Dump bailers for cement, acid, or sand dumping operations are offered in two types—the positive-displacement (PD) bailer and the gravity-feed bailer. Dump bailer uses a weighted swab piston to push, or positively displace, the bailer’s contents into the wellbore. The dump bailer does not use any explosives. Instead, a solenoid drops a weight bar from a set of collets, causing a pressure wave that moves a piston in the bottom of the bailer to release the cement. This advantage helps to make the system technically superior to other positive-displacement systems in the industry. The gravity-feed system is the most commonly used dump bailer in the industry. The gravity-feed system requires explosives to shatter the disk in the bottom of the bailer, enabling the cement to flow.
- The system’s simple design requires minimal user training, is easy to operate, and uses an explosive charge to release cement downhole—all help to control costs.The absence of internal moving parts makes the system easy to maintain, saving time.