| Popis: |
Solvent extraction is proposed as a means of recovering dissolved methane from geopressured-geothermal brines at high pressures. The assessment shows that additional investment in a high pressure solvent extraction plant preceding direct injection disposal of brines into isolated aquifers can be profitable. The technical and economic issues are discussed, and compared with other injection methods such as complete depressurization for methane recovery followed by conventional mechanical pumping. The contributions of hydraulic (pressure) energy recovery and geothermal power production are also assessed. For deep injection into the producing formation, it is concluded that methane extraction processes are not applicable, insofar as maintenance of high surface pressures provides no clear-cut energy benefits. As a first step in the evaluation of solvent extraction, the solubility of a promising solvent candidate, n-hexadecane, was measured in 15 wt % NaCl solutions at temperatures up to 150/sup 0/C. The solubility of a potential low cost solvent, No. 2 Diesel fuel, was also measured. |
