Alternative energies can be found in very challenging environments and sources. They include heavy and viscous oil deposits;
oil and gas shales;
and arctic and deepwater opportunities. Such environments and sources test the operating range of equipments. As such;
standard industry classifications in these areas and sources are often absent;
confusing;
or filled with loopholes. Therefore;
there is a need to identify and clearly state the subsurface environments of high pressure/ high temperature;