(1) Unless otherwise modified herein, the requirements of ARM 36.22.702 shall apply
to horizontal wells.
(2) For the purpose of determining the size of drilling units and the permissible
location of horizontal wells, "projected depth" as used in ARM
36.22.702 means the projected true vertical depth of the deepest horizontal
(3) A horizontal well
meets the location requirements of ARM 36.22.702 if the point where the well
bore first penetrates the common source of supply, the horizontal drainhole end
point, and every part of the well bore lying between these points meet the
minimum distance requirements from the drilling unit boundaries that would
apply to a vertical well of the same projected depth, regardless of the surface
(4) The operator of a
horizontal well may designate an optional drilling unit, which must consist of
two, three, or four contiguous drilling units of the size and shape otherwise
authorized for a vertical well of the same projected depth. The operator must
receive administrative approval of the optional drilling unit before starting
to drill the horizontal drainhole. Minimum distance requirements from drilling
unit boundaries that would apply to the contiguous drilling units apply to the
optional drilling unit, except that such requirements do not apply to the
common boundary of the contiguous units. Any operator designating an optional
drilling unit under this section must apply for proper well spacing within 90
days after the completion of a well capable of production.
(5) Within 30 days after
completion of a horizontal well, the operator must file with the board a
complete and accurate directional survey showing the location, direction, and
length of each horizontal drainhole and demonstrating that all drainholes are
at locations permitted by this rule or by a board location exception order.
(6) In those cases where
a horizontal well is drilled following an initial vertical penetration of the
target horizon, or the horizontal well includes more than one horizontal
drainhole, the completion report submitted under ARM 36.22.1011 must adequately
describe each well path.