Definition of terms and explanatory notes. The Official Methods of Analysis was first released in electronic format, as a companion to the print Official Methods of Analysis of AOAC INTERNATIONAL, 18th Edition, in 2005. For new and revised methods approved since 2005, see adoption/revision date for each method. These dates are located in either the header block at the top of the method for major modifications, or in a revision line at the bottom of the method for minor editorial revisions.
They are also known as unconventional because of the novel techniques â like fracking and horizontal drilling â used to extract the gas. Unlike shale gas, coalbed methane extraction doesnât always involve fracking â at least not in the early years of a development.hale gas and coalbed methane are known as 'unconventional' because unlike conventional sources which are found in larger, easier to access reservoirs, the gas is trapped in tiny little pockets in the shale rock or coal seams.
Fracking (hydraulic fracturing) is a term used to describe a natural gas drilling technique in which thousands of gallons of water, chemicals and sand are pumped into a shale formation to break apart rock and release the natural gas that is trapped below.ydraulic fracturing was first used to recover natural gas and oil in 1947. Halliburton was the first company to use it commercially in 1949. Today, fracking is used to stimulate thousands of oil and gas wells each year, worldwide.