Using new facies architecture models and geochemical data constraints to reconstruct Kupe and Kapuni field charge dynamics

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1 Using new facies architecture models and geochemical data constraints to reconstruct Kupe and Kapuni field charge dynamics Karsten Kroeger, Richard Sykes, Malcolm Arnot, Miko Fohrmann, Matt Hill

2 Studying plumbing systems in Taranaki Basin (PSF Programme) How does petroleum move in the subsurface Kupe, Maari Maui Tui areas How does structure and carrier bed architecture impact on sourcereservoir relationships Tui Maui A Maui B Maari 3D Manaia Maari 7.5 km km

3 Kupe area plumbing and charge A A Kupe Field Field B A B B Kupe Field Farewell Formation Fohrmann et al. 2012, Data Series 12a Hill and Milner, 2012 Report 2012/37

4 Biomarker analysis indicates Kupe and Kapuni Fields are both charged from Farewell Formation Taranaki Oil Families Sykes et al Note that Kupe and Kapuni oils/condensates cannot be separated based on source related biomarkers

5 Kupe charge dynamics Kapuni-13 Where is the Farewell Formation kitchen Kupe-1 How did the petroleum get to the Kupe and Kapuni Fields Was there an early oil charge and if yes, what happened to it N When did it all happen

6 Predicted T max ( C) onset oil expulsion for coals near top of NZ Coal Band onset oil expulsion for coals near base of NZ Coal Band onset gas generation end of oil window Using maturity data to constrain basin models Calibrated maturities of Kupe, Kapuni and Toru fluids Kapuni oil Kapuni gas condensate Kupe South oil Kupe South & Momoho-1 gas condensate Toru-1 gas condensate Predicted Rank(S r ) Rank correlates to a vitrinite reflectance of SEV In general, Kupe fluids appear slightly more mature than Kapuni fluids (but all results almost lie within the standard errors of the PLS models) Kapuni and Kupe oils appear slightly less mature than their respective condensates (which could be an artefact of phase fractionation)

7 Kupe-Kapuni model High resolution improves layer geometry, thermal properties and burial history

8 Predicted maturation history Base lower Farewell Fm coal measures 7.5 MA 0 MA Models predict rapid maturation between the Late Miocene and the present-day. The mature kitchen area expanded rapidly towards the Kupe and Kapuni Fields

9 Timing of migration and charge Kapuni Field charge Structures such as the Kupe Fault affect migration pathways and result in bypass of any late expelled Rakopi fluids bypass Kupe Fault Kapuni 13 N Kupe Fault Kupe-1 Kupe South-1 N Farewell Formation petroleum expulsion (Mtons) Kupe Field The predicted maturity of the modelled area of highest petroleum expulsion is consistent with the maturity (Ro = ) indicated by geochemical analysis. This suggests charge within the last few million years

10 Timing of migration and charge Kapuni Field Present-day petroleum expulsion (Mtons) Kapuni 13 Kupe Fault Kupe Fault Kupe-1 Kupe South-1 N Kupe Field N The predicted present-day petroleum expulsion is from shallower and less mature kitchen areas which is inconsistent with geochemical maturity data from the Kupe and Kapuni fields and a gas dominated charge

11 Charge History Late Charge (Late Pliocene Early Pleistocene) Kupe main field accumulation Gas vs oil charge depends on Source rock oil generation potential Source rock maturity Seal strength (weaker seals = higher gas vs. oil loss) TOC of mature kitchens (amount of gas generated)

12 The impact on stratal architecture and sediment composition on petroleum migration Toru-1 Axial Channel Systems P00 2km Kupe South km

13 Lower Farewell Formation: deriving facies model Flattened on P00 at P00 at 24 ms Above P00 2km 2km Kupe South-4 Kupe South-4 Kupe South-4 10 km Kupe South-4

14 Intra-FW-4: Upper Coal Measures Amplitude map flattened IntFW-3 RMS interval 0-25 ms above Toru-1 Kupe South-4 Kupe South-4 Kupe South-4 Kupe South-4

15 Stacking of carrier bed facies W Manaia Fault Toru-1 Flattened on Top Farewell E P50 P10 IntFW4 IntFW3 IntFW2 Channel sand Overbank-Coal measures IntFW1 P00 Channel heterolithic Crossline km During deposition of the Farewell Formation, the Manaia Graben formed a large synclinal structure

16 Impact of stratal architecture on migration Toru-1 Main Charge Kupe Fault System Pidgeon 2009, PR4083 Kupe-1 Facies architecture likely to control primary migration out of the source rock, migration losses and timing of migration and charge. Migration losses of oil are expected to be higher than those of gas, especially if new migration pathways are established

17 Conclusions Geochemical data constrain likely expelling kitchen areas Predicted expulsion modelling from these areas suggests charge occurred largely since the Late Pliocene Initial oil charge likely replaced by gas Facies architecture and heterogeneity likely delays migration from less mature shallower parts of the kitchen

18 Acknowledgements This project is funded by the Ministry of Business, Innovation and Employment through the -led research programme on New Zealand petroleum source rocks, fluids, and plumbing systems (contract C05X1507) We thank Schlumberger for access to PetroMod basin modelling software Thank You!