Physical properties of sandstone reservoirs: Implication for fluid mobility

Core samples representing depths of hydrocarbon-bearing zones are not readily accessible for reservoir evaluations. On the other hand, wireline logs with incorporated seismic data, which can be archived over a more extended period while retaining their original forms, are typically more available fo...

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Main Authors: Richardson M. Abraham-A, Fabio Taioli, Anthony I. Nzekwu
Format: Article
Language:English
Published: KeAi Communications Co., Ltd. 2022-10-01
Series:Energy Geoscience
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2666759222000348
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author Richardson M. Abraham-A
Fabio Taioli
Anthony I. Nzekwu
author_facet Richardson M. Abraham-A
Fabio Taioli
Anthony I. Nzekwu
author_sort Richardson M. Abraham-A
collection DOAJ
description Core samples representing depths of hydrocarbon-bearing zones are not readily accessible for reservoir evaluations. On the other hand, wireline logs with incorporated seismic data, which can be archived over a more extended period while retaining their original forms, are typically more available for research purposes. Therefore, the study relies on wireline logs with seismic data to predict the reservoirs' fluid mobility by evaluating the hydraulic (flow) units, reservoir depths, fluid saturations, and geothermal gradients. It also indicates the associated water cut (Cw) within Ritchie oil and gas field, Niger Delta considering a three-phase (oil-gas-water-bearing) reservoir (RA) and an oil-saturated reservoir (RB) delineated across three wells (RW1, RW2 and RW3). Research activities combining the presented factors to achieve the stated objectives are not quite common within the study location. It shows lower, average and upper limits of the flow unit factors and irreducible water saturation (Swirr) within the reservoirs. The study shows the relationship between hydraulic units/fluid saturations and fluid mobility/associated Cw within the sandstone reservoirs. It maximises porosity (Ф) for the theoretical flow units' prediction during qualitative and quantitative estimation based on the adopted expressions. Therefore, the study reveals that water saturation (Sw) and hydrocarbon/water ratios substantially control Cw, and other contributing factors include thermal gradients and Swirr. The flow unit factors are also significant and will encourage fluid mobility. The evaluated reservoirs (RA and RB) are below 10 400 ft (3 170 m) across wells RW1, RW2 and RW3 within the Agbada Formation of a geothermal gradient up to 2.7 °C/100 m; therefore, they have good thermal conditions to enhance hydrocarbon mobility and increase Swirr. Hence, the reservoir should feature significant hydrocarbon extraction via primary recovery. The average water cut (Cw-avg.) (12.3%) estimated for reservoir RA is within the acceptable range; therefore, the associated water production from the three-phase reservoir will not be much of a concern. In addition, simple models are presented to aid an alternative approach for predicting reservoir quality and Cw within sandstone reservoirs, especially in the absence of core samples.
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spelling doaj.art-2e27b8cc039a40d3b5f709091f93dcee2022-12-22T03:13:04ZengKeAi Communications Co., Ltd.Energy Geoscience2666-75922022-10-0134349359Physical properties of sandstone reservoirs: Implication for fluid mobilityRichardson M. Abraham-A0Fabio Taioli1Anthony I. Nzekwu2Institute of Energy and Environment, University of São Paulo (IEE-USP), São Palo, Brazil; Corresponding author.Institute of Energy and Environment, University of São Paulo (IEE-USP), São Palo, BrazilDepartment of Applied Geophysics, Federal University of Technology, Akure, (FUTA), Ondo State, NigeriaCore samples representing depths of hydrocarbon-bearing zones are not readily accessible for reservoir evaluations. On the other hand, wireline logs with incorporated seismic data, which can be archived over a more extended period while retaining their original forms, are typically more available for research purposes. Therefore, the study relies on wireline logs with seismic data to predict the reservoirs' fluid mobility by evaluating the hydraulic (flow) units, reservoir depths, fluid saturations, and geothermal gradients. It also indicates the associated water cut (Cw) within Ritchie oil and gas field, Niger Delta considering a three-phase (oil-gas-water-bearing) reservoir (RA) and an oil-saturated reservoir (RB) delineated across three wells (RW1, RW2 and RW3). Research activities combining the presented factors to achieve the stated objectives are not quite common within the study location. It shows lower, average and upper limits of the flow unit factors and irreducible water saturation (Swirr) within the reservoirs. The study shows the relationship between hydraulic units/fluid saturations and fluid mobility/associated Cw within the sandstone reservoirs. It maximises porosity (Ф) for the theoretical flow units' prediction during qualitative and quantitative estimation based on the adopted expressions. Therefore, the study reveals that water saturation (Sw) and hydrocarbon/water ratios substantially control Cw, and other contributing factors include thermal gradients and Swirr. The flow unit factors are also significant and will encourage fluid mobility. The evaluated reservoirs (RA and RB) are below 10 400 ft (3 170 m) across wells RW1, RW2 and RW3 within the Agbada Formation of a geothermal gradient up to 2.7 °C/100 m; therefore, they have good thermal conditions to enhance hydrocarbon mobility and increase Swirr. Hence, the reservoir should feature significant hydrocarbon extraction via primary recovery. The average water cut (Cw-avg.) (12.3%) estimated for reservoir RA is within the acceptable range; therefore, the associated water production from the three-phase reservoir will not be much of a concern. In addition, simple models are presented to aid an alternative approach for predicting reservoir quality and Cw within sandstone reservoirs, especially in the absence of core samples.http://www.sciencedirect.com/science/article/pii/S2666759222000348Water cutThermal gradientFluid saturationsHydrocarbon mobilitySandstone reservoirReservoir quality
spellingShingle Richardson M. Abraham-A
Fabio Taioli
Anthony I. Nzekwu
Physical properties of sandstone reservoirs: Implication for fluid mobility
Energy Geoscience
Water cut
Thermal gradient
Fluid saturations
Hydrocarbon mobility
Sandstone reservoir
Reservoir quality
title Physical properties of sandstone reservoirs: Implication for fluid mobility
title_full Physical properties of sandstone reservoirs: Implication for fluid mobility
title_fullStr Physical properties of sandstone reservoirs: Implication for fluid mobility
title_full_unstemmed Physical properties of sandstone reservoirs: Implication for fluid mobility
title_short Physical properties of sandstone reservoirs: Implication for fluid mobility
title_sort physical properties of sandstone reservoirs implication for fluid mobility
topic Water cut
Thermal gradient
Fluid saturations
Hydrocarbon mobility
Sandstone reservoir
Reservoir quality
url http://www.sciencedirect.com/science/article/pii/S2666759222000348
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AT fabiotaioli physicalpropertiesofsandstonereservoirsimplicationforfluidmobility
AT anthonyinzekwu physicalpropertiesofsandstonereservoirsimplicationforfluidmobility