Population genetics. Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure.
In the fluid-filled case, the wellbore is presumed to be full of either all liquid or gas which gets compressed as afterflow continues into the wellbore. The wellbore storage constant (C) is a function of the wellbore volume (Vw) and the wellbore fluid compressibility (cwb) as shown below: For a fluid-filled wellbore:
Viscosity is a physical property of fluids. It shows resistance to flow. In a simple example, water has a low viscosity, as it is 'thin'. Syrup or tar, on the other hand has a high viscosity, as it is 'thick, So next time you drink something think about the viscosity!. A way to test for viscosity is the speed at which the substance runs down a slope.