Surfactant selection for downhole treatments

A method comprising:

• providing a column containing first particles and second particles, wherein the first particles differ from the second particles by at least one property selected from the group consisting of:
• a mean particle diameter, a sphericity, and a chemical composition;
• providing a plurality of surfactant samples that are different and each comprise a base fluid and at least one surfactant;
• measuring a displacement rate and a displacement volume for the plurality of surfactant samples according to the following procedure:
• flowing the surfactant sample and then an oleaginous fluid through at least a portion of the column;
• measuring the displacement rate at which the oleaginous fluid displaces the surfactant sample;
• and
• measuring the displacement volume for which the oleaginous fluid displaces the surfactant sample;
• comparing the displacement rate and the displacement volume of each of the plurality of surfactant samples;
• and
• ranking the plurality of surfactant samples based on the displacement rate and the displacement volume, thereby producing a sample ranking.