Offset barrier wells in subsurface formations

A plurality of first barrier wells are formed in a formation for a first barrier. A substantially constant spacing separates adjacent first barrier wells. The formation is analyzed to determine the principal fracture direction of at least one layer of the formation. An offset distance of second barrier wells relative to first barrier wells is determined based on the principal fracture direction to limit a maximum separation distance between a closest barrier well and a theoretical fracture extending between the first barrier and the second barrier along the principal fracture direction to a distance of less than one half of the spacing that separates adjacent first barrier wells. The second barrier wells are offset from the first barrier wells by a distance that is at least substantially the same as the offset distance.