Dual Porosity Simulation of Gravity Drainage Mechanism Induced by Geological Acid Gas Storage in Naturally Fractured Reservoirs

ABSTRACT Acid gases, containing CO2 and H2S, are by‐products of gas sweetening. Geological sequestration of these gases in naturally fractured reservoirs (NFRs) is a practical method to reduce greenhouse gas emission. An industrially accepted approach to simulate fluid flow in NFRs is the dual‐poros...

Full description

Saved in:
Bibliographic Details
Main Authors: Goran Shirzad, Mehdi Assareh
Format: Article
Language:English
Published: Wiley 2025-06-01
Series:Energy Science & Engineering
Subjects:
Online Access:https://doi.org/10.1002/ese3.70094
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850213980569600000
author Goran Shirzad
Mehdi Assareh
author_facet Goran Shirzad
Mehdi Assareh
author_sort Goran Shirzad
collection DOAJ
description ABSTRACT Acid gases, containing CO2 and H2S, are by‐products of gas sweetening. Geological sequestration of these gases in naturally fractured reservoirs (NFRs) is a practical method to reduce greenhouse gas emission. An industrially accepted approach to simulate fluid flow in NFRs is the dual‐porosity method; however, this method needs multiple parameters' specifications. The main goal of this study is to develop a dual‐porosity model with improved parameters that can be used for simulation of both hydrocarbon gas gravity drainage and acid gas injection in the gas‐invaded zone of NFRs. To do so, a single‐porosity model, as the reference model, is constructed for a single matrix block (SMB) with which the equivalent dual‐porosity model's (DP) parameters are determined and matched. Then, DP is improved by a dual‐porosity vertical discrete (VD) model to consider gravity drainage. This was later enhanced by non‐neighborhood connections (NNCs) to account for re‐infiltration in stacked matrices, yielding comparable results to the reference CPU‐intensive single‐porosity simulation. A thorough sensitivity analysis is performed on acid gas injection in VD model. The results show that the most effective parameter is porosity. The permeability and NNC transmissibility only change the rate of acid gas storage and more acid gas is trapped as H2S content increases. Also, the heterogeneous distribution of porosity only influences the rate of storage when the mean porosity is constant, while permeability heterogeneity does not affect acid gas storage. The recovery factor is considerably increased to nearly 100% when the acid gas replaces hydrocarbon gas in fractured surrounding. About 7000 kmole of acid gas is stored in SMB over 4.5 years. Similar results are obtained for stacked matrices, and trapped gas is about 22,000 kmole, after 9 years.
format Article
id doaj-art-e282ea2547964d01ab411f68ee3f241a
institution OA Journals
issn 2050-0505
language English
publishDate 2025-06-01
publisher Wiley
record_format Article
series Energy Science & Engineering
spelling doaj-art-e282ea2547964d01ab411f68ee3f241a2025-08-20T02:09:00ZengWileyEnergy Science & Engineering2050-05052025-06-011363151317010.1002/ese3.70094Dual Porosity Simulation of Gravity Drainage Mechanism Induced by Geological Acid Gas Storage in Naturally Fractured ReservoirsGoran Shirzad0Mehdi Assareh1School of Chemical, Petroleum and Gas Engineering Iran University of Science and Technology Tehran Tehran IranSchool of Chemical, Petroleum and Gas Engineering Iran University of Science and Technology Tehran Tehran IranABSTRACT Acid gases, containing CO2 and H2S, are by‐products of gas sweetening. Geological sequestration of these gases in naturally fractured reservoirs (NFRs) is a practical method to reduce greenhouse gas emission. An industrially accepted approach to simulate fluid flow in NFRs is the dual‐porosity method; however, this method needs multiple parameters' specifications. The main goal of this study is to develop a dual‐porosity model with improved parameters that can be used for simulation of both hydrocarbon gas gravity drainage and acid gas injection in the gas‐invaded zone of NFRs. To do so, a single‐porosity model, as the reference model, is constructed for a single matrix block (SMB) with which the equivalent dual‐porosity model's (DP) parameters are determined and matched. Then, DP is improved by a dual‐porosity vertical discrete (VD) model to consider gravity drainage. This was later enhanced by non‐neighborhood connections (NNCs) to account for re‐infiltration in stacked matrices, yielding comparable results to the reference CPU‐intensive single‐porosity simulation. A thorough sensitivity analysis is performed on acid gas injection in VD model. The results show that the most effective parameter is porosity. The permeability and NNC transmissibility only change the rate of acid gas storage and more acid gas is trapped as H2S content increases. Also, the heterogeneous distribution of porosity only influences the rate of storage when the mean porosity is constant, while permeability heterogeneity does not affect acid gas storage. The recovery factor is considerably increased to nearly 100% when the acid gas replaces hydrocarbon gas in fractured surrounding. About 7000 kmole of acid gas is stored in SMB over 4.5 years. Similar results are obtained for stacked matrices, and trapped gas is about 22,000 kmole, after 9 years.https://doi.org/10.1002/ese3.70094acid gasdual porositygas gravity drainagegeological storagenaturally fractured reservoirs
spellingShingle Goran Shirzad
Mehdi Assareh
Dual Porosity Simulation of Gravity Drainage Mechanism Induced by Geological Acid Gas Storage in Naturally Fractured Reservoirs
Energy Science & Engineering
acid gas
dual porosity
gas gravity drainage
geological storage
naturally fractured reservoirs
title Dual Porosity Simulation of Gravity Drainage Mechanism Induced by Geological Acid Gas Storage in Naturally Fractured Reservoirs
title_full Dual Porosity Simulation of Gravity Drainage Mechanism Induced by Geological Acid Gas Storage in Naturally Fractured Reservoirs
title_fullStr Dual Porosity Simulation of Gravity Drainage Mechanism Induced by Geological Acid Gas Storage in Naturally Fractured Reservoirs
title_full_unstemmed Dual Porosity Simulation of Gravity Drainage Mechanism Induced by Geological Acid Gas Storage in Naturally Fractured Reservoirs
title_short Dual Porosity Simulation of Gravity Drainage Mechanism Induced by Geological Acid Gas Storage in Naturally Fractured Reservoirs
title_sort dual porosity simulation of gravity drainage mechanism induced by geological acid gas storage in naturally fractured reservoirs
topic acid gas
dual porosity
gas gravity drainage
geological storage
naturally fractured reservoirs
url https://doi.org/10.1002/ese3.70094
work_keys_str_mv AT goranshirzad dualporositysimulationofgravitydrainagemechanisminducedbygeologicalacidgasstorageinnaturallyfracturedreservoirs
AT mehdiassareh dualporositysimulationofgravitydrainagemechanisminducedbygeologicalacidgasstorageinnaturallyfracturedreservoirs