MXPA01000342A

MXPA01000342A - Wellhead assembly.

Info

Publication number: MXPA01000342A
Application number: MXPA01000342A
Authority: MX
Inventors: Lynn Carter Mark
Original assignee: Cooper Cameron Corp
Priority date: 2000-01-11
Filing date: 2001-01-10
Publication date: 2002-11-04
Also published as: GB2358207A; NO20010164D0; CA2328666A1; GB0030830D0; AU1000601A; FR2804164A1; NO20010164L; BR0100050A

Abstract

A wellhead system includes a tubing spool (180, fig 2B), adapted for mounting on a subsea wellhead (12, fig 2B), and a tree assembly 190 connected to the top of the tubing spool. The tubing spool and tree assembly include a concentric production flowbore P extending therethrough. An annulus circulation flow path A extends from the lower end of the tubing spool, around the tubing hanger (30, fig 2B), to a second annular space 120 and around the production and swab valves 100, 102 in the valve tree 190. A crossover port 90 may also be provided to connect the annulus flowpath A with the production flowpath P within the valve tree 190. The annulus circulation flowpath may be completely within the walls of the tubing spool and the valve tree. In use, the annulus flowpath A may be connected to the surface by a flexible conduit 250.

Description

WELL HEAD ASSEMBLY BACKGROUND OF THE INVENTION The present invention relates generally to well head systems and more particularly, to wellhead systems for circular circulation and more particularly to a wellhead system having a concentric production bore and a circular passage extending through a pipe reel and or tree assembly in the well head system. The first designs for underwater wells placed the Christmas trees on the platform. The tree included a pipe reel that held the pipe hanger that holds the production pipe through a borehole that extends from the surface into the well head on the underwater floor. E production hole through the tree, the pipe hanger and the concentric pipe to the wellhead. A side outlet was provided through the pipe reel side and under the pipe hanger to gain access to the circle formed between the production pipe and the riser. The access circular valve placed on the pipe spool controlled the flow through the side outlet. With increased water depths, the tree was placed under water and the access to the circular production pipe under the pipe hanger was reached by a diver connecting a conduit to the lateral outlet valve in the pipe carret and the conduit that It extends to the surface. To eliminate this conduit, a series of apparatuses and methods were designed to communicate with the circular production pipeline through a port that passed through the suspensor d pipe itself. The pipe hanger with ports allowed a circular pressure access from below the pipe hanger through the tree and then through the elevator or l unloading. The port extended through the pipe hanger to one side of the concentric production furnace that passed through the center of the pipe hanger. The pipe hanger with ports allowed the circular flow path to be directly connected to the tree pipe to facilitate the monitoring, ventilation, circulation, and elevation of oil by gas pressure. The disadvantage of the pipe hanger with ports was that a valve or other pressure retaining device had to be installed in the port through a pipe hanger to close the circular production pipe when the tree was removed. Males were placed in the valve access hole. Several types of valve designs were also used, such as counter-pressure valves of mobile head tip and hydraulically changed spool type valves. Due to the limited pipe hanger diameter available, frequently more than one of these valve ports had to be used to gain the circular flow area through the pipe hanger. Such valves are generally considered a responsibility from the point of view of sealing and driving reliability, the ability to test, and to achieve an indication of their positions. Gate valves co actuators and prevailing are preferred devices for control of well flow, but can not be used in the body of a pipe hanger. In addition these ports and associated valves used space around the production hole and thus restricted the size of the production hole for a given size of pipe suspension. As wells were completed even at the deepest underwater depths, it became difficult for divers to connect a conduit to the circular access valve. One method for obtaining circular access was through movable head valves placed in the ports through the pipe hanger. This allowed the fluid in the circle to flow through the pipe hanger. No cores were required to close access to the poppet valves. Once the tree was removed, the springs closed the valves. Another advantage of allowing circular flow through the suspensor d pipe was that the pipe hanger could land directly on the wellhead. This eliminated the pipe spool. The hydraulically pressurized sliding sleeves were used to open and close the ports in the circular pipe for circular access. However, access to the circular production pipeline remained a problem. A dual bore, eccentric pipe hanger was developed to address the need for reliable access to the circular production pipeline under the pipe hanger, to provide an adequate flow area through the pipe hanger and to provide a reasonably reliable device d flow control. The dual bore, eccentric pipe hanger included a vertically placed barren circular access through the body of the pipe hanger. The vertical borehole allowed the placement of an unfolded steel wire male similar to that used for the production bore itself, in the Access circular hole to close the circular access hole in the pipe hanger. This eliminated the need for valves in the ports. However, because of the size of the circular access hole, the production hole had to be moved from the center and therefore eccentrically disposed in the wellhead, for example no more concentric. The dual bore, the eccentric hanger also had to be oriented in the wellhead. In addition, the subsequent equipment also had to be oriented with respect to the dual holes in the pipe hanger. With operations occurring from a floating vessel, particularly a dynamically placed vessel, it was necessary to have an emergency disconnect so that all of the surface flow could be closed, such as through the production hole and the circular access bore, and the Elevator disconnected e case the container is disconnected from the well. The emergency disconnect also included the ability to cut any steel wire or pipe that extends through the holes in the pipe hanger into the well. Certain wellhead systems of the prior art do not have adequate emergency disconnects so that the vessel is disconnected from the site. For the dual bore, the eccentric tubing hanger required that the male be placed in either or both of the production bore and / or circular access bore in the pipe hanger, the dual bore Christmas tree and the dual bore elevator were revealed. Thus, the dual bore, eccentric pipe suspension caused the discovery of a retinue of tools and equipment commonly called the dual bore termination elevator system. This system has grown in complexity and size over the years to such an extent that from the logistic economic point of view, the efforts of field discoverers have become economically hindered. In addition, and more importantly, the completion of the dual bore h limited the size of the production bore through the pipe hanger and well head system of a particular size. To overcome the shortcomings of the dual hole completion system, a horizontal reel shaft system, called the Reel Tree termination system, was developed and marketed by Cooper Cameron. See the North American Patent 5,544,707, hereby incorporated by reference. The horizontal system of the reel shaft does not use a vertical circular access hole through the body of the pipe hanger to feed the production pipeline and instead provides a reel shaft with a lateral production passage and a passageway. flow around the pipeline and production hanger passage using hydraulically operated gate valves for flow control. The flow passage around the pipe hanger on the reel shaft has many advantages, a main advantage is its simplicity. The concentric termination, the dual bore termination, and the horizontal termination for deep water subsea wells, each have their disadvantages. At the concentric termination, the circular access valves, particularly the mobile head and spool valves, were prone to they were insecure and caused this style of termination to become out of fashion and still insecure. In addition, the space required by the suspension valves loaded in the suspension body severely limited the production of the bore size by a certain size of wellhead. In dual hole completion, the expenses and logistics of the dual hole completion elevator system were a disadvantage. In addition, the space required by the dual eccentric boreholes in the suspensor body still severely limited borehole size production by a particular wellhead. This truly holds the dual-barrel lift elevator system. The size of the elevator and the pipeline hanger tool is limited by the size of the underwater tower of the blowout preventer, typically having a bore of 18-3 / 4 inches. In a dual bore termination, if a circular inch-hole is placed next to a 9-inch production bore, the pipe hanger and production line will not pass through a 9-5 / 8-inch casing in a conventional wellhead system. A 0-3 / 4 inch housing or an 11-3 / 4 inch housing is required. A borehole termination is an alternative to dual hole completion. However, a disadvantage of the height of a hole is that it is necessary to have the ability to place a male in either the production hole or the circular access hole. This requires that the auger system has a hole selector to allow the placement of a male in either the production hole or the circular access hole. One advantage of a concentric production hole is that the tree cover for the trees does not have to be oriented. In a dua borehole completion there are two boreholes, one for production and the other for circular access, so require the tree cover to be oriented. In addition, it is necessary to land a seal in both holes. The encounters of horizontal trees project difficulties particularly for the concentric termination of large holes for holes that are 9 inches or larger. A horizontal tree requires a 9-inch test tree block for a 9-inch bore. Currently a test tree block is not available for subsea wells, although there are 9-inch land-based wells and so, there are 9-inch Christmas trees. This is usually the limitation in the marking of available tools. The lack of valve cutters in the vertical movement during the well test requires the use of BOP test trees when the horizontal tree hangers are installed to complete the well. This was revealed to allow vertical access to (usually 7-inch terminations.) Typically, the production hole for horizontal trees is 5 inches or possibly as long as 7 inches.Some in the industry are still dismayed at the safety of males in the vertical movement of the pipe hanger and prefer a more conventional design, but for the disadvantages of the dual hole designs used in their applications In the prior art designs, there must be a connector and the shaft must be oriented and connected to This connector requires the reestablishment of the communication from below from the pipe hanger to the connector, often those wells are at a depth that will not allow a diver to make the connection, so there is a need to be a practical connection for both fluid trajectories., for example, the production hole and the circular access hole, to allow circulation under the pipe suspension. The present invention overcomes the deficiencies of the prior art.

BRIEF DESCRIPTION OF THE INVENTION The present invention is a well head system having a pipe reel adapted to place an underwater wellhead and a shaft assembly on the part of the pipe reel. The pipe reel and the tree assembly include a concentric drill hole that extends for production. A pipe hanger is placed on the pipe reel to suspend the production pipeline in the hole borehole, the production pipeline that is concentrically placed in the wellhead and borehole system. The pipe reel includes a circular circulation path that extends from the circle around the production pipe under the seals that seal the pipe hanger on the pipe reel to a circular area above the pipe hanger that seals the pipeline. Such a way that provides a circular path of circulation flow that extends around the pipe hanger. The circular flow path of circulation includes at least one main valve which, together with the circular path of flow of circulation, can be placed on the wall of the pipe reel. Another circular path of flow of circulation is placed in the tree block of the tree assembly with the circular path of circulation flow communicating with the circular area at the upper end of the pipe reel and extending around the main production valve and the suction valve in the drilling hole of production of the tree block, to the upper terminal end of the tree block. A flow transfer passage communicates with the circular path of flow d circulation in the tree block with a circular main valve, a suction circulating valve, and a transfer valve that controls the flow through the circular flow path of circulation and flow transfer pass. The wellhead assembly forms two main trajectories d circulation, a circular path of circulation and a trajectory of production d circulation. The circulation production path is extended through the production line drill hole, the drill hole of the pipe hanger, the drill hole of the tree block and through the main valve d production to a flow line. The circular circulation path extends from the circular production line, through the circular flow path of circulation around the pipe hanger and through the circulating path of flow d circulation around the main production valve and the suction valve d production in the tree block. The circular production path extends to the surface through an elevator and the circular circulation path extends to the surface through a conduit, preferably outside the elevator. The conduit and preferably a reel-able hose. The well head system of the present invention provides multiple circulation paths. A main circulation path is through the circulation production path, through a hole opening down the lower end of the production pipe communicating with the circular production pipeline, and through the circular path of the pipeline. circulation to the surface through the conduit. Circulation may be provided for other purposes including oil lift by gas pressure, lift fluid removal, removal of gas captured in the circle, circulation by the loss of a pressure barrier, or circulation by the suspensor failure. pipe, among others. The present invention provides many advantages over the prior art as are more fully described in the description of preferred modes. A particular advantage of the present invention is its use for the completion of large boreholes. Another main advantage of the present invention is the provision of a concentric drill hole through the well head system thereby simplifying the apparatus and methods for the installation and use of the well head system. further, the present invention allows the use of a conventional shaft assembly with standard valves. Another main advantage of the present invention is the benefit of providing circulating access paths of circulation that are completely housed in the wall of the pipe reel and / or shaft assembly. Yet another advantage of the present invention is its ability to use a hoist elevator. u hole without a hole selector. The present invention also allows the use of a quick emergency disconnect. Other objects and advantages of the present invention will be apparent with the following description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, in which: Figure 1 is a cross-sectional elevation view of a well head system mode of the present invention; Figure 2 is a cross-sectional elevation view of another embodiment of the well head system of the present invention; Figure 3 is a diagram of the hydraulic circuit of the embodiments of Figures 1 and 2; and Figure 4 is an elevation cross-sectional view of another well head system embodiment of the present invention used in a horizontal shaft. While the invention is susceptible to various modifications and alternative forms, specific modalities thereof as are shown by way of example in the drawings and will be described here in detail. It should be understood, however, that the drawings and the detailed description thereof do not intend to limit the invention to a particular revealed form, but to the contrary, the intention is to cover all the modifications, equivalents and alternatives that fall within the spirit and scope of the invention. present invention as defined in the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention relates to methods and apparatus for a subsea wellhead assembly. The present invention is susceptible to modalities of different forms. In particular, various embodiments of the present invention provide a number of different constructions and methods of operation of the system. The embodiments of the present invention also provide a plurality of methods for using the wellhead assembly of the present invention. It is to be recognized that the different teachings of the modalities discussed below may be employed separately or in any other appropriate combination to produce the desired results. Reference above or below will be done for purposes of description upwards means towards the surface and downwards means towards the mud line.

Referring initially to Figure 1, a preferred embodiment of the present invention is shown. The well head system 10 is shown positioned on the well head 12. A pipe reel 20 is connected to the wellhead 12 by means of a spool connector 14. A sleeve 16 extends from the body of the pipe spool 22 down into the well head 12 and seals with the innermost housing hanger 18 supported on the well head 12. The sleeve 16 also provides an orientation surface 24 for orienting the suspensor d pipe 30. The pipe hanger 30 it is housed in the pipework drilling bore 26 and is landed on the support shoulder 29 on the spool body d pipe 33 to suspend the production pipe 26 in the pipe header 28. seal assembly 31 seals between the hanger of pipe 30 and the spool body d pipe 22. The pipe hanger 30 has a drill hole 33 and fluid communication with the drill hole 27 of the production pipe 26. pipe hanger 30 also includes a profile 35 for receiving a locking member such as the steel cable core (not shown). The circular production line 32 e formed between the production line 26 and the innermost casing assembled drill pipe line (not shown) on the pipe hanger 18. It can be seen that a circular flow path 34 extends to through the hole 36 of the sleeve below the pipe hanger 30. A first circular passage 40 extends from an internal opening 42 e a generally vertical portion of the wall 38 of the pipe reel body 2 below the sealant assembly 31 and preferably below the supporting shoulder 37 and through the wall 38 to an external opening 44 in the wall. A second passage 50 circulates from an internal opening 52 in a generally vertical portion of the wall above the sealing assembly 31 and through the wall 38 to an external opening 5 in the wall. A circular main valve 46 is placed on the outside of the pipe reel body 22 and includes a flow passage 48 extending between the outer ports 44., 54. The circular main valve 46 controls the flow of fluid through flow passage 48. The first and second circular passages 40, 50 together with the flow valve passage 48, form a circulating circular flow path 60 around of pipe hanger 30. Flow path 60 is external to drill hole 5 through pipe reel body 22. A shaft assembly 70 is placed on pipe reel 20. Tree assembly 70 includes a block of shaft 72 having a shaft connector 7 placed on its lower end to connect the shaft assembly 70 to the upper end of the pipe reel 20. A packing seal 76 is placed between the shaft block 72 and the spool body of the shaft. pipe 22 for sealing the connection and a closure 78 e provided for closing the connection. The gasket 76, the shaft connector 74 and the closure 78 are conventional and well known in the art. A sleeve or tube 80 extends from the counter-barrel 81 in the shaft block 72 downwards in the upper part of the pipe reel drilling bar 56 in the body 22. The seals 82, 84 seal the sleeve 80 with the block shaft 72 and the pipe reel body 22 above and below the connection between the pipe reel body 22 and the shaft block 72. A test port 86 extends through the three-block 72 to test the seal of packing 76 so that the packing metal seal 76 can be tested from the inside of the counter-barrel 81 between the seals 82, 84. The leaks around the sleeve 80 can also be monitored through the test port 86. The block The shaft 72 includes a wall 75 that forms a vertical perforation bore of concentric production 88 that extends therein and a horizontal passage of flow transfer 90 that extends laterally through the wall 75 preferably intersecting the ba concentric drilling hole 88. It should be appreciated that the flow transfer passage 90 can communicate with the drill hole 88 outside of the shaft block 22. A transfer valve 96 is attached to the outside of the shaft block 72 at the other end. 98 of the transfer passage 90. A production side hole 91 also extends through the wall 75 from the outside of the shaft body 72 to the drill hole 88. A production wing valve 94 is attached to the outside of the block. shaft 72 at one end 93 of the production side bar 91. A main production valve 100 is placed in a concentric drilling bore 88 below the joint 97 with the lateral bore d production 91 and a production suction valve 102 is placed in the concentric production drill 88 above the board at 97 of the side bore d production 91 and the drill hole 88. A flow line 162 is connected The production wing valve 94 for communicating with the production side bore 91. A production mandrel 110 projects on the counterbore 92 at the lower end of the concentric production bore 88 and is sealed with the shaft block 72 at 112. The production mandrel 110 extends downwardly in counterbore 114 in the pipe hanger 30 and is sealed at 116. The production mandrel 110 has a drill hole 118 communicating with the drill hole 88 of the shaft block 72 and with the drill hole 33 of the suspensor d pipe 30. The production mandrel 110 forms a circular passage 120 with the sleeve 8 and the drill hole 56 of the pipe reel body 22. The shaft block 72 further includes a circular passage 122 having a vertical portion extending from the inner opening 124 in a horizontal portion of the wall 75 of the shaft block 72 formed by the counter-barrel 81 and a lateral portion extending through the wall 75 to an external opening 126 in the wall 7 A second circular passage 128 has a vertical portion extending from an external upper opening 130 in the wall 75 at the upper terminal end 132 d tree block 72 and a side portion extending through the wall 75 to an external opening 134 in the wall 75. An external flow passage 136 extends between the external openings 126.134 is placed on the outside of the pipe spool body 22 and communicates the passage 138 with the flow transfer passage 90. A circular main valve 140 is placed in the external flow passage 136 below the gasket 13. with the pass-through passage 90 and a circular suction valve 142 is placed in the passage 136 upstream of the joint at 137. The circular main valve 140 and the circular suction valve 14 control the flow of fluid through passage 136 and through the passageway. of transfer 90 together with the transfer valve 96. The first and second circular passages 122, 128 together with the external flow passage 136, form a circular flow path d circulation 144 adjacent to the drill hole of concentric production 88. L trajectory flow 136 is external to drill hole 88 through block d tree 72. Thus, the circular access via circulation circular flow path 144 returned in block d e shaft 72, such that when a lift block is connected to the upper part of the shaft assembly 70, circular access is available between the lift block and the circular production line 32. In the embodiment of Figure 1, the bore of production 88 is concentric and the second circular passage 128 for circular access is outside the center. So to connect it to the shaft block 72, two connections are required, one for the bore d production 120 and another for the second circular passage 128 for circular access. A connecting mandrel 150 is placed on the upper end 132 of shaft block 72 for connection to a connector 152. The connecting mandrel 15 includes an internal counter-barrel 145 that receives the lower end of an intern sleeve 154 that extends downwardly. from the connector 152, an intermediate counter-bar 146 communicating with the second circular passage 128, and an external counter-bar 14 receiving the lower end of an external sealing sleeve 156 extending downwardly of the connector 152. The seals 155 and 157 are provided around the end of the sleeves 154, 156, respectively, to seal their connections with the mandrel 150 and the connector 152. The sleeves 154, 156 form a circular flow passage 255 in the medium communicating with the second circular passageway. 128. The connected 152 includes a production drill hole 158 communicating with the circular flow passage 255 and thus with the second circular passage 128. A pu The test piece 16 may also be provided in the connector 152 for testing the seals 157 and monitor for pressure leakage around the outer sealing sleeve 156. The connector 152 may connect the shaft assembly 70 to various equipment such as the burst preventing tower. (not shown). This allows the assembly 70 to be attached back to the surface, using the slidable tool that was used for the lower pipe hanger 30, by plugging the sliding tool into the upper end of the production drill 88 near the top. of the shaft block 72. The interior of the drill hole 88 would be sealed and the pipe rams would be closed around the line of assembled drill pipe work (not shown) on the sliding tool. A high pressure intern cap can be lowered through the BOP tower and installed inside the production bar 88 to cap inside the tree block 2 of the shaft assembly 70. If connector 152 is an 18-3 / 4 inch connector , then a reoperation drive block can also be used to connect it to the shaft assembly 70. The wellhead assembly 10 forms two main paths d circulation, a circular circulation path A and a production path d circulation P. P production circulation path extends through d production pipe drilling bore 27, through the drill hole of the pipe hanger 33, through the drill hole of the chuck d 118, through the concentric production drill 88, and through the drill hole 158 of the connector 152 or through the hole d drilling of the drive tool and drill pipe line assembled from work that extends to the surface. The circular path d of circulation A extends through the circular production pipe 32, through the circular flow path 34 in the sleeve 16, through the circulation flow path 60, through the circular passage 120. around the production mandrel 110, through the circulating circular flow path 144, through the perforation bore 160 in the connector 152 and through the throttling lines and d cushioning (not shown) connected to the burst preventer (not shown) ) to the surface. Thus, there is automatic access to the circular production pipe 32 from the top 132 of the shaft assembly 70. It should be appreciated that the circular circulation path A and the circular production trajectory P may communicate downward perforation by any of the various means, as for example a sliding sleeve, well known in the art. Thus a surface path to perforation under circulation is formed by the circulation production path P and the circular circulation path. The circulation capacity of the wellhead assembly 10 has been maintained using the most conventional production tree assembly. concentric 70. During production, suction producing valve 102 and transfer valve 96 are closed and production fluids flow upward through that portion of the circulation production path P below valve 102 and through the valves Main production 100 and the wing valve d production 94 to the flow line 162.

With respect to Figure 2, another embodiment of the d-well head system 170 of the present invention is shown. For convenience, the same reference numerals will be used for the elements in the embodiment of Figure 2 which are substantially the same as the elements of the embodiment of Figure 1. The wellhead system 170 of Figure 2 varies from the system of well head 1 in which the circular circulation paths A and P are internal to the pipe reel 180 and to the shaft assembly 190 of the well head system 170. The pipe reel 180 includes an elongated portion or an articulation 172 in which is received the circular main valve 174 and the re-operating valve 176. The first circular passage 178 extends from the internal opening 42 in the wall 38 of pipe reel body 22, through the main valve 174 and intersects e second circular passage 180 extending through the reoperation valve 17 from the internal opening 52 in the wall 38. The first and second passage 178, 180 form a flow path Circulating circulation 182 around the pipe hanger 3 which is external to the drill hole 56 through the body of the pipe reel 22 Thus the circulation circular flow path 82, the circular main valve 174, and the re-operating valve 176 are completely housed in the body of the pipe reel 22. The tree assembly 190 includes a shaft block 191 in an elongated portion or articulation 192 in which the reoperation valve 194, the circular main valve 196 and the circular suction valve 198 are housed. first circular passage 20 extends from the internal opening 124 in the wall 75 of the shaft block 191 and through the circular main valve 196 to the seal 195 with the second circular passage 20 extending through the circular suction valve 198 to the outer opening 20 at the bottom of an outer counter-barrel 234 at the upper end 208 of the tree block 191. The first and second tra circular path 200, 202 communicate with passage d pass-through 90 in joint 195. Circular main valve 196 and main suction valve 198 control fluid flow through passages 200, 202 and through pass-through passage 90, together with the transfer valve 194. The first and second circular path 200, 202 form a circulating circular flow path 21 adjacent to the concentric production drill hole. The flow path 21 is external to the drill hole 88 and the circular flow path of circulation 210, the transfer valve 194, and the circular main valves 196, 198 are completely housed in the shaft block 191. It must be appreciated that there may be other valves, such as flow isolation valves (not shown). With respect to Figures 2 and 3, the wellhead assembly 170 forms two main circulation paths, the circular circulation path A and a circulation production path P. The circulation production path is the same as described with with respect to the embodiment of Figure 1. The circular circulation trajectory A of the well head assembly 170 extends through the circular production pipe 32, through the circular flow path 34 in the sleeve 16, through of the circular flow path 182, through the circular passage 120 about the production mandrel 110, and through the circular flow path 210 to the terminal end 208 of the shaft assembly 190. As an alternative to installing a explosion prevention tower, com was described with respect to the embodiment of Figure 1, is shown a block d completion of a hole 220 installed on the part s top of the tree assembly 190. The completion block of a hole 220 requires only a drilling hole 222, as distinguished from a dual bore termination, since the production drilling holes 33, 118 in the pipe reel 180 and the production drill 88 in the shaft block 191 provide a concentric borehole bore hole. unique in the well head system 170 through which the tools can be moved in the wellbore 28. The circular circulation path A is only used for circulation using the control valves previously described. Thus, there is no steel cable or pipe that extends through the circular circulation path A that has to be cut in case of an emergency disconnect. This greatly simplifies the movement block for the elevator (not shown) connected to the termination block of a bore 220. Referring again to Figure 2, the pipe suspender 30 has already been landed and the BOP tower removed. The completion block of a bore 220 is now connected to the shaft assembly 190 for production. The bore termination block 220 includes a riser mandrel 224 connected to the stress assembly 226 which is connected to the riser (not shown) extending to the surface. It will be appreciated that the termination block will also include a drive tool and a line of assembled drill pipe work. The lifting mandrel 224 is placed on the upper end 208 d of the shaft block 191 by crimping the flanges 225 or to a connector (not shown). block 191 includes an internal counter-barrel 230 that receives the lower end of an inner sleeve 232 extending downwardly from the riser mandrel 224 and counter-barrel 234 that receives the lower end of a sealed outer sleeve 236 extending downwardly of the riser mandrel 224. Seals 233 , 235 are provided around each end of the sleeves 232, 236, respectively, to seal their connections with the riser mandrel 224 and the shaft block 191. The piercing bore 222 of the riser mandrel 224 includes the first and second stop valves. flow control 238, 240 to control flow through riser mandrel 224. Internal and external sleeves 232, 236 form a circular flow passage 242 communicating with the second circular passage 202 at the bottom of counterbore 234 as part of the passage circular flow 244, and extending through the wall mandrel riser 224 to an external connection 246 on the mandrel side elevates 224 A flow control valve 252 is placed in the flow passage 244 to control flow therein. A circular access conduit 250 is connected to the riser mandrel 22 at connection 246 and extends to the surface. The conduit 250 may be a flexible reel-able hose. The hose 250 is joined to the surface and then unwound as the completion block of a bore 220 is lowered in the raised (not shown) through open water to the shaft assembly 190. The hose 250 e is distinguished from a strangler line of calm that is a hard pipe that is section by section with the elevator. The hose 250 is external to the elevator and preferably a two-inch hose. The elevator and the hose 250 s extend to the surface for circulation through the circular path d circulation A and the circulation production path P. It should be appreciated that the flow passage 244 can communicate with the surface by an alternating path to the different surface than the duct 250. The hose 250 may be a part of the termination drive block or of the intervention drive block. It should be appreciated that the circular flow can be incorporated through an umbilical reoperator since no tool is displaced through the circular path of circulation A. All that is required is the circulation of fluid. There may be occasions when the elevator of a borehole can be connected to the shaft assembly 190 without a conduit 250. The conduit 250 not required is not contemplated to circulate the circular production 32. If the production seal is sealing and if the pipeline production 26 is in good condition it will not be necessary to have circulation capacity. Nevertheless, the duct 250 e preferred since, over time, the capacity for circulation may become necessary. It should be appreciated that duct 250 may be connected later to provide a circulation path. Circular circulation paths 182, 210 and valves 174, 176 194, 198 provide many advantages over the outer pipe and valves. Unique blocks, such as the pipe reel 180 and the tree block 191, provide greater security and confidence and require fewer connections that have to be trusted It is preferred to have circulating circular flow paths 182, 210 valves 174, 176, 194, 196, 198 internal of the pipe spool 180 and the block of trees 191. By having circular circulation passages 182, 210 close the flow path production P, the fluids in the circulating circulation passages 182, 210 retain the flow of the production fluids passing through the production path d of the P circulation thereby preventing the formation of hydrates. This is particularly advantageous in deep waters where the formation of hydrates becomes a problem. No well head system 10 or 170 requires the attachment of steel cable cores in the second circular passages 128 or 202 to close the circular circulation path A. By arranging the circular circulation passages 210 at an angle instead of vertically, pipe reels 20, 180 and tree blocks 72, 191 may be smaller in size. The present invention can allow the reduction in the height of the tree. Having a first and a second circular passage 200, 202 at an angle is particularly advantageous in the head system 170. This allows enough space to position the transfer valve 194 internally of the shaft block 191 and allows the passages 200, 202 forming the circular passage d circulation 210 extend around the transfer valve 194. Also because there is no need to have a plug in the second circular passages 128 or 202, the tree cover (not shown) may not be oriented l simplifies the design of the tree cover. The drive block for the system 10, 170 only uses plugs 154, 232 and a sleeve 148, 206, respectively, pair connectors to the top of the shaft block 72, 191, to form the circular area 155, 242 for communication with the circular pipe 32. The pressure in the circular production pipe 32 is constantly monitored. The leakage of shutters is also monitored. As the well heats, the circular pressure may increase. If an increased pressure is detected, the production s stops closing the circular pressure valve 100. The transfer valve 96, as well as the valves 140 and 46 current under the circle 32, are then opened. This allows the increased circular pressure to be vented through the flow line 162. In operation, the pipe reel 20, 180 is connected to the well head 12 by the pipe reel connector 14. The pipe hanger 30 and l Production line 26 is lowered and installed in the pipe reel 20, 180. The shaft assembly 70, 190 is subsequently lowered into a drive tool, as part of an end block, in an elevator extending from the surface . The circular flow path A and the production flow path are thus formed. A burst preventing tower is then connected by the connector 152 to the upper part of the shaft assembly 70, 190. The well is completed the completion block of a bore 220 is lowered and connected to the shaft assembly 70, 190. For the circulation between a circular flow path A and the production flow path P, a transfer opening is provided under the perforation between the drill hole 27 of the production pipe 26 and the circular production pipe 32. This can be accomplished by various means. In one example, a sliding sleeve can be placed under the perforation adjacent to the end of the production pipe 26 above the sealing block (not shown). The sliding sleeve is opened to gain access between the drill hole 27 and the circle 32 In another example, circulation can occur around the lower end of the production pipe 26 and in the circle 32 before the production block is placed . This allows the pipe hanger 30 to be landed, which the circulator removes the heavy flow, and after the production block is placed. It is still another scenario, if the production block is leaking, then there may be circulation around the lower end of the production pipeline or if the production pipeline has broken, then there may be circulation through the pipeline split. In an emergency situation, a drilling gun can be lowered below the depth and the perforated production line 26 to gain access to the circle 32. It will be appreciated that other means for flow communication can be provided under the depth between the borehole. perforation 27 of the production pipe 26 and circle 32 around the pipe 26 to allow circulation between the circulation path P and the circular circulation path A. Circulation through the circle may be desirable for various reasons such as elevation of oil by gas pressure. The gas is first pumped below the line of drill pipe assembled to work with the valve configuration so that there is flow through the transfer valve 194 forcing seawater from the drill pipe line assembled from work in the line d flow 162 before below the hole in the well. Once the seawater has been removed, the transfer valve 194 is closed allowing the gas from the surface to be pumped down the circular circulation path A to help raise the hydrocarbons above the production passage P to the surface. Circulation may be required for other reasons such as circulating around the gas captured in circle 32. Another reason for circulation is the loss of a depression barrier, such as a leak or split in the production pipe 26 or a failure of the production block . Another possibility is a failure of the pipe hanger 30, such as leakage in the seals of the pipe hanger. After the well has been completed and the hydrocarbons are flowing to the surface through the production flow path P and the riser, it may be necessary to conduct an intervention or reoperation. In a reoperation, the standing well and the main production valve 100 and the circular main valve 140, 196 are closed. The fluids are then circulated under the riser, through the pass-through valve 96, 194, and above the duct 250 to circulate out of all of the hydrocarbons within the riser. The hydrocarbons discharged in the sea are prohibited by the environmental problem. Once the carbohydrates have been removed from the elevator, to gain access to the well safely, drill hole P and circle A are circulated replacing the well fluids with a heavy sludge to control the well. The circle A drill hole P are loaded with heavy mud to dampen the well to make sure. There is also another alternative to finish the well head without the mud flowing under the well and without pressurizing and forcing the fluid back into the production zone. This is typically undesired because it adversely impacts the reservoir. With the damped well, the completion block of a drill 220 is disconnected from the axle assembly 70, 190 and then the axle assembly 70, 190 can be removed to gain access to the suspension hanger. 30 pipe for its removal and reoperation. An intervention or reoperation drive block is then lowered and connected to the pipe reel 20, 180. The embodiments of the present invention provide many advantages over the prior art and are particularly advantageous for a large hole finish. A large hole finish is defined as the completion with a 3-inch or larger production hole, and more particularly with a 3-inch or larger production hole that is concentrically placed in the well head system, and still more particularly with a 3-inch or larger production hole concentrically placed in a line d-assembled perforated drill pipe. Preferably the large bore termination is a finish with a production hole of 9 inches or larger, and more particularly to a production hole of 9 inches or larger that is concentrically placed in a line of perforated assembled punching pipe. This allows for a maximized termination in a wellhead system of minimized size. The centering of the production hole and the elimination of a circular vertical port through the pipe hanger allows the maximization of the production hole for any given wellhead. The present invention solves the great need in the industry for a simplified submarine system for the completion of large boreholes, without the need of revealing a large bore, the BOP test shaft. The present invention also provides a concentric drill hole through the wellhead system. This concentricity allows the use of a concentric drill pipe hanger that simplifies the pipe hanger drive tool since you only have to fear a hole through it and the pipe hanger installation since the pipe reel can be used to orient the pipe hanger. In addition, a subsea test shaft can also be used to move the concentric pipe hanger that allows for better control of the pipe hanger when moving on the wall. There are also safety and reservoir benefits. By using a concentric shaft assembly, the present invention provides the wellhead design with characteristics preferred by the industry, such as well accessibility from the point of view of fluid flow.

The use of a concentric pipe hanger allows the use of a conventional test stand such that the well can be discharged after the production pipe is actuated. After the well has been drilled, the formation begins to take the completion fluid that is typically not good for the reservoir. The goal is not to land the pipe hanger and remove the fluid as quickly as the termination fluids can flow out of production to minimize reservoir damage, then open the valves to produce. In terms of production timing and installation, the present invention facilitates the discharge of the well. Concentricity also simplifies the completion of large holes. The elevator block is concentric so as not to require orientation with the tree assembly it still provides all the necessary circulation. Although the orientation between the Christmas trees and the pipe spool is not required for the present invention, it is still required for other fluid couplings. The line under control depth can pass through the pipe hanger that requires plugs in the tree block to be oriented with the pipe hanger by means of which the ports in the pipe hanger will receive the plugs from the tree block . This is conventional. As an alternative, the control lines can be extenders horizontally through the pipe reel so as not to pass them through the pipeline. An advantage of horizontal connections is that as soon as a pipe hanger is loaded, the other connections can be tested to make sure everything is operating. If the ports are extended through the pipe hanger, this can not be determined until after the BOP and elevated tower have been removed and the tree installed. The disadvantage of horizontal connections is that the additional coupler plates have to be placed on the reel pipe in addition to the logistics problems.

The present invention allows the use of a conventional shaft assembly with a standard set of valves in the tree assembly in such a way that it does not require the use of cores. The circular valves can be internal or external to the tree block. The transfer valve can be internal since the circular access passages do not need to be vertical to receive the tools. The benefits of this new configuration allow the design of the "vertical tree" to revert to the simpler, simpler, concentric designs, which simplify the required tools, replaces the problematic in the circular access valves in the suspensor with the activated gate valves that they are strongly favored by the industry. One advantage of this configuration is the simplified hardware required for the implementation of the design. The present invention allows the use of a standard shaft assembly with many of the benefits of the horizontal shaft. The present invention provides circular flow around a pipe hanger and a transfer to dampen the well with access through the top of the tree assembly. The circular circulation paths 60, 182, provide a deviation around the suspensor d pipe 30 while a concentric shaft assembly is still used. The present invention also provides many advantages with respect to the connections in the wellhead system. They need not be external connections between the pipe spool 20, 180, and the shaft block 72, 191 nor between the block of trees 72, 191 and the lift block. By bringing all the circular connections back into the well head system, no external flow line connection is required. In the prior art, once the pipe hanger is loaded, there is no means to communicate with the circle unless the burst preventing tower is modified by attachment to an outer circular flow line or an ROV connection is provided.

The present invention also provides a simplified method of connecting a concentric production auger to the top of the shaft assembly yet provides two flow paths to the surface for circulation. The present invention utilizes a single bore elevator. A borehole lift is not required nor is a borehole selector to be used with the bore of a borehole. The conduit 250 provides the necessary flow path of circulation to the surface. The present invention eliminates the need for a high pressure reoperator block for circular access. It is only necessary that the well tools pass well through the concentric production hole. The chopper selector is eliminated and a line of cut valves is eliminated. All that is required is an isolation valve for the hose. The present invention is also advantageous for rapid emergency disconnects. As long as a dynamically placed borehole is used, control may be lost when the borehole drills out of position on the wellbore. The present invention allows the well to be stopped, isolated, separated from the well borer dynamically placed in a manner d seconds, thus ensuring control of the well. With respect to Figure 4, still another embodiment of the present invention is shown. The well head system 260 of Figure 4 varies from the well head systems 10, 170 in that the pipe reel 270 is a horizontal shaft with or lateral production bore 212. The well head system 260 is placed on the wellhead 262 having a bore 264 in which one or more pipeline suspenders are placed by suspending the pipeline in the borehole, including the innermost pipeline suspender 266 supporting the pipeline. . The horizontal shaft 270 is placed on top of the well head 262 by a connector 274. The horizontal shaft 270 includes a hole 276 which includes a pipe hanger orientation helix. A pipe hanger 280 is received in the bore 264 of the horizontal shaft 270 and is oriented by the steering propeller 278 in such a way that a side flow port 282 in the pipe hanger 280 is in alignment with the side drill hole 272. in the horizontal shaft 270. Seals 286, 287 are provided around the pipe hanger 280 for sealingly assembling the horizontal shaft 270 thereby sealing the production side drill holes 272 282. The pipe hanger 280 supports the pipeline of production 284 in the pipeline d ademe 268 thereby forming a circular production pipe 288. The pipe d production 284 also forms a circular area 290 with the borehole head 264 and the horizontal shaft hole 292. It should be appreciated that a second pipe suspense may be placed in the well head system 260 as shown in US Patent 5,372,199, incorporated in the present here by reference. A first circular passage 294 extends through the circle wall 295 to a circular internal main valve 296. A flow valve passage 29 extends from the circular internal main valve 296 through the re-operation valve 300 to a second circular passage 302. The second circular passage 302 s extends rearwardly through the wall 295 of the horizontal shaft 270 to an area 204 upstream of the seals 287 of the pipe suspender 280. Yet another circular line 306 communicates with the valve passageway. of flow 298 and includes a circular external valve 308 to control the flow. A transfer line 310 also communicates with the flow valve passage 298 and with the production line 312 in the flow communication with the drilling holes 272, 282. A transfer valve 314 controls the flow through the line d. transfer 310 and the main internal production valve 316 controls the flow through the production side drill holes 272, 282. A main external production valve 318 in fluid communication with the production line 31 controls the flow through the flow line 320. Although the flow valve passage 29 and the transfer passage 310 are shown extending externally of the horizontal shaft 270, it should be appreciated that either or both passages of the flow valve 298 and transfer passage 310 can be placed on the wall of the horizontal shaft 270 as described with respect to the wellhead systems 10, 170 of Figures 1 and 2. A modified conventional Christmas tree 330 is placed on the horizontal shaft 270. A male or an insulation sleeve 356 extends from the shaft 33 ° and the hole 358 in the pipe hanger 280, with seals 360 which they are provided to seal the connection. The upper shaft 330 includes a first circular passage 332 extending from the area 304 through the wall 335 of the shaft 330 to communicate with an external flow passage 334 that extends and communicates with a second passage 336 circulates backwardly extending. through the wall 335 of the shaft 330 for communicating with a counter-brace 338 at the upper end of the shaft 330. A suction-circulating valve 340 is placed in the external flow passage 334 to control the flow therein. The upper shaft 330 is connected to the upper end of the horizontal shaft 270 by a popping preventer connector 322. The upper shaft 330 includes a lower suction valve 342 and a suction upper valve 344 placed in the bore hole 346 that passes through the shaft. 330 and communicates with the drill hole 350 of the production line 284. A waste cover 352 is connected to the top of the shaft 330 by the burst prevention connector 354. The mode of the wellhead system 260 is directed to a Sweep larger than the currently available in a horizontal reel tree. The Figure shows a large bore termination and the use of smaller valves in upper shaft 330, which is essentially a suction block. The circular access and tracing around the pipe hanger 280 and around the suction valves 342, 344, and therefore no external connector is required. The well head system 260 is particularly advantageous for the terminations without guideline. While the preferred embodiments of this invention have been shown and described, modifications thereof may be made by a person skilled in the art to be away from the spirit or teaching of the invention. The modalities described here are only exemplary and not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. Accordingly, the scope of the protection is not limited to the modalities described herein, but is limited by the preceding claims that will include all equivalents of the subject matter of the claims.

Claims

CLAIMS 1. An assembly for a well head in an underwater well comprising: a reel adapted to be placed on the wellhead; a tree connected to said reel; a concentric drilling hole through said reel and tree; and a circular access hole extending at least partially through said reel and tree. 2. The assembly according to claim 1, further including a transfer drill hole communicating with said concentric drilling hole and including a transfer valve placed on said shaft. 3. The assembly according to claim 1, characterized in that said portion of said circular access hole extending through said reel is completely placed in a wall of said reel. 4. The assembly according to claim 3, further including at least one valve communicating with said portion and being placed on said reel wall. 5. The assembly according to claim 1, characterized in that the portion of said circular access hole extending through said tree is completely placed in a wall of said shaft. 6. The assembly according to claim 5, further including at least one valve communicating with said portion and which is positioned in said tree wall. The assembly according to claim 1, characterized in that said concentric drill hole has a large bore diameter. 8. The assembly according to claim 7, characterized in that said concentric drill hole has a diameter of at least inches. 9. The assembly according to claim 1, characterized in that said circular access hole extends through the connection between said reel and shaft. 10. The assembly according to claim 1 further includes a connector on said shaft having a connecting hole with said access hole communicating with said connecting hole. 11. The assembly according to claim 10, further includes a pipe hanger supported by said reel and suspending the production pipeline in the well; said production pipe forming a circle and said circular access bar communicating the circle with said connecting hole 12. The assembly according to claim 10, further includes a conduit communicating with said connecting hole and extending the surface . 13. The assembly according to claim 10, further includes a boom lift connected to said shaft by said connector, said elevator being without a bore selector. 14. The assembly according to claim 10, characterized in that said connector includes an emergency disconnect. 15. The assembly according to claim 1, characterized in that said reel includes a bore that receives a seal pipe hanger that seal said pipe and spool hanger and said circular access hole extending from the first opening in said seal. reel bore below said seals of pipe hanger to a second opening in said spool bore above said pipe suspender seals. 16. The assembly according to claim 15, further includes a lateral production port extending from said concentric drilling hole and through said shaft to a valve positioned in said shaft; said tree having valves positioned above said concentric drilling hole and below said lateral production port. 17. The assembly according to claim 15, further includes a lateral production port extending from said concentric drill hole and through said pipe and spool hanger to a valve positioned on said spool. 18. An assembly for a wellhead in a subsea well that includes: a reel adapted to be placed on the well head; a tree connected to said reel; a pipe hanger supported by said reel and suspending the production pipe in the well; a boom lift and a duct that extends to the surface; a concentric drilling hole extending from said production line, through said reel and shaft, and through said elevator of a hole and a circular access hole communicating with a circle around said production line and which extends at least partially through said reel and shaft to an upper end of said shaft, said circular bore having access communicating with said conduit extending to the surface 19. The assembly according to claim 18, characterized in that said concentric drilling borehole is an inch diameter production bore concentrically placed in at least one 7 inch assembled drilling pipeline suspended in the borehole by the head of the borehole. water well. 20. The assembly according to claim 18, characterized in that said concentric drilling hole is an inch production hole that is concentrically placed in at least one line of 9-5 / 8 inch drilling pipe suspended in the well. or the wellhead. 21. A method of circulating fluids in a subsea well which comprises: extending a drill hole concentrically through a shaft a reel and a wellhead; suspend the production pipe in the wellhead from or pipe hanger supported by the spool; extend an elevator from the tree to the surface; extend a circular access hole through the reel and tree from a circle around the production pipe to an upper end of the shaft: open an opening in the production pipeline under deep in borehole with the opening that communicates the circle with the drill hole d the production pipeline; and circulating the fluid through said drill hole, the circular access hole aperture.