Journal of Petroleum Geology, Vol.18, No.1, pp. 29- 48, 1995

©Copyright 2000 Scientific Press, Ltd.

DEPOSITIONAL MODELS AND RESERVOIR PROPERTIES OF MIOCENE REEFS, VISAYAN ISLANDS, PHILIPPINES

A. V. Carozzi*

* Department of Geology, 245 Natural History Building, University of lllinois at Urbana-Champaign, 1301 West
Green Street, Urbana, Illinois, 61801-2999, USA.

Abstract

Recent commercial discoveries offshore Palawan have propelled the Philippines into the list of oil- and gas-producing countries, and have focussed on the importance of Miocene reefs as reservoirs. This new situation has motivated the update of earlier depositional-diagenetic models for the Miocene reefs in the Visayan Islands, which is presented in this paper. These reefs consisted of an association of corals, red algae, bryozoans, and encrusting foraminifers, which formed wave-resistant, constructed, barrier-and-atoll systems along the edge of narrow shelves, with associated back-reef patch reefs and frontal pinnacle reefs. The latter also grew on structural and depositional highs and platforms among deeper water carbonate mudstones and shales.