Hydro-structural analysis of Northern Termination

of Maiella anticline

Author: Kaisar Ahmat Supervisors: Emanuele Tondi Marco Materazzi

2014-2015

Master thesis in Structural Geology and Hydrogeology

Outline

• Introduction

• Geological setting

• Materials and data

• Modelling and simulation

• Results

• Conclusion

Introduction 1 The Maiella anticline is the outermost trust-related structure of the central Apennines is one of the most important fractured carbonate aquifer in Abruzzo

Usage M3/year %Drinking water 60.7e+6 24

Electricity generation

103.3e+6 41

Irrigation 9.5e+6 3.8Not available 78.5e+ 6 31.2

Total 252e+6 100

Previous many studies has taken place about outcropping oil show in Bolognano Fm to observe directly which structural characteristics mostly influence the fluid flow in a similar fractured carbonate reservoirIn this thesis we focus more on Groundwater and control

of hydro-structures and using modelling technique try to better understand the aquifer rock properties and subsurface fluid migration pattern .

Geological sketch of the central Apennines (Vecsei & Sanders, 1999) Red square shows the Maiella Mountain

GeologyPlateform carbonate Slop to basin Outcrop carbonate platform Retrogradation, agradationCaramanico normal fault70°-

80° deep toward west

Springs Deep, shallow aquifersTar impregnation Precipitation

Hydrogeology

Geology of northern termination of Maiella

Data and materials n˚ Spring Level(m)

m.s.l.

Disc min

Mc/s

Disc max

Mc/s

Disc av

Mc/s

1 S.Giustino 479-475 0.30 1.10 0.65

2 Acquevive 462-456 0.41 2.05 1.01

3 Verde 410 224 3.56 2.56

4 Foro 420 0.47 0.63 0.57

5 Lavino 150 0.79 3.12 1.83

6 Orfento 480-405 0 0.42 0.15

Available data for modelling are spring discharge in the area and hydraulic head from interpreted cross-sections from Nanni and Rusi ,2003

5m resolution Digital Elevation Model map of Abruzzo

Average porosity ,permeability if Bolognano marly member average porosity 0.12, average permeability 60md Calcarenite member average porosity 0.24,average permeability 330md .

Thickness of lower lias to upper TriassicDolomite di Castel Manfrino formation

800-2000m

Modelling and simulation

Conceptual model

Hydrogeological units in Nanni and Rusi 2003A.

) hydrogeological complex of Jurassic-Paleocene limestone characterized by high perme- ability due to karst and fissuring; B) an aquiclude of the Bolognano Formation consisting of marly limestone and marlstone; C) marl and marly clay;D) a hydrogeological complex of highly

permeable continental detritus.

Model boundary condition and flow system

No flow Boundaryin south

No flow Boundary West-East

(constand head )Seepage face Boundary for springs

Numerical model

• Model Development

Selected code: FEFLOWsubsurface modeling system

2D mesh generation

Software GUI

TriangularAdvancing frontgeobuilder

The mesh density of 1560nodes and 2979 elements was used in Generate Automatically option to generatethe mesh for the first slice

Model geometry and materialproperty

Thickness Average porosity

Permeability

(md)

Hydraulic conductivity

(m/s)

Gessoso-solfifera Unit

300-400 0.1 50 4.93e-7

Bolognano calcarenite unit

200 0.24 330 3.26e-6

Bolognano marly unit

150 0.12 63 6.22e-7

Hydrogeological complex

1400-2000 0.1 250 2.9e-6

Simulation and calibration

y = 0.8756x + 107.77R² = 0.939

0

200

400

600

800

1000

0 200 400 600 800 1000

He

ad S

imu

late

d (

m)

Head Observed (m)

Series1

Results

Water Budget Simulated mc/s vs mc/y Measured mc/s vs mc/y Error mc/s

Total 2.346 73.893.356 2.4 75.686.400 0.054

Lavino 1.82 57.395.520 1.83 57.710.880 0.01

Foro 0.526 16.587.936 0.57 17.975.520 0.044

Observed VS measured recharge and discharge

Simulated hydraulic headwith isolines

Model including fault For increase the goodness of the model We create another model with normal faultOf lavino spring is included and we got a better result With advantage of :More close to real hydrogeological interpretation The assigned unit parameters are in more correct range

Water Budget Simulated mc/s vs mc/y Measured mc/s vs mc/y Error mc/s

Total 2.346 73.893.356 2.4 75.686.400 0.054

Lavino 1.84 58.007.318.4 1.83 57.710.880 0.01

Foro 0.51 16.083.360 0.57 17.975.520 0.06

y = 1.0987x + 188.76R² = 0.9022

0

200

400

600

800

1000

0 200 400 600 800 1000

Sim

ula

ted

(m

)

Observed (m)

Observed VS measured spring discharge and hydraulic head

Conclusion

Creating a Groundwater Model of carbonate aquifer systems with equivalent continuous approach has been found to be suitable in simulating regional groundwater flow using regional aquifer parameters adequately reproducing the regional groundwater levels with relation to observed discharge to the springs. And to improve the model goodness, we include the fault in the termination point and get a better representation of the area.

For the future model for carbonate aquifer hydrogeological analysis, we need to obtain more data in the field. So with more sufficient data we able to create more accurate coceptual and numerical model to estimate our final goal as correct estimation of carbonate aquifer rock property variation by depth and the structural control on flow pathways

!ھەممەڭالرغا رەھمەت

Thanks you all for coming !

Grazie per essere venuti!