Well x is a production well in an oil field. In oil production test with the
combination of APR test and perforation, Owen lowpressure mechanical safety ignition head is used. After the first openwell for rod casting
and perforating operation, there is no vibration caused by perforating on the ground, and there is no bubble display on the display head. After
the first shutin for 3 hours and the second openwell for swabbing, there is no fluid production in the formation, so it is judged that the
perforating gun does not detonate. According to the working principle and operation of the mechanical safety ignition head, it is judged that the
rod has been thrown and unlocked, but the striker fails to impact the initiator downward. After the pressurizing in the tubing, the perforating
was successful, the emissivity was 100%, but the negative pressure test could not be realized. According to the appearance observation of the
ignition head and the analysis of the pressure history data, the main reason why the perforating gun failed to detonate is that the killing mud
performance is poor, the mud sand and barite powder are deposited at the ignition head, and the striker cannot complete the downward movement
under the hydrostatic column pressure in the designed tubing. The result of this analysis can shed light on perforating operation in similar
wellbore environment.