Shut in procedures are specific procedures for closing a well in case of well control situation and personnel on the rig should get proper training and be familiar with these procedures. In addition, the shut in procedures must be developed and practiced for every rig activity such as, drilling, tripping, logging, running tubular, performing a drill stem test, etc.
What is the reason why we need to have the shut in procedure and frequently practice it?
The main reason to have the specific shut in procedure is to minimize kick volume entering into a wellbore when well control situation occurs. Basically, the faster to recognize kick and shut in a well, it is the better to manage a well control situation. The amount of wellbore influx that enters the wellbore are minimized when personnel respond quickly to shut the well in. It is the fact that a small amount of kick entering into the wellbore will result in lower initial shut-in casing pressure and lower casing pressure while circulating. What’s more, the lower pressure at surface will reduce the chance of breaking down hole formation, generally called underground blowout.
Who is responsible for shutting the well in?
Drillers are responsible for shut in the well. If any positive kick indications are observed, they must shut in the well first and confirm whether the well is properly shut in or not. After that, they must inform drilling supervisors on the rig.
2 types of Shut-In (Hard Shut In and Soft Shut In)
In the drilling industry, there are 2 types of shut in which are Hard Shut-in and Soft Shut-in.
- Hard shut in: It means that while drilling, choke line valves are in a closed position. When you have the well control, you just shut in a blow out preventor. The choke valves will be opened when we kill the well. The hard shut-in is the fastest method to shut in the well; therefore, it will minimize volume of kick allowed into the wellbore.
- Soft Shut In: It means that while drilling, the choke line valves are in an opened position. When the well control situation is occurred, you shut in the blow out preventor and then close choke valves to shut in the well. The soft shut in procedure allows fluid to flow through the surface choke line before the well will be completely shut in. This is the bad part of the soft shut in procedure because it doesn’t minimize size of the wellbore influx.
The shut in procedure is the company specific procedure. You need to follow your company policy to shut in the well. I personally recommend “HARD SHUT IN PROCEDURE” because it allows me to shut the well in as quickly as possible and the kick volume entering into the well bore will be minimized. Please also remember that less volume of kick you have in the well bore, the less problem you will see when you attempt to kill the well.