CN-116658685-B - Offshore installation method of flexible lining pipe

CN116658685BCN 116658685 BCN116658685 BCN 116658685BCN-116658685-B

Abstract

The invention discloses a method for installing a flexible lining pipe on the sea, which comprises the following steps of expanding and bending and dismantling two ends of a flat pipe section of a pipeline to be maintained, pulling and cutting off the lining pipes on two sides of the flat pipe section by utilizing a winch to pull through a binding wire rope and the lining pipes, discharging seawater between the lining pipes and the flat pipe section through a water discharge one-way valve arranged on a joint jacket, installing the expanding and bending, and recovering the pipeline. The flexible lining pipe offshore installation method has the advantages that the whole construction can be completed without installing ocean platforms at the two ends, namely the whole project construction is penetrated from a flat pipe section, the vertical pipe and the expansion bend are independently replaced, the lining pipe penetrating process is carried out on the sea floor, the problems that the lining pipe is easily broken due to large traction force generated by multiple bends and the gaps of the flange interfaces when penetrating on the ocean platform are solved, the method has obvious operation feasibility, and the method has the characteristics of high construction efficiency and high pipeline repairing quality.

Inventors

TANG JIANHUA
HAN XUEYAN
WANG XIAOLI
GUAN HONGXIANG
JING YONG
ZHANG WENLONG
KOU ZIJIAN
LIU HAICHAO
ZHAO DONGHONG
ZHAO KETIAN
DAI ZHISHUANG

Assignees

中海油（天津）管道工程技术有限公司

Dates

Publication Date: 20260512
Application Date: 20230418

Claims (4)

1. A method of installing a flexible liner offshore, comprising the steps of: dismantling the expansion bends, and respectively dismantling the expansion bends at the two ends of the flat pipe section by using a ship C and a ship D; Threading a steel wire rope and an inner lining pipe into the flat pipe section, wherein one of the ship C and the ship D is provided with a steel wire rope winch, the other one is provided with an inner lining pipe winch, the steel wire rope of the steel wire rope winch is connected with the inner lining pipe of the inner lining pipe winch after being threaded out of the flat pipe section, and the steel wire rope is pulled reversely to drive the inner lining pipe to be threaded out of the flat pipe section; Installing lining pipe joints, namely installing the lining pipe joints at two ends of the flat pipe section, connecting the lining pipe joints with the lining pipe, and discharging seawater between the lining pipe and the flat pipe section; the lining pipe joint is connected with the expansion bend in an installation way; The lining pipe joint comprises a joint outer sleeve, a joint core and a blind flange, wherein a first flange and a second flange are respectively arranged at two ends of the joint outer sleeve, a first groove for installing the joint core is formed in the first flange, the blind flange is connected with the first flange, the second flange is connected with the end head of a flat pipe section, a pressurizing water filling port is formed in the blind flange, and a glue injection valve and a drainage one-way valve are arranged on the joint outer sleeve; The joint outer sleeve is an axial hollow stepped hole, the stepped hole comprises a large hole close to the first flange and a small hole close to the second flange, the glue injection valve is arranged corresponding to the large hole, and the drainage one-way valve is arranged corresponding to the small hole; The hole wall of the large hole is provided with a spring pressing sheet, and the outer wall of the joint core is provided with a second groove corresponding to the spring pressing sheet; the step of installing the lining pipe joint comprises the following steps: The joint outer sleeve and the joint core are installed, the joint outer sleeve is respectively connected with the flat pipe section and the joint core, the joint outer sleeve and the joint core are respectively installed on the outer side and the inner side of the lining pipe, and solidified glue is injected into the inner side of the joint outer sleeve through the glue injection valve; the method comprises the steps of connecting a second flange with a flange at the end of a flat pipe section through flange screws, and connecting and installing a joint core through the flange screws, wherein the joint core is completely positioned in a first groove of the first flange, curing glue is injected into the joint of an inner lining pipe through a glue injection valve arranged on a joint jacket, a spring pressing sheet is collapsed due to inward pressure of the curing glue, the spring pressing sheet presses the inner lining pipe to deform the inner lining pipe, and after the curing glue reaches the curing pressure, the spring pressing sheet and the inner lining pipe are attached to a second groove of the joint core to fix the inner lining pipe and the joint core; Installing a blind flange at the joint outer sleeve; The pressure water is injected into the lining pipe through the pressure water injection port, and the seawater between the outer side of the lining pipe and the inner side of the flat pipe section is discharged through the water discharge one-way valve; and (5) removing the blind flange.
2. The method of marine installation of a flexible lining pipe according to claim 1, wherein the curing pressure of the curing glue is in the range of 20-25 mpa.
3. The method of marine installation of a flexible lining pipe according to claim 1, wherein the step of threading steel wire ropes and lining pipes into the flat pipe sections is performed using a service reel and a ball receiving reel.
4. A method of marine installation of a flexible lining pipe according to claim 3, wherein a service barrel flange is provided on the service barrel, and a first sealing ring is provided on the service barrel flange for sealing the steel wire rope.

Description

Offshore installation method of flexible lining pipe Technical Field The invention relates to the technical field of submarine pipeline maintenance, in particular to a method for installing a flexible lining pipe on the sea. Background The flexible lining pipe is mainly used for solving the corrosion problem of the steel pipe and is a nonmetallic pipeline arranged in the steel pipe, the original steel pipe can be reused, and the flexible lining pipe has better economical efficiency and feasibility in the field of marine petroleum pipelines. However, due to the complex offshore working conditions, particularly a plurality of elbows exist on one pipeline, two risers and four expansion elbows, the pulling force of the lining pipe is too large, the pipeline is easy to damage and the ocean platform facilities are damaged, and safety accidents are caused, and the other reason is that the segments of one crude oil pipeline are too many, the segments comprise the risers, the expansion elbows and flat pipe sections, at least six sections of flange interfaces are arranged, the sealing between the flanges of the submarine pipeline adopts steel ring sealing, a certain gap exists between the flanges after the steel ring sealing, the lining pipeline bulges towards the gap after the operation pressure of the lining pipe is penetrated, so that the blasting risk is caused, and the third reason is that the lining pipe is penetrated through the elbows from the platform as a whole, so that the twisting condition exists in the lining pipe at each elbow. After the lining pipeline runs, the condition that the lining pipe is knotted in the steel pipe exists, so that the transportation fault is directly caused. For the three reasons, the scheme of penetrating the lining pipe from the ocean platform as a whole is quite dangerous, and the possibility of actual operation is not provided. Disclosure of Invention In order to make up the defects of the prior art, the invention provides a flexible lining pipe offshore installation method, which can effectively avoid the risks, meanwhile, the whole construction can be completed without installing ocean platforms at two ends in the construction, the whole project construction is penetrated from a flat pipe section, and a vertical pipe and an expansion bend are independently replaced, so that the penetrating installation process of the whole lining pipe is carried out at the bottom of the sea. In order to achieve the above purpose, the present application provides the following technical solutions: a method of marine installation of a flexible liner, comprising the steps of: dismantling the expansion bends, and respectively dismantling the expansion bends at the two ends of the flat pipe section by using a ship C and a ship D; Threading a steel wire rope and an inner lining pipe into the flat pipe section, wherein one of the ship C and the ship D is provided with a steel wire rope winch, the other one is provided with an inner lining pipe winch, the steel wire rope of the steel wire rope winch is connected with the inner lining pipe of the inner lining pipe winch after being threaded out of the flat pipe section, and the steel wire rope is pulled reversely to drive the inner lining pipe to be threaded out of the flat pipe section; Installing lining pipe joints, namely installing the lining pipe joints at two ends of the flat pipe section, connecting the lining pipe joints with the lining pipe, and discharging seawater between the lining pipe and the flat pipe section; The lining pipe joint is connected with the expansion bend in an installation mode. Further, the lining pipe joint comprises a joint outer sleeve, a joint core and a blind flange, wherein a first flange and a second flange are respectively arranged at two ends of the joint outer sleeve, a first groove for installing the joint core is formed in the first flange, the blind flange is connected with the first flange, the second flange is connected with the end of the flat pipe section, a pressurizing water filling port is formed in the blind flange, and a glue injection valve and a drainage one-way valve are arranged on the joint outer sleeve. Further, the joint outer sleeve is an axial hollow stepped hole, the stepped hole comprises a large hole close to the first flange and a small hole close to the second flange, the glue injection valve is arranged corresponding to the large hole, and the drainage one-way valve is arranged corresponding to the small hole. Further, a spring pressing sheet is arranged on the hole wall of the large hole, and a second groove is formed in the outer wall of the joint core corresponding to the spring pressing sheet. Further, a second sealing ring is arranged on the second flange. Further, the step of installing the liner tube joint includes: the joint outer sleeve and the joint core are installed, the joint outer sleeve is respectively connected with the flat pipe section and the joint core, the joint