After the summer of the second year of growth the plant produces seeds. One individual can produce 100,000 to 180,000 seeds. These seeds are released in close proximity to the plant and can remain viable for over 100 years. The invasive common mullein prefers dry and sandy soils, but is adaptable to many soil types.
primary porosity. (geology). Natural porosity in petroleum reservoir sands or rocks. 1  Facebook. 2  Twitter.rimary porosity. (geology). Natural porosity in petroleum reservoir sands or rocks. 1  Facebook. 2  Twitter.
These rocks often have high porosity, and are usually âhigh permâ too. Porosity and permeability are absolutely necessary to make a productive oil or gas well. The petroleum geologist must stay focused on the porosity and permeability of the prospective reservoir. Porosity consists of the tiny spaces in the rock that hold the oil or gas. Permeability is a characteristic that allows the oil and gas to flow through the rock. You need both porosity and permeability to make a producing oil or gas formation. Porosity. Porosity of a rock is a measure of its ability to hold a fluid. Mathematically, porosity is the open space in a rock divided by the total rock volume (solid + space or holes).