N/A Mud LL with DNO

Oselvar (A-1 H, A-2 H, A-3 HT2) – Production section

What happened:

DONG handover documentation: Due to the mud cooler the mud temperature was lower, this resulted in relative higher downhole MW due to less temperature correction and higher ECD as the colder mud gives less rheology reduction. This was realised after some drilling and did cause confusion as to what mud reference temperature to use.

External Actions

When planning to use a mud cooler consider effects on downhole mud temperature, weight and rheology as well as reference temperature to use. Keep in mind that when tripping mud temperature will increase so barite suspension / sag may become an issue.