Land Subsidence Spreading Factor of the Northern Adriatic Gas Fields, Italy

Water Resources Research

et al. 2006

188

115

[1] The Emilia-Romagna coastland south of the Po River delta, Italy, has experienced a dramatic land settlement mainly due to the large groundwater withdrawal related to the local economic and tourist development started in the early 1950s. Although the use of surface water has reduced the settlement rate over the last three decades, anthropogenic land subsidence still continues in a few kilometer wide coastal strip at a rate larger than the natural one. The occurrence is reconstructed since 1946 with the aid of advanced finite element flow and poromechanical models implemented with a realistically detailed geology of the regional shallow multiaquifer system. The models have been calibrated against the piezometric, leveling, and extensometer records observed over the last 50 years, and a land subsidence prediction in 2016 is performed. The results show that the extensive groundwater pumping that occurred in the past is most likely the main cause of the recent land settlement as well because of the delayed compaction of the clay aquitards comprised between the depleted aquifers. However, the available pumping data do not allow for a thorough understanding of the current local settlement process along the coastline, which is the most vulnerable area of the Emilia-Romagna region from an environmental viewpoint. If the planned scenario of groundwater resource management will be implemented, anthropogenic land subsidence is bound to become a marginal problem for the central and northern portion of the Emilia-Romagna coastland.Citation: Teatini, P., M. Ferronato, G. Gambolati, and M. Gonella (2006), Groundwater pumping and land subsidence in the EmiliaRomagna coastland, Italy: Modeling the past occurrence and the future trend, Water Resour.

Section: Model Outcomementioning

confidence: 99%

Groundwater pumping and land subsidence in the Emilia‐Romagna coastland, Italy: Modeling the past occurrence and the future trend

Teatini

Water Resources Research

et al. 2006

188

115

“…4 in the equilibrium equations of a geomechanically isotropic porous medium (Biot, 1941;Geertsma, 1966). The porous-medium deformation caused by CO 2 injection is predicted with the aid of the finite-element poroelastic code developed by Gambolati et al (2001), properly modified to account for the non-linear hysteretic mechanical behavior exhibited by the injected formation (Baú et al, 2001). The pressure field calculated with the multi-phase finitedifference simulator ECLIPSE is interpolated over the structural finite-element grid and used as a distributed forcing function in the poro-mechanical model at every step of the transient simulation.…”

Section: Numerical Simulationsmentioning

confidence: 99%

“…Fluid confinement is guaranteed by top and bottom clay layers characterized by a very low permeability. For example, most gas fields in the Po River Plain consist of a number of hydraulically separated layers, some of which are slightly overpressurized (Baú et al, 2001;Ferronato et al, 2003b). The fact that these gas pools were formed hundreds of thousands of years ago, and the reserves are still in place, is evidence of their geological stability with respect to tectonic and diagenetic processes and of the confinement exerted by the clay beds that behave as sealing barriers.…”

Section: Introductionmentioning

confidence: 99%

Fluid-Dynamic and Geomechanical Effects of CO2 Sequestration below the Venice Lagoon

Comerlati

Environmental and Engineering Geoscience

et al. 2006

Simulation of CO 2 sequestration in deep geological formations is a multi-disciplinary effort involving the study of multi-phase flow of groundwater and carbon dioxide along with porous medium deformation caused by pore pressure increase. The latter can cause the ground surface to rise because of the reduction of the effective stress in the aquifer and consequent rock expansion. A preliminary analysis of CO 2 sequestration in a brackish aquifer between 600 and 800 m below the Venice Lagoon is presented. Using available geological, geophysical, hydrologic, and geomechanical data, and with the aid of advanced numerical models, several scenarios are addressed to investigate the potential of the proposed solution as far as both the CO 2 storage and the possible land uplift are concerned. The results show that with the most probable hydrogeological configuration the total amount of CO 2 released from nearby thermo-power plants, i.e., 20 Mt/year, can be safely sequestered, with an expected city uplift over 10 years ranging between 7 and 13 cm, depending on well configuration. This would make up for most of the anthropogenic land subsidence experienced by Venice over the last half-century and could offset between 50 and 70 percent of the ''acqua alta'' that periodically floods Venice. The simulations, however, show a high sensitivity to sand permeability and compressibility, which points to the need for new field investigations before the present preliminary proposal may be turned into an actual feasibility study.

Thermo‐hydro‐mechanical modeling of fluid geological storage by Godunov‐mixed methods

Castelletto

Numerical Meth Engineering

2012

SUMMARY The efficient solution to the coupled system of PDEs governing the mass and the energy balance in deformable porous media requires advanced numerical algorithms. A combination of mixed/Galerkin finite elements and finite volumes along with a staggered method are employed. Fluid flow and heat transfer are addressed iteratively by a fully coupled approach and the medium deformation by an explicitly coupled scheme, at each time step. Such formulation allows for stable numerical solutions, element‐wise conservative velocity fields and accurate prediction of sharp temperature convective fronts. The proposed model is experimented with in realistic applications of a deep aquifer fluid injection. Copyright © 2012 John Wiley & Sons, Ltd.