A method of functionally grading marine risers externally with a method of manufacturing thereof.

Abstract

The titled invention "A method of functionally grading marine risers externally with a method of manufacturing thereof discloses a method of manufacturing a marine riser (103) having (501) external functionally graded material (FGM) layers. Marine riser (103) is functionally graded using a cold metal transfer torch (204) and rotating welding positioner (205) by wire arc additive manufacturing. The weld torch is integrated to a linear feed system which is numerically controlled. The rotating welding positioner (205) rotation is combined with the weld torch integrated linear feed system for the functionally grading process along the external surface. The proposed method of functionally grading can achieve functional layers both along the internal and external layers to mitigate internal and external corrosion. The proposed method of functionally grading can achieve functional layers along the external layers.

Description

FIELD OF INVENTIONThe present invention relates to oil and gas industry, Particularly, the present invention relates to fabrication of oil and gas pipelines with an external functional layer. More particularly, the present invention relates to a method of functionally grading marine risers external with a method of manufacturing thereof. The advantage of the present invention is to distribute the material functions throughout the material body to achieve the maximum heat resistance and mechanical properties. The use of this invention to mitigate external corrosion.DESCRIPTION OF THE RELATED ARTOffshore platforms are used for drilling and production of oil and natural gas from oil and gas formations from the reservoir in an offshore environment. The Produced hydrocarbons are transported from the subsea production facility to the platform by the means of conductor pipes or risers. The hydrocarbons once produced are subjected to a number of separator facilities before it is transported to the processing facility separated to oil, water and natural gas. The export riser from the platform is connected to the processing facility by network of pipelines that are laid on the seafloor which facilitates the transport of hydrocarbons to the processing facility. The pipelines form a crucial part of the oil and gas production system, as a failure could cause severe environmental impact in the region. Due to the presence of hydrogen sulfide gas and other corrosive agents present in the produced oil and gas, the inner surfaces of the oil and gas pipelines are subjected to severe corrosion. The outer surface of the pipeline is in contact with seawater as a result of which the outer surfaces of the pipeline is also subject to corrosion. The pipeline material needs to possess strength and well as functional requirements like corrosion resistance. There are several methods by which corrosion can be controlled in a pipeline.OBJECT OF INVENTION1. The principal object of this invention is to design pipelines for oil and gas industry with corrosion free.2. Another object of this invention is to prevent high corrosion in an exteriorsurface of the pipelines deployed in an offshore environment.3. Another object of this invention is to fabricate oil and gas pipelines with an internal and external functional layer.4. Another object of this invention is to design a pipeline with functional layer comprises of superior material characteristics compared to the primary material on which it is deposited.5. Another object of this invention is to design a pipeline by additively adding the superior material to the parent material by wire arc additive manufacturing and a rotary welding positioner.6. Another object of this invention is to design a pipeline where superior material to be added in a form that it is micro structurally bonded to the primary material.7. A further object of this invention is add minimum quantity functional layer to satisfy the functional requirement.DETAILED DESCRIPTION OF THE INVENTIONThe present study describes a technique for functionally grading the outer surfaces of an oil and gas pipeline. The outer surfaces of the oil and gas pipelines are subjected to high corrosion in an offshore environment. The outer surface of the riser is in contact with the saline sea water. The outer surface is exposed to sea water. Functional materials are developed for several applications for improving the functionality of a parent material with regard to a specific application, like improving the corrosion resistance, high toughness or any other property which is superior to the parent material.The proposed method is for functionally grading an oil and gas pipeline is carried out using a wire arc additive manufacturing and rotary welding positioner. In this method, the pipeline is initially clamped to the rotating welding positioner. The method involves attaching the pipeline on to the rotary welding positioner. The CMT Torch moves in a linear direction at a predetermined speed. During the process of deposition of the material on the pipeline, therotary welding positioner rotates to add the material in a circular form. The linear feed of the torch and the rotary motion of the welding positioner forms adjacent layers of circular deposits which forms a microstructurally bonded functional layer on the primary parent material.The present disclosure is explained with the help of figures for a method of fabricating a functionally graded pipe using a cold metal transfer wire arc additive manufacturing equipment and a rotating welding positioner. However, such exemplary embodiments should not be construed as limitations of the present disclosure, since the method may be used for other types of oil and gas pipelines or conduits / risers segments manufactured by various combinations of graded layers using the rotating welding positioner to form a functionally graded material. A person skilled in the art may envisage various such embodiments without deviating from scope of the present disclosure.An oil and gas platform (101) installed in an offshore environment (102) is illustrated in figure 1. The oil and gas produced from the subsea production facility is transported to the oil and gas platform through a marine riser / main riser pipe segment (103). The produced oil and gas is transported to the onshore facility through an export riser connected to a pipeline network after subjecting the produced oil and gas through a series of separators (104). The produced oil and gas may possess high temperature and pressure. The produced fluids are highly corrosive in nature due to the acidic conditions, and the presence of chlorides and sulphides. The marine riser subjected to saline conditions of the ocean environment is also subjected to corrosion along the external surface. The primary material of the marine riser is functionally graded with a highly corrosion resistant material. Further embodiments of the present disclosure will now describe methods of functionally grading marine riser conduits along its inner surface and external surface.In an embodiment of the present disclosure the method of depositing a functional layer along the outer surface of the pipeline outer graded layer on the main riser pipe segment (103) is described as shown in figure 2 and 3. Figure 2 describes the experimental setup to form a pipeline segment with an externally graded functional layer (301) as shown in figure 3. The riser segment (103) is placed with its one end clamped to the rotating welding positioner (205) and rotated. The cold metal transfer weld torch (204) is attached to a carriage which is moving on a rack and pinion (201) which programmed by a numerical control. The cold metal transfer weld torch (204) is attached to a carriage (202) using height adjustable manual feed (203) to facilitate the additive process. The linear movement of the carriage (202) rotation of the carriage at a specific speed would additively add the functional layer on the main riser pipe segment (103). The cold metal transfer weld deposition parameters aredetermined by experiments. The additively added functional layer (301) is deposited on the main riser pipe segment (103) once the carriage moves from one end to the other. Here, the weld deposition parameters are selected in such a way that it forms a continuous deposit on the pipe in a circular manner as the pipe rotates in the positioner. The deposited external, functional layer (301) formed after deposition on the riser pipe segment (103) is shown in figure 3.In another embodiment, the internal (301) and external functional layers (501) can be deposited on the same riser pipe segment (103) by carrying out the deposition using respective experimental setups. In another embodiment, the additional attachment for depositing internal functional layer can be modified to fit in to the diameter requirement of the pipe. The minimum diameter of pipe for internal functional layer may be restricted by the size of the cold metal transfer torch and the associated attachments'to support it. In another embodiment, the travel length of the carriage can be modified depending on the length of the main pipe.In an embodiment of the present disclosure, the method is described for a marine riser which is cylindrical conduit. The embodiment of the present disclosure may however be applied to other metallic and non-metallic conduits and geometries where in the proposed method may deem fit and not limited to oil and gas industries. While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.SUMMARY OF THE INVENTIONTo achieve the objects, the present invention. provides a solution that a method of functionally grading marine risers externally with a method of manufacturing thereof.It is another aspect of the present invention is to fabricate the pipelines for oil and gas industry.It is one aspect of,the present invention is to fabricate the pipelines with external metal bond coating to mitigate the corrosion.It is another aspect of the present invention is to provide an additive process through the riser segment clamped to the rotating welding positioner and rotated. The cold metal transfer weld torch is attached to a carriage that is moving on a rack and pinion, the cold metal transfer weld torch be attached to a carriage using height adjustable manual feed.It is one aspect of the invention is to provide the rotating welding positioner rotation combined with the weld torch integrated linear feed system for the functionally grading process along the external surface.It is another aspect of the invention is to provide the functional layers are added to the primary material of pipeline using a cold metal transfer (CMT) wire arc additive manufacturing and rotary welding positioner along the external surface of the pipeline.It is one aspect of the invention is to provide the handle to pull down to the certain degree which makes said rubber wheel chock to rest on the connected said wheels and moved ergonomically to the required distance easily.It is one aspect of the invention is to provide the linear feed system modified to functionally grade the pipeline along its external surface.BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:The embodiment of the patent invention is illustrated with the help of accompanying drawingsThe present study discloses a method of fabricating oil and gas pipelines with an external functional layer. The functional layer is a superior material characteristics compared to the primary material on which it is deposited. The proposed study a describes a method of additively adding the superior material to the parent material by wire arc additive manufacturing and a rotary welding positioner. This method enables the superior material to be added in a form that it is micro structurally bonded to the primary material. In an embodiment, where the functional layers are added to the primary material of pipeline using a cold metal transfer(CMT) wire arc additive manufacturing and rotary welding positioner along the external surface of the pipeline. In an embodiment, where the functional layer is added in a minimum quantity to satisfy the functional requirement.BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGThe accompanying drawings are intended to provide further understanding of invention and are incorporated in and constitute a part of invention. The drawings illustrate an embodiment of invention and together with the description illustrate principle of invention.The drawings should not be taken as implying any necessary limitation on the essential scope of invention. The drawings are given by way of non-limitative example to explain the nature of the invention.For a more complete understanding of the instant invention references now made to the following description taken in conjunction with accompanying drawings.The various feature of novelty which characterize the invention are pointed out specifically in the claims which a part of description. For a better understanding of the invention, its operating advantage, specific objects by its use, reference should be made to the drawings and descriptive matter is which there are illustrated and described preferred embodiments ofinvention.Referring now to the drawings, where like numerals designate identical or corresponding parts throughout the referred views.Figure. 1 illustrates schematic view of a platform in an offshore environment where the hydrocarbons are produced through the marine riser and transported through an oil and gas pipeline to the onshore facility after separation through an export riser according to an exemplary embodiment of the present disclosure.Figure. 2 illustrates the experimental setup for adding functional material along the external surface of the main pipeline using rotating weld positioner with a liner feed cold metal transfer weld torch by additive manufacturing, according to an exemplary embodiment of thepresent disclosure.Figure. 3 shows the main pipeline (left) and additively added functionally layers to the external surface of the main pipeline (right) with according to an exemplary embodiment of the present disclosure.The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the methods illustrated herein may be employed without departing from the principles of the disclosure described herein.The invention has been explained in relation to specific embodiment. It is referred that the foregoing description is only illustrative of the present invention and it is not intended that the invention be limited or restrictive thereto. Many other specific embodiments of the present invention will be apparent to one skilled in the art from the foregoing disclosure. All substitution, alterations and modifications of the present invention, which come within the scope of the following claims, are to which the present invention is readily susceptible without departing from the spirit of the invention.The scope of the invention should therefore be determined not with reference to the above description but should be determined with reference to appended claims along with full scope of equivalents to which such claims are entitled.Advantages:• Functionally graded materials can withstand very high thermal gradient, this makes it suitable for use in structures and space plane body, rocket engine component etc.• Has the ability to inhibit crack propagation• Used in energy conversion devices.Increasing distributors' profits

Claims

1. A system (1) for a method of functionally grading marine risers externally with a method of manufacturing thereof, comprising: an oil and gas platform (101); an offshore environment (102); a riser segment (103) to transport the oil and gas platform; a separator (104) to separate the oil and gas; a rotating welding positioner (105) to cause rotation; a rack and pinion (201) controlled by program; a carriage (202) to facilitate the additive process; a cold metal transfer weld torch (204) attached to a carriage; a height adjustable manual feed (203) to facilitate the additive process; an additively added functional layer (501) deposited on the main riser pipe; an internally graded functional layer (301) formed after deposition; an extension attachment (401) moving on a rack and pinion carriage; and an additively add and form internal functional layers (501) along the inner surface of the main pipe.

2. The system as claimed in claim 1, wherein the functionally grading marine risers externally is to prevent high corrosion in an exterior surface of the pipelines deployed in an offshore environment.

3. The system as claimed in claim 1, wherein the additive process is achieved by said cold metal transfer weld torch (204) attached to a carriage (202) using height adjustable manual feed (203), comprising; placing said riser segment (103) as its one end clamped to the rotating welding positioner (205) and rotated, the said cold metal transfer weld torch (204) is attached to a carriage that is moving on a said rack and pinion (201) which programmed by a numerical control.

4. The system as claimed in claim 1, wherein the linear movement of the carriage (202) rotation of the carriage at a specific speed would additively add the functional layer on the said main riser pipe segment (103) and the cold metal transfer weld deposition parameters are determined by experiments.

5. The system as claimed in claim 1, wherein the additively added functional layer (301) is deposited on the said main riser pipe segment (103), once the carriage moves from one end to the other, the weld deposition parameters are selected in such a way that it forms a continuous deposit on the pipe in a circular manner as the pipe rotates in the positioner.

6. The system as claimed in claim 1, wherein the rotating welding positioner (205) rotation is combined with the weld torch integrated linear feed system for the functionally grading process along the external surface.

7. The system as claimed in claim 1, wherein the functional layers are added to the primary material of pipeline using a cold metal transfer (CMT) wire arc additive manufacturing and rotary welding positioner along the internal surface of the pipeline.

8. The system as claimed in claim 1, wherein the linear feed system modified to functionally grade the pipeline along its inner surface.