An Advanced Reservoir Characterization and Modeling with New High Resolution of 3D-Seismic in Complex Sandstone Reservoirs
Authors: Gibrata Muhammad A , Ameish Giamal , Aldrin R , Albloushi Amira , Lozano Jose 
Published: May 2024

A new high seismic resolution ocean bottom node (OBN) was acquired and evaluated in complex sandstone reservoirs, from shallow to deep reservoirs. The integrated reservoir characterization with new high seismic data and model are used for reservoir model in complex reservoirs. The field has overpressure, multi fluid contacts, multi-reservoir subunits, structural and stratigraphic sand discontinuities. Therefore reliable updated reservoir characterization in deep reservoirs and estimation of fluids in place requires an integrated subsurface data approach.

The advanced reservoir characterization with new seismic velocity have been implemented in the workflow of reservoir characterization. The available wells formation pressures, PVT, image log, core-logs saturation height model (SHM) and production data have been used to calibrate in the compartment and reservoir discontinuity evaluation. The new velocity high resolution of 3D-seismic has been utilized for recent pore pressure evaluation. There are variation rock properties from shallow to deep reservoirs due to reservoir compaction, overpressure reservoirs have been observed in deep reservoirs, it tends to preserve porosity and has sufficient permeability for oil productivity from the deep reservoirs. The updated reservoir model is intended to provide the oil and condensate sweet spots for further potential wells of development and appraisal in the matured oil field area.

The integrated reservoir data with the latest seismic data have been used to provide reliable and good of reservoir properties and results for updated reservoir model. The high resolution seismic has been integrated with open and cased-hole logs data such as image resistivity/density, chromatography, pulse-neutron capture and production logs have been used to verify fault, fluid contacts, contribution, water saturation changes and production optimization. And for every reservoir subunit, the formation pressure has been used to identify an initial oil water contact and reservoir compartment/sand discontinuity evaluation, thus it has provided high resolution and reliability results for complex reservoir modeling. The saturation height model (SHM) has been used, a quasi-SHM for unavailable core data in deep reservoir and PVT data have been used in the reservoir evaluation/modeling, for the development of multi-layers, over pressure and complex sandstone reservoirs. The potential oil sweet spots for further appraisal and development can be modeled in the reservoirs and fields area.

The integrated approach reservoir characterization in this paper shows the value of advanced reservoir characterization with the latest data in the complex reservoirs. It has utilized the integration updated high seismic resolution and previous reservoir fluid-rock data. The evaluation also has provided the reliable for reservoir modeling, oil in place volume, recent oil sweat spot data, field appraisal and development purposes. Classification: Public