Search results for "Core sample"

Microtomographic Quantification of Hydraulic Clay Mineral Displacement Effects During a CO2 Sequestration Experiment with Saline Aquifer Sandstone

2013

We combined a noninvasive tomographic imaging technique with an invasive open-system core-flooding experiment and compared the results of the pre- and postflooded states of an experimental sandstone core sample from an ongoing field trial for carbon dioxide geosequestration. For the experiment, a rock core sample of 80 mL volume was taken from the 629 m Stuttgart Formation storage domain of a saline sandstone aquifer at the CCS research pilot plant Ketzin, Germany. Supercritical carbon dioxide and synthetical brine were injected under in situ reservoir p/T-conditions at an average flow rate of 0.1 mL/min for 256 h. X-ray computed microtomographic imaging was carried out before and after the…

Characterization of the Altered Zone Around a Fracture in Palmottu Natural Analogue

1996

AbstractA drill core sample penetrating at a natural fracture has been analysed by helium gas techniques and by α-autoradiography. Porosity and diffusivity profiles away from the fracture have been determined and compared with structural profiles. Model calculations are used to determine the effects of sample size on the measured porosities and diffusivities.

2016

Abstract. Various geoscientific applications require a fast prediction of fracture permeability for an optimal workflow. Hence, the objective of the current study is to introduce and validate a practical method to characterize and approximate single flow in fractures under different stress conditions by using a core-flooding apparatus, in situ X-ray computed tomography (CT) scans and a finite-volume method solving the Navier–Stokes–Brinkman equations. The permeability of the fractured sandstone sample was measured stepwise during a loading–unloading cycle (0.7 to 22.1 MPa and back) to validate the numerical results. Simultaneously, the pressurized core sample was imaged with a medical X-ray…

MORPHOLOGICAL OBSERVATIONS ONCYCLOTELLA DISTINGUENDAHUSTEDT ANDC. DELICATULAHUSTEDT FROM THE CORE SAMPLE OF A MEROMICTIC KARSTIC LAKE OF SPAIN (LAKE …

2007

Two Cyclotella species were found during the electron microscopic investigation of core samples from Lake La Cruz. Cyclotella distinguenda Hustedt was subdominant in the layers 80-110 cms and C. delicatula Hustedt was frequent and abundant in the layers 20-180 cms. SEM studies revealed an interesting variation in their valve structure elements. Analyses of the morphological characteristics of these species on the basis of SEM micrographs (55 photos were taken from C. distinguenda and 95 from C. delicatula) was made it possible to complete their description. In this paper, the similarities and differences between Cyclotella distinguenda, C. delicatula and related taxa (Cyclotella azigzensis …

Orthogonal switching of AMS axes during type-2 fold interference : Insights from integrated X-ray computed tomography, AMS and 3D petrography

2017

We applied X-ray computed microtomography (μ-CT) in combination with anisotropy of magnetic susceptibility (AMS) analysis to study metamorphic rock fabrics in an oriented drill core sample of pyrite-pyrrhotite-quartz-mica schist. The sample is extracted from the Paleoproterozoic Martimo metasedimentary belt of northern Finland. The μ-CT resolves the spatial distribution, shape and orientation of 25,920 pyrrhotite and 153 pyrite grains localized in mm-thick metapelitic laminae. Together with microstructural analysis, the μ-CT allows us to interpret the prolate symmetry of the AMS ellipsoid and its relationship to the deformation history. AMS of the sample is controlled by pyrrhotite porphyro…