Minimization of contaminants in a sample chamber

摘要

A formation testing apparatus and method for obtaining samples with lower levels of contaminants is provided. Such a method can remove contaminants from a fluid sample, and can include the steps of obtaining fluid from a formation and passing a first quantity of the fluid through a sample flow line (518, 520). A connection (524) between the sample flow line and a sample chamber (532) can be opened, and a first portion of the first quantity of the fluid can be drawn into the sample chamber (532) via a floating piston. The first portion can be forced out of the sample chamber (532) , and this process can be repeated until sufficient contaminants have been removed. Finally, a second portion of the first quantity of the fluid can be drawn into the sample chamber as the fluid sample.