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Operators should ensure their plugging programs address the gas migration potential <br />associated with such conditions. Section 2 of the API Bulletin presents detailed <br />information on plugging and abandonment operations including: cementing materials <br />and placement techniques, methodologies for isolating open hole completions and <br />uncased hole, and cased hole abandonment methods. These methodologies are <br />deemed appropriate and applicable guidance for methane drainage well plugging and <br />abandonment. <br />Methane drainage well completion techniques may vary. Two typical examples of <br />methane drainage well completions are presented in Figures 1 and 2 of this guidance <br />document. Figure 1 provides an example of an open hole completion (i.e., borehole <br />that is uncased and open to the casing string above). Figure 2 shows a cased hole <br />completion with a floating perforated casing below the solid cased portion of the well. <br />These examples are typical of open hole and cased hole completions. Applicable <br />methods for plugging and abandoning open hole and cased hole completion intervals <br />are presented in Sections 2.2 through 2.4 of the API Guidance Document. <br />At a minimum, all holes must be abandoned in accordance with DMG Rule 4.07.3. If <br />the methane drainage well is completed through an aquifer(s), then sealing must be <br />completed in accordance with DMG Rule 4.07.3 (2) and the entire depth of the blank <br />casing should be sealed using cement (from the bottom to within 10 feet of the surface). <br />If no aquifer is present, the well shall be sealed by replacing a suitable media in the hole <br />and placing a suitable plug 10 feet below the ground surface to support a cement plug <br />to within three feet of the ground surface. The hole is to be marked in the field. Survey <br />coordinates should be included in the abandonment report, if available. Proof of <br />compliance for hole abandonment is required according to Rule 4.07.3(3) of the Coal <br />Regulations. <br />In situations where a bottom to top cement plug is not specifically required by <br />regulation, the DMG recommends a minimum of fifty feet of cement plug be placed at <br />the lowest point inside the solid casing, above the perforated interval of the well. The <br />cement plug should be a minimum of fifty (50) feet in length and should extend a <br />minimum of fifty (50) feet above the zone to be protected. An inflatable packer, bridge <br />plug, or other mechanical plug approved by the DMG shall be utilized as a foundation <br />for the cement plug. Proof of compliance for the hole abandonment is required <br />according to Rule 4.07.3(3) of the Coal Regulations. <br />This additional closure recommendation is included to provide protection against post- <br />closure methane migration to water and land resources. Such migration must be <br />prevented. If it is found that damage to water or land resources has occurred due to <br />inadequate methane drainage well installation and/or abandonment, then such damage <br />may be considered a noncompliance situation. Additional work to prevent and mitigate <br />such damage would likely be required. <br />The DMG recognizes that subsidence effects associated with longwall mining may <br />compromise the integrity of the methane drainage well. Subsidence due to removal of <br />4