At present, the plug valve (also known as kelly cock) used for blowout rescue in drilling site is normally open, although the flow area is very large, it can be used for internal shut in. But it can only achieve the cut-off, not the check. When the working condition requires the plug valve to enter below the rotary table surface, it must be in the normally open state. In this way, there is no internal blowout preventer on the drill string. In order to solve this problem, a check valve is often connected to the plug valve on site.In order to solve the shortage of the cock, the invention provides a multi-functional cock valve, which is simple and compact in structure, novel in form, good in reliability, multipurpose in one valve and strong in compatibility, and is suitable for the drilling technology field of petroleum industry.
This kind of multi-functional plug valve has the following characteristics:
A. It has the functions of pressure relief, blowout prevention and circulation well killing.The unique floating ball valve mechanism can easily open the ball valve and release the pressure; close the ball valve to prevent blowout; float the ball valve to implement circulation killing.
B.It has high strength and vulcanization resistance. The body of the multi-functionalplug valve is made of high-strength steel specified in API standard, and the parts are made of special metal materials resistant to sulfide stress crack, with high machining accuracy, which ensures the excellent quality of the safety tools used in oil drilling well control.
C. It has high opening pressure difference and reliable sealing performance. The control components of the multi-functional plug valve adopt high-tech sealing device to ensure the reliability of pressure and sealing. When the pressure difference in the drilling tool is less than 45MPa, it can be closed or opened easily.
D. Wide temperature range. Special sealing materials are used, and the temperature resistance range is -50° C ~ +190° C. It can adapt to the field operation under high cold and high temperature conditions.
