Once you shut in the well in and obtain shut in drill pipe pressure, you can estimate formation pressure by applying the hydrostatic pressure concept.
This following equation demonstrates you how to figure out formation pressure from the kick analysis.
Formation Pressure = SIDDP + (0.052 x Hole TVD x Current Mud Weight)
In some situation, where you drill with mud weight that is very close to balance condition (near formation pressure) and you don’t have much room to weight up due to fracture gradient limitation, from the well control perspective, you may need to drill one stand, then circulate bottom up and perform flow check. If everything is static, you can go ahead and drilling. Moreover, you need to look at the peak gas after going back to drill because it indicates how well of mud weight is. If you don’t see any gas peak, it means that your mud weight at the static condition is good. However, if you see any gas peak while drilling but it does not come from formations that you are drilling, this situation indicates that you don’t have or just enough mud weight to control the well in the static condition. You can check where the gas coming from by using a lag stroke calculation.
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. Learn about it via VDO multimedia.
Link from youtube >> http://www.youtube.com/watch?v=vPmKvm01-Hw
You have learned about the kick tolerance factor from the previous blog posting and this article will demonstrate you how to use the kick tolerance factor to determine the maximum surface pressure from it.
The formula is listed below;
Maximum surface pressure = kick tolerance factor x 0.052 x TVD of well
Where;
Maximum surface pressure in psi
kick tolerance factor in ppg
TVD of well in ft
Determine the maximum surface pressure with this following data:
Kick tolerance factor = 1.8 ppg
Hole depth = 10,000’MD/9500’TVD
Based on these data, you can calculate the maximum surface pressure like this;
Maximum surface pressure = 1.8 x 0.052 x 9500 = 889 psi
Please find the Excel sheet for this calculation 
Maximum surface pressure from kick tolerance factor
Ref book: Formulas and Calculations for Drilling, Production and Workover, Second Edition
Maximum Initial Shut-In Casing Pressure (MISICP) or Maximum allowable shut in casing pressure is the initial shut-in casing pressure that will exceed formation strength at the casing shoe resulting in broken formation at the shoe.
How can we know and calculate the MISICP?
Leak Off Test (LOT) will tell you the maximum pressure which the shoe can withstand before breaking formation at the shoe. The LOT is the combination of surface pressure and hydrostatic pressure therefore you can apply this principle to calculate the MISICP.
