Definition - What does Shear Ram mean?
A Shear Ram is a tool that is used to cut the drill pipe or tubing and seal the wellbore when the well starts to flow and control is lost. The shear rams are usually fitted with hardened and sharpened steel blades which cleanly sever the pipe in the hole. The two rams are driven together by powerful hydraulic cylinders to sever the pipe and close the wellbore when BOP is activated.
Petropedia explains Shear Ram
In the event a well blowout occurs and uncontrolled release of oil and/ or gas from the well, it becomes necessary to close the wellbore so as to avoid catastrophes. Blowout Preventers (BOP) are used in oil wells to prevent well blowouts. Rams which are components of ram blowout preventers are available in variable-bores so that a wide range of pipe diameter can get covered for sealing. The shear ram uses the shearing technique to cut the hardened steel through the drill string. The ram is usually used as the last course of action to regain the pressure control of a flowing well.