Methods and devices for filling tanks with no backflow from the borehole exit

摘要

A method for sampling fluid from a subsurface formation includes retrieving fluids from the formation using a plurality of pumps. The method also includes the steps of controlling a flow of the retrieved fluids using at least a first valve and a second valve and estimating an operating parameter of at least one pump of the plurality of pumps. The method further includes the step of controlling the first valve and the second valve using the estimated operating parameter to initiate a fluid sampling event.

主权项

1. A method of sampling fluid from a subsurface formation, comprising:
retrieving fluids from the formation using a plurality of pumps; controlling a flow of the retrieved fluids using at least a first valve and a second valve; estimating an operating parameter of at least one pump of the plurality of pumps; wherein the operating parameter relates to one of: (i) a stroke of the piston, (ii) a position of the piston, and (iii) a time to complete a stroke of the piston; controlling the first valve and the second valve using the estimated operating parameter to initiate a fluid sampling event; communicating with a fluid container via the first valve; communicating with a borehole via the second valve.