Geology
Based on information on the Neptune Energy press release, they are drilling to about 3400m TVD. They haven't specified the target formations, but we can assume Statfjord Group or Brent Group as target based on depth and offset wells. We have rich experience from drilling these reservoirs.
There are no significant stratigraphic uncertainties in the overburden, expecting a column similar to this (above), from nearby well 33/6-2 which is a bit deeper and further west. This well also explored some sandstones in Draupne, which could be a reservoir potential for the Dugong well.
There was a kick in a nearby well 34/4-3, exiting Shetland at 3555m TVD, in a brief Cromer Knoll section. Gas kick. Maybe that is what they are drilling for now?
Well Planning Issues
Doing an offset review in the area, you find this is a fearly high pressure area. Deep wells with high temperatures (up to 150C) call for some extra attention to equipment qualities.
Considering pressure issues, the upper sections have typically been drilled with WBM, and the deeper with OBM. Some wells are with 1.5 SG mud in the reservoir, which gives a rather normal reservoir pressure, while others are drilled with up to 1.97 sg mud in the reservoir. Which is high.
The reported mud weights are higher than seawater, which means there has been uncertainty about shallow hazzards. One well had an open hole pilot for the 20" section, but didn't report any incidents.
Trajectory
The well is named S, which means there is planned some deviation drilling. I would assume this is deep, and close to the reservoir as they are able to place the wellhead where they would like. There might be some shallow hazzards, seabed issues or faults they want to avoid, but that information is not available.
Our machine learning gave us lot of matches in the trajectory similarity, so there are plenty of wellbores to learn from.
Here is how these wells look in 3D:
As you can see, there are a multitude of wellbores to learn from, with shallow or deep kick offs. Some are also quite close to the well being drilled.
Casing Design
The casing design in the area looks as conventional as can be, and I'm guessing Neptune are not taking any risks on slimming their well. They are probably rather focusing on their dual derrick performance.
Summary
This seems to be a straight forward well to drill, without any significant issues. If I was in charge I would push for performance, slim down the well design and strengthen the decision process to avoid the random operational mistakes our industry is so prone to.
I spent two hours on this review, and I hope you found it useful. We know how much oil companies struggle with doing offset reviews based on data, and we provide training and the platform to get up and running in a few months.
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