Monthly Archives: July 2010

ROV Thomas Jefferson Finds Seeps Near Rigel Methane Field

Just click this link instead of reading my post and speculations to make up your own mind without my ramblings I’ve posted just for my own study:
 http://www.floridaoilspilllaw.com/at-least-six-seeps-found-near-rigel-well-southwest-of-bp-oil-blow-out-photos

…………………… Several seeps southwest of the BP blow-out were first reported on June 21, 2010 by scientists aboard the R/V Thomas Jefferson. The seepage “appears to be natural gas” (methane) according to the NOAA report  http://www.noaanews.noaa.gov/stories2010/20100620_jefferson.html

………………….Former Shell Oil executive and current Berkeley engineering professor Robert Bea is “troubled that we’re just now hearing about seeps three kilometers away, because a survey of the seabed conducted before BP drilled its well didn’t indicate anything like that,” according to the Times-Picayune http://www.nola.com/news/gulf-oil-spill/index.ssf/2010/07/gas_seeps_not_necessarily_a_pr.html

…………………………………………..July 23 JAG report image shows areas of seepage near the BP blow-out, with the majority appearing near the Rigel gas field…………………..More information on the Rigel gas field:  http://www.floridaoilspilllaw.com/breaking-feds-seepage-likely-from-the-rigel-well-a-highly-successful-unproduced-gas-field  and  http://www.floridaoilspilllaw.com/rigel-gas-field-flowing-bps-blownout    video of Coast Guard admitting seeps 3 kilometers from Mocando Oil Well site……………………………The Rigel exploration well, the Texaco OCS-G-18207 #1, was drilled in 1999 in Gulf of Mexico block MC 252 in 5200’ water depth. The well targeted a Miocene age, low-relief downthrown closure/stratigraphic trap that was supported by a strong amplitude response on the 3D seismic data. … The well encountered what was interpreted to be a 176’ thick gas-charged, low-permeability siltstone in the Rob E-age target. …The appraisal drilling by Dominion, the operator, with its partners, Mariner and Newfield, was highly successful. As a result, the Rigel field is currently being developed as a one-well subsea tieback, as part of a larger subsea system. The project is nearly complete Wednesday 16-Nov-05.  http://www.spegcs.org/en/cev/?864   …………………..

Now I am getting a bit alarmed!  I’m just a layperson trying to make connections to all the events, geology, and well sites, active as well as inactive, and the people involved.  My studies of these have lead me to understand that the area concerned is filled with salt diaper/ batholithic formations and asphaltic volcanoes of an active nature.  Now adding this information of the Rigel gas field near by the Macondo oil drill site I am amazed that anyone would undertake such a dangerous region, dangerous depth, and close proxcimity to a methane gas well of that magnitude.  I know very little, yet it sounds dangerous to me!   Again here’s this material and all these links are found here:
  http://www.floridaoilspilllaw.com/breaking-feds-seepage-likely-from-the-rigel-well-a-highly-successful-unproduced-gas-field
…………………………………………………………….Here is history of Two (2) linked (by alrea flowline) gas wells, Rigel and 17 Hands:…………………………Houston, TX … The MTS Houston Section will meet on May 25, 2006 to hear a presentation on the Rigel/17 Hands Development given by Dominion’s Project Manager, Lawrence L. Starlight. Rigel/17 Hands is a two-well, subsea, dry gas development in the Mississippi Canyon 252 area of the Gulf of Mexico, in water depths ranging from 3400 feet to 5800 feet. The two wells are tied back to the Chevron VK 900 host facility via the alrea flowline. All the equipment and controls were designed to be compatible with the existing Chevron system.  The distance from the host facility to the Rigel and 17 Hands wells is approximately 40 and 50 miles, respectively. Combined flow rates from the two dry gas wells is around 150 MMCFPD. Partners in the development are Dominion, the operator, Mariner, Murphy, Newfield and Hydro (formerly Spinnaker). The host facility and Gemini subsea manifold are owned and operated by Chevron……………………………….http://www.oilonline.com/News/NewsArticles/articleType/ArticleView/articleId/17354/MTS-Houston-presentation-May-25-to-feature-Dominions-Rigel17-Hands-Subsea-Development-in-the-GOM.aspx …………………………………………………….
More background:  Dominion Exploration and Production has made a deepwater discovery at its Rigel prospect, located at Mississippi Canyon Block 296 in the Gulf of Mexico. The discovery is located in about 5,200′ of water… drilled to a total depth of about 16,200′ and encountered 140′ of gross gas pay in the main Rob E objective…………………………Speculation about a possible impact on the Rigel well did occur at the Oil Drum. Once. About a month ago.  BP’s Deepwater Oil Spill – The Admiral on Casing and Connections, Oil Drum, June 21, 2010:  http://www.theoildrum.com/node/6637
COMMENT BY ‘LURKING’
Anybody happen to know if the Rigel or 17 Hands gas fields are in danger of being affected by fluids from the BP stovepipe?…The reason I ask is that over the last few days, I’ve seen what appear to be more gas in the plume… as if I can tell what it is when I see it. I’m referring to the globs of bluish white that you see in the plume.. not the milky dispersant from the nozzles. I have no idea what the pay depth for those two fields are, but if they are contributing to the flow… that would be bad.
RESPONSE BY ‘BIGNERD’  Funny, I was looking at that the other day.  I’ve got a map which shows what I think is the Macondo well over to the east side of the 252 block, whereas the Rigel field straddles the southern boundary.  The Seventeen Hands gas line and an oil export line from Na Kika both cross the block in the south and west.  So all other on block infrastructure looks to be about 3 km to the south and west of the Macondo well.
RESPONSE BY ‘LURKING’  The Rigel prospect has a measured depth of 16,200 feet. Macondo was drilled to 18,000 feet (and change). …[I]t seems to me that 3 to 7 miles is not that far in strata that is as close as 340 vertical feet apart and that varies from impermeable to highly porous.  [The Macondo well] had to drill past (through?) that level [of the Rigel well] with what is now a casing of dubious integrity.  *sigh….

Next in the article is a Bathymetry Map of the Macondo area and other visuals.  Main link:  http://www.floridaoilspilllaw.com/at-least-six-seeps-found-near-rigel-well-southwest-of-bp-oil-blow-out-photos

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What’s Beneath? Matt Simmons 2 Interviews

So many of the reports on the oil situation are just handsome/pretty talking heads reading their parts in complete ignorance of what they’re asking or what their guests are answering to their scripted questions. Watch these two hosts in video on Bloomberg TV from July 21, 2010.   See how absolutely uncomprehending they are.  Matt Simmons tried to tell them that three (3) separate things; the riser, blowout preventer, and the casing are completely disconnected from the drilled oil well and now it’s just a big open hole that is gushing into the Gulf of Mexico.  It was so plain to my ears, but they didn’t understand at all!
http://www.youtube.com/watch?v=DwX9RXFRJD4

I wanted to get a picture in my mind of the parts of the operation so I started looking it up and found this:
http://www.economist.com/node/16160853?story_id=16160853

The Economist May 20, 2010………………………..The riser connected Deepwater Horizon to its blowout preventer, a stack of valves on the sea floor which marked the top of the well proper (see illustration). When the rig sank, the riser broke near the top while remaining attached to the blowout preventer at the bottom, bending itself like a pretzel in its subsequent collapse. Some oil is now flowing from where the riser and the blowout preventer meet; most is coming from the broken end of the riser, which has ended up about 300 metres away on the sea floor. It is from a tube slipped into that distal end that oil is now being pumped up to Discoverer Enterprise and its attendant barges………………………………

It appears that article may have been inaccurate.  Here is another opinion:

Matt Simmons was interviewed on July 19 in a report on MSNBC by Dylan Ratigan.   http://www.youtube.com/watch?v=-2Qj6tNYMPE
Simmons said that the BOP (Blowout Preventer) was five stories tall and,  “…….What we’re seeing (on the TV cameras) is not the open hole,……… it is not a seep,…..it’s a hole in the earth caused by a drill bit operated by BP………….It’s time to say enough is enough, the whole industry is not dishonest, there are a lot of good people who work for BP………..They’re hands are tied…………….We need to start investigations by interviewing the 100 people under the top 20 people in charge who aren’t letting those 100 employees and witnesses talk”
Looking at the illustration after Simmons pointed out that the BOP was five (5) stories tall made me put together how great the pressure would have had to be to blow that assenbly out of the miles deep well up through the casing, and BOP, and then all the way up to cause the aircraft-carrier-sized-rig to explode, burn and sink. 

Enemy of the State

Enemy of the State
Julian Assange of Wiki Leaks interviewed
Some Accomplishments Listed at http://en.wikipedia.org/wiki/Wikileaks

Internet censorship lists  Wikileaks has published the lists of forbidden or illegal web addresses for several countries.  On 19 March 2009, Wikileaks published what was alleged to be the Australian Communications and Media Authority’s blacklist of sites to be banned under Australia’s proposed laws on Internet censorship.  Bilderberg Group meeting reports  Since May 2009, Wikileaks has made available reports of several meetings of the Bilderberg Group.  2008 Peru oil scandal  On 28 January 2009, Wikileaks released 86 telephone intercept recordings of Peruvian politicians and businessmen involved in the “Petrogate” oil scandal. The release of the tapes led the front pages of five Peruvian newspapers……………….Toxic dumping in Africa: The Minton report  In September 2006, commodities giant Trafigura commissioned an internal report about a toxic dumping incident in the Ivory Coast…………..9/11 pager messages  On 25 November 2009, Wikileaks released 570,000 intercepts of pager messages from the day of the September 11 attacks………………..Baghdad airstrike video  Main article: July 12, 2007 Baghdad airstrike  On 5 April 2010, Wikileaks released classified U.S. military footage from a series of attacks on 12 July 2007 in Baghdad by a U.S. helicopter that killed 12, including two Reuters news staff, Saeed Chmagh and Namir Noor-Eldeen, on a website called “Collateral Murder”. The footage consisted of a 39-minute unedited version and an 18-minute version which had been edited and annotated………………http://en.wikipedia.org/wiki/Wikileaks

Naturally-Occurring Radioactive Materials (In Oil & Gas Deposits)

 http://www.epa.gov/rpdweb00/tenorm/oilandgas.html#howmuchradiation

Oil and Gas Production Wastes

The geologic formations that contain oil and gas deposits also contain naturally-occurring radionuclides, which are referred to as “NORM” (Naturally-Occurring Radioactive Materials):
uranium (and its decay products)
thorium (and decay products)
radium (and decay products)
lead-210
Geologists have recognized their presence since the early 1930s and use it as a method for finding deposits (Ma87).

Much of the petroleum in the earth’s crust was created at the site of ancients seas by the decay of sea life. As a result, petroleum deposits often occur in aquifers containing brine (salt water). Radionuclides, along with other minerals that are dissolved in the brine, precipitate (separate and settle) out forming various wastes at the surface:  mineral scales inside pipes sludges contaminated equipment or components produced waters. Because the extraction process concentrates the naturally occurring radionuclides and exposes them to the surface environment and human contact, these wastes are classified as TENORM.    

How are drilling wastes produced?

The briney solution contained in reservoirs of oil and gas is known as “formation water.” During drilling, a mixture of oil, gas, and formation water is pumped to the surface. The water is separated from the oil and gas into tanks or pits, where it is referred to as “produced water.” As the oil and gas in the reservoir are removed, more of what is pumped to the surface is formation water. Consequently, declining oil fields generate more produced water.
While uranium and thorium are are not soluble in water, their radioactive decay product, radium, and some of its decay products are somewhat soluble. Radium and its decay products may dissolve in the brine. They may remain in solution or settle out to form sludges, which accumulate in tanks and pits, or mineral scales, which form inside pipes and drilling equipment.

How much radiation is in the wastes?

Because radium levels in the soil and rocks vary greatly, so do their concentrations in scales and sludges. Radiation levels may vary from background soil levels to as high as several hundred nanoCuries per gram. The variation depends on several factors:
concentration and identity of the radionuclides
chemistry of the geologic formation
characteristics of the production process (McA88).
The table below shows the range of activities in these wastes:
Wastes Radiation Level [pCi/g]  low          average         high
Produced Water [pCi/l]             0.1           NA               9,000
Pipe/Tank Scale [pCi/g]            <0.25       100,000
The Radiation in TENORM Summary Table provides a range of reported concentrations, and average concentration measurements of NORM associated with various waste types and materials.

Waste Types and Amounts

Each year the petroleum industry generates around 150,000 cubic meters (260,000 metric tons) of waste including produced water, scales, sludges, and contaminated equipment. The amount produced at any one oil reserve varies and depends on several factors:
geological location
formation conditions
type of production operation
age of the production well.
An estimated 30 percent of domestic oil and gas wells produce some TENORM (McA88). In surveys of production wells in 13 states, the percent reporting high concentrations of radionuclides in the wells ranged from 90 percent in Mississippi to none or only a few in Colorado, South Dakota, and Wyoming (McA88). However, 20 to 100 percent of the facilities in every state reported some TENORM in heater/treaters.

Produced Waters

The radioactivity levels in produced waters are generally low, but the volumes are large. The ratio of produced water to oil is approximately 10 barrels of produced water per barrel of oil. According to the American Petroleum Institute (API), more than 18 billion barrels of waste fluids from oil and gas production are generated annually in the United States.
Produced waters contain levels of radium and its decay products that are concentrated, but the concentrations vary from site to site. In general, produced waters are re-injected into deep wells or are discharged into non-potable coastal waters.

Scale

Scale is composed primarily of insoluble barium, calcium, and strontium compounds that precipitate from the produced water due to changes in temperature and pressure. Radium is chemically similar to these elements and as a result is incorporated into the scales. Concentrations of Radium-226 (Ra-226) are generally higher than those of Ra-228.  Scales are normally found on the inside of piping and tubing. The API found that the highest concentrations of radioactivity are in the scale in wellhead piping and in production piping near the wellhead. Concentrations were as high as tens of thousands of picocuries per gram. However, the largest volumes of scale occur in three areas:
water lines associated with separators, (separate gas from the oil and water)
heater treaters (divide the oil and water phases)
gas dehydrators, where scale deposits as thick as four inches may accumulate .
Chemical scale inhibitors may be applied to the piping complexes to prevent scales from slowing the oil extraction process. If the scales contain TENORM, the radiation will remain in solution and eventually be passed on to the produced waters.
Approximately 100 tons of scale per oil well are generated annually in the United States. As the oil in a reservoir dwindles and more water is pumped out with the oil, the amount of scale increases. In some cases brine is introduced into the formation to enhance recovery; this also increases scale formation.
The average radium concentration in scale has been estimated to be 480 pCi/g. It can be much higher (as high as 400,000 pCi/g) or lower depending on regional geology.

Sludge

Sludge is composed of dissolved solids which precipitate from produced water as its temperature and pressure change. Sludge generally consists of oily, loose material often containing silica compounds, but may also contain large amounts of barium. Dried sludge, with a low oil content, looks and feels similar to soil.
Oil production processes generate an estimated 230,000 MT or five million ft3 (141 cubic meters) of TENORM sludge each year. API has determined that most sludge settles out of the production stream and remains in the oil stock and water storage tanks.
Like contaminated scale, sludge contains more Ra-226 than Ra-228. The average concentration of radium in sludges is estimated to be 75 pCi/g. This may vary considerably from site to site. Although the concentration of radiation is lower in sludges than in scales, sludges are more soluble and therefore more readily released to the environment. As a result they pose a higher risk of exposure.
The concentration of lead-210 (Pb-210) is usually relatively low in hard scales but may be more than 27,000 pCi/g in lead deposits and sludge

Contaminated Equipment

TENORM contamination levels in equipment varied widely among types of equipment and geographic region. The geographic areas with the highest equipment readings were northern Texas and the gulf coast crescent from southern Louisiana and Mississippi to the Florida panhandle. Very low levels of TENORM were found in California, Utah, Wyoming, Colorado, and northern Kansas.  According to an API industry-wide survey, approximately 64 percent of the gas producing equipment and 57 percent of the oil production equipment showed radioactivity at or near background levels. TENORM radioactivity levels tend to be highest in water handling equipment. Average exposure levels for this equipment were between 30 to 40 micro Roentgens per hour (μR/hr), which is about 5 times background. Gas processing equipment with the highest levels include the reflux pumps, propane pumps and tanks, other pumps, and product lines. Average radiation levels for this equipment as between 30 to 70 μR/hr. Exposures from some oil production and gas processing equipment exceeded 1 mR/hr.
Gas plant processing equipment is generally contaminated on the surface by lead-210 (Pb-210). However, TENORM may also accumulate in gas plant equipment from radon (Rn-222) gas decay. Radon gas is highly mobile. It originates in underground formations and dissolves in the organic petroleum areas of the gas plant. It concentrates mainly in the more volatile propane and ethane fractions of the gas.
Gas plant scales differ from oil production scales, typically consisting of radon decay products which accumulate on the interior surfaces of plant equipment. Radon itself decays quickly, (its half-life is 3.8 days). As a result, the only radionuclides that affect disposal are the radon decay products polonium-210 (Po-210) and lead-210. Polonium-210 is an alpha emitter with a half-life of 140 days. Pb-210 is a weak beta and gamma emitter with a half-life of 22 years.

Disposal and Reuse: Past Practices

Recycling of Metals
Before the accumulation of TENORM in oil production equipment was recognized, contaminated materials were occasionally recycled for use in making steel products:
load-supporting beams in house construction
plumbing for culinary water
fencing materials
awning supports
practice welding material in class rooms.

Disposal of Wastes

When sludge fouling in water and oil storage tanks became a problem, the tanks were drained and the sludge disposed of in waste pits:
Burn pits
Earthen pits were previously used for temporary storage an periodic burning of non-hazardous oil field wastes collected from tanks and other equipment.
Brine pits
Lined and/or earthen pits were previously used for storing produced water and other nonhazardous oil field wastes, hydrocarbon storage brine, or mining wastes. In this case, TENORM in the water will concentrate in the bottom sludges or residual salts of the ponds. Thus, the pond sediments pose a potential radiological health risk. The radionuclides in these soils have been reported to be in the range from 270 to 1100 pCi/g.

Disposal and Reuse: Current Practices

Recycling of Metals
Now that the petroleum industry is aware of the potential for contamination, they take a number of precautions before recycling:
Loads of scrap metal are surveyed for hidden radioactive sources and TENORM.
Piping and equipment are cleaned before release for recycling at smelters.
Pollution control devices, such as filters and bubblers, are installed in smelter stacks to reduce airborne radiation releases.
Although much of the NORM-contaminated equipment is presently stored in controlled areas, some companies are now cleaning the equipment and proposing to store it at designated disposal sites.

Waste disposal

The average concentration of the radium in the oil and gas wastes at offsite and onsite disposal facilities is approximately 120 pCi/g.
Sludges containing elevated TENORM are now dewatered and held in storage tanks for later disposal.
Produced waters are now generally reinjected into deep wells or, in the case of offshore production facilities, are discharged into non-potable coastal waters. No added radiological risks appear to be associated with this disposal method as long as the radioactive material carried by the produced water is returned in the same or lower concentration to the formations from which it was derived. As of 1992 there are 166,000 injection wells in 31 states.
Pipes contaminated with scale are cleaned at pipe yards either by sandblasting them with high pressure water or by scraping out the scale with a rotating drill bit. The removed scale is then placed in drums and stored for later disposal.
Contaminated equipment may either be cleaned and reused by the petroleum industry; disposed; or, if radiation levels are sufficiently reduced, sold for recycle. If equipment cannot be further decontaminated to acceptable levels, it is sent to a landfill licensed to accept NORM materials.
In some cases contaminated steel may be reprocessed via smelting. During the smelting process molten steel separates from the NORM which vaporizes and is released as a gas. If the steel mill has pollution control equipment, most of the NORM is trapped in the baghouses and scrubbers. A typical smelting operation is capable of capturing 99 percent of the particulate releases.

Exposure Risks

TENORM contamination in oil production waste came to the attention of industry and government in 1986 when, during routine well work in Mississippi, barium sulfate scale in tubing was found to contain elevated levels of levels of radium-226, and thorium-232.
Because of concerns that some pipes may have contaminated the surrounding environment, radiological surveys were conducted by EPA’s Eastern Environmental Radiation Facility. These surveys showed that some equipment and disposal locations exhibited external radiation levels above 2 mR/hr and radium-226 soil contamination above 1,000 pCi/g. Some contamination had also washed into a nearby pond and drainage ditch at one site, as well as into an agricultural field with subsequent uptake of radium by vegetation.
Because TENORM contaminated wastes in oil and gas production operations were not properly recognized in the past, disposal of these wastes may have resulted in environmental contamination in and around production and disposal facilities. Surface disposal of radioactive sludge/scale, and produced water (as practiced in the past) may lead to ground and surface water contamination.
Those at risk include:
oil/radiation waste disposal workers
nearby residents/office workers.

Oil/Radiation Waste Disposal Workers

Disposal workers include those who work directly on top of uncovered waste sites. Potential risks assessed for these workers include exposures due to direct gamma radiation and radioactive dust inhalation. In addition, they may inhale radon gas which is released during drilling and produced by the decay of radium, raising their risk of lung cancer. Workers following safety guidance will reduce their total on-site radiation exposure.

Nearby Residents/Office Workers

Risks evaluated for members of the public working or residing within 100 meters of a disposal site are similar to those of disposal workers. They include: direct gamma radiation, inhalation of contaminated dust, inhalation of downwind radon, ingestion of contaminated well water, ingestion of food contaminated by well water, and ingestion of food contaminated by dust deposition.
Risks analyzed for the general population within a 50 mile radius of the disposal site include exposures from the downwind transport of re-suspended particulates and radon, and exposures arising from ingestion of river water contaminated via the groundwater pathway and surface runoff. Downwind exposures include inhalation of re-suspended particulates, ingestion of food contaminated by deposition of re-suspended particulates, and inhalation of radon gas.
Individuals working inside an office building inadvertently constructed on an abandoned NORM waste pile also face the threat of radiation exposure. Potential risks assessed for the onsite individual include exposures from direct gamma radiation, dust inhalation, and indoor radon inhalation.

http://www.epa.gov/radtown/drilling-waste.html#protect_yourself What you can do to protect yourself: U.S. Environmental Protection Agency  At this site you will find information on how to reduce total on-site radiation exposure at oil and gas drilling facilities.

What is Being Done About These Wastes

The problem of TENORM contamination is now known to be widespread, occurring in oil and gas production facilities throughout the world. It has become a subject of attention in the United States and in other countries. In response to this concern, facilities in the U.S. and Europe have been characterizing the nature and extent of TENORM in oil and gas pipe scale, evaluating the potential for exposure to workers and the public, and developing methods for properly managing these low specific-activity wastes.
Both the oil and gas industry and state regulatory agencies are currently examining and regulating TENORM in oil and gas production facilities. The API has sponsored studies to characterize accumulations of TENORM in oil field equipment and to evaluate methods for its disposal. The API has also formed an Ad Hoc Committee on Low Specific-Activity (LSA) Scale and has prepared a draft measurement protocol for identifying producing areas where NORM scale is known to exist. The Part N Subcommittee of the Conference of Radiation Control Program Directors has been working since 1983 to develop model state regulations (Part N of Suggested State Regulations for Control of Radiation) for the control of NORM. While these regulations are intended to apply generally to all NORM-containing materials, several parts would apply specifically to oil and gas industry pipe scale.
Many states with oil and gas production facilities are currently creating their own NORM regulations. For example, the State of Louisiana has regulations for NORM in scales and sludges from oil and gas production that differ from the Part N model regulations, where the State of Texas has NORM regulations similar to Part N regulations.

Resources

http://www.epa.gov/compliance/resources/publications/assistance/sectors/notebooks/oilgaspt3.pdf  Sector Notebook Project – Oil and Gas Extraction (PDF) (41 pp, 444K [about pdf format] ) 2000. U.S. Environmental Protection Agency, Office of Enforcement and Compliance Assurance  This document provides a description of the oil and gas extraction process, how to comply with EPA’s health and the environmental laws and techniques for pollution prevention.

http://www.epa.gov/radtown/drilling-waste.html#whos_protecting_you Who is Protecting you? U.S. Environmental Protection Agency  This site lists a number of federal and state agencies responsible for regulating radioactive materials and workers safety.

http://www.epa.gov/radiation/understand/health_effects.html Health Effects U.S. Environmental Protection Agency Site provides information on the health effects associated with a range of radiation exposures.

http://www.osha.gov/dts/hib/hib_data/hib19890126.html Potential Health Hazards Associated with Handling Pipe Used in Oil and Gas Production 26 January 1989. OSHA Hazard Information Bulletins. U.S. Department of Labor, Occupational Safety and Health Administration  This document warns workers of possible inhalation or ingestion of radioactive material in cutting and welding oil and gas pipes.

The American Petroleum Institute  http://www.api.org/
Trade association that represents all aspects of America’s oil and natural gas industry.

http://www.epa.gov/rpdweb00/tenorm/oilandgas.html#howmuchradiation
Last updated on Tuesday, May 18, 2010