Submarine pipeline flange underwater abutting joint installation method

Abstract

The invention discloses a submarine pipeline flange underwater abutting joint installation method. A main flange connecting device is installed on the abutting joint end of a submarine pipeline A, an auxiliary flange connecting device is installed on the abutting joint end of a submarine pipeline B, the submarine pipeline A to be butted and the submarine pipeline B to be butted are connected together through the main flange connecting device and the auxiliary flange connecting device, the negative influence of the marine condition on underwater flange connection can be removed, the influence of ship shake on the movement of the submarine pipeline A and the submarine pipeline B can be removed, underwater adjusting steps of a diver can be reduced, the diver can adjust the positions of the submarine pipeline A and the submarine pipeline B conveniently, the underwater operation difficulty degree of the diver can be reduced, the underwater operation time of the diver can be shortened, the case that flanges get close to each other in an aligned manner can be ensured, the force applied to a gasket of each flange is consistent, uniform deformation is generated, and the leakproofness of the flanges can be improved. The flange connection quality can be improved, the operating time of the support ship can be saved, the construction period of the whole fleet can be shortened, the working efficiency is improved, and the installation cost is saved.

Description

technical field [0001] The invention relates to a method for butt jointing of pipelines, in particular to a method for butt joint installation of underwater flanges of various types of seabed pipelines. Background technique [0002] In offshore oil development projects, many pipelines need to be laid on the seabed, usually there are two types of steel pipelines and flexible hoses. Used to transport oil, gas, water, mixed media or other fluid media. Steel pipelines usually include: standpipes, expansion bends, and horizontal pipes. The expansion bend connects the riser and the horizontal pipe to make them into one body, and the connection points are connected by flanges. Usually, the riser and the flat pipe are installed first, and then the angle and distance of the flange of the riser and the flat pipe are measured underwater by divers, and then the expansion bend is prefabricated on the deck of the ship, and then the flange is connected underwater. Flexible hoses general...

AI Technical Summary

Problems solved by technology

[0003] Due to sea conditions (current velocity, water temperature, water depth, visibility, etc.), divers themselves (whether the measuring equipment is well used, measuring the tightness of the steel wire), measuring equipment, the angle of the prefabricated steel elbow (the elbow is prefabricated in advance according to the design documents), the seabed Mud surface obstacles, ship crane lowering expansion bend direction and design routing error, etc., will cause the two flanges to be connected to have a certain distance from each other, dislocation, splayed mouth, etc. Divers underwater adjustment Risks such as over-adjustment and collision are also prone to occur during the process

[0004] The general practice is to lift the flange end of the sea pipe by supporting the crane on the ship, and the diver directs the underwater docking, and only one diver is allowed to work underwater at a time (safety regulations), subject to sea conditions (current velocity, water temperature) , water depth, visibility, etc.), ship heaving and shaking, pipe diameter, expansion bend length, etc., it is difficult to adjust the flange angle and pipe distance by divers' physical strength alone. The distance is long, and it is difficult for divers to get close after repeated adjustments. After the two flanges are close, there will be misalignment and a splayed mouth, which will affect the fastening of the bolts.

It can be said that it all depends on the individual ability of the divers. Not only do the divers work underwater for a long time, but the supporting ships also need to cooperate with the operation near the platform at all times, which poses great safety hazards to divers, construction ship equipment, and fixed facilities on the platform.

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