Paper: Guidelines For Selecting Cement That Will Be Perforated

Results of work performed to determine the degree of cement sheath shattering that occurs during perforation indicate the application potential of lightweight "lead" cements as "perforating" cements. Four lightweight cement candidate blends were tested and compared to conventional, normal density, tail cement. A 7 in. OD, 23 lb/ft J-55 casing test fixture was used. The formation was simulated by a piece of tubing 10.75 in. OD by 0.188 in. wall. The 10 in. thin wall tubing is not a component of normal well completions; it served to act as a simulated formation to hold cement in place. The cement was perforated with 0.42-in. dia. perforations, 90" phasing, four shots per foot (spf) with 22 gm charges placed in each test fixture. The test procedure was specifically designed to duplicate typical field conditions in the Midland, Texas, area, and to determine the amount of cement shattering that occurred while perforating. Test fixtures were sectioned after perforating, examined for cement sheath damage, and photographed.