020-11 Wyo. Code R. §§ 11-10 - Requirements for Plugging of Drill Holes and Repair, Conversion, and Plugging of Wells

(a) A plan for drill holes and well repair, plugging, and conversion shall be approved by the Administrator and included in the permit or Research and Development License application, as required by Section 6(a)(iii) of this Chapter, and shall constitute a condition of the permit.

(b) All drill holes shall be plugged in accordance with Chapter 8 of the noncoal rules and W.S. § 35-11-404.

(c) If a well lacks mechanical integrity, the operator shall repair or plug the well to prevent the movement of fluid into unauthorized zones or onto the surface caused by the lack of mechanical integrity. Repair or plugging of the well must be completed within 120 days of the testing which indicates the well lacks mechanical integrity. If the well is repaired rather than plugged, retesting of the well, in accordance with the requirements of Section 9 of this Chapter must be completed within 120 days after the repair is completed. The operator may resume use of the well upon written notification from the Administrator that the operator has demonstrated mechanical integrity.

(d) The operator shall notify the Administrator, as required by the permit or Research and Development License, before plugging a well or wells within an area permit or converting a well to uses other than those defined in Section 1(f) of this Chapter.

(e) All abandoned wells shall be plugged or converted, in accordance with the Plugging/Conversion Plan in the permit or Research and Development License, in order to assure that groundwater is protected and preserved for future use and to eliminate any potential physical hazard. A well is considered "abandoned" when it has not been used for a period of two years, unless the operator submits to the Administrator and receives approval for a non-significant revision under Section 19(c)(vi) of this Chapter demonstrating their intention to use the well again and the actions and procedures they will take to ensure that mechanical integrity of the well is maintained under Section 7(a)(i) of this Chapter and the well will not endanger any unauthorized zone or water-bearing strata in accordance with the requirements of this Chapter.

(f) A well shall be plugged to meet the requirements below, using an approved sealant material as outlined in Chapter 8, Section 2(d), to assure that plugging of the well will not allow the movement of fluids into or between unauthorized zones or water-bearing strata:

(i) The well shall be plugged using a method which prevents fluid communication and adverse changes in water quality or quantity. Sealant materials shall be emplaced in a manner that provides a water tight seal utilizing one of the approved methods detailed in Chapter 8, Section 2(e) - (g) and shall meet the following requirements:

(A) If specific sections of the casing are to be plugged with cement:

(I) The operator shall log:

(1.) The type and number of plugs to be used;

(2.) The placement of each plug including the elevation of the top and the bottom;

(3.) The method of placement of the plugs, in accordance with Section 10(f);

(II) The operator shall ensure that the well to be plugged shall be in a state of static equilibrium with the mud weight equalized top to bottom, either by circulating the mud in the well at least once or by a comparable method prescribed by the Administrator, prior to the placement of the cement plug(s); and

(III) That the placement of the cement plugs shall be accomplished by one of the following:

(1.) The Balance method;

(2.) The Dump Bailer method;

(3.) The Two-Plug method; or

(4.) An alternative method approved by the Administrator, which:

a. Includes placement of plugging materials in the interval or intervals to be sealed by methods that prevent free fall, dilution and/or separation of aggregates from sealing materials; and

b. Provides a comparable level of reliable protection to the methods identified in Section 10(f)(i).

(B) When the underground pressure head producing flow (i.e. gassy or artesian) is such that a counter-pressure must be applied to force a sealing material into the annular space, this counter-pressure shall be maintained for the length of time required for the plugging mixture to set or fully hydrate.

(C) The top of the plugging mixture of any plugged and abandoned well shall be backfilled to the surface with dry non-slurry materials or topped with a concrete cap set at least 2 feet below the ground surface and then backfilled to the surface with native earthen materials to ensure the safety of people, livestock, wildlife, and machinery in the area.

(g) In the case of an ISR operation which underlies or is in an aquifer which has been exempted under Section 11 of this Chapter, the Plugging/Conversion Plan in the permit or Research and Development License shall also demonstrate adequate protection of Underground Sources of Water (USWs). The Administrator shall prescribe aquifer cleanup and monitoring where he deems it necessary and feasible to assure adequate protection of USWs.

(h) To ensure the locations of the abandoned wells are adequately identified the operator shall:

(i) Record the boundaries of each wellfield and the location of the monitor well ring around each wellfield shall be recorded as a deed notice with the appropriate county; and

(ii) The top of the plugging mixture in each abandoned monitor well in the monitor well ring around each wellfield shall clearly show on a steel plate placed atop the sealing mixture, the permit number, well identification number, and date of plugging. All marking devices shall be installed at a minimum depth of two feet below the land surface.

(j) The operator shall report plugging and conversion activities in accordance with the requirements in Section 15 of this Chapter.

Notes

020-11 Wyo. Code R. §§ 11-10

Amended, Eff. 11/13/2018. Amended, Eff. 11/17/2022.