[thackney]

Both traditional plays and tight formations like shale fall in production due to loss of oil that is free to move through the formation. Shales typically have a much harder time to get the movement of oil due to low permability. That is why hydraulic fracturing is typically used. To create cracks that allow the oil to move to the well bore.

Without enhanced oil recovery methods, neither shale or traditional wells are going to typically produce more than 10~20% of the total oil in the ground. We have been using enhanced oil recovery methods like water flood, CO2 injection, etc for a long time in the country. Some reading on the concepts: http://www.csur.com/sites/default/files/Understanding_TightOil_FINAL.pdf http://en.wikipedia.org/wiki/Enhanced_oil_recovery

[American Constitutionalist]

In other words, to put it shortly, it's the viscosity of the oil that flows through the rock formation ? correct ? and so to speak hit up against a rock wall.
So what they do is put microscopic blasted holes in the rock to allow it to flow.
Perforating the rock.