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.
As per previous topic, driller’s method well control, it stated about overall of driller method and this post will show the detailed of driller’s method and describe in term of operation stand point as well. I separates all detailed-step of driller method into several blog post because I want to add a lot of details for each topic so you will clearly understand about driller method and you also can apply with your real life operation.
Today I will start with the first one is to shut in well and obtain pressure information
Driller’s method is one of several methods to kill the well. The main idea of driller method is to kill the well with constant bottom hole pressure. The Driller’s Method of well control requires two complete and separate circulations of drilling fluid in the well.
The first circulation removes influx with original mud weight. When starting to bring pumps up to speed, casing pressure must be held constant until kill rate is reached. Then drillpipe pressure is held constant to maintain constant bottomhole pressure which is normally equal to, or slightly greater than pore pressure. Drillpipe pressure will be held constant until influx is removed from annulus. If the wellbore influx is gas, it will expand when it comes close to surface therefore you will see an increase in pit volume and casing pressure.