In this article, we will describe the effect of friction pressure on bottom hole pressure and equivalent circulating density while performing forward circulation.
It is the typical circulating path which is from a mud pump into drill pipe. Mud is pumped down into drill string / BHA and come out of a bit. Then, the mud is flown up the annulus and return back to surface as you can see in the diagram below (Figure 1).
Figure 1 – Forward Circulation Path
Space out means that you locate your drill string at the proper location where all the BOP rams (annular and pipe rams) will not close against a tool joint. Learn about space out via this VDO.
In the first circulation of driller’s method, driller circulates gas kick with 25 spm and the initial circulating pressure (ICP) is 1600 psi. The initial shut in drill pipe pressure is 450 psi. After shift change, another driller accidentally changes pump rate to 30 spm but he still holds drill pipe pressure constant.
What will happen to bottom hole pressure?
I was asked about BOP testing procedures from my junior staff on the rig. This is very simple but important question; therefore, I would like to share with you as well about the BOP testing procedure.
Note: my reference is based on API RP 53.
-Stack-2.jpg "blow out preventer")
image from cbc.ca
General BOP testing procedures
This post will teach you how to calculate kick tolerance. This concept is very important to well design and will give you an idea how much kick you can take at particular parameters.
Firstly, I would like to be clear about the following terms;
Kick tolerance is the maximum gas influx volumes (bbl) for a designed kick intensity that can be successfully shut the well in and circulated out without breaking formation pressure at the casing shoe.
Kick intensity is the different between the maximum anticipated formation pressure and planned mud weight.
Secondly, learn how to determin kick tolerance by following steps below:
