TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The cement composition further includes a degradation catalyst, a second set retarder and a salt. Preferred Components: The water is freshwater, brackish water and/or saltwater, in any proportion.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The second set retarder is citric acid, gluconolactone, boric acid, tartaric acid or sodium pentaborate.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polymer is a thermoplastic aliphatic polyester. The first monomer is ethylene glycol, propylene glycol, butanediol, pentaerythritol or butane diol. The second monomer is ortho-, meta- or para-phthalic acid, citric acid, malic acid or naphthalene dicarboxylic acid. The polymer is polylactic acid or polyglycolic acid. The polymer is in at least a sufficient concentration such that the cement composition has a thickening time of 2-7 hours at 400 degrees F and a pressure of greater than 500 psi. The polymer is in a concentration equal to or less than a sufficient concentration such that the cement composition has a setting time of less than 48 hours at 400 degrees F. The polymer is at a concentration of 1-5 wt.% of the cement. The polymer undergoes complete degradation in a specified period of time, which is the time it takes for the cement composition to be introduced into and situated in the portion of the well to be cemented. At least a portion of the well has a bottomhole temperature greater than or equal to the glass transition temperature or melting temperature of the polymer. The polymer is in at least a sufficient concentration such that the cement composition has a thickening time of 1-7 hours at the bottomhole temperature and pressure of the well. EXAMPLE - Typical cementing composition comprised of: aliphatic polyester (quantity not specified); calcium aluminate cement (quantity not specified); water (37.6 wt.% with respect to cement); fly ash (quantity not specified); sodium hexametaphosphate (quantity not specified); polylactic acid (2 wt.%); citric acid (3 wt.%); and calcium chloride (0.5 wt.%).