Chemical injection control system and method for multiple wells

A chemical injection system for controlling the distribution of fluid from a common supply conduit into each of a plurality of petroleum wells in the general vicinity of an end of the supply conduit, the chemical injection system controlling the injection rate of a chemical fluid into each well at an individually adjustable rate, such that the injection system at each of the plurality of wells comprises an individual well injection system, the chemical injection system comprising:

• a remotely operated two position directional control valve fluidly connected to the supply conduit;
• a hollow cylinder having a cylinder bore and a first input-output port at one end and a second input-output port at an opposing second end;
• a fluid barrier within the cylinder bore, such that chemical fluid flows from the supply conduit through said control valve to one end of the cylinder bore and forces the barrier to displace a fixed volume of fluid from the cylinder bore, then through the control valve and to an injection point for the individual petroleum well, each operation of the directional control valve reversing travel direction of the barrier within the cylinder bore;
• a first damping chamber on one side of the fluid barrier;
• a second dampening chamber on an opposing side of the fluid barrier;
• one or more valve members for restricting flow from at least one of the first and second dampening chambers;
• and
• a transducer for remotely determining the flow of chemical fluid into the individual petroleum well.

A method of for controlling the distribution of a chemical fluid from a supply conduit into an individual petroleum well in the vicinity of multiple petroleum wells at individually adjustable rates, the method comprising:

• providing a remotely operated two position directional control valve fluidly connected to the supply conduit;
• providing a hollow cylinder having a cylinder bore and a first input-output port at one end and a second input-output port at an opposing second end;
• providing a fluid barrier within the cylinder bore;
• providing a first damping chamber on one side of the fluid barrier;
• providing a second dampening chamber on an opposing side of the fluid barrier;
• automatically restricting flow from at least one of the first and second dampening chamber;
• and
• operating the control valve to flow chemical fluid from the supply conduit through such directional control valve to an opposing end of the cylinder bore to move the barrier and displace a fixed volume of fluid from the cylinder bore, then through the control valve and to the injection point for the individual petroleum well.