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Pipeline Challenges Limits of Leak-Tight Pipeline Isolation Capabilities

Written By pipeline-engineer.com on Saturday, October 3, 2020 | 12:48:00 AM

(PGJ) Maintaining the integrity of piping and pipeline infrastructure continues to be of vital importance to owners and operators, particularly as a higher number of pipelines move into their fourth and fifth decade of operation, far beyond their original design life.
 

Despite this, and due to continued integrity management programs and regular inspection, these pipelines continue to operate safely. As part of an integrity management program, pipeline and piping systems require inspection, maintenance, and repair to ensure efficient and safe operation. 
Any interruption to the product flow can be costly for the operator and to the end user in terms of loss of production and potential application of penalty clauses for loss of supply.  
Loss of integrity or malfunction generating a leak to the atmosphere adds major safety consequences and environmental hazards to the loss of production and inventory costs. There are also downstream consequences of prolonged loss of supply to the clients and end users. 
To meet ever-increasing safety standards as the industry strives to continually reduce incidents, the repair and maintenance of aging process pipework and pipeline infrastructure has become increasingly important.  

STATS was contracted to provide leak-tight pipeline isolation services on three pressurized steam lines as part of a larger restoration project at a major refinery in the Middle East. 
Unlike the first project, this scope presented many challenges that would push the limits of current isolation technology and require further research and development to provide an engineered solution capable of isolating each of the high-temperature steam lines. 
The purpose of the restoration project was to rebuild sections of the refinery following a fire that caused damage and limited refinery production capacity. The steam lines to be isolated included a 30-by-30-inch (762-by-762-mm), 24-by-6-inch (610-by-152-mm) and 36-by-10-inch (914-by-254-mm) with temperature ranging from 374° F to 718° F (190° C to 381° C) and pressures from 58 psi to 609 psi (4 bar to 42 bar).
 

Because the pipework was not piggable, the only viable option was to deploy the isolation plugs at locations through a branched fitting (either by welded split tee or mechanical clamp). The clamps with equal-sized branches allowed hot tapping to be conducted to provide access for STATS branch-installed self-energized plugging (BISEP) tool to be deployed into the live steam lines.  


An additional challenge to the project was that the steam pipework was situated 66 feet (20 meters) off the ground, which required scaffolding to be erected at each location. However, space was limited due to surrounding pipework, which added further difficulties. A detailed risk assessment was conducted for each of the steam lines and isolation locations.  

  


The specialist rubber seal was selected for the project due to its performance during testing. Prior to the live deployment, final tests were conducted at the refinery using a 10-inch steam loop. This provided final confirmation that the rubber compound would perform as required at the temperature, pressure and flow conditions of the live pipelines. 


STATS isolation methodology for the high-temperature steam lines was to use the U-bends in the system as the location for the isolation. 

This allowed deployment of a modified BISEP with a single high-temperature seal into the steam line to create a heat barrier. 

The seals on the BISEP were each independently tested, and the annulus void between the seals was vented to create a leak-tight double block and bleed isolation. With the fully tested and constantly monitored BISEP isolating the steam line, an isolation certificate was issued to the client allowing breaking of containment activities to safely take place.  


The client had requested that the split tee fittings were removed from the pipeline after the workscope was completed, so STATS methodology involved using the company’s inline isolation tool to enable the fittings to be cut and removed from the pipeline.

12:48:00 AM | 0 comments

Lagos Explosion: BBC Africa Eye uncovers evidence that contradicts NNPC’s claims

Written By pipeline-engineer.com on Tuesday, September 22, 2020 | 9:09:00 AM

New evidence obtained by BBC Africa Eye contradicts the official explanation for the cause of an explosion which killed 23 people and destroyed a girls boarding school in Lagos, Nigeria, earlier in the year.The blast occurred in Soba, a residential neighbourhood of Lagos, on March 15th, 2020, at about 8:56 am.

In its reaction to the incident at the time, the Nigerian National Petroleum Corporation (NNPC) claimed the explosion occurred as a result of a truck that hit gas cylinders near one of its petroleum pipelines.



But new evidence indicates that the NNPC explanation for the cause of the blast, that decimated over 100,000 square metres of Lagos, is incorrect.

A new video evidence filmed at the explosion site, five minutes before the blast, shows a catastrophic leak of vaporised liquid at the exact location where the NNPC high-pressure petroleum pipeline runs beneath the ground through that area.



The BBC found there was no gas processing plant at the explosion’s epicentre.

Moreover, analysis of gas cylinders found at the site after the blast indicates they could not have been at the centre of the explosion when it happened.



Three specialist engineers – including experts in LPG gas safety, petroleum pipeline safety, and explosions analysis – who have examined video footage all confirm the huge leak of vaporised liquid could not have come from gas cylinders.



The BBC spoke with eyewitnesses who corroborated this claim. None of them mentioned gas cylinders or saw a collision, but four of them independently said the leak was coming out of the ground beside the heavily laden truck.





9:09:00 AM | 0 comments

API calls for pipeline permit reforms following shutdowns

Written By pipeline-engineer.com on Saturday, July 11, 2020 | 12:24:00 AM


WASHINGTON – The American Petroleum Institute released the following statement from President and CEO Mike Sommers in response to the cancellation of the Atlantic Coast Pipeline and a court ruling to shut down the Dakota Access Pipeline. "Between the Atlantic Coast Pipeline cancellation and now the ruling to shut down the Dakota Access Pipeline – we are deeply troubled by these setbacks for U.S. energy leadership. Our nation’s outdated and convoluted permitting rules are opening the door for a barrage of baseless, activist-led litigation, undermining American energy progress and denying local communities the environmental, employment and economic benefits modern pipelines provide. The need to reform our broken permitting system has never been more urgent." API represents all segments of America’s oil and natural gas industry. Its more than 600 members produce, process, and distribute most of the nation’s energy. The industry supports 10.9 million U.S. jobs and is backed by a growing grassroots movement of millions of Americans. API was formed in 1919 as a standards-setting organization. In its first 100 years, API has developed more than 700 standards to enhance operational and environmental safety, efficiency and sustainability.
12:24:00 AM | 0 comments

PT Perusahaan Gas Negara (PGN) begin construction on a 367 km Crude Oil Pipeline in the Rokan Block.

Written By pipeline-engineer.com on Sunday, June 21, 2020 | 7:00:00 PM


Jakarta (ANTARA) - Indonesia's state gas utility PT Perusahaan Gas Negara (PGN) will begin construction on a 367-kilometer (km) crude oil pipeline in the Rokan Block, Riau, in July.



The project, located in the corridors of Minas-Duri-Dumai and Balam-Bangko Dumai, will connect the Rokan oil block to Pertamina's Dumai refinery in the province.



PGN's Director of Infrastructure and Technology Redy Ferryanto stated here on Friday that the project aimed to boost synergy between subsidiaries of the PT Pertamina Group.



The project is projected to boost oil production and lifting from the Rokan Block, the backbone of national oil production, which constitutes one-third of the country's output.



"With budget allocation of some US$300 million, PGN has cut capital expenditure, with efficiency of some 30 percent. The project is estimated to become one of PGN's major projects in its target of capital expenditure for 2020. The Financial Investment Decision (FID) of the Rokan pipelines project is expected to optimize efforts to enhance efficiency," he noted.

Ferryanto affirmed that 250 thousand barrels of oil per day will be transported from Rokan to Pertamina’s refinery in Dumai.



The construction project is targeted for completion by the end of 2021.

The pipeline comprise 12 segments and three stations: Duri, Dumai, and Manifold Batang.



Pertagas, part of Indonesia's Gas Holding, will handle the construction project as well as its operations and maintenance.

The project is envisioned to have a positive impact to augment the company's revenue from crude oil transportation business, particularly for its contractors of the cooperation contract (KKKS), such as PT Chevron Pasific Indonesia (CPI), BOB Bumi Siak Posako, and other KKKS.



"Construction of the pipelines is a national strategic project to support national energy resilience. Oil production in the Rokan Block is expected to increase national oil lifting as a primary energy to boost the national economy," Ferryanto added.
7:00:00 PM | 0 comments

Fire fighting System An Overview

Written By pipeline-engineer.com on Tuesday, May 26, 2020 | 8:20:00 AM

Firefighting

Ian Sutton, in  Plant Design and Operations (Second Edition), 2017


Firewater Systems generally has four main sections:

1.
A supply of firewater. This can come from storage tanks, a firewater lagoon, or a natural body of water such as the sea or a lake or river.
2.
A pumping system that provides a sufficient flow of water to extinguish the fire.
3.
A header network of pipes, often in the form of a ring main that transfers the water from the pumps to the fire.
4.
Hydrants, nozzles, sprinklers, or other local devices for directing the firewater to the location of the emergency.




Fig.1 Below can be used to describe some of the major components of a firefighting system.


The facility is divided into zones. If a fire starts in a particular area, water will flow through the nozzles that protect that area.





If a fire occurs in one of the zones, a fusible link will fail, causing the pressure control deluge valve (PCDV) to open and the main firewater pumps to start. Water will flow out of the sprinkler heads in that zone only. The PCDV can also be tripped manually.
Individual sections can be isolated for maintenance. However, the isolation of one zone should not lead to the isolation of other parts of the system. For example, if Zone 2 in Fig. 12.1 has to be isolated, then Valves A and B will be closed. However, Valve C remains open so that firewater remains available to Zone 3.




The only exception to this policy of having two routes to a zone is with regard to noncritical areas such as the fire training grounds. Such areas can be isolated with a single valve.
There are two firefighting pumps, each with 100% capacity. If one is down for maintenance, the facility still has full firefighting capability.




Pressure is maintained in the header through use of a jockey pump. If the pressure in the header falls—indicating that the firewater is being used somewhere —the main pumps turn on. In some facilities, the jockey pump is primed with cooling water.




If freshwater is used, the main header will generally be liquid full. If it was dry, it would take a long time to fill it—something that would delay the emergency response. However, if seawater is used as the firefighting medium, the headers will normally be dry because they would otherwise be subject to corrosion. If during an emergency a normally freshwater-filled system has to be replenished with more corrosive water (such as seawater), the system can still be considered a freshwater system, assuming that prompt flushing takes place after emergency use to replace the corrosive water in the system.
The sprinkler systems downstream of their own block valves  are generally dry. It will not take long to fill them and having water permanently present could lead to leaks and corrosion.




Fig.1 shows the location of a “Critical Equipment Item.” This means that a high level of fire protection should be applied to that area, either because it is of high value or because a release could cause a major safety problem, maybe by making the fire worse. This area, therefore, is protected from both Zones 4 and 5. Consequently, were one of those zones to be out of service for any reason, the critical equipment would still be protected.




Once the fire has been brought under control the system is reset. If seawater is used, then it is important to flush the zone headers and deluge nozzles with freshwater, otherwise  corrotion products will build up.



Problems with firewater systems can be overlooked for the following reasons:
The system is rarely tested at full capacity so it is possible that it will not work as it should during an emergency. (There are less likely to be problems with hoses, hydrants, and monitors because these items are used on a more regular basis and can be tested more readily.)
The firewater pumps are usually located remotely hence they may not be checked as regularly as process equipment.




For onshore facilities, the firewater header is frequently located underground, thus protecting it from an explosion and vehicle impact. However, putting the header underground can create an “out of sight, out of mind” problem—buried systems may not be inspected and checked as thoroughly as those above ground, hence any problems are not easily seen during the routine external inspections discussed in Chapter 11, Inspection.




They may also be more subject to external corrosion  than if they were above ground. A compromise is to place the header in a below-grade trench. Doing so protects it from explosions but also allows for easy access for inspection and maintenance. This option may also reduce the cost of installation.

8:20:00 AM | 0 comments

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