Classification and quantification of pore shapes in sandstone reservoir rocks with 3-D X-ray micro-computed tomography

Abstract

Abstract. Recent years have seen a growing interest in the characterization of the pore morphologies of reservoir rocks and how the spatial organization of pore traits affects the macro behavior of rock-fluid systems. With the availability of 3-D high-resolution imaging, such as x-ray microcomputed tomography (µ-CT), the detailed quantification of particle shapes has been facilitated by progress in computer science. Here, we show how the shapes of irregular rock particles (pores) can be classified and quantified based on binary 3-D images. The methodology requires the measurement of basic 3-D particle descriptors (length, width, and thickness) and a shape classification that involves the similarity of artificial objects, which is based on main pore network detachments and 3-D sample sizes. Two main pore components were identified from the analyzed volumes: pore networks and residual pore ganglia. A watershed algorithm was applied to preserve the pore morphology after separating the main pore networks, which is essential for the pore shape characterization. The results were validated for three sandstones (S 1 , S 2 , and S 3 ) from distinct reservoirs, and most of the pore shapes were found to be plate-and cube-like, ranging from 39.49 to 50.94 % and from 58.80 to 45.18 % when the Feret caliper descriptor was investigated in a 1000 3 voxel volume. Furthermore, this study generalizes a practical way to correlate specific particle shapes, such as rods, blades, cuboids, plates, and cubes to characterize asymmetric particles of any material type with 3-D image analysis.

Fault reactivation in travertine and its impact on hydraulic transmissibility: laboratory experiments and mesoscale structures

“…Knowledge of pore/grain shape or size is essential and plays an important role in the hydromechanical behaviour and petrophysical properties of rocks (Akin et al 2009;Delle Piane et al 2015;Schmitt et al 2015;Soete et al 2015). Thus, we examined the X-ray CT images of the three samples carefully to determine the pore shape and orientations.…”

Solute mixing regulates heterogeneity of mineral precipitation in porous media

“…To quantify such pore scale processes in statistical terms, timeevolving pore size distribution (PSD) was computed by using the watershed and distance transform algorithms and Avizo's XPoreNetworkModeling module [FEI Company, 2016;Rabbani et al, 2016;Schmitt et al, 2016]. To quantify such pore scale processes in statistical terms, timeevolving pore size distribution (PSD) was computed by using the watershed and distance transform algorithms and Avizo's XPoreNetworkModeling module [FEI Company, 2016;Rabbani et al, 2016;Schmitt et al, 2016].…”

“…The analyses presented in the previous sections showed that mineral precipitation results in a highly heterogeneous alteration of the microstructure. To quantify such pore scale processes in statistical terms, timeevolving pore size distribution (PSD) was computed by using the watershed and distance transform algorithms and Avizo's XPoreNetworkModeling module [FEI Company, 2016;Rabbani et al, 2016;Schmitt et al, 2016]. The size of each identified pore was reported as the diameter of a sphere having equivalent volume ( Figure S7).…”

Pore-scale tomography and imaging: applications, techniques and recommended practice

“…2). Schlüter et al (2016) showcase the application of µ-CT imaging for the analysis soil structure deformation, whereas Schmitt et al (2016) present new research on the classification and quantification of pore shapes of reservoir rocks. Within the paper of Schoesser et al (2016), research of the penetration behavior of bentonite suspensions into noncohesive media is presented.…”