Page History
Mmax estimate for reservoir triggered seismicity
Scientific Background
Information
Scientific Background
Overall, the analyses of earthquake triggering whatever they are tectonic or anthropogenic seismicity point in time-space scale the key role of the use normalized distance versus absolute distance to relate a trigger to triggered event. For tectonic earthquakes, there are evidences that the use of the absolute distance captures earthquake- earthquake triggering patterns (as aftershock-mainshock pair) that hide the key properties of the mainshock-aftershock interactions (e.g. Bak et al 2002; Parsons and Velasco, 2009, Tahir et al., 2012, Tahir and Grasso, 2015, de Arcangelis et al 2016). This supports the link whereby the reservoir influence zone scales with reservoir (hydrocarbon field or reservoir lake ) size rather than with simple distance to a local “point-source” load, especially in the reservoir near field (e.g., Ibenbrahim et al., 1989, Grasso et al. 2018). Grasso et al. (2018) suggest that surface reservoir impoundment (onset of production for hydrocarbon field) impacts the upper crust in the same way as earthquake slip changes upper crust stresses. The surface reservoir load modifies the state of stress, specifically the vertical stress and the effective stresses, through pore-pressure changes, in an area that scales with Lr, the reservoir length (Grasso et al.2018). The same way goes for conventional hydrocarbon reservoir depletion (e.g. Segall et al. 1994).
This application proposes to estimate of Mmax on two different basis: (i) from the frequency of Mmax values as deduced the worldwide data base for the considered geo-resource production; it corresponds to a Mmax probability for a given time period; (ii) when available a second possible Mmax estimate is the one deduced from the size of the geo-resource production (representative length of the reservoir); (iii) Then the user must compared the two outputs to derive uncertainties.
...
...
...
...
J.-R. Grasso, A. Karimov, D. Amorese, (2018b), Anthropogenic Seismicity as aftershocks of geo-resource production ? Implication for Mmax estimates, reservoir impoundment case, Geophysical journal international , submmitted
...
...
...
...
...
Step by Step
How to use the application
After the User adds the Application into his/her personal workspace, the following window appear on the screen (Figure 1):
Figure 1. Input window of estimate of maximum possible magnitude from induced deformation.
The user is now requested to fill the fields shown above:
...
1) Target magnitude - magnitude value to be used for possible Mmax
...
distribution
...
2) Reservoir length – Length of the reservoir to be used for possible Mmax
...
distribution
...
3) Input data – the user should choose one of the data: water reservoir or hydrocarbon reservoir. Both data come from HiQuake: The human-induced earthquake database. (2016) The data can be found online https://inducedearthquakes.org/
...
After defining the aforementioned parameters, the user shall click on the "Run" button and the calculations are performed. The Status changes from 'CREATED' through 'RUNNING' and finally 'FINISHED' and the output is created and plotted in the main window just below "RUN" button.
Figure 3(a,b) The outputs of possible Mmax estimation for water reservoir case:
(a)
- blue line – recorded Mmax (maximum magnitude) values from worldwide
...
- red circle – occurrence probability for target magnitude
(b)
- solid line - distribution of Mmax (maximum magnitude) with the reservoir length (Wells and Coppersmith 1994)
- circle points - global reference events for the water reservoir case
- upper red diamond – expected maximum magnitude value, based on imposed reservoir length
- bottom red diamond – expected average magnitude value, based on imposed reservoir length.
- dashed line - the Bath law for a tectonic
...
aftershock
- α - a priori constant; α = 2.2 and 2.4 for the water reservoir and hydrocarbon reservoir cases respectively.
Note user gets the same type of 2 output plots for hydrocarbon reservoir case.
...