Detecting and Compensating for the Effects of Pump Half-Stroking

摘要

Various methods for detecting and accounting for the effects of half-stroking by a pump are provided. In one embodiment, a method includes operating a pump of a downhole tool to pump fluid from a formation through the downhole tool and determining pressure differentials between a formation pressure and pressure of the fluid within the downhole tool. The pressure differentials for each of a forward stroke and reverse stroke of the pump can be summed and then compared to enable identification of onset of half-stroking by the pump. Additional systems, devices, and methods are also disclosed.

主权项

1. A method comprising:
operating a pump of a downhole tool to pump fluid from a formation through the downhole tool; determining pressure differentials between a formation pressure and pressure of the fluid within the downhole tool; summing pressure differentials between the formation pressure and the pressure of the fluid within the downhole tool for a forward stroke of the pump; summing pressure differentials between the formation pressure and the pressure of the fluid within the downhole tool for a reverse stroke of the pump; and comparing the summed pressure differentials for the forward stroke to the summed pressure differentials for the reverse stroke to enable identification of onset of half-stroking by the pump.