HI J and J The issue with #4 was mainly the very porous and...

HI J and J

The issue with #4 was mainly the very porous and fractured nature of the bottom intervals ,not only did the drilling mud get lost into the formation but also the cement when they put the casing in. They couldn't / didn't have enough length in the perforations to go through the cement and reach the formation. They also had that problem to a degree in the lower C17 and upper C18 even behind the casing and it may be the reason they are using a large perforating gun. Salt was not an issue in #4 .

In #5 they hit a salt lense I,m not sure if 3 D would have picked it up or not,
they also used a lighter Mud weight in #5 presumably to cut down on mud lost into the formation. So the lessons they took from #4 to help mitigate issues were foiled by salt in #5 it seems.

I don't believe having 3D would have made them change anything it's often a case of finding what the geology is like when you drill into it and then try and deal with it.

3D is great for finding the best places to drill for planning the development ,the depth and thickness ( to a degree)of intervals and establish the size of the field also find faults etc but does have some limitations on the nature of intervals.

If they do continue with C18-19 in future wells and encounter salt they would probably try and get it behind casing before it started to intrude into hole . If 3 D was able to pick it up it would certainly be helpfull... hope that helps a little Oilman may be able to add more.

Cheers Whisky