The US Geological Survey (USGS) cited estimates of the methane (CH4) trapped in global methane hydrate (aka methane clathrate, Fire Ice, etc.) deposits are 3600 times more than the 2016 US consumption of natural gas. The 2016 US consumption of natural gas (natural gas is mostly methane), according to Donn Dears, was 27.5×10^12 cubic feet.
The estimate of trapped gas in the deposits ranges from 10^17 to 5×10^18 cubic feet*. Those are estimates and further those estimates probably include some amount of methane hydrate that will never be economical to produce. Even so, oil reserves that were supposed to have peaked many years ago, keep growing because of new technology. eg. Fracking. So, who knows?
*(For the non-engineer or scientist that might not know how much that is, it can be restated as 1 followed by 17 zeros to 5 followed by 18 zeros cubic feet of natural gas.)
Where are the hydrate deposits found?
Methane hydrate deposits are found (or predicted) to be associated with continental margins and onshore permafrost areas. The chart below global areas where deposits are to be found.
First, let’s discuss where the methane originates. Methane is largely produced by micro-organisms that act on the plankton that has accumulated deep in the ocean floor sediments. In the upper layers of the sediment where the temperature and pressure are suitable, the rising CH4 bubbles are captured in very cold water and the hydrate is formed. While methane produced biogenically is considered the most widespread source, there is another source. Thermogenic methane is produced where high pressures and high temperatures cook organic matter.