I had the following question come to me in an email this morning and it's really a good question:
I’m working in Nigeria as a tool pusher. Doing a Shell job. They always pump sweeps , LCM and Slugs with two pumps. I tell them it is wrong to do that -that only one pump should be on the hole while pumping these products, then chase with two pumps.
Is that right or wrong? I have been taught that all my life.
As for myself I have also been taught to pump with 1 pump-until the last rig I worked on where we always pumped with 2 pumps.
The reason I have always suspected was using 1 pump would not cause you to dilute your Sweep, Pill or Slug with System Mud-BUT
the last rig I was on fed BOTH pumps with 1 Charge Pump to both suctions on both pumps-so to pump a Sweep, Pill or Slug I just had to switch 1 charge pump valve to send it to both pump suctions....
Each time I had a new companyman on the rig-he ALWAYS wanted to make sure I was pumping Sweeps, Pills & Slugs with 1 pump-then when I explained that 1 Charge Pump fed both pumps with the switching of a single valve-
then they ALWAYS said to use both pumps in this way...
I am curious as to they way all of you prefer to do this operation and I will share the results with the individual that has asked the question.