Here's an interesting link for those who want to understand...

Here's an interesting link for those who want to understand "intergranular" porosity as mentioned in today's report and permeability which will be crucial to GDN's production testing.

http://www.sjgs.com/exploration.html

This is a partial quote:

Reservoir Rock - If a rock has enough porosity and permeability that oil or gas can flow through it, then the rock is a potential reservoir. Although the amount of pore space may not be very much, most rocks, in particular sandstones and conglomerates, have at least some porosity. If enough pores are present, the pores are large enough, and the pores are interconnected so that fluids flow through them (i.e., the rock is permeable), then the rock is a potential petroleum reservoir. With sandstones, a porosity of 18% or more is usually needed for an economic oil reservoir. Gas flows easier than oil, so as little as 12% porosity may be enough for a gas reservoir. Less porosity, perhaps as little as 9%, is enough if the reservoir is also fractured. Because of fracturing, limestone and dolomite reservoirs can have much lower porosities than sandstone reservoirs, yet be capable of producing greater amounts of oil.

Porosity and permeability are important, but a petroleum reservoir needs to contain hydrocarbons as well. In most reservoirs, the pores are filled entirely with a salty solution called formation water, but in a few reservoirs some oil or gas is present as well. A general rule of thumb is that 40% or more of the pore fluids must be hydrocarbons (i.e., the water saturation is less than 60%) in order for the reserovir to be economic enough to produce. If the water content is greater, then the oil tends to stay behind and the reservoir produces only water. These types of reservoirs are said to be "wet". If the water saturation is less, then the reservoir may be "productive". Whether or not it will be "economic" to produce and make any money will depend not only on the rate of production, but also on how long the well will produce.