NMR based fractal analysis in shale under different confining pressure, and its correlation to Archie's cementation exponents.

This study delves into the complexity of shale pore structures through fractal dimension analysis of nuclear magnetic resonance (NMR) data under varying confining pressures. Focusing on nine illite-rich shale samples, we investigate how confining pressure influences the pore size distribution, particularly narrowing meso- and macropores. Our analysis utilizes two distinct models to calculate fractal dimensions: Model 1 categorizes pores into micro and meso + macro based on cutoffs, while Model 2 considers all pore sizes collectively.

Strain measurement with multiplexed FBG sensor arrays: An experimental investigation.

In conventional rock mechanics testing, radial strain measuring devices are usually attached to the sample's surface at its mid-height. Although this procedure provides a realistic picture of the lateral deformation undergone by homogeneous samples, however, this assumption may not be accurate if the tested rock has significant heterogeneity. Fibre Bragg Grating (FBG) sensors have recently been introduced to various rock testing applications due to their versatility over conventional strain gauges and radial cantilevers.

Mathematical modeling and computer simulation of needle insertion into soft tissue.

In this study we present a kinematic approach for modeling needle insertion into soft tissues. The kinematic approach allows the presentation of the problem as Dirichlet-type (i.e.

Pore Structure Changes Occur During CO Injection into Carbonate Reservoirs.

Observations and modeling studies have shown that during CO injection into underground carbonate reservoirs, the dissolution of CO into formation water forms acidic brine, leading to fluid-rock interactions that can significantly impact the hydraulic properties of the host formation. However, the impacts of these interactions on the pore structure and macroscopic flow properties of host rock are poorly characterized both for the near-wellbore region and deeper into the reservoir. Little attention has been given to the influence of pressure drop from the near-wellbore region to reservoir body on disturbing the ionic equilibrium in the CO-saturated brine and consequent mineral precipitation.

Characterization of Darai Limestone Composition and Porosity Using Data-Constrained Modeling and Comparison with Xenon K-Edge Subtraction Imaging.

Data-constrained modeling is a method that enables three-dimensional distribution of mineral phases and porosity in a sample to be modeled based on micro-computed tomography scans acquired at different X-ray energies. Here we describe an alternative method for measuring porosity, synchrotron K-edge subtraction using xenon gas as a contrast agent. Results from both methods applied to the same Darai limestone sample are compared.

Infrared attenuated total reflectance spectroscopy: an innovative strategy for analyzing mineral components in energy relevant systems.

The direct qualitative and quantitative determination of mineral components in shale rocks is a problem that has not been satisfactorily resolved to date. Infrared spectroscopy (IR) is a non-destructive method frequently used in mineral identification, yet challenging due to the similarity of spectral features resulting from quartz, clay, and feldspar minerals. This study reports on a significant improvement of this methodology by combining infrared attenuated total reflection spectroscopy (IR-ATR) with partial least squares (PLS) regression techniques for classifying and quantifying various mineral components present in a number of different shale rocks.