Device and method for slanting a conductor casing

Abstract

A device and a method are for slanting a conductor casing when establishing a petroleum well where a supporting pipe has been inserted into the seabed. The supporting pipe is arranged to receive the conductor casing. The supporting pipe is provided with a casing shoe at a vertical distance below it upper end portion, the casing shoe forming a through casing-shoe opening eccentric relative to the supporting pipe.

Claims

1. A device for slanting a conductor casing when establishing a petroleum well wherein a suction foundation includes an outer jacket and a supporting pipe, the supporting pipe and the outer jacket being arranged to be inserted into the seabed, the supporting pipe being arranged to receive the conductor casing, wherein the supporting pipe is provided with a casing shoe at a vertical distance below an upper end portion of the supporting pipe, the casing shoe forming a through casing-shoe opening eccentric relative to the supporting pipe, wherein at its upward-facing side, the casing shoe is given at least one sloping face which is arranged to guide the conductor casing towards the casing-shoe opening.

2. The device according to claim 1, wherein the casing-shoe opening has a center axis which is slanted relative to a center axis of the supporting pipe.

3. The device according to claim 1, wherein a guide plate which has a through guide opening eccentric relative to the supporting pipe is releasably arranged at the upper end portion of the supporting pipe.

4. The device according to claim 3, wherein the conductor casing, when extending through the guide opening and the casing-shoe opening is slanted relative to the supporting pipe.

5. The device according to claim 1, wherein the conductor casing comprises a lower, first conductor-casing portion and an upper, second conductor-casing portion, the second conductor-casing portion being bent.

6. The device according to claim 1, wherein the conductor casing is formed to absorb loads from a valve arrangement at the seabed.

7. The device according to claim 1, wherein the conductor casing is connected to a supporting frame.

8. A method for slanting a conductor casing when establishing a petroleum well wherein a suction foundation includes an outer jacket and a supporting pipe, the supporting pipe and the outer jacket being arranged to be inserted into the seabed, the supporting pipe being arranged to receive the conductor casing, wherein the method comprises: arranging a casing shoe at a vertical distance below an upper end portion of the supporting pipe, the casing shoe forming a through casing-shoe opening eccentric relative to the supporting pipe; inserting the suction foundation into the seabed; arranging a guide plate, which has a through guide opening eccentric relative to the supporting pipe, in a releasable manner at the upper portion of the supporting pipe; and moving the conductor casing, slanted relative to the supporting pipe, through the guide opening and the casing-shoe opening and down into the seabed.

9. The method according to claim 8, wherein the method, when the conductor casing comprises a lower, first conductor-casing portion and an upper, second conductor-casing portion, includes arranging the second conductor-casing portion, which is bent, in the supporting pipe.

10. The method according to claim 8, wherein the method includes filling cement slurry between the supporting pipe and the conductor casing.

11. The method according to claim 8, wherein the method includes letting the conductor casing absorb loads from a valve arrangement at the seabed.

12. The method according to claim 8, wherein the method includes connecting the conductor casing to a supporting frame.

13. A system for establishing a petroleum well, the system comprising: a supporting pipe defining a central axis; and a casing shoe defining a casing-shoe opening, the casing shoe configured to be situated below a seabed at a lower end portion of the supporting pipe; wherein a central axis of the casing-shoe opening is eccentric relative to the central axis of the supporting pipe, and wherein the casing-shoe opening is configured to permit passage of a conductor casing therethrough into the seabed at a slant relative to the central axis of the supporting pipe.

14. The system according to claim 13, further comprising a plurality of supporting plates encircling the supporting pipe.

15. The system according to claim 14, further comprising an outer jacket, wherein the plurality of supporting plates couple the supporting pipe to the outer jacket at the lower end portion of the supporting pipe.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In what follows, an example of a preferred embodiment and method is described, which is visualized in the accompanying drawings, in which:

(2) FIG. 1 shows a principle sketch, in vertical section, of a device according to the invention, the device having been inserted into the seabed;

(3) FIG. 2 shows a plan view of the device of FIG. 1;

(4) FIG. 3 shows the same as FIG. 1, but after a guide plate has been fitted;

(5) FIG. 4 shows the same as FIG. 3, but with a conductor casing placed in the device;

(6) FIG. 5 shows the device after the conductor casing has been inserted into the seabed; and

(7) FIG. 6 shows the same as FIG. 5 after a second conductor casing has been installed in the device.

DETAILED DESCRIPTION OF THE DRAWINGS

(8) In the drawings, the reference numeral 1 indicates a device, which comprises a suction foundation 2. The suction foundation 2 includes an outer jacket 4 and a supporting pipe 6, which is open both at an upper end portion 8 and at a lower end portion 10. A lid plate 12 sealingly connects the outer jacket 4 to the supporting pipe 6. A number of vertically set supporting plates 14 are arranged as well, encircling the supporting pipe 6 and connecting the supporting pipe 6 to the outer jacket 4 at the lower end portion 10 of the supporting pipe 6. In this exemplary embodiment, the outer jacket 4 and the supporting pipe 6 have a common center axis 16.

(9) The suction foundation 2 is provided, in a manner known per se, with pump pipes, not shown, in order to be inserted into the seabed 18 to a position as shown in the figures. A casing shoe 20 is arranged at a vertical distance 22 under the upper end portion 8, preferably at the lower end portion 10 of the supporting pipe 6. The casing shoe 20 is formed with a casing-shoe opening 24 extending through it, here in the form of a somewhat slanted bore with a center axis 24a which is eccentric relative to the center axis 16 and thereby relative to the supporting pipe 6. The casing shoe 20 is formed, at its upward-facing side, with a sloping face 25 which is arranged to guide the conductor casing 30 towards the casing-shoe opening 24 when it is being moved against the casing shoe 20.

(10) At the upper end portion 8 of the supporting pipe 6, a guide plat 26 with a guide opening 28 extending through it is arranged temporarily, as is shown in FIGS. 3 and 4.

(11) When a conductor casing 30 is to be inserted into the seabed 18, the conductor casing 30 is placed in the supporting pipe 6, the conductor casing 30 initially extending through both the guide opening 28 and the casing-shoe opening 24, see FIG. 4. The guide opening 28 and the casing-shoe opening 24 are arranged in the desired radial directions relative to the center axis 16, which ensures that the conductor casing 30 will take a desired slant 32 in a desired direction.

(12) In FIG. 5, the conductor casing 30 has been inserted into the seabed 18 and the guide plate 26 has been removed. In the preferred embodiment, the conductor casing 30 includes a lower, first conductor-casing portion 30 which is straight and which forms the portion that is inserted into the seabed 18, and an upper, second conductor-casing portion 30 which is bent and which extends in a communication-enabling manner from the first conductor-casing portion 30 up above the seabed 18.

(13) The conductor casing 30 may be attached to the supporting pipe 6, for example by cement slurry 34 being pumped in, forming concrete in the annulus between the supporting pipe 6 and the conductor casing 30. Via other well components not shown, the conductor casing 30 absorbs forces from a valve arrangement 36. In some cases, it may also be relevant to connect the conductor casing 30 to a supporting frame 38.

(14) Using the suction foundation 1 constitutes a preferred embodiment, but the supporting pipe 6 may also be inserted into the seabed 18 in some other way.

(15) It should be noted that all the above-mentioned embodiments illustrate the invention, but do not limit it, and persons skilled in the art may construct many alternative embodiments without departing from the scope of the attached claims. In the claims, reference numbers in parentheses are not to be regarded as restrictive. The use of the verb to comprise and its different forms does not exclude the presence of elements or steps that are not mentioned in the claims. The indefinite article a or an before an element does not exclude the presence of several such elements.

(16) The fact that some features are indicated in mutually different dependent claims does not indicate that a combination of these features cannot be used with advantage.