Of the 5 largest basins, with over 20,000 km and 4 km plus of sediments, only one (Taranaki) has seen more than reconnaissance exploration. The other basins have barely been scratched, with results that in all cases remain inconclusive. There is a wide potential still untested in New Zealand.
Two examples are presented:
The Wanganui Basin, where the older part of the sequence has never been drilled. Wells were located on buried hills with older sediments onlapping along flanks. There are extensive updip wedgeouts and potential for structural-stratigraphic trap combinations. Aspects of source rock and flushing, while initially thought of as downgrading prospects, may look more favourable upon proper evaluation.
East Coast Basin. With very thick. Cretaceous-Tertiary sediments, multiple deformation, local unconformities and facies changes, this is one of the more exiting basins, measuring 40,000-50,000 km2 on and offshore. Oil and gas generation is widespread, source rocks being of Paleocene and Cretaceous age. Potential reservoirs are Cretaceous and Miocene sandstones and Oligocene and Pliocene limestones, the latter of excellent qualities. Lower Tertiary, undercompacted and gas-charged mudstones may be an additional target for gas production. Shale diapirism has contributed widely to structural trap formation. Since 1960, only 14 wells have been drilled, of which I offshore. This amounts to 0.3 wells per 1,000 km2, or 0.6 m/km2.
Get full access to this article
View all access options for this article.
References
1.
AndertonP.W. (1981). Structure and evolution od the South Wanganui Basin, New Zealand. N.Z. Journal of Geology and Geophysics. 24, 39–63.
2.
BeuA.G.Grant-TaylorT.L.HornibrookN. de B. (1980). The Te Aute limestone faceis. Poverty Bay to Northern Wairarapa. 1:250 000. N.Z. Geol. Survey Miscellaneous Series Map 13 (2 sheets) and notes (36 p.). New Zealand Department of Scientific and Industrial Research, Wellington.
3.
DarleyJ.H. (1969). Taradale-I well completion report. BP Shell Aquitaine & Todd Petroleum Development Ltd. N.Z. Geol. Survey open-file Petroleum Report 331.
4.
DarleyJ.H.KirbyK.F.S. (1969) Rakaiatai-I well completion report. BP Shell Aquitaine & Todd Petroleum Development Ltd. N.Z. Geol. Survey open-file Petroleum Report 330.
5.
DeanP.HillP.J.MilneA.D. (1976) A review of the hydrocarbon potential of the PPL 38002 area, East Coast, North Island. BP Shell Aquitaine & Todd Petroleum Development Ltd. N.Z. Geol. Survey open-file Petroleum Report 670.
6.
De BovckJ.F. (1986) Post Rere-I review, PPL 38082. Petroleum Corporation of New Zealand. N.Z. Geol. Survey open-file Petroleum Report 1231.
7.
De CaenR.F.B. (1968) An examination of Wanganui carbonates Hawkes Bay, North Island. New Zealand BP Shell Aquitaine & Todd Petroleum Development Ltd. N.Z. Geol. Surv. open-file Petroleum Report 382.
8.
De CaenR.F.B.DarleyJ.H. (1969) Tongaporutuan sediments, Hawke's Bay, North Island, New Zealand. BP Shell Aquitaine & Todd Petroleum Development Ltd. N.Z. Geol. Surv. open-file Petroleum Report 383.
FeldmeyerA.E.JonesB.C.FirthC.W.KnightJ. (1943) Geology of the Palmerston North- Wanganui Basin “West Side”, North Island, New Zealand. The Superior Oil Company of New Zealand Ltd. N.Z. Geol. Surv, open-file Petroleum Report 171.
11.
FlemingC.A. (1953) The geology of Wanganui Subdivision. N.Z. Geol. Surv. Bull. 52.
12.
GibbonsM.J. (1980) A review of the maturity and source rock potential in the Gisborne region, East Coast Basin North Island, New Zealand. N.Z. Geol. Surv. oppen-file Petroleum, Report 835, 75–81.
13.
HarmsenF.J. (1985) Lithostratigraphy of Pliocene strata, central and southern Hawke's Bay. New Zealand. N.Z.J. Geol. Geophys.28, (3), 413–433.
14.
HedbergH.D. (1974) Relation of methane generation to undercompacted shales, shale diapirs, and mud volcanoes. Amer. Ass. Petrol. Geol. Bull.58 (4), 661–673.
15.
HefferK.MilneA.D.SimpsonC. (1976) Well completion report Hawke Bay-1, offshore East Coast. North Island, New Zealand. BP Shell Aquitaine & Todd Petroleum Development Ltd. N.Z. Geol. Surv. open-file Petroleum Report 667.
16.
HornibrookN. de B. (1972) Waitangi Station-I well, International Pacific Exploration. N.Z. Geol. Surv. open-file Petroleum Report 81.
17.
JablonskiE. (1934) General report on the geology and oil possibilities of the Gisborne land district. Vacuum Oil Co. N.Z. Geol. Surv. open-file Petroleum Report 119.
18.
JäckliR. (1957) Review of the Superior Oil Company report on the Rangitikei area. Shell d'Arcy and Todd Oil Services Ltd. N.Z. Geol. Surv. open-file Petroleum Report 410.
19.
JacksonR.G. (1982a) An assessment of the organic maturity of the well Opoutama-I, East Coast. BP Oil Exploration Co. of N.Z. Ltd. N.Z. Geol. Surv. open-file Petroleum Report 903.
20.
JacksonR.G. (1982b) The geochemistry of Cretaceous to Miocene outcrop samples from the East Coast Fold Belt of North Island, New Zealand. BP Research Centre. N.Z. Geol. Surv. open-file Petroleum Report 916.
21.
KatzH.R. (1974) Recent exploration for oil and gas. In Economic geology of New Zealand, 2nd edition, ed. WilliamsG.J., Australasian Institute of Mining and Metallurgy Monograph Series 4, 463–480.
22.
KatzH.R. (1975) Ariel Bank - an offshore Late Cenozoic structure, and the problem of acoustic basement on the East Coast, North Island, New Zealand. N.Z. J. Geol. Geophys., 18, (1), 93–107.
23.
KatzH.R. (1979) Alpine uplift and subsidence of foredeeps. In The origin ofthe Southern Alps, eds. WalcottR.I.CresswellM.M.. The Royal Society of New Zealand Bull. 18, 121–130.
24.
KatzH.R. (1981) Probable gas hydrate in continental slope east of the North Island, New Zealand. J. Petroleum Geology3, (3), 315–324.
25.
KatzH.R. (1982) Evidence of gas hydrates beneath the continental slope. East Coast, North Island, New Zealand. N.Z. J. Geol. Geophys.25, (2) 193–199.
26.
KatzH.R.WoodR.A. (1980) Submerged margin east of the North Island. New Zealand and its petroleum potential. In Symposium on petroleum potential in island arcs, small ocean basins, submerged margins and related areas. United Nations Economic and Social Commission for Asia and the Far East. CCOP/SOPAC Technical Bulleting 3, 221–235.
27.
LaingA.C.M. (1961) The geology and petroleum prospects of the Dannevirke area. BP Shell & Todd Petroleum Development Ltd. N.Z. Geol. Surv. open-file Petroleum Report 318.
28.
LaingA.C.M. (1972) Well completion reports Rotokautuku-I, Te Horo-I. Te Puia-I. Alliance Petroleum (Australia). N.Z. Geol. Surv. open-file Petroluem Reports255. 256, 257.
29.
LehnerE. (1974) Oil and gas. In Economic geology of New Zealand, 2nd edition, ed. WilliamsG.J., Australasian Institute of Mining and Metallurgy Monograph Series 4. 331–356.
30.
LeslieW.C.HollingsworthR.J.S. (1972) Exploration in the East Coast basin. New Zealand. J. Australian Petrtoleum Exploration Association, 12, 39–44.
31.
LoweS.P.O'ReillyS. (1980) The geochemistry of outcrop samples, well cuttings samples and an oil seepage sample from the Gisborne area of the North Island, New Zealand. N.Z. Geol. Surv. open-file Petroleum Report835, 62–63.
32.
McLernonC.R. (1978) Indications of petroleum in New Zealand. N.Z. Geol. Surv. open-file Petroleum Report839 (I). 53–125.
33.
MooreP.R. (1978) Geology of western Koranga Valley, Raukumara Peninsula. N.Z. J. Geol. Geophys.21, (1), 1–20.
34.
PalmerJ. (1985) Sandstone sample from near Tahora, Gisborne, PPL 38082. New Zealand. Petroleum Corporation of New Zealand Technical Note. N.Z. Geol. Surv. open-file Petroleum Report 1142.
35.
PhizackerlyP.H.RobinsonW.G. (1962) Ruakituri-I well completion report. BP Shell & Todd Petroleum Development Ltd. N.Z. Geol. Surv. open-file Petroleum Report 324.
36.
PickM.C. (1962) The stratigraphy, structure and economic geology of the Cretaceo-Tertiary rocks of the Waiapu district, New Zealand. Ph.D. thesis Geolgy Department, University of Bristol (lodged in the University library).
37.
RiddM.F. (1970) Mud volcanoes in New Zealand. American Association of Petroleum Geologists Bull. 54, (4), 601–616.
38.
Robertson Research (1980) Petroleum geochemical evaluation of samples from the Northland, Waikato, North Wanganui and South Wanganui basins, North Island, New Zealand. Petroleum Corporation of NZ (Exploration) Ltd. N.Z. Geol. Surv. open-file Petroleum Report 768.
39.
SelleyR.C. (1987) British shale gas scrutinized. Oil & Gas Journal. 85, (24), 62–64.
St JohnD.H.CopeR.N.GibsonG.W. (1964) Parikino-I exploration well resume. Shell BP & Todd Oil Services Ltd. N.Z. Geol. Sun. open-file Petroleum Report 452.
42.
StrongS.W.S. (1931) Ejection of fault breccia in the Waimata Survey District, Gisborne. N.Z.J. Science and Technology12, (5), 257–267.
43.
Superior Oil Co. of N.Z. Ltd. (1942a) Data and correspondence Young-l (N148/01) with Schlumberger log. N.Z. Geol. Surv. open-file Petroleum Report 603.
44.
Superior Oil Co. of N.Z. Ltd. (1942b) Data and correspondence Stantiall-l (N143/02) with Schlumberger log. N.Z. Geol. Surv. open-file Petroleum Report 604.
45.
ZimmermannM.A.FaberJ. (1967) Opoutama-I well completion report. New Zealand Aquitaine Petroleum Ltd. N.Z. Geol. Surv. open-file Petroleum Report 504.
