Carbon Dioxide Capture, Utilization & Sequestration Technical Section

Because the U.S. tax code contains language for CO2 storage sites tax credits of $85 per metric ton, the amount of CO2 injected per year is typically discussed using some dollar value for metric tons injected per year.  These sequestration sites are typically on the order of millions of metric tons per year.  The units I have personally seen in "authoritative" documents to refer to millions of metric tons of CO2 per year are not consistent. For example, I've seen MM tonnes/yr, mmt/yr, MMT/yr, MT/yr, Mt/yr, and probably more.  I have not been able to find any official statement by SPE on the correct units for abbreviating "million metric tons per year."

We all have opinions on this, but does SPE have any official directives, guides, or standards on preferred units to abbreviate "million metric tons per year"? 

Because the U.S. tax code contains language for CO2 storage sites tax credits of $85 per metric ton, the amount of CO2 injected per year is typically discussed using some dollar value for metric tons injected per year.  These sequestration sites are typically on the order of millions of metric tons per year.  The units I have personally seen in "authoritative" documents to refer to millions of metric tons of CO2 per year are not consistent. For example, I've seen MM tonnes/yr, mmt/yr, MMT/yr, MT/yr, Mt/yr, and probably more.  I have not been able to find any official statement by SPE on the correct units for abbreviating "million metric tons per year."

We all have opinions on this, but does SPE have any official directives, guides, or standards on preferred units to abbreviate "million metric tons per year"? 

Because the U.S. tax code contains language for CO2 storage sites tax credits of $85 per metric ton, the amount of CO2 injected per year is typically discussed using some dollar value for metric tons injected per year.  These sequestration sites are typically on the order of millions of metric tons per year.  The units I have personally seen in "authoritative" documents to refer to millions of metric tons of CO2 per year are not consistent. For example, I've seen MM tonnes/yr, mmt/yr, MMT/yr, MT/yr, Mt/yr, and probably more.  I have not been able to find any official statement by SPE on the correct units for abbreviating "million metric tons per year."

We all have opinions on this, but does SPE have any official directives, guides, or standards on preferred units to abbreviate "million metric tons per year"? 

Because the U.S. tax code contains language for CO2 storage sites tax credits of $85 per metric ton, the amount of CO2 injected per year is typically discussed using some dollar value for metric tons injected per year.  These sequestration sites are typically on the order of millions of metric tons per year.  The units I have personally seen in "authoritative" documents to refer to millions of metric tons of CO2 per year are not consistent. For example, I've seen MM tonnes/yr, mmt/yr, MMT/yr, MT/yr, Mt/yr, and probably more.  I have not been able to find any official statement by SPE on the correct units for abbreviating "million metric tons per year."

We all have opinions on this, but does SPE have any official directives, guides, or standards on preferred units to abbreviate "million metric tons per year"? 

The issue is by no means unique to CO2 sequestration. Take LPG for example. Reservoir engineers will work with oilfield units, barrels (bbl) for the volumes produced, but LPG traders like to work with weight in metric tonne (mt or te) and the shippers tend to work with volume in cubic metres or cubes (cbm). Of course, at the end of the day we are really selling energy, which depending on the part of the world you are in might be millions of British thermal units (mmbtu) or Joules (J). Then you can add that some regions prefer metric over oilfield units, which just creates more confusion.

Bottom line is that you won't find a standard. There are too many industries, cultures and historical backgrounds involved. The most important thing is that you are consistent in how you use the units yourself, and that you always pay attention to them. As a wonderful reviewer once said to me, "if you're going to be wrong, at least be consistently wrong"...

As for guidance on CO2 itself, the best analogy would be LNG. The most common usage I see in that industry is 'mtpa' for million tonnes per annum (N.B., note careful use of 'tonne'). A tonne is a 1,000 kg and has the abbreviation 't'. Million (or technically mega, but no-one says "mega tonnes per annum" when talking) is 'm' and thousand is 'k'. There is no ambiguity if you way tonne, so you don't need to precede ton with 'metric' to distinguish between a short or long ton. Double 'm' as in mmbbl for million barrels is very peculiar to the oil industry and won't travel well outside our industry. Best to avoid it in my opinion.

Because the U.S. tax code contains language for CO2 storage sites tax credits of $85 per metric ton, the amount of CO2 injected per year is typically discussed using some dollar value for metric tons injected per year.  These sequestration sites are typically on the order of millions of metric tons per year.  The units I have personally seen in "authoritative" documents to refer to millions of metric tons of CO2 per year are not consistent. For example, I've seen MM tonnes/yr, mmt/yr, MMT/yr, MT/yr, Mt/yr, and probably more.  I have not been able to find any official statement by SPE on the correct units for abbreviating "million metric tons per year."

We all have opinions on this, but does SPE have any official directives, guides, or standards on preferred units to abbreviate "million metric tons per year"? 

Because the U.S. tax code contains language for CO2 storage sites tax credits of $85 per metric ton, the amount of CO2 injected per year is typically discussed using some dollar value for metric tons injected per year.  These sequestration sites are typically on the order of millions of metric tons per year.  The units I have personally seen in "authoritative" documents to refer to millions of metric tons of CO2 per year are not consistent. For example, I've seen MM tonnes/yr, mmt/yr, MMT/yr, MT/yr, Mt/yr, and probably more.  I have not been able to find any official statement by SPE on the correct units for abbreviating "million metric tons per year."

We all have opinions on this, but does SPE have any official directives, guides, or standards on preferred units to abbreviate "million metric tons per year"? 

Hello everyone,

As already mentioned within this conversation, SPE would provide good accountability in the disambiguation about the most preferable units to be used, but I guess it all goes back to the definitions of units in which we may be using in our writings, providing that we define the units conversion numbers.

Another organization that provides reference and guidance is ISO (The International Organization for Standardization), which states that this kind of discussions sheds light on "technical standards that could be applied for the quantification and verification of greenhouse gas emissions (GHG) and reductions from CCS (carbon capture and storage) projects. ISO has also creat working groups for that porpuse (ISO/TR 27915:2017(en), Carbon dioxide capture, transportation and geological storage - Quantification and verification).

Other efforts, also have been provided by UN forums in the frame of the KYOTO protocol (authorized) which have regulations on the Climate Change of implementations mechanisms for clean development projects to reach the environmental goals (limit the global warming temperatures between 1.5 to 2 Centigrade). 

At the end all aims in the clear evaluation and economical benefits of documenting CCS, transportation and entitled trading's within country's and internationally. (UNCTAD/GDS/GFSB/Misc.6).

Thanks for topic conversation and hope SPE gathers together a group to catch up in providing references.

Jose Antonio Rodriguez Pimentel 

Because the U.S. tax code contains language for CO2 storage sites tax credits of $85 per metric ton, the amount of CO2 injected per year is typically discussed using some dollar value for metric tons injected per year.  These sequestration sites are typically on the order of millions of metric tons per year.  The units I have personally seen in "authoritative" documents to refer to millions of metric tons of CO2 per year are not consistent. For example, I've seen MM tonnes/yr, mmt/yr, MMT/yr, MT/yr, Mt/yr, and probably more.  I have not been able to find any official statement by SPE on the correct units for abbreviating "million metric tons per year."

We all have opinions on this, but does SPE have any official directives, guides, or standards on preferred units to abbreviate "million metric tons per year"? 

Hello everyone,

As already mentioned within this conversation, SPE would provide good accountability in the disambiguation about the most preferable units to be used, but I guess it all goes back to the definitions of units in which we may be using in our writings, providing that we define the units conversion numbers.

Another organization that provides reference and guidance is ISO (The International Organization for Standardization), which states that this kind of discussions sheds light on "technical standards that could be applied for the quantification and verification of greenhouse gas emissions (GHG) and reductions from CCS (carbon capture and storage) projects. ISO has also creat working groups for that porpuse (ISO/TR 27915:2017(en), Carbon dioxide capture, transportation and geological storage - Quantification and verification).

Other efforts, also have been provided by UN forums in the frame of the KYOTO protocol (authorized) which have regulations on the Climate Change of implementations mechanisms for clean development projects to reach the environmental goals (limit the global warming temperatures between 1.5 to 2 Centigrade). 

At the end all aims in the clear evaluation and economical benefits of documenting CCS, transportation and entitled trading's within country's and internationally. (UNCTAD/GDS/GFSB/Misc.6).

Thanks for topic conversation and hope SPE gathers together a group to catch up in providing references.

Jose Antonio Rodriguez Pimentel 

Because the U.S. tax code contains language for CO2 storage sites tax credits of $85 per metric ton, the amount of CO2 injected per year is typically discussed using some dollar value for metric tons injected per year.  These sequestration sites are typically on the order of millions of metric tons per year.  The units I have personally seen in "authoritative" documents to refer to millions of metric tons of CO2 per year are not consistent. For example, I've seen MM tonnes/yr, mmt/yr, MMT/yr, MT/yr, Mt/yr, and probably more.  I have not been able to find any official statement by SPE on the correct units for abbreviating "million metric tons per year."

We all have opinions on this, but does SPE have any official directives, guides, or standards on preferred units to abbreviate "million metric tons per year"?