System and methods for pretests for downhole fluids

A system, comprising:

• a downhole acquisition tool housing comprising a pretest system configured to collect at least one of pressure or mobility information that enters the downhole acquisition tool from a sample line, a guard line, or both;
• and
• a data processing system configured to execute the pretest sequence by collecting fluid from the sample line only, the guard line only, or both the sample line and the guard line;
• wherein the data processing system comprises one or more tangible, non-transitory, machine-readable media comprising instructions to:
• performing a pretest sequence by:
• controlling a valve assembly to a first valve configuration that enables the fluid to flow into the downhole tool via one or more flowlines toward a pretest system, wherein the one or more flowlines comprises the sample line only, the guard line only, or both the sample line and the guard line;
• and drawing in the fluid through the one or more flowlines;
• and
• controlling the valve assembly to a second valve configuration, wherein the second valve configuration is different from the first valve configuration and is configured to block the one or more flowlines from drawing in the fluid.