Gas Reservoir Composition Testing and Analysis.
Intertek provides reservoir gas composition testing, including routine C1 to C6+ testing and extended gas analysis, and determination of inorganic gases like CO2 and N2. Clients are given critical analyses in the assessment of reservoir productivity for both wildcat and production well scenarios.
Gas composition analysis capabilities include stable carbon isotope analysis, allowing determination of the genetic origin of gas in the subsurface, continuity of reservoirs, and sourcing mechanisms for inorganic gases.
Professional sampling and analysis services for the determination of heavy metals in gas (Hg, As) are available, in addition to routine analysis for sulphur based elements such as H2S and Mercaptans. The elements hydrogen, carbon, nitrogen, oxygen and sulphur include two or more naturally occurring isotopes which do not undergo radioactive decay. These isotopic elements are key constituents of hydrocarbon reservoirs. The presence of stable isotopes are powerful tracers of geological processes, including fluids.
Gas Composition technical services:
* Composition Analysis of Gases, C1, C2, C3, C4, C5, C6, C7, C8 and higher, including N2 and CO2
* Calculation of Heating Value, Relative Density and Compressibility Factor. ASTM D1945-96, ASTM D3588-98
* C1 to C5+ Headspace Gas analysis GC/FID
* Stable Isotope Analysis of Gases Isotope using Mass Spectrometer
* Real Time Measurement of Methane Isotopes
* Natural Gas Testing
Hydrocarbon gases detected and analyzed include Methane, Ethane, Propane, Butane, Pentane and higher. Gas sources include dissolved gas, associated gas, non-associated gas, natural gas liquids, sweet gas and sour gas. Non-hydrocarbon gases include Nitrogen and Carbon Dioxide.
Natural Gas Composition services:
* Coalbed Methane and Shale Gas Services
* Gas Hydrates Evaluation and Testing
* LPG and LNG Testing and Inspection
* Natural Gas Testing
Wednesday, April 13, 2011
Thursday, March 10, 2011
Gas Composition
There is precise information on the proportions of all gases in the atmosphere except one and that one is water vapor, the overwhelmingly most important greenhouse gas.
The water vapor component of the atmosphere varies around the Earth from near zero in the deserts, both hot and cold, to perhaps seven percent in tropical marine environments.
It also varies vertically from the surface to the stratosphere. And it also varies over time.
It is said that the global average water vapor content of the atmosphere is between one and three percent and that it varies between two and four percent, although there may not be much empirical backing for those limits.
It appears that these figures publicized for the water vapor content of the atmosphere are for only the lower near-surface part. There is very little water vapor in the stratosphere, but of course there is very little atmosphere in the stratosphere either.
It is strange and perplexing that there are no widely available statistics on the water vapor content of the atmosphere. The spatial variation of the water vapor content is no greater than in the case of temperature.
Focusing solely on greenhouse gases is misleading because it leaves out an even more important factor in the greenhouse effect, namely the role of clouds.
Most people have observed how much colder it is at night when there is a clear sky compared to what it is when the sky is overcast.
The clouds are much more effective in absorbing the thermal radiation from the Earth and radiating back down than the greenhouse gases.
The greenhouse effect of the gases is the same on the clear and the cloudy night but it is much colder without the clouds.
It is not obvious how to combine measures of the prevalence of greenhouse gases with the prevalence of clouds to come up with a single measure of the absorption potential of the atmosphere. There is however a way.
What comes out of Beer's Law is that the quantity that is relevant for radiation absorption is the number of moles of greenhouse gases, weighted by their radiative efficiency, over an area of Earth's surface.
This is called the optical depth of the atmosphere. It does not matter whether the absorbing gas is concentrated in one part of the optical path or uniformly distributed.
The same principle applies to the spatial distributions. What matters is the number of molecules of the radiation absorbing materials.
It thus does matter whether those molecules are in vapor, liquid or solid state.
The approximate mass of all water substances in the atmosphere is 12.9×1018 grams. The amount of carbon dioxide is 3×1018 grams.
These figures are converted into mole by dividing by the molecular weight in grams. The molecular weight of H2O is approximately 18 and that of CO2 is 44.
Thus the moles of the two substances in the atmosphere are 72×1016 for H2O and 6.8×1016 for CO2. The ratio of these two quantities is 10.6. Thus if the volume share of CO2 in the atmosphere is 0.039 of 1 percent then that of H2O is 0.41 of 1 percent.
In order to display the relative proportions of the different gases of the atmosphere properly some value must be used for water vapor. The value of 0.41 of 1 percent will be used.
The composition of the atmosphere can be given by mass, volume or the number of molecules.
It is the molecular composition, which is equivalent to volume composition, that is relevant for such matters as radiation absorption and that is what is given below.
Water vapor shows up on this scale as a significant portion of the atmosphere but the value for carbon dioxide (CO2), at 0.0387 of 1 percent is too small to be visible.
If only the greenhouse gases are displayed the level for CO2 is perceptible.
The water vapor component of the atmosphere varies around the Earth from near zero in the deserts, both hot and cold, to perhaps seven percent in tropical marine environments.
It also varies vertically from the surface to the stratosphere. And it also varies over time.
It is said that the global average water vapor content of the atmosphere is between one and three percent and that it varies between two and four percent, although there may not be much empirical backing for those limits.
It appears that these figures publicized for the water vapor content of the atmosphere are for only the lower near-surface part. There is very little water vapor in the stratosphere, but of course there is very little atmosphere in the stratosphere either.
It is strange and perplexing that there are no widely available statistics on the water vapor content of the atmosphere. The spatial variation of the water vapor content is no greater than in the case of temperature.
Focusing solely on greenhouse gases is misleading because it leaves out an even more important factor in the greenhouse effect, namely the role of clouds.
Most people have observed how much colder it is at night when there is a clear sky compared to what it is when the sky is overcast.
The clouds are much more effective in absorbing the thermal radiation from the Earth and radiating back down than the greenhouse gases.
The greenhouse effect of the gases is the same on the clear and the cloudy night but it is much colder without the clouds.
It is not obvious how to combine measures of the prevalence of greenhouse gases with the prevalence of clouds to come up with a single measure of the absorption potential of the atmosphere. There is however a way.
What comes out of Beer's Law is that the quantity that is relevant for radiation absorption is the number of moles of greenhouse gases, weighted by their radiative efficiency, over an area of Earth's surface.
This is called the optical depth of the atmosphere. It does not matter whether the absorbing gas is concentrated in one part of the optical path or uniformly distributed.
The same principle applies to the spatial distributions. What matters is the number of molecules of the radiation absorbing materials.
It thus does matter whether those molecules are in vapor, liquid or solid state.
The approximate mass of all water substances in the atmosphere is 12.9×1018 grams. The amount of carbon dioxide is 3×1018 grams.
These figures are converted into mole by dividing by the molecular weight in grams. The molecular weight of H2O is approximately 18 and that of CO2 is 44.
Thus the moles of the two substances in the atmosphere are 72×1016 for H2O and 6.8×1016 for CO2. The ratio of these two quantities is 10.6. Thus if the volume share of CO2 in the atmosphere is 0.039 of 1 percent then that of H2O is 0.41 of 1 percent.
In order to display the relative proportions of the different gases of the atmosphere properly some value must be used for water vapor. The value of 0.41 of 1 percent will be used.
The composition of the atmosphere can be given by mass, volume or the number of molecules.
It is the molecular composition, which is equivalent to volume composition, that is relevant for such matters as radiation absorption and that is what is given below.
Water vapor shows up on this scale as a significant portion of the atmosphere but the value for carbon dioxide (CO2), at 0.0387 of 1 percent is too small to be visible.
If only the greenhouse gases are displayed the level for CO2 is perceptible.
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