Carbonate reservoir rocks are characterised by challenging pore systems due to a range of original textures and solid component sizes and multiple subsequent diagenetic alterations. Such complexities can result in highly variable permeability values and flow outcomes across the reservoir. This work explores the role of textural heterogeneities on the fluid transport properties within Coquina limestones. Three cylindrical samples with a diameter of 38 mm and lengths from 55 to 78 mm were examined. These samples’ bulk measured vertical permeability ranged from 37 to 95 mD, a rather small variation for carbonates. X-ray tomography was used on water saturated samples to visualise their pore space (in 3D) and to calculate their porosity, saturation and surface area/pore volume ratio profiles (2D averages). Flow experiments performed while acquiring High-Speed Neutron tomographies were also performed to visualise the water front propagation within the sample in order to assess, in-situ, the impact of the observed local heterogeneities on flow. Our results show the significant impact of Coquina’s heterogeneity on front propagation. While a piston-like front was observed in one sample, unstable front propagation (fingering) was dominant in two others. These changes were attributed to local textural heterogeneities previously resolved by the x-ray tomography.
|Number of pages||10|
|Publication status||Published - 2019|
|Event||12th HSTAM International Congress on Mechanics 2019 - Thessaloniki, Greece|
Duration: 22 Sept 2019 → 25 Sept 2019
|Conference||12th HSTAM International Congress on Mechanics 2019|
|Period||22/09/19 → 25/09/19|
- fluid transport