Stratigraphy and Reservoir-analog Modeling of Upper Miocene Shallow-water and Deep-water Carbonate Deposits: Agua Amarga Basin, Southeast Spain

Abstract

This study documents the basin-wide stratigraphic characterization and 3-D reservoir-analog modeling of upper Miocene carbonate deposits in the Agua Amarga basin, southeast Spain. Paleotopography and relative fluctuations in sea level were primary controls on the deposition of shallow-water heterozoan and subsequent deep-water photozoan-dominated, coarse- and fine-grained gravity flow deposits and interstratified hemipelagic-pelagic sediments. Gently sloping basin paleotopography in conjunction with two successive periods of shallow marine inundation promoted in situ deposition of shallow-water volcaniclastic skeletal packstone-grainstones and skeletal grainstones. Distribution of these deposits was important in modifying paleotopography prior to deposition of deep-water strata. Deep-water deposits following basin inundation consisted of interstratified sediment gravity flows and hemipelagic-pelagic sediments. Focused-flow and dispersed-flow deposits documented in this study challenge traditional paradigms. The major control on the development of these systems was the presence or absence of a paleotopographic feature that focused debris shed from the linear platform margin into the basin. Resulting facies distributions, depositional geometries, and ratios of coarse- to fine-grained sediment within the focused-flow system suggest that similar deposits in the subsurface would make prolific hydrocarbon reservoirs.