Connect with us

Features

When Deadman could not prevent disaster

Published

on

Biggest marine oil spill in history

 

By Captain Chandra
Godakanda Arachchi
Member of Company of Master Mariners
Gladstone LNG (Oil and gas producer and exporter)

Deepwater Horizon (DH) was a semi-submersible drill rig, which operated in a depth of approximately 1600 metres in the Gulf of Maxico. On charter to British Petroleum (BP), it was drilling possibly to a depth of 2,600 metres below the seabed about 50 miles off the Louisiana coast, within the exclusive economic zone of the US when an explosion occurred on 10 April 2010, killing 11 and injuring 17; 94 workers on board were rescued.

Crude oil and natural gas from the DH well continued to flow post explosion for 87 days until BP finally managed to cap it on 15 July 2010 and shut the flow. Consequently, the incident caused an unprecedented spill (780,000 cubic meters of crude oil as per the government data) although BP mentioned a lower amount. Worse, an unestimable amount of gas escaped into the atmosphere. The accident took a heavy toll on marine life, shore birds, shorelines, beaches, etc., even beyond the Gulf of Mexico. Dolphins, tuna, turtles, etc., died in large numbers. BP took up the challenge of cleaning up the mess, spending huge amount of dollars. Extensive cleaning continued for four long years. BP established a fund, the Gulf Coast Claims Facility with US$ 20 billion, to settle the claims.

The amount of crude oil that escaped from DH well is about 19 times what gushed out of the tanker, Exxon Valdez, which grounded in Alaska in 1989. This amount would have been sufficient for the Sapugaskanda Refinery for more than 100 days.

What went wrong on the fateful day? Here is what is thought to have happened!

Drilling an oil well is a highly skilled and specialised work. Once the site is determined for drilling post seismic surveys of the area, then a drilling rig is assembled at the correct location with all required material including safety gear. Drilling rigs use pipes which are about 20 metres in length, join these together as the drill head finds its way down. Drilling involves creating a flow path (deep hole or a well bore) under reservoir pressure thousands of meters below earth surface. The drill head can pass through various layers of earth crust, which can contain oil, gas and water under pressure, and this can lead to a dangerous unplanned release of oil and gas (or ‘kicks’). If a “kick” is not arrested in time, it can lead to a blowout of oil and gas from the well. In order to control such ‘kicks’, there is a specific piece of safety equipment known as “blowout preventer (BOP), installed close to the seabed, fitted on a larger pipe connected to the rig. Essentially, the drill pipe which is smaller is located inside this larger pipe. The space between the larger pipe and the drill pipe is called the annulus. In order to arrest unplanned ‘kicks’ in the first instance, drilling mud is pumped into the annulus space to create a barrier between the reservoir and the rig pipe work. BOP is used for emergency shutdown (ESD) in case drilling mud fails to arrest the ‘kicks’. The BOP, a complex piece of safety equipment operated electrically under hydraulic pressure, consists of additional layers of protection, depending on the level of the emergency. It will be curtains for the well bore if the last line of defence, “Deadman” is activated as it effectively seals the annulus and the drill pipe completely. Deadman is, therefore, used only as a last resort.

On 20 April, 2010 it was yet another evening for the crew on DH. They had to contend with various operational matters in the process of drilling the wellbore at Mundo Prospect. They were drilling in 5,000 feet of water, a depth not easy at all to reach for any emergency work. There was an undetected ‘kick’ occurring at 2045 hrs with oil and gas moving quickly up the annulus to the rig with 126 crew members on board. Oil and gas pressure was forcing the drill mud on to the rig at 2140 hrs. The crew responded by activating the upper annulus preventer in the BOP. However, activation of BOP did not seal the well, and oil and gas continued to gush out. The crew then responded by closing the pipe shear ram (hydraulic rams crushing the outer pipe to get a seal). Pipe shear rams appeared to have sealed the annulus successfully although that turned out to be only a temporary fix. Oil and gas continued to flow above the rams, which eventually found an ignition source at 2149 hrs, causing an explosion on the rig. As the rams had partially blocked the annulus the pressure above them beginning to drop, creating a big pressure differential between the drill pipe and the annulus. The drill pipe shut from the top at the time was subject to pocket pressure. Investigators believe that huge differential pressure may have contributed to buckling (or bending) of the drill pipe in the centre, thereby shutting mechanisms and rendering them ineffective as rams could not reach the shut-off position. This proved to be catastrophic. Investigators have expressed concern that existing rigs may face similar situations.

Deadman can be operated manually by the crew as a last report or it gets activated automatically when conditions for such activation occur like the loss of main power, hydraulic pressure and communication for the logic controller to send the output (signal) to activate the mechanism. The rig had lost power due to the explosion, and hydraulic pressure owing to the disruption of the hydraulic pressure units, which were probably damaged due to the explosion, thereby causing a loss of pressure. Communication to Deadman from logic controller was also lost. Deadman has a separate logic controller though it is linked to the main logic controller all the time whilst monitoring the conditions and remaining ready for automatic activation if required. Deadman, when activated, under right conditions essentially crushes the pipe work thereby sealing the well bore completely.

Deadman is operated not by main power but by uninterrupted power supply (UPS -battery backup) with 27V and 9 V batteries to power emergency functions and operate shear ram blades. In fact, there is a secondary back-up system (redundant system) for shear rams emergency shutdown as well. But the investigators found evidence to suggest that this vital piece of equipment to be used as a last resort had been wrongly wired and did not function. One system of Deadman shear ram blades got activated, but it faced the problem of the buckled pipe line and could not seal the pipeline completely. If the pipeline not been bucked, the shear ram blades would have greatly reduced the impact of the incident. There was nothing else to stop the massive oil spillage and destruction of the rig.

DH continued to burn for two days before sinking. Crude oil and gas from the well bore continued to pollute the Gulf of Mexico for 87 days. Emergency shutdown systems (ESD), whether on a rig, ship or in any other plant in operation are very important equipment; they must be maintained and tested regularly as required, if disasters like the aforesaid one are to be averted.



Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Features

Strong on vocals

Published

on

The group Mirage is very much alive, and kicking, as one would say!

Their lineup did undergo a few changes and now they have decided to present themselves as an all male group – operating without a female vocalist.

At the helm is Donald Pieries (drums and vocals), Trevin Joseph (percussion and vocals), Dilipa Deshan (bass and vocals), Toosha Rajarathna (keyboards and vocals), and Sudam Nanayakkara (lead guitar and vocals).

The plus factor, where the new lineup is concerned, is that all five members sing.

However, leader Donald did mention that if it’s a function, where a female vocalist is required, they would then feature a guest performer.

Mirage is a very experience outfit and they now do the Friday night scene at the Irish Pub, in Colombo, as well as private gigs.

 

 

Continue Reading

Features

Dichotomy of an urban-suburban New Year

Published

on

Ushered in by the ‘coo-ee’ of the Koel and the swaying of Erabadu bunches, the Sinhala and Tamil New Year will dawn in the wee hours of April 14. With houses to clean, preparation of sweetmeats and last-minute shopping, times are hectic…. and the streets congested.

It is believed that New Year traditions predated the advent of Buddhism in the 3rd century BC. But Buddhism resulted in a re-interpretation of the existing New Year activities in a Buddhist light. Hinduism has co-existed with Buddhism over millennia and no serious contradiction in New Year rituals are observed among Buddhists and Hindus.

The local New Year is a complex mix of Indigenous, Astrological, Hindu, and Buddhist traditions. Hindu literature provides the New Year with its mythological backdrop. The Prince of Peace called Indradeva is said to descend upon the earth to ensure peace and happiness, in a white carriage wearing on his head a white floral crown seven cubits high. He first plunges, into a sea of milk, breaking earth’s gravity.

The timing of the Sinhala New Year coincides with the New Year celebrations of many traditional calendars of South and Southeast Asia. Astrologically, the New Year begins when the sun moves from the House of Pisces (Meena Rashiya) to the House of Aries (Mesha Rashiya) in the celestial sphere.

The New Year marks the end of the harvest season and spring. Consequently, for farming communities, the traditional New Year doubles as a harvest as well. It also coincides with one of two instances when the sun is directly above Sri Lanka. The month of Bak, which coincides with April, according to the Gregorian calendar, represents prosperity. Astrologers decide the modern day rituals based on auspicious times, which coincides with the transit of the Sun between ‘House of Pisces’ and ‘House of Aries’.

Consequently, the ending of the old year, and the beginning of the new year occur several hours apart, during the time of transit. This period is considered Nonegathe, which roughly translates to ‘neutral period’ or a period in which there are no auspicious times. During the Nonegathe, traditionally, people are encouraged to engage themselves in meritorious and religious activities, refraining from material pursuits. This year the Nonegathe begin at 8.09 pm on Tuesday, April 13, and continues till 8.57 am on 14. New Year dawns at the halfway point of the transit, ushered in bythe sound of fire crackers, to the woe of many a dog and cat of the neighbourhood. Cracker related accidents are a common occurrence during new year celebrations. Environmental and safety concerns aside, lighting crackers remain an integral part of the celebrations throughout Sri Lanka.

This year the Sinhala and Tamil New Year dawns on Wednesday, April 14, at 2.33 am. But ‘spring cleaning’ starts days before the dawn of the new year. Before the new year the floor of houses are washed clean, polished, walls are lime-washed or painted, drapes are washed, dried and rehang. The well of the house is drained either manually or using an electric water pump and would not be used until such time the water is drawn for first transaction. Sweetmeats are prepared, often at homes, although commercialization of the new year has encouraged most urbanites to buy such food items. Shopping is a big part of the new year. Crowds throng to clothing retailers by the thousands. Relatives, specially the kids, are bought clothes as presents.

Bathing for the old year takes place before the dawn of the new year. This year this particular auspicious time falls on April 12, to bathe in the essence of wood apple leaves. Abiding by the relevant auspicious times the hearth and an oil lamp are lit and pot of milk is set to boil upon the hearth. Milk rice, the first meal of the year, is prepared separate. Entering into the first business transaction and partaking of the first meal are also observed according to the given auspicious times. This year, the auspicious time for preparing of meals, milk rice and sweets using mung beans, falls on Wednesday, April 14 at 6.17 am, and is to be carried out dressed in light green, while facing east. Commencement of work, transactions and consumption of the first meal falls on Wednesday, April 14 at 7.41 am, to be observed while wearing light green and facing east.

The first transaction was traditionally done with the well. The woman of the house would draw water from the well and in exchange drop a few pieces of charcoal, flowers, coins, salt and dried chillies into the well, in certain regions a handful of paddy or rice is also thrown in for good measure. But this ritual is also dying out as few urban homes have wells within their premises. This is not a mere ritual and was traditionally carried out with the purification properties of charcoal in mind. The first water is preferably collected into an airtight container, and kept till the dawn of the next new year. It is believed that if the water in the container does not go down it would be a prosperous year. The rituals vary slightly based on the region. However, the essence of the celebrations remains the same.

Anointing of oil is another major ritual of the New Year celebrations. It falls on Saturday, April 17 at 7.16 am, and is done wearing blue, facing south, with nuga leaves placed on the head and Karada leaves at the feet. Oil is to be applied mixed with extracts of Nuga leaves. The auspicious time for setting out for professional occupations falls on Monday, April 19 at 6.39 am, while dressed in white, by consuming a meal of milk rice mixed with ghee, while facing South.

Traditionally, women played Raban during this time, but such practices are slowly being weaned out by urbanization and commercialisation of the New Year. Neighbours are visited with platters of sweetmeats, bananas, Kevum (oil cake) and Kokis (a crispy sweetmeat) usually delivered by children. The dichotomy of the urban and village life is obvious here too, where in the suburbs and the village outdoor celebrations are preferred and the city opts for more private parties.

 

 

Continue Reading

Features

New Year games: Integral part of New Year Celebrations

Published

on

Food, games and rituals make a better part of New Year celebrations. One major perk of Avurudu is the festivals that are organised in each neighbourhood in its celebration. Observing all the rituals, like boiling milk, partaking of the first meal, anointing of oil, setting off to work, are, no doubt exciting, but much looked-forward-to is the local Avurudu Uthsawaya.

Avurudu Krida or New Year games are categorised as indoor and outdoor games. All indoor games are played on the floor and outdoor games played during the Avurudu Uthsava or New Year festival, with the whole neighbourhood taking part. Some of the indoor games are Pancha Dameema, Olinda Keliya and Cadju Dameema. Outdoor games include Kotta pora, Onchili pedeema, Raban geseema, Kana mutti bindeema, Placing the eye on the elephant, Coconut grating competition, Bun-eating competition, Lime-on-spoon race, Kamba adeema (Tug-o-War) and Lissana gaha nageema (climbing the greased pole). And what’s an Avurudhu Uthsava sans an Avurudu Kumari pageant, minus the usual drama that high profile beauty pageants of the day entail, of course.

A salient point of New Year games is that there are no age categories. Although there are games reserved for children such as blowing of balloons, races and soft drinks drinking contests, most other games are not age based.

Kotta pora aka pillow fights are not the kind the average teenagers fight out with their siblings, on plush beds. This is a serious game, wherein players have to balance themselves on a horizontal log in a seated position. With one hand tied behind their back and wielding the pillow with the other, players have to knock the opponent off balance. Whoever knocks the opponent off the log first, wins. The game is usually played over a muddy pit, so the loser goes home with a mud bath.

Climbing the greased pole is fun to watch, but cannot be fun to take part in. A flag is tied to the end of a timber pole-fixed to the ground and greased along the whole length. The objective of the players is to climb the pole, referred to as the ‘tree’, and bring down the flag. Retrieving the flag is never achieved on the first climb. It takes multiple climbers removing some of the grease at a time, so someone could finally retrieve the flag.

Who knew that scraping coconut could be made into an interesting game? During the Avurudu coconut scraping competition, women sit on coconut scraper stools and try to scrape a coconut as fast as possible. The one who finishes first wins. These maybe Avurudu games, but they are taken quite seriously. The grated coconut is inspected for clumps and those with ungrated clumps are disqualified.

Coconut palm weaving is another interesting contest that is exclusive to women. However men are by no means discouraged from entering such contests and, in fact, few men do. Participants are given equally measured coconut fronds and the one who finishes first wins.

Kana Mutti Bindima involves breaking one of many water filled clay pots hung overhead, using a long wooden beam. Placing the eye on the elephant is another game played while blindfolded. An elephant is drawn on a black or white board and the blindfolded person has to spot the eye of the elephant. Another competition involves feeding the partner yoghurt or curd while blindfolded.

The Banis-eating contest involves eating tea buns tied to a string. Contestants run to the buns with their hands tied behind their backs and have to eat buns hanging from a string, on their knees. The one who finishes his or her bun first, wins. Kamba adeema or Tug-o-War pits two teams against each other in a test of strength. Teams pull on opposite ends of a rope, with the goal being to bring the rope a certain distance in one direction against the force of the opposing team’s pull.

Participants of the lime-on-spoon race have to run a certain distance while balancing a lime on a spoon, with the handle in their mouths. The first person to cross the finish line without dropping the lime wins. The sack race and the three-legged race are equally fun to watch and to take part in. In the sack race, participants get into jute sacks and hop for the finish line. The first one over, wins. In the three-legged race one leg of each pair of participants are tied together and the duo must reach the finish line by synchronising their running, else they would trip over their own feet.

Pancha Dameema is an indoor game played in two groups, using five small shells, a coconut shell and a game board. Olinda is another indoor board game, normally played by two players. The board has nine holes, four beads each. The player who collects the most number of seeds win.

This is the verse sung while playing the game:

“Olinda thibenne koi koi dese,

Olinda thibenne bangali dese…

Genath hadanne koi koi dese,

Genath hadanne Sinhala dese…”

Continue Reading

Trending