For the drilling industry especially when we talk about well control, there are 2 types of shut in which are Hard Shut-in and Soft Shut-in. This post will describe both shut in types and I wish I would be helpful for you all 🙂
Hard shut in: It means that while drilling choke line valves (HCR) are in the closed position; it will be opened after the well is shut in. The hard shut-in is the fastest method to shut in the well; therefore, it will minimize volume of kick allowed into wellbore.
With static wellbore condition, any gas entering into mud while tripping is called “Trip Gas”. Gas will be seen while circulating bottom up after tripping back in hole again. Trip gas is caused by swabbing effect while tripping out of hole.
If you see a lot of trip gas after circulating out, this situation indicates that the wellbore is almost in a balance condition.
“Connection Gas” is distinct increase of gas above a normal background gas level when bottom up occurs after a connection. If you see a small high gas peak in short period of time and when you calculate back you will see that it comes from every connection, you can suspect that this is the Connection Gas.
Shut in Well Procedures
The shut in procedure must be developed and practiced for every rig activity such as:
• Shut in while drilling
• Shut in while tripping
• Shut in while running casing, tubing, completion, etc.
• Shut in while performing workover operation
• Shut in while logging
• Shut in while performing drill stem test
What is the main reason why we need to have the shut in procedure and frequently practice it?
This is the second part of the possible kick indications that I would like to share with you.
Decrease in d-Exponent Value
Normally, trends of d-Exponent will increase as we drill deeper, but this value will decrease to lower values than what we expect in transition zones. By closely monitored d-Exponent, d-Exponent chart will be useful for people on the rig to notify the high pressure transition zones.
Read and understand about d-Exponent and learn how to calculate d-Exponent and normalized d-Exponent (corrected d-Exponent)
