RECO3D: Development of a tool for automatic recognition of fractures on 3D outcrops.

The scientific context

Fractures represent discontinuities in rock that can be formed by multiple geological processes and play an important role in many contexts. They are particularly important in the analysis of the stability of slopes or wells, are the hosts of mineralization exploited in mining, or are important vectors of fluid circulation for various applications whether in geothermal energy or in the field of oil & gas. This is particularly the case in so-called “non-conventional” reservoirs where hydraulic and mechanical modeling must take these elements into account to be effective.

Classic analyses are done using maps or counting along a measurement line (called scan-line) to characterize and include fractures in models. They make it possible to determine the distribution of fractures in space, their orientations, lengths, connectivity, etc. The more robust the data collected and the more properties the models integrate, the more complete the representation of the geological object will be. However, two significant difficulties are encountered when it comes to transposing the measured properties to the digital modeling of objects:

  1. The fracture network is a complex 3D object and the transposition between measurements in maps (2D) or from scan lines (1D) is not easy and requires adding hypotheses and/or simplifications which make the less precise models.
  2. Fractures are present from the scale of the grain of the rock to kilometric surfaces that it is never possible to study as a whole. Fractures measuring decametric to hectometric in length are also the most undersampled even though they play a leading role on the scale of an underground reservoir.

The RECO3D project

The objective of the RECO3D project is to take advantage of the development of drones & Lidar to characterize fractures with a triple goal:

  1. The characterization of fractures of decametres to hectometres length on quarry and cliff plans that are not accessible to the field geologists
  2. Lay the foundations of a 3D fracture characterization tool, in order to reduce the uncertainties in modeling fracture networks.
  3. Automate the recognition and characterization of fracture planes in order to gain efficiency.

The proposed operational workflow takes place in 3 stages, from the acquisition of 3D data on outcrop to the analysis of the properties of the fracture network:

This tool can now be used in geological studies where characterization of rock fracturing is necessary. Do not hesitate to contact us for further informations.

The development of this tool benefited from BPI France funding, in collaboration with the start-up Tessael, which specialized in the digital modeling of geological objects. This is a first step towards the creation of a complete tool for explicit modeling of fracture networks and the characterization of the flow and geomechanical properties of this type of object.

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