Multiphysics modeling of CO2 sequestration in a faulted saline formation in Italy

doi:10.1016/j.advwatres.2013.04.006

Advances in Water Resources

Volume 62, Part C, December 2013, Pages 570-587

https://doi.org/10.1016/j.advwatres.2013.04.006 Get rights and content

Highlights

•
Coupled wellbore-reservoir modeling captures the allocation of CO₂ injection fluxes.
•
Facies models at the reservoir scale affect the CO₂ volume that can be stored.
•
Geomechanical constraints play an important role relative to safe geological disposal.

Abstract

The present work describes the results of a modeling study addressing the geological sequestration of carbon dioxide (CO₂) in an offshore multi-compartment reservoir located in Italy. The study is part of a large scale project aimed at implementing carbon capture and storage (CCS) technology in a power plant in Italy within the framework of the European Energy Programme for Recovery (EEPR). The processes modeled include multiphase flow and geomechanical effects occurring in the storage formation and the sealing layers, along with near wellbore effects, fault/thrust reactivation and land surface stability, for a CO₂ injection rate of 1 × 10⁶ ton/a. Based on an accurate reproduction of the three-dimensional geological setting of the selected structure, two scenarios are discussed depending on a different distribution of the petrophysical properties of the formation used for injection, namely porosity and permeability. The numerical results help clarify the importance of: (i) facies models at the reservoir scale, properly conditioned on wellbore logs, in assessing the CO₂ storage capacity; (ii) coupled wellbore-reservoir flow in allocating injection fluxes among permeable levels; and (iii) geomechanical processes, especially shear failure, in constraining the sustainable pressure buildup of a faulted reservoir.

Introduction

Storage of CO₂ in deep geological formations such as depleted hydrocarbon reservoirs and saline aquifers is a promising strategy that could reduce mankind’s greenhouse gas emissions while continuing to meet the world energy needs. CO₂ injection into the subsurface may give rise to a variety of physical and chemical processes. These processes must be reliably understood to quantify the amount of CO₂ that can be safely stored in a selected geological formation according to its thermo–hydro–chemo–mechanical properties and the required injection rates.

One of the six CO₂ carbon capture and storage (CCS) demonstration projects recently selected in the framework of the European Energy Programme for Recovery (EEPR, http://ec.europa.eu/energy/eepr/) is located in Italy. The project is aimed at capturing 1 × 10⁶ ton/a of CO₂ from a power plant (PP in the sequel) flue stream and sequestering it underground. The storage formation is located offshore in a large foredeep basin filled by a several-km thick sedimentary succession close to the PP. The recommendation of detecting the site offshore to prevent possible Not In My Back Yard (NIMBY) oppositions and the requirement of avoiding any possible CO₂ contamination of CH₄ reservoirs scattered through the study area, have led to the selection of a multi-compartment structure, seated between 1100 and 2500 m below sea level (bsl) and called RESERVOIR in the sequel, as a possible site to store the carbon dioxide.

The present paper is focused on the multi-disciplinary study needed to understand the capability of the RESERVOIR structure to store CO₂ at the planned injection rate and, in particular, to quantify the period of time over which CO₂ may be safely injected. The study takes advantage of a large dataset of geological, geophysical, hydrological, petrophysical, and geomechanical information (Sections 3.3, 3.4) acquired over the last decades mainly for hydrocarbon exploration purposes [1], [2], [3], [4], [5]. The first step of the study consisted of the setting up of the geological model of the selected site (Section 2) as revealed by the seismostratigraphic (Section 3.1) and structural (Section 3.2) analysis of three-dimensional (3D) seismic data carried out by the Italian National Institute of Oceanography and Experimental Geophysics (OGS). The multiphysics modeling approach used in the study is then reviewed (Section 4). Multiphase flow simulations at the reservoir scale have been performed by IFP Energies Nouvelles (IFPEN) and multiphase temperature-dependent coupled wellbore-reservoir flow simulations at the well scale by Saipem S.p.A.. This two scale approach is a trade-off between the numerical effort for regional simulation and space resolution at the injection wells, as the simulation of the entire geological structure requires computational cell dimensions that are unable to capture near wellbore gradients. Although near-wellbore and field-scale simulations are actually uncoupled, a significant effort has been made to use the same rock properties, thermodynamic conditions, vertical discretization and impacted reservoir volume. Geomechanical issues are addressed by an advanced geomechanical simulator developed by the University of Padova (UNIPD). As the study is focused on the environmental and safety issues in CO₂ sequestration, geomechanics is coupled to the flow-dynamics simulation at the reservoir scale only. Geomechanical issues at wellbore scale, typically wellbore stability, are not addressed. The results for two plausible scenarios are presented (Section 5), followed by a brief discussion on major uncertainties that characterize the modeling outcome (Section 6). A few final remarks close the paper (Section 7).

Section snippets

Regional geology

The analysis of available seismic profiles and borehole composite logs allowed for reconstructing the main phases of the Neogenic evolution of the study area, through the identification of main depositional sequences (Fig. 1(a)). The RESERVOIR structure occurs mainly in the Layer-4 formation, which was deposited in the Early-Middle Pliocene. It consists of fine to coarse-grained sands intercalated with clayey layers, with a thickness ranging from a few-up-to 30 m [6]. Locally, thick

Seismostratigraphic setting

The RESERVOIR structure is 4.5 × 2.7–3 km wide, spanning the 1100–2500 m bsl depth range. The correlation of the available 3D seismic data with the borehole information led at first to the identification of the major sequence boundaries, represented in increasing age order by (Fig. 1(a)):

1.
the base of the Layer-1 formation;
2.
the base of the Pleistocene sequence;
3.
the reservoir top (i.e. top of the Layer-4 formation);
4.
the top of the Miocene sequence.

The seismic reflector that marks the lower boundary of the

Modeling approach

The present section aims at providing an overview of the modeling tools used in the analysis of the different processes. A flowchart summarizing the interaction between the various models/codes is provided in Fig. 8.

Modeling results

In the present section the numerical results relative to the two VSH and SS scenarios are presented. The consequences of these two scenarios, in terms of reservoir flow and geomechanical effects, are discussed in detail. Concerning the near well processes, at the present stage of development the focus has been on scenario SS. In both scenarios the following assumptions hold: (i) the initial conditions for the formation pressure and temperature shown in Fig. 6 are prescribed along with a NaCl

Discussion

The present study provides a representative and comprehensive review of the steps that are required to implement geological CCS in a real storage site. Based on both historical data from previous analyses and new information from the ongoing project, a large database is created for the characterization of the RESERVOIR and the surrounding formations from the structural, hydro-geological, petrophysical, and geomechanical point of view. Generally speaking, two levels of uncertainty can be

Conclusions

Predicting the amount of CO₂ that can be safely stored in a geological reservoir is a complex but important task for any real project of geological carbon dioxide sequestration. The complexity is even greater if the injected formation exhibits a faulted setting with several compartments.

In order to perform a reliable prediction of the involved multiphysical processes, an accurate site-specific investigation addressing the geological setting, and the petrophysical, hydrological and geomechanical

Acknowledgements

The research was supported by ENEL Ingegneria e Innovazione S.p.A. The authors are indebted to Monia Politi (ENEL S.p.A.) for her continuous and dedicated effort in coordinating the study. The three anonymous reviewers are acknowledged for helpful suggestions that contributed to improve significantly the quality of the presentation.

References (58)

C. Chiarabba et al.
A new view of Italian seismicity using 20 years of instrumental recordings
Tectonophysics
(2005)
F. Donda et al.
CO₂ storage potential of deep saline aquifers: the case of Italy
Int J Greenhouse Gas Control
(2011)
T. Giorgis et al.
2D modeling of salt precipitation during the injection of dry CO₂ in a depleted gas reservoir
Energy Conv Manag
(2007)
A. Prada et al.
Modification of Darcy’s law for the threshold pressure gradient
J Pet Sci Eng
(1999)
Y. Le Gallo et al.
Coupled reaction-flow modeling of diagenetic changes in reservoir permeability, porosity and mineral compositions
J Hydrol
(1998)
A. Battistelli et al.
TMGAS: a new TOUGH2 EOS module for the numerical simulation of gas mixtures injection in geological structures
Int J Greenhouse Gas Control
(2009)
I. Soreide et al.
Peng–Robinson predictions for hydrocarbons, CO₂, N2, and H2S with pure water and NaCl brine
Fluid Phase Equilib
(1992)
S. Quinones-Cisneros et al.
The friction theory for viscosity modeling: extension to crude oil systems
Chem Eng Sci
(2001)
A. Battistelli et al.
The simulator TOUGH2/EWASG for modelling geothermal reservoirs with brines and non-condensible gas
Geothermics
(1997)
T. Driesner
The system H2O-NaCl. Part II: Correlations for molar volume, enthalpy, and isobaric heat capacity from 0 to 1000 °C, 1 to 5000 bar, and 0 to 1 X-NaCl
Geochim Cosmochim Acta
(2007)

J. Rutqvist et al.

Estimating maximum sustainable injection pressure during geological sequestration of CO₂ using coupled fluid flow and geomechanical fault-slip analysis

Energy Conv Manag

(2007)

W. Spakman

Tomographic-images of the upper mantle below central-Europe and the Mediterranean

Terra Nova

(1990)

R. Fantoni et al.

Tectono-sedimentary setting of the Po plain and Adriatic foreland

Rend Lincei-Sci Fis Nat

(2010)

D. Scrocca

Thrust front segmentation induced by differential slab retreat in the Apennines (Italy)

Terra Nova

(2006)

M. Ghielmi et al.

Sedimentary and tectonic evolution in the eastern Po plain and Northern Adriatic Sea area from Messinian to Middle Pleistocene (Italy)

Rend Lincei-Sci Fis Nat

(2010)

Carles P, Egermann P, Lenormand R, Lombard JM. Low permeability measurements using steady-state and transient methods....

M.C. Leverett

Capillary behavior in porous solids

Trans Soc Pet Eng AIME

(2007)

R.H. Brooks et al.

Hydraulic properties of porous media

Hydrol Papers

(1964)

Bennion B, Bachu S. Relative permeability characteristics for supercritical CO2 displacing water in a variety of...

K. Pruess et al.

Formation dry-out from CO₂ injection into saline aquifers: 1. Effects of solids precipitation and their mitigation

Water Resour Res

(2009)

Pruess K, Oldenburg CM, Moridis GJ. TOUGH2 User’s guide, Version 2.0. Tech. Rep. Report LBNL-43134, Lawrence Berkeley...

Lenormand R. Interpretation of mercury injection curves to derive pore size distribution. In: Paper SCA2003-52...

J. Dainelli et al.

Regional assessment of sealing faults through pore-pressure analysis in the Northern Adriatic

First Break

(1993)

D. Baù et al.

Basin-scale compressibility of the Northern Adriatic by the radioactive marker technique

Geotechnique

(2002)

M. Ferronato et al.

Interpretation of radioactive marker measurements to evaluate compaction in the Northern Adriatic gas fields

SPE Reserv Eval Eng

(2003)

M. Ferronato et al.

II cycle compressibility from satellite measurements

Geotechnique

(2013)

G. Gambolati et al.

Stress–strain analysis in productive gas/oil reservoirs

Int J Numer Anal Methods Geomech

(1999)

P. Teatini et al.

Water-gas dynamics and coastal land subsidence over Chioggia Mare field, Northern Adriatic Sea

Hydrogeol J

(2000)

P. Teatini et al.

Geomechanical response to seasonal gas storage in depleted reservoirs: a case study in the Po river basin, Italy

J Geophys Res

(2011)

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Multiphysics modeling of CO2 sequestration in a faulted saline formation in Italy

Highlights

Abstract

Introduction

Section snippets

Regional geology

Seismostratigraphic setting

Modeling approach

Modeling results

Discussion

Conclusions

Acknowledgements

Tectonophysics

Int J Greenhouse Gas Control

Energy Conv Manag

J Pet Sci Eng

J Hydrol

Int J Greenhouse Gas Control

Fluid Phase Equilib

Chem Eng Sci

Geothermics

Geochim Cosmochim Acta

Energy Conv Manag

Tomographic-images of the upper mantle below central-Europe and the Mediterranean

Terra Nova

Tectono-sedimentary setting of the Po plain and Adriatic foreland

Rend Lincei-Sci Fis Nat

Thrust front segmentation induced by differential slab retreat in the Apennines (Italy)

Terra Nova

Sedimentary and tectonic evolution in the eastern Po plain and Northern Adriatic Sea area from Messinian to Middle Pleistocene (Italy)

Rend Lincei-Sci Fis Nat

Capillary behavior in porous solids

Trans Soc Pet Eng AIME

Hydraulic properties of porous media

Hydrol Papers

Formation dry-out from CO2 injection into saline aquifers: 1. Effects of solids precipitation and their mitigation

Water Resour Res

Regional assessment of sealing faults through pore-pressure analysis in the Northern Adriatic

First Break

Basin-scale compressibility of the Northern Adriatic by the radioactive marker technique

Geotechnique

Interpretation of radioactive marker measurements to evaluate compaction in the Northern Adriatic gas fields

SPE Reserv Eval Eng

II cycle compressibility from satellite measurements

Geotechnique

Stress–strain analysis in productive gas/oil reservoirs

Int J Numer Anal Methods Geomech

Water-gas dynamics and coastal land subsidence over Chioggia Mare field, Northern Adriatic Sea

Hydrogeol J

Geomechanical response to seasonal gas storage in depleted reservoirs: a case study in the Po river basin, Italy

J Geophys Res

Multiphysics modeling of CO₂ sequestration in a faulted saline formation in Italy

Formation dry-out from CO₂ injection into saline aquifers: 1. Effects of solids precipitation and their mitigation