Section 240.455  Horizontal Drilling

a)         For purposes of this Subpart a horizontal well is a wellbore which has an overall length within the reservoir of twice the thickness of the reservoir.

b)         An oil or gas production well may be developed with one or more horizontal drainholes drilled from a single vertical wellbore and may be considered a single well and permitted in accordance with the provisions of Subpart B.

c)         If the proposed horizontal well will be part of an enhanced oil recovery project, the spacing requirements for all portions of the horizontal drainholes shall comply with Section 240.430(b).

d)         If the proposed well is to be a primary recovery well, the spacing requirements for all portions of the horizontal drainholes shall comply with Section 240.410, or if a modified or special drilling unit is requested, in compliance with Section 240.460 and/or 240.465.

(Source:  Amended at 21 Ill. Reg. 7164, effective June 3, 1997)