Negative Mud LL with DNO

Oselvar (A-1 H, A-2 H, A-3 HT2) – P&A

What happened:

We had a lot of friction in a long and deviated well A3 with brine.

What was planned:

Use 1,35 SG CaCl2 brine in the well until CBL logging of the 9 5/8″ casing was finished. Wireline logging was supposed to go faster in brine than in OBM.

What was learned:

This affected tripping times out of the well, lost 4-6 hrs every trip. We had problems setting bridge plugs on mechanical setting tool due to 90 MT difference in up/down weights. This cost us over 24 hrs non productive time. In general wear and tear on all equipment due to aggressive salt brine.

What actions are required:

Displace to OBM to reduce friction ASAP in wells A1 and A2. If wireline logging takes twice as long, it will still be a lot less NPT than operating with high friction for many days tripping. I assume that the CBL / USIT log quality can be the same with OBM.

What Was Done

Followed the planned program. We displaced well to OBM after the wireline logging had been completed.