Update: Bush to urge lifting of ban on offshore drilling
“With gasoline now over $4 a gallon, tomorrow he will explicitly call on Congress to also pass legislation lifting the congressional ban on safe, environmentally friendly offshore oil drilling,” White House spokeswoman Dana Perino said on Tuesday.
Offshore Drilling
The following post is a reply to Dan Daniels who recently visited this blog and left a comment at Bering Sea Drilling .
Dan Daniels wrote:
I was the District Manager for Sedco Forex responsible for exp[l]oration activities on the West Coast of the US including the Bering Sea. I had two semi-submersible drilling vessels working in the Bering Sea when environmental concerns required us to cease drilling activities.
In the 8 plus years we, as a company, operated in this area we NEVER had an environmental issue (not so much as a st[y]rofoam cup going over the side) – this with daily high scrutiny from the Department of the Interior. I even received an award on behalf of our company for this accomplishment.
I believe strongly that with proper controls, commitment from management, training and overview offshore drilling can be accomplished without detriment to the environment. The issue lies almost exclusively with shipping the product, not developing the field. We should make every effort to carry out the require exploration and focus our efforts on improving the transportation aspects of moving the petroleum products
An offshore Oil/Gas platform.
Mr Daniels,
We [the FEWW moderators] believe the problems are much more extensive than you have stated. The areas of greatest concern are
- Impacts of excessive energy consumption.
- Climate Change.
- Other impacts of excessive CO2 and other GHG pollution created by the consumption of fossil fuels, e.g., oceans acidification.
- Marine pollution, habitat destruction and other damage caused by offshore oil and gas drilling including
- Exploration
- Production
- Transportation
- Storage
- Delivery
The specific items of concern include:
- Flaring and venting
- greenhouse gas emissions
- Decommissioning of oil and gas installations
- oil storage tank disposal
- Pollution created by drill cuttings
- Produced waters, muds and fluids
- Subsidence
- Spills
- piping
- Environmental impact of products
- Health impact of processes in products
- Spoilage of sensitive ecological areas and habitat destruction
- Waste disposal
- Health impact of processes in products
- Impact on Marine Mammals and other life forms
- Human Health Impact
- Climate Change
- Release of benzene, methanol, sulfur and other harmful chemicals to the environment
- Discharge of ballast waters
- Release of tank cleaning water
- Impact on ecosystems
The following excerpts are from Sense and Nonsense:The Environmental Impacts of Exploration on Marine Organisms Offshore Cape Breton, by David Lincoln.
Sense and Nonsense
The environmental impacts of the Oil and Gas Industry’s exploration operations are pervasive. No country or province which has been exposed to a prolonged history of offshore hydrocarbon exploration has been left untouched by the inevitable accidents and unforeseen consequences of the petroleum industry.
The fishing industry is usually the first sector to be impacted by these exploration activities. This normally occurs when fishermen are told to remove their boats and gear from an area so that a seismic vessel can begin generating noises.
By far the loudest noises generated by the offshore petroleum industry are those produced by seismic survey equipment. This equipment is designed to create very loud noises, the echoes of which reflect off geological strata deep within the seabed and are used to locate likely places for drilling wells. The sounds were at one time made by explosives, which could kill fish at a range of some hundreds of meters, but the almost universal seismic equipment now used offshore is an array of “airguns”.
Seismic Effects on Fish and Marine Mammals
Experiments on the effects of seismic shooting on abundance and catch of cod and haddock were conducted in the Barents Sea. The Norwegian studies looked at the effects of an airgun using a combination of scientific-survey and commercial fishing techniques. The fish survey work extended across a circle 40 nautical miles in diameter (a maximum range of some 33 km from the airgun survey area) and continued until five days after the seismic work was completed..”
Since the fall of the Iron Curtain, information has begun to flow out about the Russian experience with decades of exploration activity in the Caspian and Barents Seas. These reports differ markedly from the rather subdued observations in Western Bloc countries. Dr Stanislav Patin in his 1999 book entitled “Environmental Impacts of the Offshore Oil and Gas Industry” recalls a catastrophic ecological situation in the Caspian Sea in the 1960’s. “I was a member of the Special Government Committee on this issue and witnessed firsthand the dramatic ecological consequences of the explosive use, including mass mortality of Caspian sturgeons (up to 200,000 large specimens).”
Exploration Drilling
Despite industry claims, the companies do not yet know for certain which type of hydrocarbon (oil, gas, condensate or a combination of these fluids. will be encountered). Vintage seismic data from the 1980’s cannot accurately distinguish between oil and gas and geochemistry, if available, is often difficult to interpret. Before drilling, the companies will conduct a hazard survey primarily to reduce the chances of encountering shallow gas which could be disastrous.
Shallow seismic surveys of the upper few hundred meters of the seabed are often carried out to determine the structure of the sediments and scan for potential hazards to drilling (e.g., shallow gas pockets). These hazards will be described in greater detail in the section on shallow gas blowouts.
The Drilling Phase
Under normal circumstances, the predominant discharges during drilling, would be the “cuttings”; small chips of rock cut by the drill in forming the well, and the “muds” used in the drilling process to cool and lubricate the drill, carry the cuttings out of the hole and counter-balance the pressure of gas, when that is reached. These discharges, their fates and their environmental effects have been the most intensively studied (and argued) aspect of the offshore petroleum industry’s environmental effect.
Mud and Cuttings Discharges: Water Based Muds (WBMs)
Besides their intended constituents, drill muds, both Water Based Muds (WBMs) and Oil Based Muds (OBMs), often contain high levels of heavy metal contamination. WBMs, despite their water base, also often contain appreciable amounts of oil: under some circumstances, it is necessary to add a “pill” of oil to the circulating WBM and this is usually left in the mud, gradually being dispersed through it and ultimately discharged
with it.
The overall quantities of WBM discharged can be high. While the water naturally disperses into the ocean, the other constituents represent substantial contamination. The eight exploratory wells drilled with WBM on Georges Bank in 1981-2, for example, resulted in some 4000 tons of barite and 1500 tons of bentonite clay being discharged.
Mud and Cuttings Discharges: Water Based Muds (WBMs)
Besides their intended constituents, drill muds, both Water Based Muds (WBMs) and Oil Based Muds (OBMs), often contain high levels of heavy metal contamination. WBMs, despite their water base, also often contain appreciable amounts of oil: under some circumstances, it is necessary to add a “pill” of oil to the circulating WBM and this is usually left in the mud, gradually being dispersed through it and ultimately discharged with it.
The overall quantities of WBM discharged can be high. While the water naturally disperses into the ocean, the other constituents represent substantial contamination. The eight exploratory wells drilled with WBM on Georges Bank in 1981-2, for example, resulted in some 4000 tons of barite and 1500 tons of bentonite clay being discharged.
Water-Based Mud
The composition of drilling mud may be changed often during drilling in response to conditions encountered. In practice, this usually means that mud weight is gradually increased by adding barite and other chemicals to control the natural pressure increase with depth. When this happens suddenly, the mud is dumped in bulk and a new batch is mixed (often with heavier properties in anticipation of increased pressure). Analysis of the drilling waste scenario data (volume density and weight) could yield a likely
composition. It is indeed strange that adult scallops are highly sensitive to barite but show relatively low sensitivity to used water based mud cuttings.
Furthermore, dozens of organisms have already been subjected to varying compositions of drilling mud and the toxicity results are known and well reported. Of 415 acute lethal bioassays lasting 48-144 hrs with 68 drilling muds involving 70 species, 8% showed 50% mortality (LC50) below 10,000 ppm.
Ecosystem Impacts
“There is concern that the routine discharge of wastes during drilling for oil and gas could impact valuable fishery resources. Recent studies have indicated that intensive drilling efforts in the North Sea have caused detrimental effects in adult and larval fish and benthic invertebrates at greater distances from drilling platforms than previously envisaged”.
Abundance of benthic organisms near one N.J. rig site plunged from 8011 animals /sqm before drilling to 1729 animals /sq m. during drilling. One year after drilling was completed, the number had risen to only 2638 animals /sq m. Diversity was also impacted from 70 to 38 species /0.02 sq m rebounding only to 53 species /0.02 sq m one year afterwards.
Discharges and Shellfish
Laboratory experiments have shown barium uptake, from WBM-contaminated sediments and foods, by both flounder and lobster juveniles but there does not seem to be any evidence for its biomagnification up the food chain. In the experimental setting, the contaminants suppressed growth of both species and enhanced lobster mortality but this was with concentrations of 9 g barium per kilogram of sediment and a 98 or 99-day …
Certainly, its finer grain size should ensure that it is at least as mobile as the barite and probably more so. Recent research has shown that scallops are peculiarly susceptible to barite and bentonite, prolonged exposure to even concentrations as low as 10 mgl-1 (less than 10 ppm) being fatal, while levels as low as 2 mgl-1 can affect scallop growth.
“As mush as 90% of the discharged solids settle directly to the bottom. (Brandsma 1980). The remaining 10% including clay-sized particles and soluble materials is diluted by the current and dispersed over large areas8. ” Furthermore “during the entire [one well] scenario a total of 468 MT of drilling mud and 2569 MT of cuttings are released to the marine environment.
Now that it has been shown that drilling eight wells spread detectable levels of barite over much of Georges Bank, the COPAN drilling near Sable Island spread flocculant material some kilometers from the source, Norwegian oil production has affected benthic communities over some 100 sq km around major platforms and that background sediment hydrocarbon levels seem to be rising in the United Kingdom sector of the North Sea, the relevance of such impacts can no longer be ignored.
Shallow Gas Blowouts
One of the greatest risks to the environment during the exploration phase is a shallow gas blowout. This is particularly true if the flow is associated with a condensate discharge which frequently occurs. […] Once flow has started, it is almost inevitable that a blowout will occur.
“Cratering occurs when flow outside the casing displaces large volumes of surface sediment. The eruptive force of blowouts can be dramatic and has been documented as lifting large boulders weighing several hundred pounds into the air and dropping them as much as 150 ft from the well site.
“Records show that if a shallow gas blowout does not bridge within the first one to two days, then the well will probably continue to blow for an extended period of time, i.e., weeks or months. Some have continued for years.”
Adams includes a chart condensed from a database of 950 shallow gas blowouts. Of the 56 rigs listed more than half suffered extensive damage or the total loss of the rig.
The truth is that the biological impacts of gas and condensate spills have been poorly studied until recently. Even the Uniacke gas blowout which released condensate in 1984 was not evaluated for biological impacts. Gas blowouts such as occurred in India in 1999 are poorly reported and not studied in detail. It is ludicrous for the industry to argue that gas wells have little impact on the ecosystem when they have not looked carefully at the marine organisms effected and no long-term studies on productivity or reproductive success following exposure are known to exist.
Related Links:
List of references cited for Sense and Nonsense:The Environmental Impacts of Exploration on Marine Organisms Offshore Cape Breton, by David Lincoln, is available at the URL: http://www.sierraclub.ca/national/oil-and-gas-exploration/sense-and-nonsense.pdf
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