the in-line shaft. 5. A wellhead unit in accordance with

   00270. 0080 any of the foregoing, characterized in that the in-line shaft comprises a one-piece housing containing the in-line valve or each in-line valve, the vertical through-hole drilling and the lateral drilling. 6. A wellhead unit in accordance with any of the foregoing, characterized in that the in-line valve or each in-line valve is a balloon valve. 7. A well head unit according to any of the preceding ones, characterized in that the valve or each valve is operated in hydraulic or electric form. A wellhead unit according to any of the preceding ones, characterized in that the in-line shaft has a second vertical through hole with a lateral perforation aligned with a corresponding lateral perforation of the horizontal shaft. A method for completing or terminating a well head unit according to any of the preceding claims, characterized in that it comprises installing a wellhead housing; install an anti-explosion shutter in the head housing; insert a pipe support through the explosion-proof plug and the well head housing and place it inside the wellhead housing; introduce the tree in line through the anti-explosion shutter and in the housing of the well head above the pipe support; with the valve or with each closed valve of the tree in line, remove the anti-explosion shutter; introduce the horizontal tree on the tree in line and place it on top of the accommodation in

   00270. 0080 a position such that the lateral perforation of the horizontal shaft is aligned with the lateral perforation of the tree in line; cover the vertical through hole of the tree in line above the lateral perforation; and open the valve or each in-line tree valve to allow the production fluid to flow through the wellhead unit. A method for completing or terminating a well head unit according to any of claims 1 to 8, characterized in that the method comprises the steps of installing a wellhead housing in a wellhead that is not yet exposed to all the pressure of the production fluid; locate the horizontal shaft directly in the well head housing, install an anti-explosion shutter on the horizontal shaft; drilling and additionally tubing the well through the horizontal shaft and the anti-explosion shutter; insert a pipe support through the explosion-proof shutter and the horizontal shaft and place it inside the well head housing or the horizontal shaft; introduce the tree in line through the anti-explosion shutter and the horizontal tree and place it above the pipe support, with the lateral perforation of the tree in line aligned with the lateral perforation of the horizontal tree; with the valve or each valve of the tree in closed line, remove the anti-explosion shutter; plug the vertical through-hole of the tree in line above the lateral perforation; and open the valve in line or each valve in line to allow the production fluid to flow through the well head unit. 11. A method according to claim 8, characterized in that it additionally comprises the step of

   00270. 0080 place a removable sleeve on the horizontal shaft to protect the lateral perforations of the horizontal shaft during the drilling and tubing processes.

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