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.
A liquid or gaseous mixture (a. âfracking fluidâ) is injected into the well, under high. pressure, to create fractures in a specific rock layer. Before fracking, the well is sealed with steel pipe. and cement (âcasingâ).