Wyoming Administrative Code › Agency 055 - Oil and Gas Conservation Commission › Sub-Agency 0001 - General Agency, Board or Commission Rules › Chapter 3 - OPERATIONAL RULES, DRILLING RULES › Section 3-18 - Plugging of Wells, Stratigraphic Tests, Core, or Other Exploratory Holes (Form 4)

Current through July 13, 2024
(a) It shall be the
				duty of any Owner, Operator, or person who assumes ownership, or contractor,
				drilling any well, seismic, stratigraphic test, core, or other exploratory
				hole, whether cased or uncased, regardless of diameter, to plug said hole in
				accordance with the requirements of the Supervisor or as set forth hereinafter
				and in a manner sufficient to properly protect all fresh water bearing
				formations and possible or probable oil or gas bearing formations.
(b) For wells as defined in Chapter 1,
				Section 2(lll) of these Rules and Regulations, and all stratigraphic test wells
				being abandoned, plugging must be accomplished by the following:
(i) All cement and additives shall consist of
				API class cement and additives, unless use of non-API cement and additives has
				prior approval from the Supervisor.
(ii) Wells without production casing must be
				plugged by placing cement plugs of at least one hundred foot (100') length
				consisting of approved cement and additives, mixed at a density approved by the
				Supervisor or his Authorized Agent over the following:
(A) Open hole porous and permeable
				formations;
(B) At least every two
				thousand five hundred feet (2,500') if porous and permeable formations are not
				encountered;
(C) In the base of the
				surface casing and at least one hundred feet (100') inside the casing at the
				surface. If multiple casing strings are present, a minimum one hundred foot
				(100') plug will be placed in the annulus between each casing string at the
				outside casing shoe and a minimum one hundred foot (100') plug in each annulus
				at the surface;
(D) At any other
				depth as required by the Supervisor;
(E) The spacer between all cement plugs must
				be a fluid consistent with that which was used to drill the well or as approved
				by the Supervisor.
(iii)
				Wells with production casing must be plugged by placing cement plugs of at
				least one hundred foot (100') length consisting of approved cement and
				additives, mixed at a density approved by the Supervisor or his Authorized
				Agent at least every two thousand five hundred feet (2,500'), in the base of
				the surface casing, and at least one hundred feet (100') inside the casing at
				the surface. If multiple casing strings are present, a minimum one hundred foot
				(100') plug must be placed in the annulus between each casing string at the
				outside casing shoe, and a minimum one hundred foot (100') plug in each annulus
				at the surface.
(A) Prior to commencing
				plugging operations, all produced fluids must be circulated from the well using
				fresh water or other fluid as required to maintain an overbalance of the
				producing formation.
(B) All
				perforations must be isolated by squeeze cementing utilizing a mechanical
				cement retainer set no more than fifty feet (50') above the uppermost
				perforation, or by a method approved by the Supervisor. The volume of cement
				will be no less than the volume between the retainer and the deepest
				perforation plus fifty percent (50%) excess. A minimum one hundred foot (100')
				plug must also be placed on top of the cement retainer. If access to the
				perforated areas of the wellbore has been lost, alternative procedures may be
				proposed by the Owner/Operator. The Supervisor shall determine or approve which
				method and the quantity of cement that shall be used or the alternative method
				of plugging, if access to perforations is lost;
(C) The Owner/Operator may leave the
				production casing in place, provided that the Owner/Operator demonstrates that
				the casing exhibits mechanical integrity in a manner prescribed or approved by
				the Supervisor. If casing fails a mechanical integrity test, the casing leaks
				must be isolated and squeeze cemented utilizing a mechanical cement retainer,
				or by a method approved by the Supervisor.
(D) If it is determined that any formation
				containing fresh water and potable water, as defined under Chapter 1, Section
				2(t) of these Rules and Regulations, was not sealed or separated when
				production casing was cemented, the casing must be perforated at the base of
				the fresh water and potable water zone and squeeze cemented utilizing a
				mechanical cement retainer, or by a method approved by the Supervisor, with a
				volume of cement sufficient to cover the formation. The Supervisor may also
				require the production casing to be perforated at a depth of the shoe of the
				surface casing and that cement be squeezed or circulated through the
				perforations through the uncemented zone; and,
(E) If an attempt is made to recover
				production casing after the retrievable part of the production casing has been
				removed, cement must be circulated to fill at least a one hundred foot (100')
				interval of which fifty feet (50') must be inside the casing stub. The
				remainder of the hole shall be plugged in the manner prescribed under
				subsection (b)(i) of this section.
(iv) Powder River Basin Coalbed Methane
				Wells.
(A) The minimum density requirement for
				cement slurry shall be 13.5 pounds per gallon (ppg) with no less than
				twenty-five percent (25%) of cement by weight with a yield not greater than
				1.29 cubic feet per sack. The Supervisor may approve alternate cement blends
				submitted by the Operator.
(B) Each
				completed section of the well shall be isolated by filling the underreamed or
				perforated section of the hole with bentonite hole plug extending a minimum of
				twenty feet (20') above the completed section, or isolating the underreamed or
				perforated section with a mechanical bridge plug set no higher than thirty feet
				(30') above the underreamed or perforated section. The Supervisor may approve
				other material for the openhole portion in lieu of the bentonite hole
				plug.
(C) The bentonite plugs
				and/or mechanical bridge plugs shall be topped with a one hundred foot (100')
				cement plug, and one hundred foot (100') plugs will also be set every seven
				hundred fifty feet (750') along with a one hundred foot (100') plug at the
				surface.