Experimental and numerical investigation of sandstone deformation under cycling loading relevant for underground energy storage

Considering the storage capacity and already existing infrastructures, underground porous reservoirs are highly suitable to store green energy, for example, in the form of green gases such as hydrogen and compressed air. Depending on the energy demand and supply, the energy-rich fluids are injected and produced, which induces cyclic change of...

Impact of clay mineralogy on the petrophysical properties of tight sandstones

A full petrographic and petrophysical characterization of tight sandstones has been conducted as part of ongoing study of Carbon Dioxide Enhanced Oil and Gas Recovery (CO₂-EOR/EGR) and CO₂sequestration. The main purpose of this study is to give novel perception into the interplay of the rock characteristics and fluid...

Sandstone body character and river planform styles of the lower Eocene Willwood Formation, Bighorn Basin, Wyoming, USA

ABSTRACT The lower Eocene Willwood Formation of the Bighorn Basin, Wyoming, USA, is an alluvial succession with a sand content varying around 25 palaeoenvironments and palaeoclimates, as well as sedimentological and stratigraphic analysis. Channel dynamics were studied at a relatively low resolution throughout the basin over the geological time...

The Stress-Memory Effect of Fracture Stiffness During Cyclic Loading in Low-Permeability Sandstone

The hydraulic performance and mechanical stability of open fractures are crucial for several subsurface applications including fractured geothermal reservoirs or nuclear waste repositories. Their hydraulic and mechanical properties (fluid flow and fracture stiffness) are both strongly dependent on the fracture geometry. Any change in...

New insights into guar gum as environmentally friendly polymer for enhanced oil recovery in high-salinity and high-temperature sandstone reservoirs

Chemical enhanced oil recovery (EOR) processes are usually used as additives for hydrocarbon production due to its simplicity and relatively reasonable additional production costs. Polymer flooding uses polymer solutions to increase oil recovery by decreasing the water/oil mobility ratio by increasing the viscosity of the displacing water....

Contact angle measurement for hydrogen/brine/sandstone system using captive-bubble method relevant for underground hydrogen storage

Subsurface porous formations provide large capacities for underground hydrogen storage (UHS). Successful utilization of these porous reservoirs for UHS depends on accurate quantification of the hydrogen transport characteristics at continuum (macro) scale, specially in contact with other reservoir fluids. Relative-permeability and capillary...

Permeability Evolution During Shear Zone Initiation in Low-Porosity Rocks

Using an innovative experimental set-up (Punch-Through Shear test), we initiated a shear zone (microfault) in Flechtingen sandstone and Odenwald granite under in situ reservoir conditions while monitoring permeability and fracture dilation evolution. The shear zone, which has a cylindrical geometry, is produced by a self-designed piston...

Injection related issues of a doublet system in a sandstone aquifer: A generalized concept to understand and avoid problem sources in geothermal systems

This study proposes a concept and presents a workflow to examine potential reasons for low injectivity of sandstone aquifers. Injection related problems are a major challenge for the sustainable utilization of geothermal waters. In order to completely understand and avoid the geothermal reinjection problems, potential problem sources acting...

Origin and distribution of grain-coating and pore-filling chlorite in deltaic sandstones for reservoir quality assessment

Grain-coating chlorite preserves porosity and permeability through the inhibition of quartz cement whereas pore-filling chlorite blocks pore-throats and diminishes reservoir quality. The aim of this study is to determine the origin and principal mechanisms which govern the distribution of grain-coating and pore-filling chlorite in Jurassic...

Predicting the Dielectric Response of Saturated Sandstones Using a 2-electrode Measuring System

4-electrode setups are usually used to measure the dielectric response (complex conductivity) of sandstones, as it is known that 2-electrode systems are sensitive to unwanted electrode polarization at low frequency. Moreover, electrode polarization (EP) occurs in the frequency range where the characteristic relaxation associated to the grain...

Relationship between the size of the samples and the interpretation of the mercury intrusion results of an artificial sandstone

Mercury intrusion porosimetry (MIP) measurements are widely used to determine pore throat size distribution (PSD) curves of porous materials. The pore throat size of porous materials has been used to estimate their compressive strength and air permeability. However, the effect of sample size on the determined PSD curves is often overlooked....

The impact of reduction of doublet well spacing on the Net Present Value and the life time of fluvial Hot Sedimentary Aquifer doublets

This paper evaluates the impact of reduction of doublet well spacing, below the current West Netherlands Basin standard of 1000 to 1500 m, on the Net Present Value (NPV) and the life time of fluvial Hot Sedimentary Aquifer (HSA) doublets. First, a sensitivity analysis is used to show the possible advantage of such reduction on the NPV. The...

Original and pyrometamorphical altered Bentheimer sandstone: Petrophysical properties, surface and dielectric behavior

Bentheimer sandstone is a quartz-rich permeable hard sedimentary rock used for core flooding experiments. When fired to stabilize clays (subjected to high temperatures), pyrometamorphical phase changes induce texture and pore framework alteration. As a consequence the new dielectric response may influence wettability. The literature regarding...

Salt precipitation due to supercritical gas injection: I. Capillary-driven flow in unimodal sandstone

Drying and salt precipitation in geological formations can have serious consequences for upstream operations in terms of injectivity and productivity. Here we investigate the consequences of supercritical CO2 injection in sandstones. The reported findings are directly relevant for CO2 sequestration and acid–gas injection operations, but might...

Numerical modeling of CO2 mineralisation during storage in deep saline aquifers

Simulations are performed to evaluate the feasibility of a potential site within the Rotliegend sandstone formation in the Dutch subsurface at a depth of around 3000 m for CO2 sequestration using the numerical simulator CMG-GEM. Three CO2 storage trapping mechanisms are studied: (1) mobility trapping, (2) solubility trapping, and (3) mineral...

Size effect of concrete and sandstone

A series of uniaxial tension experiments has been conducted to investigate the size effect on strength and fracture energy of concrete and sandstone. The experiments were carried on specimens of six different sizes in a scale range of 1:32. Depending on the material and the curing conditions a stronger or weaker size effect on the nominal...

Dry and hydraulic extensile fracturing of porous impermeable materials

Extensile hydraulic fracturing of mortar is investigated and compared to extensile dry fracturing of sandstone. The extensile fracture experiments have been performed in a Hookean cell in deformation control. The cell allows for axial loading and radial fluid pressure loading of cylindrical specimens. Variables in the experiments are the load...