Disassembling the bearing unit through fixed offshore platforms

 

(57) Abstract:

Usage: when developing oil and gas fields. The inventive method of dismantling end-to-end support blocks of fixed offshore platforms is that the separation of the reference block of fixed platforms on the seabed substrate carry out cutting of the legs of the support block by means of explosion. Why in the first stage, full cut several feet of the bearing unit carried out without the use of expensive special crane installation vessel. Final separation of the reference block from the seabed substrate is carried out after him slinging on the crane hook Assembly of the vessel. In addition to reducing the impact used shaped charges on the environment cutting produce consistently through circular and rectangular shaped charges low power. 1 C.p. f-crystals, 4 Il.

The invention relates to the protection of the environment and can be used in the development of offshore oil and gas fields.

The known method of cutting the casing pipe in the well, providing the installation on pipes special attachments for machine cutting and subsequent upturn is I through the cutters, the long duration of the work.

The closest in technical essence and the achieved result of the present invention, selected as a prototype, is a way of dismantling end-to-end support blocks of fixed offshore platforms using OEC, including Parking crane installation vessel for offshore stationary platform slinging reference block on the crane hook Assembly of the vessel, consistent cutting of the legs of the support unit consisting of a rack block, precast elements and anchors combined borsalini piles, installation of the clamp after a full slice of each of the corner legs of the support block and the rise of the reference block on the boats.

The disadvantages of this method is:

1. The greater complexity, the complexity and duration of activities associated with the Department of legs thrust blocks from the soil Foundation layer by layer underwater OEC each metal element, i.e., first cut the rack of the reference block, then driven element and progressing all the layers of the combined anchor Borsalino piles, and after cutting each metal layer is required to carry out time is by using a special crane installation vessel during production operations;

3. Installation of special clamps under water after it is cut from each corner of the foot support block to ensure immobility production safety work by diver-cutter under water;

4. For a long time diver-cutter under water;

5. Compliance with the stringent requirements for safety when performing work;

6. Significant consumption of oxygen.

The aim of the invention is to reduce the complexity, simplify and cheapen the process of dismantling thrust blocks, while ensuring the protection of fish and security of operations.

This goal is achieved by the fact that according to the way of dismantling end-to-end support blocks of fixed offshore platforms including Parking crane installation vessel for offshore stationary platform, slinging the reference block on the crane hook Assembly of the vessel, cutting the legs of the support block and the rise of the latter on the craft, the separation of the reference block from the seabed substrate are, for example, sharp-Bang, and in the beginning they cut two angular and one opposite the middle of the foot support block completely, then the remaining one medium and two angular legs of the support block p is on fixed offshore platform, slinging the reference block on the crane hook Assembly of the vessel, and then produce the segment remaining anchors combined borsalini piles and the rise of the reference block on the craft.

Comparative analysis of the prototype shows that the proposed method differs in that the separation of the reference block from the seabed substrate are, for example, sharp-Bang in the following sequence: at the beginning they cut one medium and two angular legs of the support block completely, then produce cutting racks and driven elements piles remaining one medium and two angular legs of the support block, and then make Parking the crane installation vessel for offshore stationary platform, then strupat removable bearing block on the crane hook Assembly of the vessel and complete the cutting of the remaining anchors combined borsalini piles and the rise of the reference block on the craft. Thus, the present invention conforms to the criterion "novelty".

The study of other known technical solutions in the art, the features that distinguish the invention from the prototype, namely that the separation of the reference block from the soil of the seabed carried out, for example, reebu the criterion of "substantial differences".

In Fig.1 is a diagram slinging and Dismounting of the bearing unit, front view; Fig. 2 - diagram of the foot support block in the underwater zone of Fig.3 - diagram of the cutting sequence of the legs of the support block in plan; and Fig.4 - scheme of cutting the legs of the support block by means of elongated shaped charges.

The following figures introduced the following notation: a reference block 1; lines - 2; hook - 3; front support block 4; driven element piles - 5; anchor combined Borsalino pile 6 and 7; cement stone in the annular space 8, and the legs of the support block- 9, 10, 11, 12, 13, 14; annular elongated cumulative charge - 15; rectilinear shaped charge 16.

Disassembling the bearing unit is as follows. Cutting the explosion produced using oblong shaped charges mounted on the legs of the support block. Removable bearing block pyramidal type includes six legs (Fig.3).

First, completely cut off (separated from the bottom of the sea) one medium 11 and two corner 9 and 10 on the opposite side legs of the reference block 1. Then in the remaining legs of the support block, the two angular - 12, 13 and one medium 14, cut the rack 5 and driven elements 6. After completing these reblock 1 using sling 2 stropiccia hook 3, what provides support for the bearing unit in subsequent operations by cutting anchors combined borsalini piles 6 and 7, the legs 12, 13 and 14. During the cut - explosion cement stone 8, located between the metal elements are destroyed and do not require additional effort.

At the last stage zastrelennyj unit 1 is lifted up on the deck of the crane Assembly of the vessel.

To protect the fish when the work is foreseen to use charges of low power, which produce a layer-by-layer cutting of the legs of the support block by means of circular and rectilinear oblong shaped charges with a protective device. Cutting the explosion of each leg of the support block carried out in layers, as follows (Fig.4).

Initially, the support leg 4 install two elongated annular shaped charge 15. They are set at a distance of 30-50 cm After detonation of these charges on the pipe set 2 straight-line charge 16.

The charges are set at an angle 180about.

The length of the straight line of the charge should be 4-5 cm longer than the distance between the ring cuts. After the explosion straightforward charge pipe splits into 2 elements. The CEM is the fact that pipe. The subsequent cutting elements piles 6,7,8 smaller diameter is similar.

1. DISASSEMBLING the bearing UNIT THROUGH a MARINE PLATFORM, comprising Parking the crane installation vessel for offshore stationary platform, slinging the reference block on the crane hook Assembly of the vessel, cutting the legs of the support block and the rise of the last on the ship, characterized in that, to reduce complexity, simplify and reduce the cost of dismantling the bearing unit made with six legs, while ensuring protection of fish and security operations, before Parking the sheets are cut legs of the bearing unit on the ground level of the seabed by means of explosion, at first, they cut one medium and two angular legs on the opposite side of the support block, then the remaining one medium and two angular legs of the support block produce cutting rack unit and driven elements of piles, then make Parking the crane installation vessel for offshore stationary platform, slinging the reference block on the crane hook Assembly of the vessel, and then produce the segment remaining anchors combined borsalini piles and the rise of the reference block on plasmids is using circular and rectilinear oblong shaped charges with a protective device in stages, in the beginning they cut the rack of the support block by means of the explosion of the two annular charges set at a distance from each other, then to the pipe mount two straight charge at an angle 180owith subsequent cutting elements piles in the same way.

 

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