The first well you drill meeting the productivity criteria after the unit agreement is formed establishes an initial participating area. When you establish an initial participating area, lands that contain previously existing wells in the unit meeting the productivity criteria (see §3137.82 of this subpart), will—

(a) Be added to that initial participating area as a revision, if the well is completed in the same producible interval; or

(b) Become a separate participating area, if the well is completed in a different producible interval (see also §3137.88 of this subpart for wells that do not meet the productivity criteria).