Workovers are standard practice. The EXR workover and the Lucky Fox one...theres multiple wells being worked over everyday at QGC and Origin, all producing wells. Theres crews who go around disconnecting instruments, just for workovers and downhole gauge replacements.
I know of a well that had 3 workover in about 4 months. It bogged twice. I know because I had to help with the disconnect reconnect and also replaced an HPU on the well. The well kept silting up. Tonnes of restarts. It was running at low rpm on the pump, doing low rates. It was around 400m deep. Nothing major. Was done with a small workover rig.
EXR oversized pumps expecting higher water flows, if they had undersized it would of been tears from HC...better to be prepared. With the likelihood of workovers early on it isnt a big deal to downsize. Thankfully there arent high water rates.
As far as collapsing coals being a learning, that has always been the case and it isnt a new learning for anyone involved in this from any of the junior explorers in Mongolia. Everyone knows about collapsing the wells, and the dewatering controllers do a good job of maintaining well water rates as set.
For your question about synchronous water flow rates, the pressures are monitored downhole to work out the water level local to each well and feeds into the PID water control at the wellsite, and the monitoring wells measure pressure at a distance away. Wells in the same field can often run large differences in water levels and flow rates. But you can trend when downhole pumps start and stop across a field, through pressure monitoring at the monitoring wells.
The water monitoring bores in Surat Basin do this extremely well and very accurately. Though some are spaced well away from producing wells.
(20min delay)