Statistical analysis of conduit dimension distributions within karstic systems

Yves Frantz and Pauline Collon and Philippe Renard. ( 2018 )
in: 2018 Ring Meeting, ASGA

Abstract

Despite intensive explorations by speleologists, karstic systems remain only partially described as many conduits are not accessible to humans. Paleokarsts are buried karstic systems with a significant reservoir potential but they are not easily identifiable on seismic images, which leads to a huge uncertainty on the network location and the conduits geometry. Thus, it becomes necessary to resort to stochastic simulation to better assess that uncertainty, one of the main approach being to reproduce the topology and geometry information already observed on known networks. The height and width of the conduits are directly measured by speleologists. The general width- height ratio of different networks was already studied but no generic study seems to have be done on their spatial repartition. It leads to a lack of constraints when simulating conduit dimensions (sections or volumes) during modeling. In this study, we analyse a set of different explored karstic systems to check if there are typical distributions of height, width and section of conduits within the network. We thus analyse the average radius and width-height ratio of the conduits. We found that the distribution is rather continuous spatially and the range of variations is relatively limited inside the different networks. A small increase of the values along with the node degree was also observed. It leads to a better understanding of these key point aspects for ow simulations and opens new possibilities to improve stochastic simulations and their results.

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BibTeX Reference

@INPROCEEDINGS{,
    author = { Frantz, Yves and Collon, Pauline and Renard, Philippe },
     title = { Statistical analysis of conduit dimension distributions within karstic systems },
 booktitle = { 2018 Ring Meeting },
      year = { 2018 },
 publisher = { ASGA },
  abstract = { Despite intensive explorations by speleologists, karstic systems remain only partially described
as many conduits are not accessible to humans. Paleokarsts are buried karstic systems with a
significant reservoir potential but they are not easily identifiable on seismic images, which leads to
a huge uncertainty on the network location and the conduits geometry. Thus, it becomes necessary
to resort to stochastic simulation to better assess that uncertainty, one of the main approach being
to reproduce the topology and geometry information already observed on known networks.
The height and width of the conduits are directly measured by speleologists. The general width-
height ratio of different networks was already studied but no generic study seems to have be done
on their spatial repartition. It leads to a lack of constraints when simulating conduit dimensions
(sections or volumes) during modeling.
In this study, we analyse a set of different explored karstic systems to check if there are typical
distributions of height, width and section of conduits within the network. We thus analyse the
average radius and width-height ratio of the conduits. We found that the distribution is rather
continuous spatially and the range of variations is relatively limited inside the different networks.
A small increase of the values along with the node degree was also observed. It leads to a better
understanding of these key point aspects for 
ow simulations and opens new possibilities to improve
stochastic simulations and their results. }
}