Pipeline Gooseneck

A gooseneck (or goose neck) is a 180° pipe fitting at the top of a vertical pipe that prevents entry of water. Common implementations of goosenecks are ventilator piping or ducting for bathroom and kitchen exhaust fans, ship holds, landfill methane vent pipes, or any other piping implementation exposed to the weather where water ingress would be undesired. It is so named because the word comes from the similarity of the pipe fitting to the bend in a goose's neck.

Gooseneck may also refer to a style of kitchen or bathroom faucet with a long vertical pipe terminating in a 180° bend.

To avoid hydrocarbon accumulation, a thermosiphon should be installed at the low point of the gooseneck.

 Bibliography :
http://en.wikipedia.org/wiki/Gooseneck_%28piping%29
http://www.merriam-webster.com/dictionary/gooseneck

Subsea Tie in system

Subsea Tie-in Systems

Subsea flowlines are used for the transportation of crude oil and gas from subsea wells, manifolds, off-shore process facilities, loading buoys, S2B (subsea to beach), as well as re-injection of water and gas into the reservoir. Achieving successful tie-in and connection of subsea flowlines is a vital part of a subsea field development.

Vertikal tie in system

Subsea fields are developed using a variety of tie-in solutions. Over the past decade, FMC Technologies has developed a complete range of horizontal and vertical tie-in systems and associated connection tools used for the tie-in of flowlines, umbilicals and jumper spools sizes 2” - 36” and for single and multibore application. FMC’s horizontal and vertical tie-in systems have been extensively installed in many of the deepest, highest pressure and largest diameter subsea applications around the world.

Vertical Tie-in Systems

Vertical connections are installed directly onto the receiving hub in one operation during tie-in. Since the Vertical Connection System does not require a pull-in capability, it simplifies the tool functions, provides a time efficient tie-in operation and reduce the length of Rigid Spools.

Stroking and connection is carried out by the the Connector itself, or by the ROV operated Connector Actuation Tool (CAT) System.

Horizontal Tie-in Systems

Horizontal Tie In system

Horizontal Tie-in may be used for both firstend and second-end tie-in of both flowlines, umbilicals and Jumper spools. The termination head is hauled in to the Tie-in point by use of a subsea winch. Horizontal Tie-in may be made up by Clamp Connectors operated from a Tie-in tool, by integrated hydraulic connectors operated through the ROV, or by non-hydraulic collet connectors with assistance from a Connector Actuation Tool (CAT) and ROV. Horizontal connections leave the flowline/umbilical in a straight line, and is easy to protect if overtrawling from fishermen should occur.

Bibliography : http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCoQFjAA&url=http%3A%2F%2Fwww.fmctechnologies.com%2F~%2Fmedia%2FSubsea%2FTechnologies%2FTieInSystems%2FColleteral%2FSubsea%2520Tie%2520In%2520Systems_low%2520res.ashx%3Fforce%3D1%26track%3D1&ei=CkLPVJTyOc_v8gXctoHACQ&usg=AFQjCNFjkS1ah2m-bzSTWjfoH7Jo02ZvMw&sig2=qJA1wo9XeXVtbxxQILvmTg&bvm=bv.85076809,d.dGc

Pipe in Pipe Flowline

A PiP (pipe-in-pipe) is a pipe inserted inside another pipe. The created intermediate annulus can be used to place an insulation material usually known as dry insulation. Indeed this insulation material is protected by the outer pipe from the hydrostatic pressure and from water penetration. PiP generally allow reaching optimized thermal performance compared with wet insulated lines.

ITP pipe-in-pipe flowline solutions are unique since they combine excellent thermal performance with a fast offshore Field Joint (FJ) technique.

On one hand, the ITP solution offers the best thermal performance in the market within the most compact design due to the features of the proprietary IzoflexTM insulation that can be described as follows: - Best as-installed thermal conductivity on the market (7mw/mK). - Mineral structure: silica based, no ageing. - Wide temperature application range (-195 to 900 °C/-320 to 1600°F) - Base material proven in industries such as aeronautics, automotive & nuclear since the 1960's - In operation since 1998 in subsea oil and gas flowlines. - Load bearing insulation: no need for centralizers, the IzoflexTM acts as a continuous centralizer due to its excellent compressive strength. On the other hand, ITP developed a specific Field Joint solution for J-lay and S-lay operations to achieve enhanced layrates and therefore reduce the cost of offshore installation by a factor of at least 2 compared with conventional PiP designs. Please refer to ITP Field Joint section. ITP Pipe-in-Pipes are suited for shallow, deep and ultra deep water as well as HP/HT fields.		Pipe-in-Pipe using ITP swaged end design

1. Pipe-in-Pipes for shallow and deep water applications

ITP systems are particularly well suited for shallow, deep and ultra deep offshore projects: - The pipe in pipe structure accommodates large hydrostatic pressure. - Due to the low thermal conductivity of IzoflexTM, only a thin layer of insulation is required to obtain highly insulated systems, which reduces the outer pipe size and thickness, thus reducing weight and costs (less welding time, less steel). - The compact & efficient insulation allows long tiebacks and long cooldown time. - For J-lay & S-lay, the specific ITP Field Joint (FJ) allows a quick offshore installation (one single weld offshore). - The ITP single/double/quad joint design offer integrated water stop and buckle arrestor every 12/24/48 metres.

Insulation of Quad Joints (48m/158ft) for DeepWater Rosa, Angola

Double Joints assembly yard, Forvie North project	Double Joints ready for collection, Bonga project

2. High Pressure/High Temperature

High Pressure (HP), typically 500bar+ (7252psi+) internal pressure, has a major impact on the flowline design since it can lead to very high wall thicknesses, which makes the fabrication and installation more complex (longer welding times, heavier system ...) High temperature (HT), typically greater than 90°C (194°F) , means that the system operates over a great temperature range between non-producing situations, such as installation, shutdown and the operational case. It implies the use of specific materials to address issues such as fatigue life. ITP offers solutions that comply with HP / HT requirements & constraints: - The insulation, IzoflexTM, can operate up to 900°C (1650°F) without any damage. - The high thermal efficiency of the system allows reducing the flowline thermal variations (increasing fatigue life). - ITP provided the first HP/HT PiP in the North Sea, the (SHELL ETAP project) operating since 1998 at 610bar-155°C/8847psi-311°F. Bibliography : http://www.itp-interpipe.com/products/pipe-in-pipes/pipe-in-pipes.php

Forvie HP/HT Project

Pig Launcher

Pig traps are used for inserting pigs into a pipeline then launching, receiving, and finally removing them without flow interruption. Pig traps are not generally proprietary products and are usually made to a specification drawn up by the user. However, pig trap closures are proprietary products and form a critically important part of a pigging system. Safety is a major consideration in the selection of a closure. All closures must have a built-in safety lock which prevents them being opened while the trap is pressurised.

   

Pig Launcher and Receiver with GD Closure (263 psig at 185°F) view project details	High Pressure Pig Launcher and Receiver (671 psig at 175°F) view project details
Pig Launchers and Receivers (512 psig at 100°F) view project details	Pig Launchers and Receivers with Safety Locking System (675 psig at 200°F) view project details
Standard Pig Launcher Application Standard Pig Receiver Application

 

Bibliography :

http://www.circorenergy.com/pipeline-solutions/pig-launchers-and-receivers.php

http://www.swecofab.com/pig-launcher-receivers.htm

http://ppsa-online.com/about-pigs.php

 

how does pipeline pigging work

While buildup in a pipeline can cause transmittal slows or even plugging of the pipeline, cracks or flaws in the line can be disastrous. A form of flow assurance for oil and gas pipelines and flowlines, pipeline pigging ensures the line is running smoothly.

The maintenance tool, pipeline pigs are introduced into the line via a pig trap, which includes a launcher and receiver. Without interrupting flow, the pig is then forced through it by product flow, or it can be towed by another device or cable. Usually cylindrical or spherical, pigs sweep the line by scraping the sides of the pipeline and pushing debris ahead. As the travel along the pipeline, there are a number functions the pig can perform, from clearing the line to inspecting the interior.

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Foam pig Source: www.pollypig.com

There are two main hypotheses for why the process is called "pipeline pigging," although neither have been proved. One theory is that "pig" stands for Pipeline Intervention Gadget. The other states that a leather-bound pig was being sent through the pipeline, and while it passed, the leather squeaked against the sides of the pipe, sounding like a squealing pig.

Engineers must consider a number of criteria when selecting the proper pig for a pipeline. First, it's important to define what task the pig will be performing. Also, size and operating conditions are important to regard. Finally, pipeline layout is integral to consider when choosing a pig.

Because every pipeline is different, there is not a set schedule for pigging a line, although the quantity of debris collected in a pipeline and the amount of wear and tear on it can increase the frequency of pigging. Today, pipeline pigging is used during all phases of the life of a pipeline.

Types of Pipeline Pigs

Although first used simply to clear the line, the purpose of pipeline pigging has evolved with the development of technologies. Utility pigs are inserted into the pipeline to remove unwanted materials, such as wax, from the line. Inline inspection pigs can also be used to examine the pipeline from the inside, and specialty pigs are used to plug the line or isolate certain areas of the line. Lastly, gel pigs are a liquid chemical pigging system.

Debris after piggingSource: www.ppsa-online.com

Similar to cleaning your plumbing line, utility pigs are used to clean the pipeline of debris or seal the line. Debris can accumulate during construction, and the pipeline is pigged before production commences. Also, debris can build up on the pipeline, and the utility pig is used to scrape it away. Additionally, sealing pigs are used to remove liquids from the pipeline, as well as serve as an interface between two different products within a pipeline. Types of utility pigs include mandrel pigs, foam pigs, solid cast pigs and spherical pigs.

Pipeline pigSource: www.pipeline-pigging.com

 

Inspection pigs, also referred to as in-line inspection pigs or smart pigs, gather information about the pipeline from within. . The type of information gathered by smart pigs includes the pipeline diameter, curvature, bends, temperature and pressure, as well as corrosion or metal loss. Inspection pigs utilize two methods to gather information about the interior condition of the pipeline: magnetic flux leakage (MFL) and ultrasonics (UT). MFL inspects the pipeline by sending magnetic flux into the walls of the pipe, detecting leakage, corrosion, or flaws in the pipeline. Ultrasonic inspection directly measures the thickness of the pipe wall by using ultrasonic sounds to measure the amount of time it takes an echo to return to the sensor

Specialty pigs, such as plugs, are used to isolate a section of the pipeline for maintenance work to be performed. The pig plug keeps the pipeline pressure in the line by stopping up the pipeline on either side of where the remedial work is being done.

A combination of gelled liquids, gel pigs can be used in conjunction with conventional pigs or by themselves. Pumped through the pipeline, there are a number of uses for gel pigs, including product separation, debris removal, hydrotesting, dewatering and condensate removal, as well as removing a stuck pig.

Because there now exist multi-diameter pipelines, dual and multi-diameter pigs have been developed, as well.

Bibliography :

https://www.rigzone.com/training/insight.asp?insight_id=310&c_id=19

Crack on offshore pipeline

Introduction

High pressure long distance pipelines transporting gas, crude oil or products are inspected by intelligent pigs for the location of defects. These inspections are an important contribution to the continued safe operation of these pipelines.

Typical defects are geometrical anomalies, metal loss and crack-like defects. Intelligent pigs are measuring robots which are propelled through the pipeline to detect defects, using appropriate measuring techniques.

For geometrical anomalies, pigs with mechanical sensors have been used for many years. It is customary to inspect new pipelines with calliper pigs prior to commissioning.

In the 1970s metal loss (corrosion) was the type of anomaly that caused the development of the first intelligent pigs. For metal loss two technologies are customarily used: the ultrasonic method, which measures the wall thickness directly, or the magnetic flux leakage (MFL) method, which responds to the change of the magnetic field in the presence of metal loss.

The ultrasonic method is the more accurate method, but a coupling liquid is required to apply the ultrasonic pulse to the pipe wall. It is therefore mainly used in liquid pipelines. The MFL method, on the other hand, does not require a coupling liquid and is therefore the preferred method for gas pipelines. Both types of instrument have been operated for many years and play a central role in the upkeep and maintenance of high pressure long distance pipelines.

During the 1990s longitudinal crack like defects began to appear additionally in more and more pipelines causing serious problems. This led to the development of a new generation of crack detection pigs.

Types of Cracks

Even though isolated fatigue cracks have been seen since the 1970s, it was the increased appearance of stress corrosion cracking (SCC) defects in the 1990s that led to some spectacular pipeline failures in Russia and North America. Figure 1 shows typical SCC colony.

SCC develops in pipelines under narrowly defined conditions. These include: susceptibility of the steel, moisture of the soil, soil chemistry, quality of the coating, variable stress and highly increased temperatures. SCC first appeared in the above mentioned areas mainly in high pressure pipelines directly downstream of compressor stations and now also occurs more and more often in liquid pipelines, even though these lines do not display increased temperatures.

Apart from SCC, metal fatigue cracks are becoming increasingly common, mainly due to the increasing accumulated number of pressure cycles in the aging pipeline population.

Cracks, which influence the structural integrity of the pipeline, are mainly longitudinally orientated, caused by the predominant stress distribution in the steel. Fatigue cracks can grow both from the internal or the external surface of the wall. Because of the growth mechanism, SCC cracks are external defects.

Bibliography :

http://pipeliner.com.au/news/crack_detection_in_gas_pipelines/043294/