Originally posted by Just Wondering
I think they are trying to pump enough mud past the holes so when they turn off the mud pumps it doesn't get pushed back out?
No. They are not pumping mud past the holes.
Yes. They do want it so that it doesn't get pushed back out when they turn the mud off.
You have the busted riser at the top with the holes in it that we are watching now.
You have the blow out preventer (BOP) under that. It isn’t completely sealing off the well. But it is the only restriction in the system.
You have the choke and kill lines at the bottom of the BOP (restriction) that they are pumping the mud in.
You have the well head at the bottom of all that.
When mud enters the through the choke kill lines, it can take one of two paths. Go down, into the well. Or go up through the BOP and out the riser/
Remember this. When you have a restriction. Flow is proportional to pressure. If you increase flow, you will have to increase pressure to achieve that
flow. If you increase pressure, then flow will increase.
When you pump mud in, it will increase the pressure in the well head. That is because it is a competing flow. The mud is competing for outlet volume.
10 units of oil coming out through an opening. If you add 1 unit of mud, it will either restrict the flow of oil if the oil source can’t produce any
more pressure, or push up the pressure, until 11 units total can push through the same restriction.
If you do not pump mud in fast enough. The oil/gas will just carry the mud along with it, out the top of the BOP/riser. The increased pressure will
slow the oil flow a bit, but not stop it.
At a critical point, if you pump mud just fast enough. It will take up all the volume of the outlet leak. It will push the wellhead pressure so high
that the oil can’t push it’s way out. The mud hogs all the available outlet capacity.
Past the critical point. If you continue to increase pumping capacity. You would increase the pressure past the static pressure of the well below.
When that happens, mud will flow into the well.
When you get enough mud in the well, it will kill the flow.
The critical property of drilling mud isn’t it’s stickiness. It is it’s weight. It is heavily doped with metals. It is far heaver than oil or
water. It is basically liquid steel. When you get a large column of drilling mud in a pipe, it acts like a steel ram rod pushing down the hole. It
literally pushes the oil back down the hole with it’s shear weight. Once you get enough mud in the hole, and get it stabilized/gas bled off. You no
longer have to apply pressure at the top. It will hold the well in check by it’s self. That is basicly the normal state a well is in when it is
being drilled. A blowout happens when you don’t have enough mud in the column to hold the well in check. When that happens, the whole column starts
moving upward. That is called a kick. That is what the BOP is designed to catch.