Acoustic determination of piston position in a modular dynamics tester displacement pump and methods to provide estimates of fluid flow rate

摘要

A method for determining a piston position in a downhole tool, having steps of providing a transducer in the downhole tool, wherein the tool has a piston used to create a vacuum for the downhole tool, providing a transducer tone burst to provide acoustic energy toward the piston, reflecting the transducer tone burst by a surface of the piston, receiving the transducer tone burst at a receiver, calculating time of flight for the transducer tone burst and determining the piston position in the downhole tool based upon the calculated time of flight of the transducer tone burst.

主权项

1. A method for determining a piston position in a positive displacement pump of a downhole tool, comprising:
providing a transducer in the downhole tool, wherein the positive displacement pump has a piston used to create a vacuum for the downhole tool; contacting a surface of the piston with a fluid disposed within a fluid chamber of the positive displacement pump; providing a transducer tone burst of acoustic energy across the fluid chamber and toward the surface of the piston; reflecting the transducer tone burst by the surface of the piston; receiving the transducer tone burst at a receiver; calculating time of flight for the transducer tone burst; and determining the piston position in the positive displacement pump based upon the calculated time of flight of the transducer tone burst.