Geologically based integrated approach for zonation of a Late Jurassic–Early Cretaceous carbonate reservoir; a case from Persian Gulf

Abstract

In this study, our attempt is to integrate sedimentological and petrophysical data for reservoir evaluation in the sequence stratigraphic framework. Petrographic analysis of the Late Jurassic–Early Cretaceous Fahliyan Formation reservoirs of two oilfields in the northwest of the Persian Gulf led to recognition of twelve microfacies. They can be classified into four facies associations, including open marine, shoal, lagoon and tidal flat, which are deposited in a homoclinal ramp carbonate. Sequence stratigraphy of the studied successions led to the recognition of three third-order depositional sequences based on vertical changes in microfacies and gamma ray analysis. Except for the upper boundary of the third sequence, the other sequence boundaries are type I (SBT.1). Dissolution is the most important diagenetic feature that affected the lower depositional sequence which is caused by the development of subaerial exposure after the deposition of the Fahliyan Formation, whereas cementation is the main diagenetic feature affecting the second- and third depositional sequences, causing their lower reservoir quality. In order to identify the flow units, the flow zone index methods, porosity throat radius (R35) and modified Lorenz based on stratigraphy were applied. The key wells studied in this area have shown good correlation throughout the studied oilfields which may potentially be used for hydrocarbon exploration and field development in the Late Jurassic–Early Cretaceous deposits of the Persian Gulf. This study integrates geological and petrophysical data (rock typing) toward sequence stratigraphic framework.

The Impact of Detrital Minerals on Reservoir Flow Zones in the Northeastern Bredasdorp Basin, South Africa, Using Core Data

“…The results produced the cumulative storage capacity (porosity multiplied by the bed thickness) and cumulative flow capacity (permeability multiplied by bed thickness). The cumulative flow capacity is plotted on the vertical axis against the cumulative storage capacity on the horizontal axis to produce a graph used to estimate storage and flow capacities [43,50,51]. Line segments and slopes of the graph separated by an inflexion point are used to represent flow and storage capacities.…”

Investigation of the Cretaceous total petroleum system using wireline logs, core, and geochemical data in Bahrah Field, Northern Basin, Kuwait

“…2). The oil migrates from the Sulaiy Formation (Upper Jurassic-Lower Cretaceous) to the Cretaceous reservoirs; Zubair, Burgan, Mauddud, Wara, Ahmadi, and Mishrif formations, while the oil has been produced unconventionally from the Jurassic source rocks (Asadi et al 2021;Fox and Ahlbrandt 2002;Stern and Johnson 2010;Jassim and Goff 2006).…”