Apparatus for controlling a pressure control assembly in a hazardous area

An apparatus for controlling a plurality of choke assemblies, wherein each choke assembly includes a housing having an inlet and an outlet in fluid communication with a wellbore, a fixed plate located between the inlet and the outlet and having an orifice therethrough for communicating fluid from the inlet to the outlet, a choke plate rotatably retained against the fixed plate and having an orifice therethrough, wherein the choke plate is rotatable to adjust a size of an orifice resulting from the relative positions of the orifice through the choke plate and the orifice through the fixed plate and is further rotatable to close the resulting orifice to prevent fluid communication therethrough, the apparatus comprising:

• an air source;
• an air purge system in fluid communication with the air source;
• a remote operating panel receiving data from at least one remotely located wellbore sensor, the remote operating panel comprising:
• an airtight housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the housing;
• a toggle switch located on the housing for selecting one of the choke assemblies to be controlled;
• a plurality of operator controls located on the housing for manually controlling operation of the selected choke assembly;
• a display located on the housing for visually displaying values of data received from the wellbore sensor;
• a local operating panel corresponding to each choke assembly being controlled, wherein each local operating panel is in electronic communication with the remote operating panel, each local operating panel comprising:
• an airtight local panel housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the panel housing;
• and
• a local operator controller having an operator interface for receiving operator instruction input into the local panel, and operable to receive operator instructions from the remote panel and transmit operator instructions;
• and
• an actuator corresponding to each choke assembly and coupled thereto, the actuator comprising:
• a motor in an explosion-proof housing coupled to the choke plate and operable to adjust the orifice through the choke plate, wherein the motor receives electronic communication of the operator instructions transmitted by the local operator controller;
• and
• a position indicator coupled to the choke plate for sensing the orifice opening and providing feedback of the choke plate position to the motor.

An apparatus for controlling pressure in a wellbore comprising:

• a choke assembly comprising:
• a housing having an inlet and an outlet in fluid communication with the wellbore;
• a fixed plate between the inlet and the outlet having an orifice therethrough for communicating fluid from the inlet to the outlet;
• a choke plate rotatably retained against the fixed plate and having an orifice therethrough;
• wherein the choke plate is rotatable to adjust a size of an orifice resulting from the relative positions of the orifice through the choke plate and the orifice through the fixed plate and is rotatable to close the resulting orifice to prevent fluid communication therethrough;
• an air source;
• an air purge system in fluid communication with the air source;
• a remote operating panel receiving data from at least one remotely located wellbore sensor, the remote operating panel comprising:
• an airtight housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the housing;
• a plurality of operator controls located on the housing for manually controlling operation of the choke assembly;
• and
• a display located on the housing for visually displaying values of data received from the wellbore sensor;
• a local operating panel in electronic communication with the remote operating panel, the local operating panel comprising:
• an airtight local panel housing in fluid communication with the air purge system, wherein air from the air purge system is circulated through the panel housing;
• and
• a local operator controller having an operator interface for receiving operator instruction input into the local panel, and operable to receive operator instructions from the remote panel and transmit operator instructions;
• and
• an actuator coupled to the choke assembly to control pressure within the wellbore, the actuator comprising:
• a motor in an explosion-proof housing coupled to the choke plate and operable to adjust the orifice through the choke plate, wherein the motor receives electronic communication of the operator instructions transmitted by the local operator controller;
• and
• a position indicator coupled to the choke plate for sensing the orifice opening and providing feedback of the choke plate position to the motor.