RU2508223C1 - Mooring turret of drilling ship - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: according to the invention, inside the housing of a drilling ship mooring turret, which has a cylindrical housing with a drilling shaft and an anchor retention system of the ship, in its lower part there installed is an annular cylindrical structure with ballast compartments, which can move vertically along guides below the main plane of the drilling ship. Inside the shaft there arranged are deflectors located along the perimeter of the shaft on its walls above the ship waterline.

EFFECT: invention of a drilling ship mooring turret structure allows protecting a riser pipe at drilling operations under ice conditions and protecting against flooding of an upper deck of the drilling ship through the drilling shaft at stormy drift or at transition of the drilling ship under conditions of considerable disturbance, especially at negative air temperature contributing to formation of ice on deck structures of the drilling ship.

2 dwg

Description

The invention relates to the field of exploration and exploration vessels, and in particular to offshore exploration drilling, and relates to the issue of ensuring the protection of the riser during drilling operations in ice conditions and protection against flooding of the upper deck of the drilling vessel through the drill shaft during storm drift.

A well-known turret of an exploratory drilling drilling vessel and production vessel of the FPSO type, anchored on anchors, providing a turn of the vessel to reduce the windwave effect on its prototype hull ("Turret for drilling or production ships", No. 5359957 from 11/11/1994, Norsk Hydro as Oslo , Norway and Swivel device, No. US 6302048 B1 of 10.16.2001, Hitec Systems AS, Forus).

However, it is not possible to use the well-known turret for vessels operating in the Arctic and Far Eastern seas due to the lack of protection of the riser from mechanical damage by ice floes passing under the bottom of the vessel during drilling operations in ice conditions and the lack of protection against flooding of the upper deck of the drilling vessel through the drilling shaft during storm drift (100-year storm) or during the transition of a drilling vessel in conditions of significant disturbance, especially at negative air temperature, which contributes to icing of decks of drilling vessel designs.

The objective of the invention is to protect the riser from mechanical damage by ice floes passing under the bottom of the vessel during drilling operations in ice conditions and to protect against flooding of the upper deck of the drilling vessel through the drill shaft during storm drift

For this, inside the turret hull of a drilling vessel having a cylindrical hull with a drill shaft and an anchor holding system for the vessel, according to the invention, an annular cylindrical structure with ballast compartments is installed in its lower part, which is configured to vertically move along guides below the main plane of the drilling vessel. Inside the mine there are deflectors located along the perimeter of the mine on its walls above the waterline of the vessel.

An annular cylindrical structure with ballast compartments, made with the possibility of vertical movement along the rails, provides, by collecting the ballast in the ballast compartments from the surrounding body of water and falling below the main plane of the drilling vessel, to protect the riser from external mechanical action of the ice passing under the bottom of the vessel.

Deflectors located along the perimeter inside the shaft above the waterline provide a decrease in the speed and pressure of the water flow entering the shaft from the bottom by changing the direction of its movement, and thereby prevent water from entering the deck.

The essence of the invention is illustrated by drawings, where

Figure 1 - General view of the proposed turret of a drilling vessel;

Figure 2 - protection of the deck of the drilling vessel from flooding through deflectors.

Inside the hull of the turret 1 of the drilling vessel 2, in its lower part, an annular cylindrical structure 3 with ballast compartments 4 is installed to protect the riser 5 from damage by ice 6, with the possibility of vertical movement down below the main plane 7 of the drilling vessel along the guides 8, taking water ballast (figure 1).

In the case of the turret 1 there is a shaft 9, inside of which during drilling operations a riser 5 is formed.

Along the perimeter, on the walls 10 of the shaft 9 above the water line 11 of the vessel 2, deflectors 12 are installed to reduce the speed and pressure of the water stream 13 during significant waves and to prevent flooding of the upper deck of the drilling vessel through the drilling shaft 9, especially at negative air temperature, which contributes to icing of the deck structures of the drilling vessel (figure 2).

The proposed turret works as follows.

When conducting drilling operations in ice conditions, the ballast compartments 4 of the annular cylindrical structure 3 are filled with water from the surrounding body of water, and it falls along the guides 8 down below the main plane 7 of the drilling vessel, thereby protecting the riser 5 from the external mechanical impact of the ice 6 passing under the bottom of the vessel 2.

When the drill vessel passes in conditions of significant excitement or during storm drift (100-year storm), especially at negative air temperature, which contributes to icing of the deck structure of the drill vessel, the upper deck of the drill vessel is protected from flooding through the drill shaft 9 by deflectors 12 located inside perimeter on the walls 10 of the shaft 9 above the water line 11, providing a decrease in the speed and pressure of the water stream 13 entering the shaft 9 from the bottom by changing the direction of its movement.

The proposed invention turret of the drilling vessel provides protection of the riser from mechanical damage by ice floes passing under the bottom of the vessel during drilling operations in ice conditions and protection from flooding of the upper deck of the drilling vessel through the drill shaft during storm drift (100-year storm) or when the drilling vessel under conditions significant disturbance, especially at negative air temperature, which contributes to icing of the deck structures of the drilling vessel, not only during the navigation period, but also in ice conditions and wish to set up to ensure safe drilling operations in the Arctic and Far Eastern shelf, which is an important advantage compared with existing drilling vessels oil and gas industry, as well as drilling equipment increases productivity while reducing the complexity of drilling operations, which distinguishes it from the prototype.

Claims (1)

Turret of a drilling vessel having a cylindrical hull with a drill shaft and an anchor holding system for the vessel, characterized in that an annular cylindrical structure with ballast compartments is installed inside the turret hull, with the possibility of its vertical movement along the guides below the main plane of the drilling ship and inside the shaft there are deflectors located along the perimeter of the shaft on its walls above the ship’s waterline.

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