A field evaluation of geopressured brine injectability was completed during September 22 to 25, 1980 at the DOE, Brazoria test site in Texas. Membrane filters, with pore sizes of 0.4-..mu..m and 10.0-..mu..m, were used as the basis for obtaining suspended solids data and for developing performance-life estimates of typical spent brine injection wells. Field measurements were made at 130/sup 0/C and line pressures up to 3800 psig. Scale inhibited (phosphonate-polyacrylate threshold-type, carbonate scale inhibitor), prefiltered-scale-inhibited, and untreated brine were evaluated. Test results indicated that raw brine was highly injectable, while scale-inhibited brine had extremely low quality. The poor injectability of scale-inhibited brine resulted from partial precipitation of the scale inhibitor.