AUTOCHOKE

Uniquely engineered pacesetting drilling choke

The uniquely designed AUTOCHOKE is the pacesetting high-pressure drilling choke from M-I SWACO. The AUTOCHOKE incorporates a sliding shuttle connected to a dynamic trim sleeve. Flow from the well passes through the inlet and is controlled by the action of the shuttle assembly. As it slides back and forth the shuttle assembly adjusts the position of the dynamic trim relative to the circular orifice of the matching static trim.

An increase in annulus pressure or a decrease in the hydraulic set point pressure will cause the shuttle assembly to move away from the static trim, increasing the orifice size. This allows fluid to flow from the well and decrease the casing pressure until it equals the set point pressure.

A decrease in casing pressure or an increase in the set point pressure will cause the shuttle assembly to move toward the static trim, decreasing the orifice size. This reduces the fluid flow from the well, increasing the casing pressure until it equals the set point pressure.

The set point pressure applied to the backside of the shuttle assembly is adjusted by a pressure regulator and measured by the set point gauge located on the choke control panel. The annulus pressure is applied to the front side of the shuttle assembly.