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1. Background <br />During the past four years, American Soda LLP, (ASLLP) has been <br />evaluating options to fulfill the permit requirement of characterizing the size and <br />shape of an ASLLP nahcolite solution mining cavity. Through meetings with the <br />BLM, EPA, and CDMG, the combination of using cross-hole seismic and cavity <br />displacement emerged as the most promising methods. <br />ASLLP submitted a proposal to the EPA, CDMG, and BLM on June 20, 2003. <br />The proposal included across-hole seismic method and a full displacement of <br />the cavity fluid utilizing methane gas. The proposal included the drilling of an <br />additional production well adjacent to the cavity being characterized and <br />testing the storage of methane gas in the solution mined cavity. The proposed <br />plan depended upon synergies with the full capacity 2004 ASLLP production and <br />operations plan. The agencies approved the plan. <br />On September 10, 2003, Solvay America acquired ASLLP from the Williams <br />Companies and American Alkali. Solvay asked ASLLP to evaluate lower <br />production plans for 2004. The 2004 production and operation plan was 60% less <br />than the previous 2004 plan. The lower production plan eliminated the drilling of <br />additional production wells. <br />In October, 2003, Solvay, inquired as to the possibility of revising the <br />approved cavity characterization plan to eliminate the gas displacement phase <br />and reduce the plan's dependence for an additional production well to be <br />drilled. <br />On December 1 b, 2003, ASLLP meet with representatives of the EPA, <br />CDMG, and BLM to discuss possible revisions to the plan. ASLLP proposed a <br />downhole seismic method to characterize the solution mining cavity. Discussions <br />during the meeting illustrated the value of a partial displacement to provide a <br />cross check of the seismic method. The revised cavity characterization plan was <br />comprised of fwo phases as follows: <br />Downhole Seismic Profiling -Ten high temperature hydrophones would <br />be lowered into the short string of 4'/z"tubing. Wireline explosive <br />charges would be lowered down the long string of 4 ~/s" tubing. Upon <br />detonating the charges, the hydrophones will measure the velocity of <br />the seismic reflection of the seismic signal of the charges which will be <br />used to calculate a mathematical model of the cavity. fie model will <br />provide a distribution of cavity diameters, but will not be oriented to a <br />reference direction. The model should be effective in modeling the <br />top one half to two thirds of the cavity. <br />2. Fluid Displacement -The fluid in the top ten to twenty feet within the <br />cavity would be displaced with nitrogen, carbon dioxide, or methane <br />