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:
Flowback water (aka backflow water) is the murky, salty water from fracing natural gas wells. It consists of frac fluid which returns to the surface (aka the frac load recovery) as well as produced water. This water contains clay, dirt, metals, chemicals and even diesel that may have been added. The frac load recovery can be anywhere from 15-40% percent of the volume of fluid that is injected, that is forced down a well, and it flows back over a period of 3-4 weeks after fracing--most of it within 7 to 10 days. More than half of the frac fluid remains in the formation.