I asked the question earlier in one of the XST threads, "How do...

I asked the question earlier in one of the XST threads, "How do we determine the size of the resource, being either MMcf, Bcf or the much anticipated Tcf?" (or words to that effect).

Haven't received an answer yet but still feel it's important that we all know, so we all have the right expectations.

Anyway found this,

Metrics of Gas Measurements

The metrics of gas measurements depends on the information needed in applications and the convenience of transactions. The energy of a gas, the vapor pressure of a gas, its volume (or its liquid volume), or its mass may be measured. Factors such as temperature, pressure, and purity affect these properties of the gas.

It is intriguing how methods have evolved to measure up an invisible (usually) and a gaseous state of matter. The advanced science of gas measurement has state-of-the-art technology in this era.

Natural gas (methane) is measured in volume (cubic meters or cubic feet) at the resource well. One cubic foot of natural gas is the volume of gas contained in 1 cubic foot, at standard temperature and pressure. Generally, the gas production measured from the reserves ranges in thousands or millions of cubic feet. Thus, a trillion cubic feet of gas fill up a 2-mile sided-cube!

Impact of Chemicals, Gases, or Water Vapor on Energy Content of Natural Gas

The energy content of natural gas varies from different reserves, due to the presence of other chemicals, gases, or even, water vapor. When ethane, propane, butane, and other heavier hydrocarbons are present in the natural gas, the energy content increases. In the presence of other gases such as carbon dioxide or hydrogen sulfide, the energy content decreases.

Doesn't appear we are going to know to the size of the resource straight of the bat.

Hope this helps.

@blackitalian, here's your chance to contribute something worth reading, Hopefully, something factual?