Executive Summary
This brief report examines various engineering aspects of oil spill disasters. It provides that oil disasters can occur when engineering controls, such as a blow out malfunctions, are not met. It also highlights a number of recent major oil disasters and measures undertaken to prevent and mitigate resulting effects. It concludes with recommendations calling for, among other things, aggressive enforcement of drilling regulations, extensive risk assessment programs, and shifting to renewable sources of energy to avoid overreliance on fossil fuels.
Introduction
The demand for oil will continue to rise as the world economy continues to grow. This is because oil, to a large extend, is the major driver of world economies (Fingas 2010). To meet this demand, oil companies are increasingly venturing offshore, in search for natural gas and crude oil deposits beneath ocean floors.
Offshore drilling is a delicate process that occurs at extremes condition of a very high pressure and thousands feet below the sea level.Such an undertaking require high expertise in personnel and sophisticated drilling equipment. Offshore oil spills are one of the worst manmade disasters that can occur.
Lessons from previous disasters show that oil spill results in widespread environmental degradation, loss of life and property, as well as immense financial losses (Petroleum 2011). Engineering controls form one of the major aspects of controlling and mitigating the effects of oil spills.
The purpose of this report is to examine a number of engineering approaches that have been executed in the wake of recent oil spill disasters. This report will inquire the engineering aspects of manmade disasters and oil spills with special focus on oil rigs, causes of oil disasters, engineering response to oil disasters and prevention. Recent major oil disasters will also be presented.
Oil rigs
A drilling rig or oil rig is a structure housing the equipment used to drill for water or natural gas from beneath the earth’s surface (Max Energy Limited 2006). Oil rigs are used in the extraction process of crude oil or gas. They are primarily used during exploration and commercial mining to bore a hole on the ground or ocean floor so that oil can be produced (Max energy Limited 2006).
Drilling rigs are huge structures and they rest on floating structures called platform. They consist of special pumps used to circulate drilling mud, drill bit and the casing used for cooling and removing debris during drilling. Most drilling rigs also feature adjoined workers quarters. (Max energy Limited 2006).
According to the US government’s website naturalgas.org, there are two broad categories of oil rigs: movable and fixed. Movable rigs are always smaller and are used during exploration stages. Examples of such rigs are the drilling barges, jack-up rigs, semi-submersible rigs and drill ships. For commercial exploitation of viable quantities of natural gas and crude oil deposits large fixed rigs are used. These ones are: Fixed platforms, Seastar platforms, Tension-leg platform and star platform.
Major oil disasters
On April 20th 2010, a blast occurred on the Deepwater Horizon rig which was drilling for British Petroleum Oil Company (BP). In the aftermath of the blast, vast amount of crude oil leaked into the Gulf of Mexico water, 11 workers were killed (Meinhold 2010). The rig caught fire before the newly completed Macondo was cemented. Later investigation reports indicated that the rig’s blowout preventers malfunctioning has a big role in the eventual burnt out (Gulf of Mexico Oil Spill 2010).
During the Gulf war in 1991, Iraqi forces opened the channels transporting oil in Kuwait as they flee advancing US army. As a result, over 240 million of crude oil spill into the Persian Gulf.
In 1979, the Ixtoc 1 oil well in the Bay of Campeche, Mexico collapsed after a pressure build up (Casselman 2001). This caused an explosion and a prolonged leakage during which over 140 million of crude oil leaked. In 1976 two full supertankers collided in the Trinidad and Tobago, West Indies resulting the loss of 26 lives and oil spill spillage estimated at 88 million liters.
Other major oil spillage are the Fergame valley in Uzbekistan in 1992 (87.7 million), ABT summer of the Angolan coast in 1991 (80million), the Amoco Cadiz in 1978 off Brittany, France (68.7 million) and the MT Haven Tanker Disaster of 1991 in Genoa Italy (42million) (Casselman 2010) These are just but a few cases selected.
Causes of oil disasters
According to Srinivasan and Halada (2008), the primary causes of engineering calamities are combinations of human factors, design flaws, material failures and extreme conditions or environment.
Borchardt (2010) of ASM’s Mechanical Engineering magazine has listed blow outs as one of the major causes of oil spills. Blow out refers to a surge of oil and gas up the well bore and into the surrounding habitat when a very high pressure of natural gas and crude oil is not well managed in deep water reservoirs.
Between 1980-2008, 173 blowout occurred in drilling projects in the Gulf of Mexico alone (Hoffman 2010). Borchardt attributes the 2010 Deepwater Horizon disaster in Gulf of Mexico to a massive blow out. He states that such occurrences are the case for wells drilled under the depth of ocean exceeding 3000 feet where pressure reaches over 23000 pounds per square inch.
On the other hand, Carl Hoffman, in Popular mechanics, is of the opinion that human and ineffective regulatory oversight also play significant role in oil disasters. He cites poor risk assessment and complacency by regulatory bodies as some of the main causes of the 2010 BP oil disaster.
Hoffman sentiments are shared by Romm (2010) in Climate Progress who cites a number of publications that point to the oil company in question (BP) “recklessness” for lacking safety plans to prevent disaster of such magnitude. Oil disaster also occurs in ocean accidents such as supertankers collisions (Burckhardt 2010).
Emergency fixing and prevention
According to Borchardt (2010) there is a number of measures designed to prevent oil spill during drilling. The aim of these measures is to control the pressure of oil and gas coming up from the well. One of the techniques involves using a drilling fluid to create hydrostatic pressure to check the upward pressure of gas and oil from the ocean well.
Upon completion of drilling, the well is usually filled with completion fluid to prevent the leakage of oil and gas from the deposits rocks. In case the fossil fuel deposits are not of a viable quantity, the well is usually sealed with cement. In this case, the cement displaces the drilling fluid in the well bore, which exits via pipes for storage in tanks on top of the platform (Offshore drilling 2011).
For improved safety and control of emergency spills, oil rigs are fitted with blow out preventers that are designed to prevent the escaping gas and oil from well bore (Borchardt 2010).
Combating emergency oil spills has also involved placing a concrete reinforced with steel dome shaped casing over the mouth of the wellbore (Menihold 2010). This was attempted successfully during the BP oil leak. After the dome is installed the entrapped oil is pumped up to storage tanks.
Freundenrich and Strickland (2010) advocate for thorough operation procedure in supertankers to prevent oil leaks. They propose regular checks on piping system and well as on seals.
Other techniques used to control spillage involve the use of equipment such Dispersants, skimmers vacuums, and booms (Davies 2010). The dispersant breaks up oil particles so that mix them with water thus reducing oil sludge floating to shorelines (Casselman 2010).
Booms are used to confine oil on water within a certain region, it can be further removed using other equipment such as vacuums.
Conclusion
Oil exploration is a complex and risky undertaking that involves extracting oil and natural gas deposits thousand of feet beneath the ocean floor. Sophisticated oil rigs are used to harvest viable quantities of oil and natural deposits. Oil rigs together with other equipment involved in the extraction and transportation of crude oil are prone to unexpected failure.
These catastrophes are influenced by a number of factors that include human factors, design flaws, material failure and extremes of conditions. Engineers are charged with the task of creating designs with less chances of failure. To deter future oil disasters engineering controls need to be complemented with other factors, such as enhanced human efficiency and compliance of necessary oil by oil companies.
Recommendations
Basing on the findings of the research conducted for this report, the following is recommended:
- Enforcement of compliance with local and international regulations by oversighting authorities especially in regard to deepwater oil explorations
- Frequent auditing of oil drilling rigs and companies by international independent agencies to ensure adherence to best industry practices
- Further research into ways of enhancing safe drilling at ocean deep waters.
- Heavy penalties and revocation of operating license for negligent companies.
- Adoption of alternative sources of energy to reduce over dependence on fossil fuel deposits. These include renewable sources of energy such as solar, wind, tidal wave, as well as Hydroelectric power
References
“Gulf of Mexico Oil Spill (2010)“. The New York Times. Web.
“Petroleum“, Pollution Issues Sept 4, 2011,. Web.
Burckhardt, J. K. 2010, ‘Avoiding blowout’, Mechanical Engineering. Web
Casselman, A. 2010. ‘10 biggest oil spills in history’, Popular Mechanics. Web.
Davies, S.2010, ‘BP oil spill disaster cleanup efforts in the Gulf of Mexico’, Engineering & Technolog. Web.
Fingas, M. 2010, Oil Spill Science and Technology. Gulf Professional Publishing, Elsevier.
Freundenrich, C. & Strickland, J. 2010, ‘How Oil drilling works’, Energy Production, Environmental Science, How stuff works, Australia, pp.1-9.
Hoffman, C. ‘Investigative Report: How the BP, oil rig Blowout happened’, Popular Mechanics. Web.
Max energy Limited 2006, Oil rigs and platforms. Web.
Meinhold, B. 2010, ‘First oil container dome shipped to Deepwater Horizon spill’. Web.
Offshore drilling 2011, Naturalgas. Web.
Srinivasan, V. & Halada G, ‘Disasters and Learning Form Failure’, State University of New York. Web.