Annen avdeling PROTOKOLL Annen avdelings ... - Patentstyret

Annen avd. sak nr. 7592 82
11. The patented system includes a wellhead housing 50 (blue) having a tree sub 60 (yellow)
landed and connected to the top of the wellhead housing 50. The tree 62 (orange) is connected to
the top of the tree sub 60. The upper oriented tubing hanger 64 (light green) supporting tubing 66
(light blue) is disposed within the tree 62 and not the tree sub 60 as does the communication
nipple 41 in D9. The tubing 66 extends through the tree sub 60 and into the concentric oriented
lower tubing hanger 56 (green) to provide dual path communication between the tree 62 and
lower tubing hanger 56 in the wellhead housing. A subsea wellhead can be in the ground of the
seabed or in a mud bucket below the seabed, and the tree sub may be 20 feet above the wellhead
where the horizontal tree is located. In such an example, the tubing 66 would have to be at least
20 feet long to extend from the tree to the wellhead and straddle the subsea tree sub 60. As
indicated above, D9 does not have a hanger in tree 46 with tubing extending through the
connector 40 and into inner hanger 30.
12. The tree sub 60 of the patent and connector 40 of D9 are comparable components, each
connecting the tree (62, 46, orange) to the wellhead (50, 20, blue). At page 6, line 7-12, “the tree
62 is removed,” leaving the tree sub 60 connected to the wellhead 50. This may be accomplished
because the upper tubing hanger 64 is mounted in the tree 62 and not in the tree sub 60 as
distinguished from D9 where the communication nipple 41 is mounted in the connector 40 and
not in tree 46.
13. The lower oriented tubing hanger 56 of the patent is disposed within the wellhead 20 and
may be retrieved in its entirety through the tree sub 60 and tree 62. However, the tubing hanger
assembly 26 of D9 with the nested inner and outer hangers 30, 31 does not allow the entire tubing
hanger assembly 26 to be retrieved because outer tubing hanger 31 (red) has an outer diameter
greater than the diameter of flow bore 48 and is encapsulated between the connector 40 and
packoff 24/production casing 23. Therefore neither D9 nor D1 teach a lower tubing hanger that
can be retrieved through the tree.
14. D9 is a variation between the design of Figure 4 (KD91213) and that of Figure 5 shown in
the Through-Bore Christmas Tree Article Exhibit B. Figure 4 illustrates the National non-oriented
concentric tubing hanger system with a connector 40A mounting tree 46 to the wellhead 20. A
communication nipple 51 connected to the lower end of connector 40A stabs into wellhead tubing
hanger 30A to provide communication between the tubing hanger 30A and the flowbore of
connecter 40A and tree 46. (See the first full paragraph on page KD091208 of Exhibit B.)
However, the flowbore through connector 40A and tree 46 has a diameter smaller than the outer
diameter of tubing hanger 30A such that the hanger 30A cannot be retrieved through the flowbore
of connector 40 and tree 46. This is remedied in Figure 5 with the “Through Bore Tree” that has
an enlarged diameter flowbore which will allow the hanger 30B supported in the flowbore of the
connector 40 to pass through tree 46. D9 modifies connector 40A with the enlarged flowbore of
Figure 5 to allow the passage of wellhead inner tubing hanger 30 through the connector and tree.
But because the communication nipple 51 of Figure 4 is connected to the lower end of connector
40A and would not allow the passage of wellhead inner tubing hanger 30, communication nipple
51 of D9 was made retrievable.
15. Thus, communication nipple 51 of D9 was made retrievable to allow the retrieval of the
wellhead inner tubing hanger 30 and not to permit the tree 46 to be disconnected from the
wellhead and be retrieved, which is an alternative concept to the problem solved by the claimed
invention. (See the last sentence in paragraph 3 of the McIntosh Declaration.) The tree 46 of D9
does not present the problem solved by the claimed invention because the tubing hanger 30 is
mounted in the wellhead 20 and not in the tree 46. National did not solve the problem by its
design of Figure 5 where the tubing hanger 30B of Figure 5 is mounted in the connector 40 below
tree 46. The connector 40 and tree 46 of Figure 5 cannot be retrieved without removing tubing
hanger 30B and the tubing supported by hanger 30B. In the claimed invention the upper tubing
hanger 64 is mounted in tree 62 and hangs tubing 66 down to lower tubing hanger 56 so that tree
62 can be retrieved without retrieving lower tubing hanger 56 and tubing 58. If it had been