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,. <br />Abandonment -Proposed Rules 2.05.4 and 4.07 <br />Our recommendation is to require a high quality completion, filling the entire <br />annuls with sulfate resistant cement, then fill the un-pefrorated portion of the <br />casing with sulfate resistant cement upon abandonment. We believe this will <br />provide the best practical protection to the surface and subsurface environments. <br />The proposed rule states that: <br />"Approximately 50 feet below the top of the perforated casing, a bentonite <br />seal would be placed to create a foundation for cement slurry fill." <br />In our judgement, the attempt to set any type of plug beneath the top of the <br />perforation zone would be difficult, time consuming, expensive and ultimately <br />ineffective. The subsidence induced fractures in the "gob" or caving zone of a <br />longwall panel provide passages through which cement should easily flow down <br />into the rubblized gob zone, making it next to impossible to set a cement plug <br />and to fill the casing with cement slurry from that point upward. For the same <br />reasons we also find the case for attempting to remedy an inadequate annulus <br />cement job via the proposal to force cement up around the bottom of the casing <br />from a platform 50 feet beneath the top of the perforation zone hard to support. <br />We believe the key to a successful abandonment is a successful <br />install/completion in the first puce. Once that has been accomplished, plugging <br />off the casing is a relatively easy matter. <br />Figure 1 is an example of our recommendation for the proper compietion of a <br />----- de-Aas well --- ----- ------------ <br />Figure 2 degas-well following abandonment. <br />Thank you, for the opportunity to comment on these proposed regulations. <br />Shouid there be questions please call 970-929-5277. <br />Stewart <br />