is most commonly used to plug wells other materials can also be used for example unconsolidated well plugging materials bingham plastic material geopolymer cements made of aluminum and silicon sandabag thermaset a non reactive polymer with a curing process activated by temperature and the like can be used as plugging materials the cement level is usually observed after cement has set for 24 hours if the cement has fallen back the casing is typically re filled with cement back to the top of the plugging interval typically once the plug is placed and set it is then tested any suitable test can be performed to confirm the integrity of the barrier s or as dictated by applicable regulations after the well is plugged testing is required to ensure that the plug is a placed at the proper level and provides zonal isolation the plug can be verified by tagging its top pump pressure testing or swab testing typically a leak test is performed in the leak test a pressure is applied to the barrier equal to or higher than the maximum differential pressure that the barrier can be exposed to the acceptable leak rates shall be zero unless other values are given alternatively or in addition to a leak test another cbl can be run in addition a gamma ray neutron log may be required by some states these tests may confirm the quality and placement of.