Current through Register Vol. 61, No. 4, April 1, 2022
Proper completion and decommission require adequate protection of the
environment and of aesthetic qualities of the surface in the area of
(2) An information hole
or seismic shot hole is properly completed for the purposes of this chapter
when the permittee demonstrates to the satisfaction of the department that the
information hole or shot hole has been constructed to the standard and
requirement of the permit.
information hole or seismic shot hole is considered properly plugged and
abandoned, for the purposes of this chapter, when the conditions of ORS
520.991 and these rules are
fulfilled and the permittee has shown to the satisfaction of the department
that all proper steps have been taken to protect groundwater and surface water
from contamination resulting from the drilling or drilling related activities
and to prevent the commingling of fluids between zones or the conveyance of
fluids to the surface.
holes must be plugged and all related disturbance must be reclaimed in
accordance with these rules as soon as practical. A hole may not be left
unplugged for longer than 30 days from the completion of operations without
prior written approval from the department.
An Information hole must be cemented from
the bottom up to a depth 4 feet from the ground surface through tubing to
prevent cross-flow, erosion, waste, or contamination of groundwater.
(a) The hole must be filled and pressure
grouted from bottom to top with cement, consisting of a neat cement weighing in
excess of 15.0 pounds per gallon with not less than a viscosity of 36 (API Full
(b) In no case may
sand or aggregate be added to cement grout seal mixtures;
(c) Other fluids may be used upon approval of
(d) Cement grout
used as a sealing material must be placed or forced upward from the bottom of
the hole in one continuous operation without significant interruption. If
temporary outer surface casing is used in the construction of the hole, it must
be withdrawn as the grout is placed;
(e) The top of all casing strings must be cut
off at least 4 feet below ground surface and buried to a depth of at least four
feet in such a manner as not to interfere with soil cultivation.
All seismic shot holes must be
plugged and reclaimed in a manner that prevents vertical movement of water in
(a) Seismic shot holes encountering
groundwater must be cased and sealed with unhydrated bentonite at least 3/8
inch in diameter to 10 feet above the groundwater before explosives are used.
Unhydrated bentonite materials used in plugging of a hole must be specifically
designed for sealing wells and be within industry tolerances for dry western
sodium bentonite. The bentonite must be placed in the hole in a manner that
prevents cross-flow, waste or contamination of groundwater.
The following requirements apply to
seismic shot holes not encountering groundwater:
(A) Such shot hole must be sealed with
unhydrated bentonite at least 3/8 inch in diameter below the elevation that the
explosives are used;
(B) Above the
elevation that the explosives are used unhydrated bentonite at least 3/8 inch
in diameter must be added from the top of the bentonite to the
(C) A nonmetallic plug
must be set at a depth of 3 feet below ground surface; cuttings added above the
nonmetallic plug must be tamped;
(D) The operator must place a bentonite plug
no less than 10 feet in length. If the shot hole is less than 10 feet in
length, the entire hole must be plugged with unhydrated bentonite at least 3/8
inch in diameter.
(E) A small mound
of cuttings must be left over the hole to allow for settling; and
(F) Any cuttings deposited on the surface
around the seismic hole or information hole must be raked or otherwise spread
so that the cuttings do not exceed 2 inches of the pre-existing land surface,
except for a small mound left for settling.
(c) A seismic shot hole that encounters
groundwater and caves in after detonation of an explosive charge must provide
for the protection of groundwater by reopening the hole and plugging with
cement and by placing a mound over the hole for settling as provided in
subsections (3)(C) and (3)(D) of this rule.
(d) Alternative plugging procedures and
materials may be utilized with the department's written approval when the
operator has demonstrated to the department's satisfaction that the
alternatives will protect water quality.
(7) All ground disturbance related to well
site operation must be reclaimed to a secondary beneficial use that is
compatible with the applicable local land comprehensive plan and land use
(8) Affidavit on
completion: Within 60 days after an information hole or seismic shot hole is
plugged, the operator must file a written statement with the department
certifying that the well was properly plugged and affected areas