¶ Drilling with Maximum Mud Weight
It is a post installation burst load (since the internal pressure is greater than external pressure) even though it is more relevant to check the stability of the string for the possibility of wear. It is required for all drilling strings. Internal pressure assumes the highest mud weight used to drill the subsequent open holes (for the string with one or more subsequent liners). External pressure assumes mud-mix fluid density above TOC, cement-mix fluid density below TOC to prior shoe if TOC is above previous shoe, pore pressure in the cemented open hole. Circulating temperature is defaulted as string temperature profile.
¶ Internal Pressure profile
Internal pressure profile is obtained by using the highest mud weight in subsequent open hole(s). pi(z) = Cρmz where,
- C = conversion factor, 0.051948 psi/(ppg×ft)
- ρm = the highest mud weight in the DSOH, ppg
- pi(z) = internal pressures at depth z, psi
- z = true vertical depth of interest, ft
The string with one or more subsequent liners will have multiple similar loads with the drilling mud weight in each subsequent liner hole sections.
¶ External Pressure profile
External pressure profile is according to Blade protocol
¶ Temperature profile
Circulating temperature profile is assumed as default. Use the circulating temperature profile from thermal simulator if available otherwise, use one of the temperature profiles discussed here.