RU2681807C1 - Turret of drilling vessel - Google Patents

Abstract

FIELD: soil or rock drilling; mining.SUBSTANCE: invention relates to the field of geological exploration and offshore drilling and concerns the setting of a drilling vessel at anchorage at the point of drilling. Proposed turret of the drilling vessel contains the upper part and the lower part, which is a buoy with a control system for buoyancy, connected to the lower part of the anchor system and attached to the upper part of the turret using hydraulic locking devices made with the possibility of lowering and lifting to grip the response parts of the anchor chains, the chains of the holding anchor system are attached to the upper part of the turret on the winch drums using hydraulic tensioning devices.EFFECT: technical result consists in improving the operational characteristics of the device due to the possibility of individual adjustment of the tension of each of the chains of the anchor system and the possibility of reverse connection of the buoy without using auxiliary vessels.1 cl, 6 dwg

Description

The invention relates to the field of geological exploration and vessels for offshore drilling, and is intended for anchoring a drilling vessel at a drilling point, as well as for protecting a riser (offshore drilling riser) from floating ice.

Known methods for undocking the upper part of the turret and the anchor system attached to the buoy, disclosed in the patents of the Russian Federation No. 2487044 and 2485003. It should be noted that the structures shown in these patents are designed to work only with oil platforms (vessels of the FPSO type), therefore, imply the presence of many risers and flexible pipelines that are attached to the buoy and pass through the central shaft of the turret. As follows from the designs and methods of docking and undocking, proposed in patents 2487044 and 2485003, their use on a drilling vessel is impossible.

Also known is the design described in RF patent No. 2224681, which involves the tension of anchor chains by means of winches placed on the turret table, but does not provide for the possibility of disconnecting the vessel from the anchor system by undocking.

The closest in technical essence and the achieved result is a turret, described in RF patent No. 2508223, which is intended for use on a drilling vessel. Inside the hull of the turret 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, made with the possibility of its vertical movement along the 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.

The disadvantage of this technical solution is the difficulty of setting the drilling vessel equipped with this turret to the anchorage, since this requires the use of underwater remotely controlled vehicles, and when working in ice it is very difficult.

The objective of the invention is the creation of a turret specifically designed for use on a drilling vessel, which has a flooded and detachable buoy, with the ability to individually adjust the tension of each of the chains of the anchor system and the possibility of reconnecting the buoy without the use of auxiliary vessels.

This problem is solved in that the turret of the drilling vessel contains an upper part and a lower part, which is a buoy with a buoyancy control system, connected to the lower part of the anchor system and connected to the upper part of the turret using hydraulic locking devices made with the possibility of lowering and lifting capture mating parts of the anchor chains, while the chains of the holding anchor system are fixed on the upper part of the turret on the winch drums using hydraulic tensioning devices.

The design proposed in this patent relates to the equipment of drilling vessels, namely, it implies the use of a single riser (sea drilling riser), which, according to the well-known method of removing and setting the drilling vessel to the drilling point, must be fully raised before any movement of the drilling vessel. The design used a detachable flooded buoy connected to the lower part of the anchor system and connected to the upper part of the turret using eight hydraulic locking devices, which in turn can be lowered and raised to capture the counterparts of the anchor chains, as well as using hydraulic cylinders located on the turret table, adjust the tension of each of the chains.

The proposed turret differs from the prototype in that the chains of the retaining anchor system are mounted not on the ship’s hull, but on the turret itself on the winch drums using hydraulic tensioning devices, as well as using a detachable buoy with a buoyancy control system. These differences allow you to connect and disconnect the drilling vessel from the buoy without the use of auxiliary vessels, which distinguishes the proposed design from the prototype.

The upper parts of the anchor chains passing through the detachable buoy, have in their design reciprocal (passive) parts of hydraulic locks, which during the attachment of the buoy to the turret are captured using active hydraulic locks located on the anchor chains, which, in turn, are wound on the winch drums .

In FIG. 1 shows a sketch of a turret in a static position, FIG. 2 shows a drilling vessel when positioned relative to a buoy; FIG. 3 shows the buoy ascent process; FIG. 4. shows the process of capturing a buoy; FIG. 5 shows the process of adjusting the tension of the anchor chains. In FIG. 6 is a sketch of a detachable buoy device.

The turret of the drilling vessel consists of the upper part 1 of the turret, the lower part 2 of the turret (buoy with buoyancy control system 3), through the buoy pass chains 4 of the anchor system, at the ends of which the reciprocal (passive) parts of hydraulic locks are fixed 5. On the table of the upper part of the turret the hydraulic cylinders 7 of the tensioning devices are fixed to the drums of the winches 6, on which chains with the upper (active) parts of the hydraulic locks 8 are wound.

The buoyancy control system is a flooded / blown ballast compartment.

The device operates as follows: buoy 2 with a buoyancy control system 3 and anchor chains 4 of a pre-selected length corresponding to the depth of the sea at the drilling site, is transported and installed using auxiliary vessels, and using a buoyancy control system (buoyancy is preferably regulated using flooding of the internal cavities of the buoy) is flooded at a certain depth. After that, the drilling vessel 9 by the well-known method, using the dynamic positioning system (Fig. 2), rises to a position above the buoy 2. Then, using the buoyancy control system 3, the buoy 2 is ascended and captured by hydraulic locks 8, which are fixed on the bottom of the anchor chains, which in turn are located on the drums of the winches 6 around the perimeter of the upper part 1 of the turret.

After capturing buoy 2, it is pulled up (Fig. 4) upward and docked with the upper part 1 of the turret using guides. Thus, the buoy is prevented from turning relative to the top of the turret.

When the vessel is still at the drilling point, the tension of each of the anchor chains 4 is adjusted using the hydraulic cylinders 7. (Fig. 5.) The position of the buoy 2, which acts as protection against floating ice that breaks in, is also regulated by the tension of the chains 4. under the hull of the vessel. The narrowing on the top of the turret protects the winch drums and the deck of the mine shaft from flooding with sea water.

Claims (1)

A turret of a drilling vessel, comprising an upper part and a lower part, which is a buoy with a buoyancy control system, connected to the lower part of the anchor system and connected to the upper part of the turret using hydraulic locking devices, capable of lowering and lifting to capture the mating parts of the anchor chains, while the chains of the holding anchor system are fixed on the upper part of the turret to the winch drums using hydraulic tensioning devices.

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