SU1030242A1 - Method of careening self-raising floating drilling platforms - Google Patents

Abstract

THE METHOD OF LOOPING OF SELF-LIFTING FLOAT DRILLING INSTALLATIONS, containing supporting columns with buoyancy tanks located below the waterline, consists in redistributing the force of gravity and maintaining, by means of lowering the supporting columns, in order to reduce the difficulty, in order to reduce the difficulty, in order to reduce the difficulty, in order to reduce the difficulty, in order to reduce the difficulty, in order to reduce the difficulty, in order to reduce the difficulty, by the skill, to reduce the difficulty, with the difficulty, in order to reduce the difficulty, by working strength, to reduce the difficulty, by the skill, by means of reducing the basic columns, by the supporting columns with buoyancy tanks at an angle to the vertical, defined by the expression ".. where MKR is the heeling moment created; H is the magnitude of the movement of the supporting columns; P is the strength of the support plates and buoyancy tanks; O. - force to support supporting columns and buoyancy tanks.

Description

The invention relates to shipbuilding, in particular, to a full-scale experiment to determine the metacentric height by heeling.

The known method of banking ships and other floating equipment by moving solid ballast roll along the deck from side to side I.

The disadvantage of this method is that it is necessary to have a solid roll-ballast in the form of metal weights and the laboriousness of moving them around the deck, which is usually done by the crew.

There is also known a method for heeling self-lifting floating drilling rigs containing supporting columns with buoyancy tanks located below the waterline, consisting in redistributing gravity and maintaining by lowering supporting columns 2.

However, such an inclining method cannot be used for installations in which the buoyancy tanks of the supporting columns are below the waterline, since lowering the supports on one side of the installation does not increase the submerged volume, as a result of which installation does not occur. Therefore, in this case, it is necessary to use either the traditional method of moving solid ballast roll along the deck, or to retrofit the supporting columns with additional buoyancy tanks, which leads to an increase in labor intensity and additional costs.

The purpose of the invention is to reduce the laboriousness of heeling.

To achieve this goal, according to the method of heeling of self-lifting floating drilling rigs containing supporting columns with tanks - floatation, located below the waterline, which involves redistributing the force of gravity and maintaining by lowering the supporting columns, tilting the drilling rig is performed by moving all the supporting columns with buoyancy tanks at an angle to the vertical, defined by the expression

MKR

Or, - arc sin

NSR-a)

where McR is the heeling moment created; H is the magnitude of the movement of the supporting columns;

p is the strength of the support plates and buoyancy tanks;

Q-force supporting support columns

and buoyancy tanks. FIG. 1 shows the proposed self-lifting floating drilling unit in the area of buoyancy tanks, the supporting columns of which are inclined at an angle E with respect to the vertical, the cross-section; in fig. 2 is a diagram of the action of forces when all supporting columns are moved.

The hull 1 of the self-lifting floating drilling unit is in the transport position afloat, while the supporting columns 2 are lifted up and their buoyancy tanks 3 are below the waterline 4. In the hull 1 there are ballast tanks 5. The rig is subject to the force of gravity 6 attached at the center of gravity point 7, and the support force 8 is applied at the center point 9 of the magnitude. In equilibrium with the standing, these forces act in a single vertical.

The inclination of the installation according to the proposed method is created as follows.

The supporting columns 2 are inclined at an angle of 00 together with the housing 1 by receiving liquid, ballast into the tank 5. Then all the supporting columns 2 are lowered, which causes the force of gravity 6 and the supporting forces 8 to move in the direction constituting the angle Q with vertical, consequently, to the displacement of the center of gravity from point 7, at 10, and the center of magnitude from point 9 to point 11. This results in a pair of forces with arm 12, the action of which causes the heeling moment and roll angle to occur. labor intensity Considerations for jackup rigs and use to dispense from a rigid roll-ballast.

Claims (1)

METHOD FOR SELF-LIFTING FLOATING DRILLING UNITS HELDING METHODS containing support columns with buoyancy tanks located below the waterline, consisting of GO> the distribution of gravity and support by lowering the support columns, characterized in that, in order to reduce the difficulty of heeling, the inclination of the rig is carried out by moving all the support columns with buoyancy tanks at an angle to the vertical, determined by the expression M _cr - created heeling moment; - the magnitude of the movement of the support columns; - Gravity of supporting columns and buoyancy tanks; -the power to maintain support columns and buoyancy tanks.