Patent ID: 8813840

Claim:
A system for accessing a subterranean zone of shale, the system comprising: a drilling pad at a surface; a first wellbore extending from the surface con g a first substantially vertical portion extending into a subterranean zone and a first substantially horizontal drainage bore extending from the first substantially vertical portion and proximate to the subterranean zone; a second wellbore extending from the surface compromising a second substantially vertical portion extending into the subterranean zone and a second substantially horizontal drainage bore extending from the second substantially vertical portion and proximate to the subterranean zone, wherein the first and second substantially horizontal drainage bores extend in the subterranean zone in different directions from each other; a third wellbore extending from the surface comprising a third substantially vertical portion extending into the subterranean zone and a third substantially horizontal drainage bore extending from the third substantially vertical portion and proximate to the subterranean zone; a fourth wellbore extending from the surface comprising a fourth substantially vertical portion extending into the subterranean zone and a fourth substantially horizontal drainage bore extending from the fourth substantially vertical portion and proximate to the subterranean zone, wherein the third and fourth substantially horizontal drainage bores extend in the subterranean zone in different directions from each other; the first, second, third and fourth wellbores each extending from non-common surface locations on the drilling pad at the surface, the surface locations closely spaced to each other on the drilling pad; wherein the subterranean zone is shale; and, wherein the first, second, third, and fourth wellbores each produce a fluid extracted from the subterranean zone through the substantially horizontal drainage bores.