GNS Science

Karsten Kroeger, Richard Sykes, Malcolm Arnot, Miko

Fohrmann, Matt Hill

Using new facies architecture models and

geochemical data constraints to reconstruct Kupe

and Kapuni field charge dynamics

GNS Science

Studying plumbing systems in Taranaki Basin

(PSF Programme)

How does petroleum move in the subsurface?

How does structure and carrier bed architecture impact on source-

reservoir relationships?

Manaia

Maari

Maui A

Maui B

Tui ?

7.5 km

0 7.5 15km

Kupe, Maari – Maui – Tui areas

Maari 3D

GNS Science

Kupe area plumbing and charge

A

B

Fohrmann et al. 2012, GNS Science Data Series 12a

Hill and Milner, 2012 GNS Science Report 2012/37

Kupe Field A A’

B B’

Farewell Formation

Kupe Field

Kupe Field

GNS Science

Sykes et al. 2012

Biomarker analysis indicates Kupe

and Kapuni Fields are both

charged from Farewell Formation

Taranaki Oil Families

Note that Kupe and Kapuni

oils/condensates cannot be separated

based on source related biomarkers

GNS Science

Kupe charge dynamics

• Where is the Farewell Formation

kitchen?

• How did the petroleum get to the Kupe

and Kapuni Fields?

• Was there an early oil charge and if

yes, what happened to it?

• When did it all happen?

N

Kapuni-13

Kupe-1

?

GNS Science

Using maturity data to constrain basin models

430

435

440

445

450

455

460

465

470

475

480

11.0 12.0 13.0 14.0 15.0 16.0 17.0

Pre

dic

ted

Tm

ax (

°C)

Predicted Rank(Sr)

Kapuni oil

Kapuni gas condensate

Kupe South oil

Kupe South & Momoho-1 gas condensate

Toru-1 gas condensate

onse

t o

il e

xp

uls

ion f

or

co

als

nea

r to

p o

f N

Z C

oa

l B

and

onset gas g

enera

tion

onset oil

expuls

ion f

or

coals

near

base o

f N

Z C

oal B

and

end o

f oil

win

dow

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)

Calibrated maturities of Kupe, Kapuni and Toru fluids

Rank 14.1 ─ 14.8 correlates to a vitrinite

reflectance of 1.2 ─ 1.35

GNS Science

Kupe-Kapuni model

High resolution improves layer geometry, thermal properties and burial history

GNS Science

Predicted maturation history

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

Base lower Farewell Fm coal measures

GNS Science

Timing of migration and charge

Structures such as the

Kupe Fault affect

migration pathways

and result in bypass of

any late expelled

Rakopi fluids

Kupe Fault

Kupe Fault

Kupe Field

Kapuni Field

The predicted maturity of the modelled area of

highest petroleum expulsion is consistent with the

maturity (Ro = 1.2─1.35) indicated by geochemical

analysis. This suggests charge within the last few

million years

N

Kupe-1

Kupe South-1

Kapuni 13

N Farewell Formation

petroleum expulsion (Mtons)

bypass charge

GNS Science

Timing of migration and charge

Kupe Fault

Kupe Fault

Kupe Field

Kapuni Field

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

N

Kupe-1

Kupe South-1

Kapuni 13

N

Present-day petroleum

expulsion (Mtons)

GNS Science

Charge History

Kupe main field accumulation

Late Charge (Late

Pliocene Early Pleistocene)

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)

GNS Science

2km

P00 Toru-1

Kupe South-4

7.5 km

The impact on stratal architecture and

sediment composition on petroleum migration

Axial Channel

Systems

GNS Science

Lower Farewell Formation: deriving facies model

at P00 2km

Kupe South-4

Flattened on P00

?

at 24 ms

Above

P00

?

2km

? ?

?

10 km

Kupe South-4 Kupe South-4 Kupe South-4

GNS Science

Intra-FW-4: Upper Coal Measures

?

?

?

?

?

?

?

?

?

?

RMS

interval

0-25 ms

above

Amplitude

map

flattened

IntFW-3

Kupe South-4 Kupe South-4 Kupe South-4 Kupe South-4

Toru-1

GNS Science

Stacking of carrier bed facies

Channel sand

Overbank-Coal

measures

Channel

heterolithic

E W

Crossline 2720

Toru-1 Toru-1

Manaia Fault P50 P10 IntFW4

P00

IntFW1

IntFW2

IntFW3

Flattened on Top Farewell

During deposition of the Farewell

Formation, the Manaia Graben

formed a large synclinal structure 2 km

GNS Science

Impact of stratal architecture on migration

Kupe-1

Toru-1

Kupe Fault

System

Main Charge

Pidgeon 2009, PR4083

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

GNS Science

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

GNS Science

We thank Schlumberger for access to PetroMod basin modelling software

Acknowledgements

This project is funded by the Ministry of Business, Innovation and Employment

through the GNS Science-led research programme on New Zealand petroleum

source rocks, fluids, and plumbing systems (contract C05X1507)

Thank You!