Well Control - Slim Hole Drilling
Slim Hole Drilling which, for the purpose of well control, means hole sizes of 4 3/4" and smaller, will impose certain restrictions on well killing techniques and will require well planning to take care of these limitations.
1 General
Annular friction losses are an important aspect in Slim Hole Drilling, especially with regards to well control. Higher than required bottom hole pressures may occur during well killing operations if the ECD is not taken into account. Also, during drilling/circulating operations, it is possible to have an unnoticed potential kick situation . . .