Frac water hauling

I don't haul water but I can answer question. During completion while the wells are being fraced they are hauling water. Lots of water. Not all wells are fraced.
They are called ducs.......Drilled UnCompleted.

 

The Frac water comes in via large 'ponds' then they use pumps . When there are no fresh water wells around, you need truckload of fresh water to fill up said pond.

For the flow back - water usually go into frac tanks as of they can separate oil and water. the water is then either thrown in a pond or in other frac tanks; which then needs to be disposed off . It used to be done with trucks however nowadays it s maybe connected to a water line heading directly to the disposal.
excess oil in the flow tank can be transferred to stock tanks, where it sits about a day, then the water is pulled out of the bottom and oil is ready to be picked up by Oil haulers. OR transferred across location to an existing battery in the larger tanks and then sold through Lact/pipeline.

During drilling process, they use brine. - hauling brine to retention pond via trucks.
during work on a well , brine is used also quite often in combination of a kill truck or a hot oiler - basically they put pressure down the well so nothing gets out.

Water trucks can also be used to clean stuff , goes from the nice easy get the rain water out of containment, clean up spills in the middle of a pasture; to clean up sludge in either batteries or worst those Poseidon tanks. That needs to be disposed of in 'solid disposal' as opposed as the regular SWD; and you need to wash your tank afterward ; same when doing concrete jobs... unless you want to go break up cement later on with your hammer inside the baffles.

To answer the question about a pad with multiple wells; they usually frac them one after the other, and when its time for the flow back; they ll have all running at the same time,. However each well will be separated; that way they know what flows what amount etc.

side note. Don't haul acid in you nice shiny aluminum tanker

 

After Wells are drilled they start what is called Flowback. Mixture of salt water, sand, and some oil. The salt water and sand are from the fracking process.

Stop using the word stimulation. Nobody in the oilfield uses that word.