After kick has been circulated out of the well, the mud pumps can be shut down and the well must be secured. While shutting down the pumps, it is a good practice to gradually close the choke instead of suddenly shut in.
You must keep in mind that while shutting down pumps, you must keep casing pressure constant achieved by manipulating the choke. This procedure is to ensure that constant bottom hole pressure is maintained during the shutdown.
After the pumps are brought up to desired kill rate and drill pipe pressure stabilize, personnel must observe and record the drillpipe pressure. For the first circulation, you must hold drill pipe pressure constant in order to maintain constant bottom hole pressure. To achieve maintain drill pipe pressure constant, personnel must manipulate the choke while circulating.
I completed about well control formulas from previous blog post and then I would like to continue about driller’s method in details.
You can read previous about driller’s method here!!!
Today, I post about 1st step of establishing circulation in driller’s method, bring the pumps up by holding casing pressure constant.
The idea of holding casing pressure constant while bring up pumps is to maintain constant bottom hole pressure.
Bring pump up to circulating rate, typically about 2-5 BPM, by holding constant casing pressure. The reason why we need to hold constant casing pressure is to maintain constant bottom hole pressure.
This part of well control formulas will demonstrate you more about some equations frequently used in snubbing operation. In Well Control Formulas Part 5, I show just only some snubbing formulas and this part will show the rest of them.
I wish you would enjoy reading my blog post.
Buoyed Weight of Open Ended Tubulars (Wb),lb
For this formula, you just use the buoyancy factor and multiply it with weight of pipe in the air.
Buoyed Weight of Closed Ended Tubulars without fluid in the pipe (Wb),lb
This formula below is different from the 1st formula because it is used for the closed ended pipe. Weight in the air will be subtracted with buoyancy weight of pipe ran in hole.
Note: 24.5 is conversion factor to make the unit in gallon.
This part of well control formula series (part#5) will show you following equations: mud increment for volumetric, lube increment for lubricate and bleed, bottle capacity required for koomey unit, volume of usable fluid, and snubbing force for snubbing operation. Later on, I will show you how to apply equations to particular situation. Anyway this is part 5 and total will be 8 parts.
Mud Increment for Volumetric Method (MI), bbl
Lube Increment for Lubricate and Bleed Method (LI), bbl
