| Item | Trouble | Cause | Settlement |
| 1 | The medium inside well flows out from the clearance between the body and door. | Seal ring between the body and side door is damaged. Connection bolts released between the body and side door. There is dust or damage on the body and side door seal surface. | Change damaged seal ring. Screw up all connection bolts. Remove surface dust and repair damaged parts. |
| 2 | Ram movement direction is not conformance with nameplate mark of control valve. | The pipelines between control panel and BOP have been connected wrongly. | Reverse pipes that connect BOP. |
| 3 | Hydraulic system is in order, but ram can not closed fully. | There are foreign materials, sand and mud on ram contact ends. | Wash ram and side door. |
| 4 | The medium inside well flows into the cylinder and there contains water in cylinder oil. | Piston rod seal ring damaged. Piston rod distortion or surface scratch. | Change damaged piston piston rod seal ring. Repair the damaged piston rod. |
| 5 | BOP hydraulic part cannot hold pressure. | BOP cylinder, piston, piston rod, seal ring damaged, seal surface scratched. | Replace all damaged seal rings and repair seal surface or change it with the new parts. |
| 6 | There is leakage on side door connections. | Seal surface scratched, seal ring worn. | Repair seal surface and replace seal ring. |
| 7 | It cannot hold pressure when ram closed. | Ram seal rubber damaged. Upper seal surface of the ram chamber damaged. The ram size is not in accordance with the drilling tool in the well. | Change ram seal rubber. Repair seal surface. Change the relevant size ram. |
| 8 | Control pipe is in order, but ram cannot he opened with hydraulic pressure. | The locking shaft isn't unlocked. Ram plugged with sand and mud. Piston seal ring damaged. | Unlock locking shaft. If damaged, change it. Remove sand and mud. Increase control pressure. Change piston seal ring. |
