05.07.2009

What is special about uranium? Some atoms are so unstable that they can split, or fission, thereby releasing energy. Some atoms need only a nudge from a neutron to fission. They are called “fissile”. In nature, there is only one fissile isotope, uranium-235. This makes uranium unique among the chemical elements. Uranium ore is mined and refined into a yellow colored solid uranium compound referred to as “yellow cake”. The yellow cake is converted into various uranium metal alloys or compounds to be used as nuclear fuel What is the composition of natural uranium? Uranium in nature has three isotopes. Only 0.72 percent of uranium isotopes is the fissile isotope, uranium-235. Most uranium, 99.2745 percent, is uranium-238. The rest, 0.0055 percent, is uranium-234. Uranium-238 and uranium-234 are not fissile, but they are still valuable. They are called “fertile,” which are atoms that become fissile when they absorb or capture a neutron. Uranium-234 absorbs a neutron and turns into uranium-235. Uranium-238 absorbs a neutron and eventually turns into plutonium-239, which is fissile but not found in nature. What is enriched uranium? The amount of uranium-235 compared to uranium-238 determines how energetic nuclear fuel is. Natural uranium is not energetic enough to use as fuel in light water reactors; it cannot sustain fission reactions. Instead, such reactors need uranium with a higher fraction of uranium-235 than is found in nature, which is called “enriched”. Light water reactors use fuel that is generally three to five percent uranium-235. When used in current nuclear power plants, one uranium pellet the size of the tip of your little finger is equivalent to the energy provided by 1,780 pounds of coal, 17,000 cubic feet of natural gas, or 149 gallons of oil. One ton of uranium produces the same energy as between 10,000 tons and 16,000 tons of oil. Some of the added advantages of uranium is that it comes from diverse sources with the main suppliers operating in politically stable countries which supplies potentially available for hundreds of years. In addition, the high density of uranium means that transport is less vulnerable to disruption and storage than is the case with fossil fuels.

Upstream (exploration and production), midstream (processing and transportation) and downstream (refining and marketing) operations.

Three component sectors define the global oil and gas industry: upstream, midstream, and downstream:

1. Upstream segment of natural gas business – Exploration and Production (E&P) – The E&P cycle includes exploration, appraisal, development, production and abandonment. This phase includes exploration, development, production and marketing of natural gas. Everything from acquiring the seismic data (acquisition, processing and interpretation thereof), processing other data such as well logs, core analysis, integrating all the data, carrying out appraisals, making reserves estimations and chances of success, making decision as to drill or not to drill exploration well, carrying out drilling with the appropri9ate rig, to the phase of development of the field which includes to safely and economically install the appropriate facilities to produce the hydrocarbons discovered in the field.

2. Midstream segment of natural gas business – This is the link between the exploration and production of natural gas or oil and its consumption by end-users. It consists of natural gas gathering, processing, storage and transportation of Petroleum (crude oil, natural gas, LNG). The transportation is done via the construction and operation of high pressure transmission systems and low pressure distribution networks and/or Liquefied Natural Gas facilities (liquefaction, shipping and regasification). The processing phases includes the process of converting the raw fluids from the wellbore into sales quality hydrocarbons and wastes. The process includes inter alia issues such as separators (separates oil, gas and water): compressors (increases pressure to drive the gas); dehydration (removes water from gas); metering (measures volumes/energy of the gas); slug catcher (entry separator designed to cope with surges of fluids). The Transmission and Distribution (T&D) section includes high pressure transmission system and low pressure distribution network pipelines to supply natural gas to the end consumer

3. Downstream segment of the oil and gas business – refers to the refining of crude oil and the Sale & Marketing of natural gas and products derived from the refining of crude oil to end consumers. The end consumers include mostly the gas fired power generation plants and/or industrial and commercial consumers

Thus we have:
Exploration and production
Processing
Transmission and Distribution
LNG
End-Users

The exploration and production portions of the oil and gas industry.

A well located high on a structure where the oil-bearing formation is found at a shallower depth

Located up the slope of a dipping plane or surface. In a dipping (not flat-lying) hydrocarbon reservoir that contains gas, oil and water, the gas is updip, the gas-oil contact is downdip from the gas, and the oil-water contact is still farther downdip