Pressure drop tester for water injection well mouth

The utility model discloses a pressure drop tester for a water injection well mouth. The pressure drop tester is designed for improving the accuracy and continuity of a water injection well pressure drop test and reducing labor intensity. The lower end of a pressure measuring cylinder of the tester is connected with a lower joint provided with a central passage. The upper end of the pressure measuring cylinder is connected with a plug. A pressure sensing and storing device sealed by a sealing ring and provided with a radial pressure relief opening is arranged inside the pressure measuring cylinder. The upper end of the pressure sensing and storing device is connected with a battery housing. A special battery and an adjusting spring arranged above the special battery are arranged inside the battery housing. According to the pressure drop tester for the water injection well mouth, unattended operation of the well mouth pressure drop test can be achieved, pressure drop test data required for profile control can be automatically and accurately obtained, and the problems that a traditional manual pressure drop test wastes time and labor, and data accuracy is poor are solved.