MULTI-CYCLE CIRCULATING SUB
The Multi-Cycle Circulating Sub is a sub which can provide multiple open and close the circulation between sub’s inside and outsideby dropping the ball at the wellhead. The sub will be opened and closed by each ball dropped from the wellhead. The sub is suitable for horizontal and extended-reach wells.It is usually used in the cleaning and leaking process.
SPECIAL BYPASS VALVE
The special bypass valve is a tool that provides circulation through the pressure difference. It is an ideal tool for use in large angle of inclination and horizontal wells.
INCREMENTAL CIRCULATING VALVE (BYPASS VALVE)
Incremental circulating valve is a kind of by-pass valve, connect it close to drill bit before drilling oil and gas layer, and when drill bit was blocked in killing well operation, the by-pass valve can set up a new circulation channel and continue to implement killing well operation.