Pumpjack production well including venturi fluid sensor and capacitive flow sensor

A pumpjack monitoring and control system for a well, including:

• an in-line fluid sensor, operatively coupled to receive the fluid output of a pumpjack connected to a wellhead of the well, and to generate at least pressure and capacitance signals in response to the fluid output, said fluid sensor comprising:
• a) a cylindrical venturi including first and second coaxial cylinders, wherein the first coaxial cylinder is located within the second coaxial cylinder, said coaxial cylinders forming a continuous, consistent, and uniform gap between an outer surface of the first coaxial cylinder and an inner surface of the second coaxial cylinder, the cylindrical venturi causing a controlled thickness of non-stratified fluid flow through the gap;
• b) a first fluid pressure sensor located on an inlet to the cylindrical venturi;
• c) a second fluid pressure sensor located upstream of an outlet of the cylindrical venturi;
• d) a capacitive sensor operatively associated with the cylindrical venturi, the capacitive sensor including a pair of conductive surfaces located on opposing sides of the gap in the cylindrical venturi;
• and
• a controller, operating in accordance with a set of pre-programmed instructions, said controller receiving output from said fluid sensor, said controller processing the output and using said output to monitor the pumpjack output and to report the performance of the pumpjack, and totalize the amount and types of liquids pumped from the wellhead.

A fluid monitoring system, including:

• an in-line fluid sensor, operatively coupled to receive the fluid output of a source of fluid, and to generate at least pressure and capacitance signals in response to the fluid output, said fluid sensor comprising:
• a) a cylindrical venturi including first and second coaxial cylinders, wherein the first coaxial cylinder is located within the second coaxial cylinder, said coaxial cylinders forming a continuous, consistent, and uniform gap between an outer surface of the first coaxial cylinder and an inner surface of the second coaxial cylinder, the cylindrical venturi causing a controlled thickness of non-stratified fluid flow through the gap;
• b) a first fluid pressure sensor located on an inlet to the cylindrical venturi;
• c) a second fluid pressure sensor located upstream of an outlet of the cylindrical venturi;
• d) a capacitive sensor operatively associated with the cylindrical venturi, the capacitive sensor including a pair of conductive surfaces located on opposing sides of the gap in the cylindrical venturi;
• and
• a controller, operating in accordance with a set of pre-programmed instructions, said controller receiving output from said fluid sensor, said controller processing the fluid sensor output to monitor the fluid passing through said sensor and to identify the presence of impurities in the fluid.