Download Symposium on petroleum potential in Island arcs, small ocean

UNITED NATIONS ECONOMIC AND SOCIAL COMMISSION FOR
ASIA AND THE PACIFIC
COMMITTEE FOR CO-ORDINATION OF JOINT PROSPECTING FOR
MINERAL RESOURCES IN SOUTH PACIFIC OFFSHORE AREAS
(CCOP/SOP AC)
TECHNICAL BULLETIN
No.3
SYMPOSIUM ON PETROLEUM POTENTIAL IN
ISLAND ARCS, SMALL OCEAN BASINS,
SUBMERGED MARGINS AND RELATED AREAS
Held in Suva, Fiji, 18-21 September 1979
New Zealand Department of Scientific and Industrial Research, Wellington, 1980
FOREWORD
On behalf of the Government of Fiji, I extend to all of you our very warm
welcome.
We consider ourselves privileged and honoured to be able to host this gathering
of eminent men and women of science; We thank the Committee for Coordination
of Joint Prospecting for Mineral Resources in South Pacific Offshore Areas, better
known as CCOP/SOPAC, the UNDP, and ESCAP for their efforts in initiating,
organising and funding this Symposium.
The Symposium, entitled 'Petroleum Potential in Island Arcs, Small Ocean
Basins, Submerged Margins and Related Areas, marks a milestone in the scientific
and economic development of the South Pacific, as I understand that all the areas
of the southwest Pacific may be classified as island arcs, small ocean basins, or
submerged margins. Because of these geologic features and because 200-mile
exclusive economic zones have been delineated by many of our island nations, this
Symposium is of special relevance to us. Our small island nations depend
exclusively on imported petroleum and are therefore very vulnerable to the
inflationary effects of all the various recent price increases. It is our hope therefore
that this Symposium will result in increased prospectivity of our region and give us
some hope that we too can perhaps become oil-producing countries.
The petroleum potential of geologic structures characteristic of this area has
been little understood. Except in Indonesia, and perhaps the Philippines, island arcs
and basins have seen very little exploration. The better understanding of plate
tectonics, the improved economics of drilling in deep water, recent successes in the
Philippines, the impending petroleum shortage, the astronomical price increases,
and the political vicissitudes of traditional oil-producing countries have refocused
attention on the petroleum potential of this hitherto unattractive and unknown area
for exploration. Until recently many companies would not give a thought to
exploring in the southwest Pacific, because they considered this area too young and
too volcanic. However, systematic geologic mapping has revealed that these areas
are not entirely volcanic but have large areas of marine sedimentary rocks, source
rocks, and the heat necessary for the hydrocarbon transformations. The discovery
of a genuine oil seep in Tonga in 1968 and known seeps and gas discoveries in
Papua New Guinea have further increased interest in this region.
It is the policy of the Fiji Government to encourage petroleum exploration.
Towards this end, it enacted in 1978 a new Petroleum (Exploration and
Exploitation) Act that replaces the outdated Oil Mining Act of 1915. While still
catering for onshore exploration with which the 1915 Act was mainly concerned,
the 1978 Act provides the legal framework for the regulation and control of
offshore petroleum activities.
We are aware that in many other countries Governments are attempting to play a
bigger role in the petroleum industry. While we are following these developments
with interest, we do not feel that Fiji at the moment is in a position to undertake
such an enlarged role. Recognising that our economy is small, that we lack the
necessary expertise, and that we have other development priorities, we prefer to see
private companies undertake oil exploration, for which we have granted them
generous concessionary terms. We have backed these terms by our record since
independence of a stable political system, a stable Government, and a stable
economy. Having become independent towards the end of the development decade
of the 1960s, and not professing any particular political or economic ideology
except the Pacific way of moderation and compromise, we in Fiji are prepared to
be pragmatic about oil exploration.
Four oil exploration licences over a total of 31,000 km2 have been granted to
overseas companies on attractive terms. These terms include a partial tax holiday while
investment is being recouped, guaranteed stability of tax rate, waiver of export tax,
interest withholding tax, and customs duties on exploration equipment, liberal foreign
exchange regulations, and other Government undertakings. While other countries
receive up to 21 % on sales as royalties, our legislation has fixed this at a moderate
amount of from 10 to 12%.
While other proven petroleum province countries are able to demand a 60% tax rate
from the first year of operations, we in Fiji would be pleased with a 60% return after the
companies have recouped their capital investment. Some people have criticised our
concessions as being too generous to the exploration companies. But we believe that
until discoveries are made it is to our benefit to encourage active exploration and early
drilling - and this cannot be done by onerous terms. However, we are not just giving
away licences on soft terms, but prefer to give careful and serious consideration to each
application on merit depending on the work programme and conditions offered to
Government. Seven applications for four other areas are under consideration at the
moment.
We are cautiously optimistic that the excellent exploration programmes being carried
out at present will continue to produce positive results. We are aware that some
innovative new techniques such as Curie Point isotherm interpretation and offshore
geochemical sampling have been used to high grade our prospects, and we are looking
forward to a drilling programme in our offshore areas in early 1980.
The 1980 drilling programme cannot avoid highlighting the recent Gulf of Mexico
blowout, which followed by a decade the Santa Barbara blowout. In spite of these
calamities, which underscore the weaknesses of man and nature, the oil industry has to
be congratulated for its excellent record in ensuring the safety of rigs and petroleum
operations at sea over the past 30 years. And I would not be remiss in expecting that the
companies will do their utmost to maintain their enviable safety record when planning
drilling programmes in our south seas islands.
The excitement of a seismic ship negotiating our reef-infested waters and of a firstever drill ship in our waters should not obscure the fact that much of the critical work is
done in quiet far-off laboratories by men and women like yourselves. For it is upon
your design and techniques and your analysis and interpretation of data that the major
decisions depend. If it were not for the refinements in the state of your science, it is
quite certain that jungles, polar climates, deep seas, apparently sterile basins, and
difficult overthrust belts would not be the foci for the intensive exploration that they are
now experiencing and for the renewed hopes for fossil fuel upon which the world is so
dependent.
For so long, the South Pacific has been the subject Of the stereotyped image of
balmy beaches, guitar-strumming males, and comely South Pacific beauties. What has
been less popularised is the growing concensus among scientists in every discipline that
the South Pacific is one of the new exciting frontiers of science. It is our every hope
that this petroleum symposium will underscore this growing consensus and will
contribute to an enhanced understanding of the petroleum potential of our island arcs,
small ocean basins, submerged margins, and related
areas.
With these words I hereby declare the Symposium open.
William J Clark
Minister for Lands and Mineral Resources, Fiji
Suva, 18 September 1979.
CONTENTS
Foreword - Opening Address by the Minister for Lands and Mineral
Resources, Fiji, the Honourable William J Clark ..................................................................3
Exploration Frontiers - A Quartet of Challenges.
A V Martini ........................................................................................................................ 7
National Development Policies and Legal Framework for Petroleum Exploration
in the Southwest Pacific.
P Hohnen and R N Richmond .......................................................................................... 15
Global Eocene Plate Reorganization: Implications for Petroleum Exploration.
Evan S Richardson and Peter ARona ..............................................................................25
Aeromagnetic Investigations and Sea Floor Spreading History in the Lau Basin
and Northern Fiji Plateau.
Norman Z Cherkis ............................................................................................................37
Seismic Refraction Studies in the New Hebrides and Tonga Area.
B Pontoise, G V Latham, 1 Daniel, 1 Dupont, and A B Ibrahim. '" ................................. 47
Basin Development in the Solomon Islands and Their Petroleum Potential.
H R Katz .......................................................................................................................... 59
A Sedimentary Structure Southwest of Viti Levu, Fiji: The Baravi Basin.
B M Larue, 1 Y Collot, and A Malahoff ........................................................................... 77
Mariana Forearc Tectonics.
Cary L Mrozowski and Dennis E Hayes ..........................................................................85
Late Quaternary Uplift History from Emerged Reef Terraces on Santo and
Malekula Islands, Central New Hebrides Island Arc.
C louannic, F W Taylor, A L Bloom, and M Bernat ........................................................ 91
A Sedimentary Basin in the Central New Hebrides Arc.
1 N Carney and A Macfarlane ........................................................................................109
The Structure of the Yasawa Islands and Its Plate Tectonic Significance.
B L Wood ........................................................................................................................121
Potential Delineation of Island Arc Tectonics by Foraminiferal Distribution
Patterns.
Ian Deighton and David Taylor ..................................................................................... 131
Petroleum Potential of Jamaica: A Case Study of Part of an Ancient Island Arc.
Anthony N Eva ............................................................................................................... 143
Review of Heat Flow Studies in the Eastern Asia and Western Pacific Region.
Seiya Uyeda .................................................................................................................... 153
The Maturation History of the Epicontinental Basins of Western Australia.
A C Cook and A 1 Kantsler ............................................................................................. 171
Geothermal Occurrences in the Southwest Pacific.
Malcolm E Cox …………………………………………………………………………………..197
Submerged Margin East of the North Island, New Zealand, and Its Petroleum
Potential.
H R Katz and R A Wood ................................................................................................. 221
Some Aspects of Reservoir Characteristics in Japanese Oil and Gas Fields, with
Special Reference to Their Depositional Environments.
H Miyazaki, Y Ikebe, and M Ukai ................................................................................... 237
Exploration and Development of the Nido Reef Complex Oil Discovery,
Philippines.
Allen G Hatley and Robert Y Harry ................................................................................ 253
Geochemical Techniques for Petroleum Exploration.
Leo Horvitz .................................................................................................................... 261
Review of Recent Activities by CCOP in the Field of Hydrocarbon Resources.
CCOP Project Office ..................................................................................................... 273
Two Years of Drilling in Deepwater.
W E Whitney .................................................................................................................. 277