Loïs Letellier

PhD Thesis (2024 - 2027)

Title : Assisted borehole interpretation and multi-well stratigraphic correlation for geothermal modeling

Supervisors : Guillaume Caumon (RING Team), Cécile Robin (Université de Rennes 1)

The characterization of stratigraphic architecture from sparse borehole data is essential to understand the heterogeneity and nature of the rocks in sedimentary basins. Correlation uncertainties have been shown to impact the volume of sediments deposited through time (Edwards et al., 2018), the facies proportions in reservoir flow units (Lallier et al., 2016) and the hydrodynamic reservoir behavior (Lallier et al., 2012). However, the impact of correlation uncertainties on the performance of geothermal reservoirs or on CO₂ sequestration has not received much attention. Therefore, a first objective of this work is to quantify the impact of stratigraphic uncertainty on geothermal fluid circulation.

To address this question, the PhD project will define new approaches to propagate and quantify uncertainties in well log interpretation, stratigraphic correlation, and layer interpolation. The research methodology will first address the two-dimensional case between two wells, before considering more challenging cases in three dimensions with multiple wells. Analog models will be considered to calibrate and test the methodology, before considering real stratigraphic data from the Paris Basin.

Keywords: Stratigraphy, Petrophysics, Well log interpretation, Sedimentology