Nalysis and research on the bypass valve of continuous circulation sub for gas drilling

The continuous circulation sub for gas drilling can effectively address problems such as hole bottom pressure being hard to control, the operation pressure window between formation pore pressure and break pressure being small, severe wellbore ballooning effect and accident influx of oil or gas. A bypass valve for continuous circulation sub is designed in the side hole of the sub body. No matter it is open or closed, the circulating media will produce impact force on it, which may damage its strength, and the circulation medium may leak out when it is closed. The ANSYS software was used to simulate the mechanical behavior of the valve under both closed and open conditions, and furthermore analyzed the dangerous section of the valve body. The result shows that this valve construction satisfies the strength demands under various working environments and the bypass valve needs to be securely sealed when closed. The research also completed the design and analysis of the sealing pair for the bypass valve.