A device for cleaning the inner surface of a riser annulus installed on an offshore platform

Abstract

The present invention discloses a device for cleaning the inner surface of the riser annulus, which can freely move up and down along the inner tube under the traction of an operating wire rope. At the same time, the sandblasting device equipped on the device can move in the circumferential direction of the annulus, spraying abrasives around to treat the outer surface of the riser and the inner surface of the protective tube. The deck control personnel can observe the treatment situation through a camera and control the up and down amplitude of the device. The treatment of the inner surface of the riser annulus can be achieved, providing a guarantee for further maintenance work.

Description

Technical Field

[0001] The invention relates to an annulus inner surface cleaning device, in particular to a standpipe annulus inner surface cleaning device. Background Art

[0002] The submarine pipeline riser has a special structure. The external corrosion area of ​​the riser starts from the atmospheric zone, passes through the splash zone, tidal zone, full immersion zone, and sea mud zone. The corrosion situation is complex and changeable, especially the splash zone, which is the hardest hit area for external corrosion in the marine environment. Leakage incidents of submarine pipeline risers are mostly caused by corrosion.

[0003] Since the riser is connected to the submarine pipeline via the bottom deck (intertidal zone), the upper part of the platform is completely closed, and conventional technical means cannot clean and repair its internal space. In most cases, after the riser leaks, it is passively repaired and replaced. This passive maintenance practice not only loses precious maintenance opportunities and causes environmental damage, but also has the problem of long maintenance cycles and high overall costs.

[0004] When performing the riser filling and maintenance service, the surface attachment inside the annulus must be cleaned first, and the surface treatment is made to about Sa2.5, and then the riser annulus filling service is performed. Since the size of the riser annulus is about 40mm to 60mm, under the condition of not destroying the overall structure and carrying out local cutting (300mm×300mm) to clean the outer wall of the riser and the inner wall of the protective pipe, there is currently no device for cleaning the inner surface of the riser annulus in use. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a standpipe annulus inner surface cleaning device which can perform in-situ online cleaning operations in the narrow space of the standpipe annulus without removing the standpipe.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The internal surface cleaning device of the riser annulus of the present invention comprises an annular chassis and an annular external gear mounted on the annular chassis, a plurality of spring-type universal balls are mounted on the inner wall of the annular external gear, a T-shaped slot is opened on the bottom wall of the annular external gear in the circumferential direction, a T-shaped slider matching the shape of the T-shaped slot is rotatably mounted in the T-shaped slot, two brackets are symmetrically fixed in the vertical direction on the top wall of the annular external gear, a wire rope lifting lug is fixed on each bracket, the T-shaped slider is fixed to the inner ring edge of the top wall of the annular chassis by bolts, the inner ring diameter of the annular chassis is the same as the inner ring diameter of the annular external gear, and the two are coaxially arranged;

[0008] The bidirectional vane-type pneumatic motor is fixed on the top wall of the annular chassis located outside the annular external gear through a bracket, and a driving gear is installed on the rotating shaft of the pneumatic motor arranged in the vertical direction, and the driving gear is meshed with the annular external gear;

[0009] A sandblasting tube is arranged vertically through the annular chassis, a sandblasting nozzle is installed at the bottom outlet of the sandblasting tube, the inlet of the sandblasting tube is used to connect an external sandblasting supply device, a micro camera is installed on the top wall of the annular chassis through a bracket, and the micro camera can be rotated and aligned with the outer wall of the inner tube of the vertical pipe and the inner wall of the protective tube of the casing under the drive of the annular chassis. The annular chassis and the annular external gear are both annular structures composed of multiple identical petal structures connected and fixed.

[0010] The beneficial effect of the present invention is that it can implement in-situ online cleaning operations in the narrow space of the riser annulus without removing the riser. The method has low construction cost and short operation time. More importantly, it does not require production to be stopped to replace the riser, and it is easy to operate and greatly reduces the work intensity of construction personnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings described herein are used to provide further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0012] Figure 1 It is a structural schematic diagram of the standpipe annulus inner surface cleaning device of the present invention;

[0013] Figure 2 for Figure 1 The equally divided structure of the annular external gear in the device shown;

[0014] Figure 3 for Figure 1 A schematic diagram of the equally divided structure of the annular chassis in the device shown;

[0015] Figure 4 for Figure 3 A schematic diagram of the connection of the structure shown;

[0016] Figure 5 for Figure 1 A cross-sectional view of the connection between the annular external gear and the annular chassis in the device shown;

[0017] Figure 6 for Figure 1 The schematic diagram of installation and use of the device shown;

[0018] Figure 7 for Figure 1 A top view of the device shown;

[0019] Figure 8 for Figure 7 AA cross-sectional view of the device shown. DETAILED DESCRIPTION

[0020] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] As shown in the accompanying drawings, the internal surface cleaning device of the riser annulus of the present invention comprises an annular chassis 4 and an annular external gear 1 mounted on the annular chassis 4. A plurality of spring-type universal balls 3 are mounted on the inner wall of the annular external gear 1. Preferably, six spring-type universal balls 3 are evenly mounted in the same circumferential direction of the inner wall of the annular external gear 1. When in use, the annular external gear 1 is used to be mounted on the outer wall of the inner tube 13 of the casing. The spring-type universal balls 3 can ensure that the internal surface cleaning device of the riser annulus moves freely up and down along the inner tube 13 to reach the annulus position to be processed. A T-shaped slot is opened on the bottom wall of the annular external gear 1 in the circumferential direction, and a T-shaped slider 15 matching the shape of the T-shaped slot is rotatably mounted in the T-shaped slot. Two brackets are symmetrically fixed in the vertical direction on the top wall of the annular external gear 1, and a wire rope lifting lug 2 is fixed on each bracket to ensure that the wire rope is easy to hang and the traction force is uniform.

[0022] The T-shaped slider 15 is fixed to the inner ring edge of the top wall of the annular chassis 4 by bolts 10. The inner ring diameter of the annular chassis 4 is the same as the inner ring diameter of the annular external gear 1 and the two are coaxially arranged.

[0023] The bidirectional blade-type pneumatic motor 7 is fixed on the top wall of the annular chassis 4 located outside the annular outer gear 1 through a bracket, and a driving gear is installed on the rotating shaft of the pneumatic motor 7 arranged in the vertical direction, and the driving gear is meshed with the annular outer gear 1. The bidirectional blade-type pneumatic motor 7 can control its forward and reverse rotation through the air source, and this component is the key to determining the rotation of the annular work platform. In the present invention, the control method of the pneumatic motor 7 is to work in a fixed mode of reciprocating rotation of one circle forward and one circle reverse, and its speed is adjustable.

[0024] A sandblasting tube 5 is arranged vertically through the annular chassis 4, and a sandblasting nozzle 8 is installed at the bottom outlet of the sandblasting tube 5. The preferred sandblasting nozzle 8 adopts a straight tube sand head structure, which can not only overcome the problem that the conventional sandblasting head cannot be accommodated in a small space, but also ensure that the abrasive can be sprayed uniformly all around. The inlet of the sandblasting tube is used to connect an external sandblasting supply device. The micro camera 6 is installed on the top wall of the annular chassis 4 through a bracket. Driven by the annular chassis 4, the micro camera 6 can be rotated to align with the outer wall of the inner tube 13 of the riser and the inner wall of the protective tube 14 of the sleeve. On the one hand, the wear of the micro camera 6 caused by sandblasting is effectively reduced, and on the other hand, it is also convenient to observe the outer wall of the inner tube of the riser and the inner wall surface of the protective tube after sandblasting. Due to the small space, a two-way short focal length wide-angle camera is selected to simultaneously check the inner and outer surfaces of the annular space formed between the inner tube of the riser and the protective tube, and obtain the video picture to the greatest extent.

[0025] The annular chassis 4 and the annular outer gear 1 are both annular structures formed by docking and fixing multiple petals (preferably six petals) of the same petal structure. As an embodiment of the present invention, one end of each petal structure is recessed downward to form a concave platform and the lower part of the other end is recessed inward to form an upper convex shoulder. Positioning grooves 11 are respectively opened in the vertical direction on the concave platform and the upper convex shoulder. The convex shoulder of one petal structure of two adjacent petal structures is supported on the concave platform of the other petal structure and is fixedly connected by a latch 12 passing through the positioning grooves 11 of the two petals.

[0026] The installation and use methods of this device are as follows:

[0027] When the device is used, the six-petal structure of the annular chassis 4 is fed into the annular space one by one, and quickly assembled together through the positioning groove 11 and the bayonet 12. The T-shaped slider 15 is installed in the T-shaped groove of the annular external gear 1, and the equally divided parts are fed into the annular space one by one, and quickly assembled together through the positioning groove 11 and the bayonet 12. The T-shaped slider 15 is fixed to the annular chassis 4 by bolts 10, so that the annular external gear 1 and the annular chassis 4 are connected as a whole and can rotate synchronously.

[0028] When in use, the wire rope lifting lug 2 is hung with a wire rope, the external sand supply equipment is connected to the inlet of the sandblasting tube 5, the micro camera 6 and the pneumatic motor 7 are connected to the computer on the platform through a signal line, and the air pipe is connected to the pneumatic motor 7.

[0029] Under the condition that two windows (300mm×300mm) are cut symmetrically along the radial direction of the protective tube 14 on the upper part of the casing, the device is installed in the annulus of the sea pipe riser that needs to be cleaned, and the wire rope is released. The device slides down under the action of gravity, and the device moves on the inner tube 13 of the riser through the spring-type universal ball 3 to reach the annulus position to be processed, and starts to supply sand so that the sandblasting nozzle 8 sprays sand to clean the outer wall of the inner tube 13 and the outer wall of the protective tube 14 on the surface. The computer outputs a signal to drive the pneumatic motor 7 to rotate, and the pneumatic motor 7 drives the annular chassis 4 to rotate around the annular outer gear 1, and then drives the sandblasting nozzle 8 to rotate synchronously with the rotation of the annular chassis 4, so as to perform rotary sandblasting on the pipeline. During the rotation process, the micro camera 6 can synchronously observe the cleaning status of the outer wall of the inner tube 13 and the outer wall of the protective tube 14 through video. The deck control personnel can observe the processing situation through the computer connected to the camera, and control the up and down amplitude of the device by controlling the wire rope and gravity. The processing of the inner surface of the riser annulus can be achieved, providing a guarantee for further maintenance work.

Claims

1. Riser annulus inner surface cleaning device, characterized by: It comprises an annular chassis and an annular external gear mounted on the annular chassis, a plurality of spring-type universal balls are mounted on the inner wall of the annular external gear, a T-shaped slot is opened on the bottom wall of the annular external gear in the circumferential direction, a T-shaped slider matching the shape of the T-shaped slot is rotatably mounted in the T-shaped slot, two brackets are symmetrically fixed on the top wall of the annular external gear in the vertical direction, a wire rope hanging ear is fixed on each bracket, the T-shaped slider is fixed to the inner ring edge of the top wall of the annular chassis by bolts, the inner ring diameter of the annular chassis is the same as the inner ring diameter of the annular external gear, and the two are coaxially arranged; The bidirectional blade-type pneumatic motor is fixed on the top wall of the annular chassis located outside the annular outer gear through a bracket; the bidirectional blade-type pneumatic motor is controlled by an air source for forward and reverse rotation, and the control method of the pneumatic motor is to work in a fixed mode of reciprocating rotation of one circle forward and one circle reverse, and the speed of the pneumatic motor can be adjusted. A driving gear is installed on the rotating shaft of the pneumatic motor arranged in the vertical direction, and the driving gear is meshed with the annular outer gear; A sandblasting tube is arranged vertically through the annular chassis, a sandblasting nozzle is installed at the bottom outlet of the sandblasting tube, the inlet of the sandblasting tube is used to connect an external sandblasting supply device, a micro camera is installed on the top wall of the annular chassis through a bracket, and the micro camera can be rotated and aligned with the outer wall of the inner tube of the vertical pipe and the inner wall of the protective tube of the casing under the drive of the annular chassis. The annular chassis and the annular external gear are both annular structures composed of multiple identical petal structures connected and fixed.

2. The device for cleaning the inner surface of the riser annulus according to claim 1, characterized in that: One end of each petal structure is recessed downward to form a concave platform and the lower part of the other end is recessed inward to form an upper convex shoulder. Positioning grooves are respectively provided in the concave platform and the upper convex shoulder in the vertical direction. The convex shoulder of one petal structure of two adjacent petal structures is supported on the concave platform of the other petal structure and is fixedly connected by a pin passing through the positioning grooves of the two petals.

3. The device for cleaning the inner surface of the riser annulus according to claim 1 or 2, characterized in that: Six spring-type universal balls are evenly installed in the same circumferential direction of the inner wall of the annular external gear.

4. The device for cleaning the inner surface of the riser annulus according to claim 3, characterized in that: The sandblasting nozzle adopts a straight tube scattered sand head structure.

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