TY - THES

T1 - Sorption of Nanomaterials to Rock

AU - Scheurer, Christian

N1 - no embargo

PY - 2021

Y1 - 2021

N2 - Nanoparticles have gained close attention over the recent years in many industries but especially so in the oil and gas. Various researches have been investigating, for instance, the use of surface-modified silica nanoparticles in reservoir rock applications. In this work, the interaction of silica nanoparticles and sandstone rock was investigated using a combination of various experimental approaches. Among others, fluid-fluid and rock-fluid interactions were assessed by means of fluid compatibility, batch sorption experiments and single-phase core floods. The underlying task was to gain a better understanding on the factors influencing nanoparticle adsorption to the rock material. In the experimental approach, diol and polyethylenglycol (PEG) surface-modified silica nanoparticles were tested using two brines differing in ionic strength, plus sodium carbonate (Na2CO3) and Berea and Keuper outcrops (core plug and crushed form). Core flood effluents were analysed to define changes in concentration and a rock�s retention compared to a tracer. Field Flow Fractionation (FFF) and Dynamic light scattering (DLS) in selected effluent samples were performed to investigate changes in size distribution. Adsorption was evaluated using UV-visible Spectroscopy and scanning electron microscopy (SEM). Highest adsorption was observed in brine with high ionic strength whereas the use of alkali reduced the adsorption. Crushed material from Berea rock showed slightly higher adsorption compared to Keuper rock whereas temperature had a minor effect on adsorption behaviour. In single phase core-flood experiments no effects on permeability have been observed. The used nanoparticles showed a delayed breakthrough compared to the tracer and bigger particles passed the rock core faster. Nanoparticle recovery was significantly low for PEG-modified nanoparticles in Berea, suggesting high adsorption. SEM images indicate, that adsorption spots are defined via surface roughness rather than mineral type. Despite an excess of nanoparticles in the porous medium monolayer adsorption was the prevailing type observed. Investigation of nanoparticle interactions with rocks required the development and improvement of methods to evaluate concentration history and recovery. The understanding obtained is crucial for further research in this area and application in a possible field trial.

AB - Nanoparticles have gained close attention over the recent years in many industries but especially so in the oil and gas. Various researches have been investigating, for instance, the use of surface-modified silica nanoparticles in reservoir rock applications. In this work, the interaction of silica nanoparticles and sandstone rock was investigated using a combination of various experimental approaches. Among others, fluid-fluid and rock-fluid interactions were assessed by means of fluid compatibility, batch sorption experiments and single-phase core floods. The underlying task was to gain a better understanding on the factors influencing nanoparticle adsorption to the rock material. In the experimental approach, diol and polyethylenglycol (PEG) surface-modified silica nanoparticles were tested using two brines differing in ionic strength, plus sodium carbonate (Na2CO3) and Berea and Keuper outcrops (core plug and crushed form). Core flood effluents were analysed to define changes in concentration and a rock�s retention compared to a tracer. Field Flow Fractionation (FFF) and Dynamic light scattering (DLS) in selected effluent samples were performed to investigate changes in size distribution. Adsorption was evaluated using UV-visible Spectroscopy and scanning electron microscopy (SEM). Highest adsorption was observed in brine with high ionic strength whereas the use of alkali reduced the adsorption. Crushed material from Berea rock showed slightly higher adsorption compared to Keuper rock whereas temperature had a minor effect on adsorption behaviour. In single phase core-flood experiments no effects on permeability have been observed. The used nanoparticles showed a delayed breakthrough compared to the tracer and bigger particles passed the rock core faster. Nanoparticle recovery was significantly low for PEG-modified nanoparticles in Berea, suggesting high adsorption. SEM images indicate, that adsorption spots are defined via surface roughness rather than mineral type. Despite an excess of nanoparticles in the porous medium monolayer adsorption was the prevailing type observed. Investigation of nanoparticle interactions with rocks required the development and improvement of methods to evaluate concentration history and recovery. The understanding obtained is crucial for further research in this area and application in a possible field trial.

KW - Nanopartikel

KW - Adsorption

KW - Lagerstättengestein

KW - Siliziumdioxid

KW - Oberflächenmodifikation

KW - silica

KW - nanoparticles

KW - adsorption

KW - rock

KW - surface

KW - FFF

KW - DLS

KW - SEM

KW - BET

KW - EDL

KW - DLVO

M3 - Master's Thesis

ER -