How will the bottom hole pressure (BHP) be affected when light or heavy mud is pumped?

The bottom hole pressure (BHP) is influenced by the density of the drilling mud being used and the dynamics of the well. When light or heavy mud is pumped, the BHP responds to changes in mud density, which alters the hydrostatic pressure exerted by the mud column in the wellbore.

When a lighter drilling mud is introduced, it generally leads to a decrease in hydrostatic pressure because the overall density of the fluid column is reduced. Conversely, pumping heavier mud increases the hydrostatic pressure applied at the bottom of the well, thus increasing the BHP.

The option indicating that BHP will decrease or increase based on displacement accurately reflects this interaction. Transitioning from one mud weight to another affects the hydrostatic pressure due to the changes in density, thereby impacting the BHP correlated to the displacement of the different muds. This relationship highlights the significance of mud weight management in maintaining well control during drilling operations.