Higher heating value and lower heating value of natural gas

There are two ways to define the energy content of natural gas in common use — Higher Heating Value (HHV) and Lower Heating Value (LHV). The difference can be especially important when reviewing the performance of engine-driven systems. Higher Heating Values for a fuel include the full energy content as defined by bringing all products …

Geomagnetic survey

Large-scale geological structures that might hold oil or gas reservoirs are invariably located beneath non-productive rocks, and in addition this is often below the sea. Geophysical methods can penetrate them to produce a picture of the pattern of the hidden rocks. Relatively inexpensive gravity and geomagnetic surveys can identify potentially oil-bearing sedimentary basins, but costly …

Graben

A relatively low-standing fault block bounded by opposing normal faults. Graben (used as both singular and plural) can form in areas of rifting or extension, where normal faults are the most common type of fault. Between graben are relatively high-standing blocks called horsts