Tool Introduction

Internal pressure circulation valve is a full bore, internal pressure differential operated circulation valve that can be used in casing wells and open hole wells. It applies internal pressure differential to open the circulation hole at the end of testing and before drilling, providing an overcurrent channel for the pipe string during the drilling process. It is usually used as a backup circulation valve.

Structural characteristics

① The internal pressure circulation valve is mainly composed of an upper joint, an operating core shaft, a lower joint, a shear pin, and a locking ring;

② During the process of going down the well, the internal and external pressure difference on the operating core shaft is balanced, and the shear pin ensures that the circulation hole is always in a closed state;

③ After the packer seat is sealed, the force generated by the internal and external pressure difference acting on the operating core shaft cannot exceed the shear value of the installed shear pin, otherwise the circulation hole will be opened in advance.

operation

When operation is required, apply pressure from the inside of the pipe column to the shear pressure value of the shear pin, and the shear pin will be cut off. The operating core shaft will descend to open the circulation hole, and the locking ring will lock the operating core shaft in the open position of the circulation hole. Subsequently, the tool circulation hole will always be in an open state.

technical parameter