Accurate flow-in measurement by triplex pump and continuous verification

A method, comprising:

• providing a multiplex pumping system comprising multiple multiplex pumps for pumping fluid downhole in a drilling operation;
• and
• calculating a volumetric efficiency of a first multiplex pump while the multiplex pumping system pumps fluid downhole;
• wherein the volumetric efficiency is calculated from a suction flow rate into the first multiplex pump and a theoretical discharge volume pumped out of the first multiplex pump.

A system, comprising:

• a fluid source;
• multiple multiplex pumps, each multiplex pump comprising:
• a crankshaft;
• at least one position sensor disposed on the crankshaft;
• multiple chambers, each chamber having an inlet in fluid communication with the fluid source via an inlet flowline and an outlet;
• multiple pistons, each piston slidingly engaged within the chamber;
• and
• multiple connecting rods, each connecting rod extending from one of the pistons to the crankshaft;
• a motor connected to the crankshaft;
• and
• a calibration tank selectively in fluid communication with the inlet of one of the multiplex pumps at a time.

A system, comprising:

• multiple triplex pumps fluidly connected to a fluid source via inlet flowlines;
• a Coriolis meter disposed along a first inlet flowline;
• and
• at least one secondary flowline fluidly connecting a portion of the first inlet flowline upstream the Coriolis meter to one or more different inlet flowlines.