阅读说明：本技术 一种水下立管维修方法 (Underwater riser maintenance method ) 是由 吴佩 曹丕廷 金国飞 陆辉文 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种水下立管维修方法,包括以下步骤：步骤一、对待修复立管的表面进行检查；步骤二、在待修复区域的表面涂覆液态金属环氧修复剂,形成第一修补层；步骤三、在第一修补层的表面涂覆水下环氧修复剂,固化形成第二修补层；步骤四、在第二修补层的表面喷涂双向玻璃纤维复合涂料,采用螺旋喷涂的方式缠绕喷涂两层,边喷涂边喷水,形成第三修补层。本发明选取特定的化学修补材料对立管的待修复表面进行补强修复,经压力试验验证修复后的立管是否能够达到使用要求,保证了施工的安全,大大减少了管道失效带来的不必要损失,降低了生产成本,适合所有失效范围较小的立管的修复,对后续立管类修复具有一定的借鉴意义。(The invention discloses a method for maintaining an underwater riser, which comprises the following steps: the method comprises the following steps of firstly, inspecting the surface of a riser to be repaired; coating a liquid metal epoxy repairing agent on the surface of the area to be repaired to form a first repairing layer; coating an underwater epoxy repairing agent on the surface of the first repairing layer, and curing to form a second repairing layer; and step four, spraying the bidirectional glass fiber composite coating on the surface of the second repairing layer, winding and spraying the two layers in a spiral spraying mode, spraying water while spraying, and forming a third repairing layer. The method selects a specific chemical repairing material to reinforce and repair the surface to be repaired of the stand pipe, and verifies whether the repaired stand pipe can meet the use requirement through a pressure test, so that the construction safety is ensured, unnecessary loss caused by pipeline failure is greatly reduced, the production cost is reduced, the method is suitable for repairing all stand pipes with smaller failure ranges, and has certain reference significance for subsequent stand pipe repair.)

1. A subsea riser service method, comprising the steps of: the method comprises the following steps that firstly, the surface of a stand pipe to be repaired is checked, if sharp protrusions exist on the surface of the stand pipe to be repaired, the protrusions need to be polished to reduce local stress, an area to be repaired on the surface of the stand pipe to be repaired is defined, and the area to be repaired is polished to 8-40 meshes of roughness;

coating a liquid metal epoxy repairing agent on the surface of the area to be repaired to form a first repairing layer, wherein the liquid metal epoxy repairing agent is an epoxy repairing agent taking steel as a filling material, is in a daub shape and can be cured at room temperature;

coating an underwater epoxy repairing agent on the surface of the first repairing layer, and curing to form a second repairing layer, wherein the underwater epoxy repairing agent is a high-fiber reinforced type tripolymer and comprises liquid epoxy resin, a high polymer and aliphatic polyamine;

and step four, spraying the bidirectional glass fiber composite coating on the surface of the second repairing layer, winding and spraying two or more layers in a spiral spraying mode, spraying water while spraying to form a third repairing layer, wrapping a pre-fastened plastic tape outside the third repairing layer, penetrating the plastic tape and the third repairing layer through a ratchet wheel, and releasing water and gas in the third repairing layer.

2. The method for maintaining the underwater riser according to claim 1, wherein a pipeline made of the same material as the riser to be repaired is used as a comparison detection pipeline in the construction process, the repair method of the comparison pipeline is the same as the construction method of the riser to be repaired, the number of the comparison pipeline is set to be 2, one is used for field test, and the other is used for keeping files.

3. A method of subsea riser service as in claim 2, wherein the hardness of the repair site of the control pipeline is measured at 1.25 working pressures, and after applying the first repair layer the hardness of the repair site is greater than 40N/m³After the third repairing layer is coated, the hardness of the repaired part is more than 60N/m³。

4. The method for repairing an underwater riser as claimed in claim 1, wherein the second repairing layer is applied at a thickness of 30-60mil and under a temperature of 25 ℃ for 20 min.

5. The method for repairing a subsea riser according to claim 1, wherein said third repair layer is applied at 24 ℃ for 20 min.

Technical Field

The invention belongs to the technical field of oil exploitation, and particularly relates to a method for maintaining an underwater riser.

Background

In recent years, pipelines of various offshore oil platforms such as Bohai Bay and the like have serious leakage conditions, cannot be normally used, and have larger potential safety and environmental protection hazards.

Riser repair is a complex and systematic task involving several aspects including economy, safety, and various risk assessments. There are many factors that cause risk, including environmental factors, human factors, etc. In the actual operation of the riser, the situation that the difference exists between the design and the actual operation of the riser often occurs, and the integrity of the riser is influenced to a certain extent due to the difference of the working conditions. The medium that the riser needs to transport, once changed, can also affect the integrity of the riser to some extent.

The traditional method for repairing the main replacement pipeline of the stand pipe has the advantages of high replacement cost and large engineering quantity, and for the stand pipe with a smaller failure range, the repair mode is adopted, so that the material cost is greatly wasted, and the aim of environmental protection and sustainable development is contradicted.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the underwater riser maintenance method, which can be used for carrying out reinforcement repair on the riser with a small failure range, greatly reduces unnecessary loss caused by a failed pipeline and reduces the production cost.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a method for maintaining an underwater riser, which comprises the following steps:

the method comprises the following steps that firstly, the surface of a stand pipe to be repaired is checked, if sharp protrusions exist on the surface of the stand pipe to be repaired, the protrusions need to be polished to reduce local stress, an area to be repaired on the surface of the stand pipe to be repaired is defined, and the area to be repaired is polished to 8-40 meshes of roughness;

coating a liquid metal epoxy repairing agent on the surface of the area to be repaired to form a first repairing layer, wherein the liquid metal epoxy repairing agent is an epoxy repairing agent taking steel as a filling material, is in a daub shape and can be cured at room temperature;

coating an underwater epoxy repairing agent on the surface of the first repairing layer, and curing to form a second repairing layer, wherein the underwater epoxy repairing agent is a high-fiber reinforced type tripolymer and comprises liquid epoxy resin, a high polymer and aliphatic polyamine;

and step four, spraying the bidirectional glass fiber composite coating on the surface of the second repairing layer, winding and spraying two or more layers in a spiral spraying mode, spraying water while spraying to form a third repairing layer, wrapping a pre-fastened plastic tape outside the third repairing layer, penetrating the plastic tape and the third repairing layer through a ratchet wheel, and releasing water and gas in the third repairing layer.

As an optimal technical scheme, in the construction process, a pipeline which is made of the same material as that of the stand pipe to be repaired is used as a comparison detection pipeline, the repair method of the comparison pipeline is the same as that of the stand pipe to be repaired, 2 parts of the comparison pipeline are set, one part of the comparison pipeline is used for field test, and the other part of the comparison pipeline is used for reserving files.

Preferably, the hardness of the repaired part of the control pipeline is measured under the condition of 1.25 times of working pressure, and after the first repairing layer is coated, the hardness of the repaired part is more than 40N/m³After the third repairing layer is coated, the hardness of the repaired part is more than 60N/m³。

As a preferable technical scheme, the construction thickness of the second repairing layer is 30-60mil, and the construction condition is that the construction is carried out for 20min at 25 ℃.

Preferably, the third repairing layer is constructed at 24 ℃ for 20 min.

Compared with the prior art, the invention has the beneficial effects that: the method selects a specific chemical repairing material to reinforce and repair the surface to be repaired of the stand pipe, and verifies whether the repaired stand pipe can meet the use requirement through a pressure test, so that the construction safety is ensured, unnecessary loss caused by pipeline failure is greatly reduced, the production cost is reduced, the method is suitable for repairing all stand pipes with smaller failure ranges, and has certain reference significance for subsequent stand pipe repair.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

The embodiment provides a method for maintaining an underwater riser, which comprises the following steps:

the method comprises the steps of firstly, inspecting the surface of a riser to be repaired, processing the surface of the riser to be repaired on a damaged part by referring to NACE2/Sa2.5, if sharp protrusions exist on the surface of the riser to be repaired, polishing the protrusions to reduce local stress, defining a region to be repaired on the surface of the riser to be repaired, and polishing the region to be repaired until the roughness is 8-40 meshes.

And step two, coating a liquid metal epoxy repairing agent on the surface of the area to be repaired to form a first repairing layer, and testing the hardness of the repaired part after 12 hours. In this embodiment, the liquid metal epoxy repair agent is APS or APS-L manufactured by DEVCON, which is an epoxy repair agent using steel as a filler, is in the form of a mastic, and can be cured at room temperature for filling, repairing, and bonding the surface of a metal object. Comprises an agent A and an agent B, and the agent A and the agent B are fully mixed before use. For repairs or repairs where welding of metal or brazing is inconvenient. It is easy to use, even on vertical surface, it can be machined, can be used for binding aluminium, cement and other metals, and is resistant to several chemical substances, acid, alkali and various solvents.

And step three, coating an underwater epoxy repairing agent on the surface of the first repairing layer, and curing to form a second repairing layer. In the embodiment, the underwater EPOXY repairing agent adopts EPOXY UW produced by G-shine company, is a high-fiber reinforced type tripolymer, and utilizes liquid EPOXY resin, high polymer and aliphatic polyamine as curing agents to separate out water. The construction thickness is 30-60 mil. Mixing and mixing ratio of 1: 1 by volume. The construction time is 20min at 25 ℃, and the higher the temperature is, the shorter the time is. The application temperature of the epoxy resin is 50 ℃ F minimum (10 ℃ C.) and 275 ℃ F maximum (135 ℃ C.) in a dry environment; a minimum of 50 ° F (10 ℃) in a humid environment and a maximum of 160 ° F (71 ℃).

And step four, spraying the bidirectional glass fiber composite coating on the surface of the second repairing layer, winding and spraying two layers in a spiral spraying mode, spraying water while spraying to form a third repairing layer, wrapping a pre-fastened plastic tape outside the third repairing layer, penetrating the plastic tape and the third repairing layer by using a ratchet wheel, releasing water and gas in the third repairing layer, taking down the pre-fastened plastic tape, and testing the hardness of the repairing part after 12 hours. In the embodiment, the bidirectional glass fiber composite coating adopts a BANDAGE UW product produced by G-shine company, and the product ensures proper content ratio of fiber to resin, so that the performance of the glass fiber system is more reliable and stable. The construction thickness is determined by engineering calculation. The mixing and mixing rate are not required. The construction time is 75 DEG F (24 ℃) for 20min, and the high-temperature time is shortened. The application temperature is a minimum of 40 degrees Fahrenheit (4 degrees Celsius) and a maximum of 150 degrees Fahrenheit (66 degrees Celsius), and the maximum service temperature is 194 degrees Fahrenheit (90 degrees Celsius).

BANDAGE UW properties are shown in table 1.

In the construction process, a pipeline with the same material as that of the stand pipe to be repaired is used as a comparison detection pipeline, the repair method of the comparison pipeline is the same as that of the stand pipe to be repaired, 2 parts of the comparison pipeline are set, one part of the comparison pipeline is used for field test, and the other part of the comparison pipeline is used for reserving files. Measuring the hardness of the repaired part of the control pipeline under the condition of 1.25 times of working pressure, wherein after the first repairing layer is coated, the hardness of the repaired part is more than 40N/m³After the third repairing layer is coated, the hardness of the repaired part is more than 60N/m³。

Although the present invention has been described in detail with respect to the above embodiments, it will be understood by those skilled in the art that modifications or improvements based on the disclosure of the present invention may be made without departing from the spirit and scope of the invention, and these modifications and improvements are within the spirit and scope of the invention.