so you know formation properties... probably also have an idea how far boundaries are from geologist/geophysicist, likely width from thickness for this geological environment etc...

simulate how much (minimum) time you need to see it clearly on derivative. as pressure disturbance will reach boundary you will need another log cycle if it is practically possible. get few scenarios to get a range... account for a gauge type and interferences...

do you have surface readout or it is luxury? then you can stop test earlier