MONOHULL DRILLSHIP

• US 20180043972A1
• Filed: 03/07/2016
• Published: 02/15/2018
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Gustomsc Resources B.V. (NOV, Inc.)
• Original Assignee: Gustomsc Resources B.V. (NOV, Inc.)
• Inventors: ZIJDERVELD, Govert Hendrik Teunis, HENDRIKS, Sjoerd Maarten, WASSINK, Alian Willem Johannes
• Granted Patent: US 10,315,733 B2
• Time in Patent Office: Days
• CPC Class Codes: B63B 2003/147 Moon-pools, e.g. for offshore drilling vessels
• CPC Class Codes: B63B 35/4413 Floating drilling platforms, e.g. carrying water-oil separating devices
• CPC Class Codes: E21B 15/02 specially adapted for underwater drilling E21B15/04 takes precedence
• CPC Class Codes: E21B 19/002 specially adapted for underwater drilling E21B19/09, E21B19/143 take precedence

Abstract

The invention relates to a monohull drillship (1), comprising an elongated hull (2) extending in the length direction (3) of the drillship. Said hull (2) is provided with at least one open moon pool (4) arranged to be located at the waterline (5) during use of the drillship. The drillship (1) is arranged for multiple-activity operations, e.g. simultaneous drilling and casing handling, in such a manner that drilling equipment can be passed through said at least one moon pool (4) at at least two locations (7, 8), i.e. at at least two so-called well centres, which are spaced apart from each other in at least a direction (6) substantially transverse to the length direction (3) of the hull of the drillship.

Claims

1. A monohull drillship, comprising:

an elongated hull extending in a length direction of the drillship, said hull being provided with at least one open moon pool arranged to be located at the waterline during use of the drillship,

wherein the drillship is arranged for multiple-activity operations or multiple-activity drilling, in such a manner that drilling equipment can be passed through said at least one moon pool at at least two locations, the at least two locations being at least two well centres or drill centres, which are spaced apart from each other in at least a direction substantially transverse to the length direction of the hull of the drillship.

2. The drillship according to claim 1, wherein the hull of the monohull drillship is a streamlined hull and/or has a ship-shaped design.

3. The drillship according to claim 1, wherein the length-beam ratio of the ship is at least 4.

4. The drillship according to claim 1, wherein at least two of the at least two well centres are arranged as a main well centre.

5. The drillship according to claim 1, wherein at least two of the at least two well centres are spaced from each other substantially only in said direction substantially transverse to the length direction of the hull of the drillship.

6. The drillship according to claim 1, wherein a first one of said well centres is located on the port side of the drillship and a second one of said well centres is located on the starboard side of the drillship, wherein a lateral distance over which the first well centre is spaced away from a virtual longitudinal vertical centre plane is substantially equal to a second lateral distance over which the second well centre is spaced away from said centre plane.

7. The drillship according to claim 1, wherein at least two of the at least two well centres are located at a common moon pool at the at least one moon pool or at the same one of multiple moon pools.

8. The drillship according to claim 7, wherein the common moon pool has an elongated design, and wherein the length direction of the elongated common moon pool is extending in a direction substantially transverse to the length direction of the hull of the drillship.

9. The drillship according to claim 8, wherein the at least two well centres are spaced from each other in at least the length direction of said elongated common moon pool.

10. The drillship according to claim 8, wherein the elongated common moon pool has a horizontal cross-section, substantially at the waterline level, which horizontal cross-section has a substantially rectangular shape.

11. The drillship according to claim 10, wherein a ratio between the length of the horizontal cross-section, which length extends substantially in the width direction of the drillship, and the width of the horizontal cross-section, which width extends substantially in the length direction of the ship, is a least 9:

7.

12. The drillship according to claim 1, wherein the at least one open moon pool, which is arranged to be located at the waterline during use of the drillship, is defined at least partly by means of side walls extending from lower wall ends thereof, which are configured to be located below the waterline during use of the drillship, in an upward direction towards higher wall ends thereof, which are configured to be located above the waterline during use of the drillship.

13. The drillship according to claim 1, wherein the drillship is provided with a derrick arranged for multiple-activity operations or a multiple-activity rig.

14. The drillship according to claim 1, wherein the drillship is a self-propelled drillship comprising at least a main propulsion engine and/or comprising multiple individual thrusters.

15. The drillship according to claim 1,

wherein the drillship is provided with at least two feeding systems for feeding drilling equipment to the first well centre, wherein a first one of said feeding systems is located in front of the first well centre and a second one of said feeding systems is located at a rear side of the first well centre, and/or

wherein the drillship is provided with at least two feeding systems for feeding drilling equipment to the second well centre, wherein a first one of said feeding systems is located in front of the second well centre and a second one of said feeding systems is located at a rear side of the second well centre.

16. The drillship according to claim 1, comprising:

a feeding system for supplying at least t of the at least two well centres from a fore deck, and/or

a feeding system for supplying at least two of the at least two well centres from an afterdeck.

17. The drillship according to claim 11, wherein the ratio between the length of the horizontal cross-section and the width of the horizontal cross-section is at least 7:

5.