Thermal Effects of Magmatism on Surrounding Sediments and Petroleum Systems in the Northern Offshore Taranaki Basin, New Zealand

Abstract

In the past two decades, numerical forward modeling of petroleum systems has been extensively used in exploration geology. However, modeling of petroleum systems influenced by magmatic activity has not been a common practice, because it is often associated with additional uncertainties and thus is a high risk associated with exploration. Subsurface processes associated with volcanic activity extensively influence all the elements of petroleum systems and may have positive and negative effects on hydrocarbon formation and accumulation. This study integrates 3D seismic data, geochemical and well data to build detailed 1D and 3D models of the Kora Volcano—a buried Miocene arc volcano in the northern Taranaki Basin, New Zealand. It examines the impact of magmatism on the source rock maturation and burial history in the northern Taranaki Basin. The Kora field contains a sub-commercial oil accumulation in volcanoclastic rocks that has been encountered by a well drilled on the flank of the volcano. By comparing the results of distinct models, we concluded that magmatic activity had a local effect on the thermal regime in the study area and resulted in rapid thermal maturation of the surrounding organic matter-rich sediments. Scenarios of the magmatic activity age (18, 11 and 8 Ma) show that the re-equilibration of the temperature after intrusion takes longer (up to 5 Ma) in the scenarios with a younger emplacement age (8 Ma) due to an added insulation effect of the thicker overburden. Results of the modeling also suggest that most hydrocarbons expelled from the source rock during this magmatic event escaped to the surface due to the absence of a proper seal rock at that time.

Down under and under Cover—The Tectonic and Thermal History of the Cooper and Central Eromanga Basins (Central Eastern Australia)

“…The high heating rates in combination with fast subsidence caused all source rocks to transform considerable amounts of their kerogen into oil and gas, simultaneously in a relative short period of time. During such rapid heating, petroleum expulsion and thus accumulation can occur faster from source rocks than at other times due to creation of overpressure and micro-fracturing [116][117][118].…”

Petroleum System Modeling of a Fold and Thrust Belt: A Case Study from the Bannu Basin, Pakistan

“…Furthermore, subsurface modeling is particularly important and relevant in the case of fold and thrust belts where most of the hydrocarbons are stored in structural traps. Heat flow is one of the most important Energies 2023, 16, 4710 2 of 26 boundary conditions in basin modeling as it aids in understanding the thermal maturity of the basin [14,15]. It is the critical parameter for the maturation of organic matter and the generation of hydrocarbons and their migration [16,17].…”

Geophysical and Geochemical Evidence for a New Mafic Magmatic Province Within the Northwest Shelf of Australia

“…Mafic igneous rocks have been reported from sedimentary basins across the Northwest Shelf of Australia, identified primarily from hydrocarbon exploration data (Table 1). Igneous rocks are often overlooked or avoided during hydrocarbon exploration (Kutovaya et al., 2019; Schutter, 2003) and no outcrop of these igneous rocks has yet been identified from the region. Few studies have investigated these units specifically, so they remain poorly understood.…”