LL with PGNiG

Tomcat (6501/10-1) – Other

PSA: Q

Question 1. Brønn 6305/10-1 «Tomcat» er definert som en exploration well. Vi ber om bekreftelse på at dette er en «wildcat».
Oversendelse av: PUN 2022. “Offset Analysis”, Doc No. PGNiG-TOMC-D-CA-0001. Date: 20.05.2022. Rev.01.

Question 2. PGNiG ber om en “option to temporarily suspend the well in a discovery case is being assessed”.
Havtil ber i den anledning om en redegjørelse for plan for «temporarily suspend» og om dette er ihht NORSOK D-010 rev. 5/2021 3.58 der «suspension» er definert. Tilsvarende for «Temporary abandoned» i NORSOK D-010 Rev.5/2021 i 3.61 og 3.62.
Vi ber om en oppdatert brønnbarrieretegning for denne perioden med oversikt over planlagte brønnbarrierer og tilhørende monitorering.

Question 3. Det er satt opp en «slight warning» for grunn gass på Level 5 (50 meter) fra PWL.

Question 4. Hva er mitigerende tiltak under boring av 9 7/8» pilothull

Question 5. Vi ber om en oversikt over HPHT trening og planlagt dato for DWOP.

PSA: A

Reply 1. PGNiG confirms Tomcat is classified as a ‘wildcat’/exploration well:
The Tomcat well is testing the Cretaceous Lysing play, which is well known in the Norwegian Sea, but has not been successfully tested before in this area.

1. There are very few well penetrations in the Tomcat area that reach the depth of the Lysing Fm, which is believed to be the equivalent stratigraphic level of the Tomcat prospect.

2. The burial depth of Tomcat is the deepest of any well in the Ormen Lange area when measured from seabed.

3. The nearest well penetrating this level is 6305/12-2, which is located 30 km to the east. This well is also the closest of any wells. Data acquisition in this well was affected by technical problems and borehole cavings, and several key logs are missing over the relevant depth interval.

4. The most recent well to drill to the same stratigraphic target level as Tomcat is the 6305/5-C-3 H (Ormen Lange Deep North) drilled in 2022 about 60 km to the north. The well did not encounter reservoir and data acquisition was limited. The Tomcat well offset analysis document, and the PUN and Shell evaluation of the Fugro shallow geohazards summary are attached.

Reply 2. PGNiG does not intend to suspend the well but will retain an option to temporarily P&A the well after reaching TD and running required petrophysical logs. This will allow PGNiG to return to location and re-enter the well to complete the potential HPHT data acquisition bypass coring at a later date when weather may be more favourable and outside the environmentally restricted window for drilling operations in oil-bearing layers, between 1st April to 15th June.

The Temporary P&A barrier schematic, attached, will be completed by cementing back the open hole into the production casing, the cement will be tagged, dressed off and pressure tested to 70 bar over FG at shoe, as per NORSOK D010. A VO intercept retrievable bridge plug will be set inside the 9 7/8” production casing at a minimum depth of 1200m TVD RKB, to ensure the differential pressure in a displacement to gas case below the intercept plug is less than 7500 psi (differential pressure rating of intercept plug).

The required trawl protection cover will be installed on the wellhead after the BOP has been retrieved.

Reply 3. The shallow geohazards mitigation is to drill a 9 7/8” pilot hole with a GR/RES LWD suite (logging while drilling) from the 30” conductor shoe to the planned 20” casing shoe depth with a Riserless Mud Return (RMR) system in place. Should the RMR system not be used, due to sea state or other reasons,, the plan is to revert to conventional pilot hole drilling without RMR with returns to seabed, and displace to seawater hydrostatic to check for shallow gas.

Drilling a pilot hole with RMR is an additional shallow geohazard (shallow gas and water flow) mitigation that ensures wellbore stability with less formation swelling and sealing of unstable shallow formations by having an inhibited mud system. The hydrostatic will always remain in overbalance using 1.30-1.40 SG density water-based mud system. The shallow gas operational procedures will be included in Drilling Operational Procedures. A shallow gas drill will also be performed with relevant crew offshore prior to drilling the 9 7/8” pilot hole.
Refer to Drilling Program for shallow gas contingency plan in the scenario where the 20” casing is set shallower than planned.

Reply 4. The Odfjell DSY rig crews have attended Maersk HPHT Theory/Simulator simulator training on the previous HPHT wells drilled in 2023 by Well Expertise, PGNiG’s well management contractor. PGNiG will conduct a Maersk HPHT Theory/Simulator refresher course in Kristiansund prior to drilling the potential HPHT well interval.

The drilling planning process also includes familiarisation with the HPHT drilling procedures and practices. The DWOP meeting will be scheduled two to three weeks before spud date. The DWOP meeting will introduce the rig and services companies to the safety plans, geology, drilling programme, master equipment listing, logistic plans, drilling lookahead schedule and detailed operational procedures. PUN is contractually obliged to be able to take over the rig 10th May 2024, but delays in the rig schedule push the spud to 3 qtr., unless we manage to jump the rig well schedule que. The current tentative date for the DWOP meeting is 26th April 2024. Havtil will be invited to join the DWOP.