RE: When is news from Turkey6 Jul 2023 20:30
Telli,
The service provider would have done a pre-job analysis of the perforating run.
For this they would have used data such as the mud type the guns would be run in (probably water), the casing wall thickness & grade of steel used, the strength of the cement used in cementing the 9 5/8" casing in place and an estimate of the hole size (drilled was 12 1/4", actual likely a bit larger).
From this, they can then estimate the energy left in the shot when it reached the formation.
Using local data on the formation properties (they couldn't use actual data, as no logs were run), they can then work out how far into the formation the shot would have gone and the tunnel diameter that would be produced.
The results would be used to determine the most optimum charge spacing (i.e. number of shots per foot) and gun centralisation inside the casing.
The diagram in the link below gives a better visual.
https://3.bp.blogspot.com/-muUZcNCuK38/UsVa75_AlaI/AAAAAAAAA_U/HAcdNcDxC68/s1600/6.jpg
Using the smaller charges that can be fitted in the 4 5/8" gun is not optimal in the 9 5/8" casing, but by eccentrically centralising the gun so it is hard up against the casing, they can maximise the formation penetration by those shaped charges closest to the casing.
In those circumstances, normally all the charges would have been in a vertical line, but the photo of the gun had a spiral pattern. So the ones opposite that are fired into the fluid in the hole and have to travel a couple of inches through it before the copper slug hits the casing wall so are unlikely to have fully penetrated the casing.
However, the charges up against the 9 5/8" casing would certainly have perforated the casing itself, and should have gone some distance into the formation.
All they can tell from analysis of the test data is that after the guns were fired, no formation fluid flowed into the Well.
UKOG have chosen to interpret that as evidence that the charges did not penetrate the formation.
For this to be the case, either the hole must be significantly larger than estimated (unlikely, as they would get an effective calliper from when cement returned to surface during the 9 5/8" cement job) or the perforation tunnels were blocked by perforation debris (the remains of the copper slug and rock crushed during the perforation).
This is possible, but there are ways to get that out after the gun is recovered back to surface.
An alternative explanation is that the perforating guns worked as advertised and penetrated the formation, but there was simply nothing there to flow.
I know which my money is on...
BTW, why UKOG chose to reference the CCL log in their RNS, I have no idea - it has nothing to do with whether or not the run was a success.