Figure F1. Plot of PORC (porosity using plug volume measured by caliper) vs. PORM (porosity using plug volume measured by mercury displacement). Only in one case (plug 244; Table T1) is PORC substantially less than PORM, apparently reflecting an exceptional error in this particular PORC measurement. "Control" plugs selected for good cylindrical shape are represented by solid squares.

Figure F1. Plot of PORC (porosity using plug volume measured by caliper) vs. PORM (porosity using plug volume measured by mercury displacement). Only in one case (plug 244; Table T1) is PORC substantially less than PORM, apparently reflecting an exceptional error in this particular PORC measurement. "Control" plugs selected for good cylindrical shape are represented by solid squares.