Chemostratigraphic And Lithostratigraphic Characterization Of The Lower To Middle Miocene Monterey Formation And Equivalent Strata Of Long Beach Oil Field: Los Angeles Basin, California

Abstract

The stratigraphy of the fine-grained Monterey Formation is relatively poorly studied within the subsurface of the Los Angeles Basin compared to the sandstone reservoirs, and there has been only one public study of the overall subsurface composition and lithostratigraphy of the Monterey. Even less is known about the lateral and stratigraphic heterogeneity of the Monterey Formation and equivalent rocks. This study will carry out a compositional analysis using geochemical and petrographic methods to divide the Monterey Formation into different chemostratigraphic units based on variations in geochemical and mineralogic data acquired from core, cuttings and well logs in order to refine existing lithostratigraphic correlations. This approach is needed due to the structural complexity and intercalation of discontinuous sandstone and igneous units. The analysis will establish if fine-grained sedimentary strata within the study location share compositional similarities and how well they may correlate with other areas within the Los Angeles Basin. Subsurface petrophysical data will be integrated with laboratory analysis of mineralogy and geochemical composition to identify chemostratigraphic zones or lithofacies that may exist within the Monterey Formation in the Long Beach oil field (Signal Hill). The study area beneath the Long Beach oil field is located immediately adjacent to the Newport-Inglewood fault zone which possibly developed unique and local syntectonic depositional bathymetries and environments during initial rifting that would have evolved through time. As a result, this study will characterize the Monterey Formation and its equivalents along the Newport-Inglewood fault zone in the Long Beach oil field, where the association with the fault could be of unique importance for localized depositional setting, dependent composition, rock properties and petroleum potential.

AAPG Datapages/Search and Discovery Article #90372 © 2020 AAPG Pacific Section Convention, 2020 Vision: Producing the Future, Mandalay Beach, Oxnard, CA, April 4-8, 2020 (Cancelled)