Optimising the under-reamer string design for wells at Hai Thach field, Nam Con Son basin
Optimising the under-reamer string design for wells at Hai Thach field, Nam Con Son basin
According to the drilling program approved for Hai Thach field, the drilling section below the 16” casing liner (14.85” internal diameter) will be carried out by two separate BHAs: first drilling the 12.25” section by PDC bit to the section target, then under-reaming the wellbore to 14.5” and 16.5” diameter in order to run 13.625” casing string. Using two separate BHAs for reaming the wellbore certainly leads to a time increase in the run in hole (RIH) and pull out of the hole (POOH) of the dril