Influence of Sandstone Mineralogy on the Adsorption of Polar Crude Oil Components and Its Effect on Wettability

The crude oil–brine–rock (COBR) system is a combination of contacting phases where polar organic molecules in crude oil, inorganic ions from the brine phase, and charged mineral surfaces participate in complex interactions. One of the surface phenomena that occur in the COBR system is the adsorption of polar crude oil components, which can directly affect the capillary forces and wettability of the rock. The purpose of this research work was to determine polar organic component (POC) adsorption trends for sandstones of different origins and mineralogical compositions. Adsorption preferences for acidic and basic POCs were quantified by potentiometric titration during dynamic core flooding tests using modified crude oil. The influence of POC adsorption on wettability was investigated by evaluating capillary forces during the displacement of oil in a spontaneous imbibition (SI) process. The results of this work showed a clear relationship between the intensity of POC adsorption and sandstone mineralogy. Greater adsorption capacity and a predominant affinity for bases compared to that for acids were found in the sandstone material containing a sufficient amount of reactive illite clay minerals. On the other hand, the sandstone material consisting mainly of quartz with an insignificant content of kaolinite clay did not show a pronounced tendency to adsorb POCs. All the studied rock materials have also shown a significant impact of POC adsorption on capillary forces and wettability, confirmed during SI tests. As a result, a detailed mineralogical analysis along with crude oil chemistry is required to properly evaluate sandstone wettability and competently plan core flooding laboratory studies.publishedVersio

Experimental investigation of rotation resistance moment energy spectra in multicylindrical circular Couette system with independently rotating cylinders

The torque of the rotational resistance in the Ku-Etta multi-cylinder system rotating in the direction towards each other is measured. The experiments were carried out for three values of the kinematic viscosity of the working fluid that fills the multicylinder system: water at a temperature of 24 °C (viscosity 0.9 cSt), an aqueous solution of glycerol at 20 °C and 41 °C (2.5 cSt and 5.2 cSt). An attempt is made to investigate the features of a viscous flow in the multicolor Couette flow system from the analysis of the energy spectra of the moment of resistance to rotation of cylinders

Mechanism of primary and secondary oil flooding for recovery from sandstone by low salinity water

Master's thesis in Petroleum engineeringLow salinity water flooding (LSW) as an enhanced oil recovery (EOR) method has been discussed by many researchers, but consistent approved mechanism is still not found. The main reason of lack of clear understanding of the process is complexity of the oil/brine/rock interactions. Therefore, theme of this project was chosen to study the mechanism(s) behind the low salinity EOR by flooding different brines through the sandstone cores and analyzing obtained data. This thesis contains a literature review, experimental and discussion parts. Experiments were made for two different sandstone types (Bentheimer and Berea) and two different core lengths. LSW effects were studied as a primary injection fluid and secondary injection fluid - EOR (after flooding with synthetic sea water – SSW). Oil recovery and pressure drop across the core were detected and for effluent water samples were measured pH, ions concentration and amount of silicon/aluminum. This work was made with the intention of improving the understanding of processes during flooding with low salinity brine. The idea was to study different sandstone types and define relationship between core length and amount of brine/rock interactions. Results showed that the main reason for improved oil recovery by using LSW brines can be the wettability changing of the rock surface. Possible underlying reason for this process is sandstone minerals dissolution, which was confirmed by increased amount of K+ in effluent water samples. pH of effluent water samples showed stably higher values than pH of influent LSW, which can be the consequence of minerals dissolution. Possible double layer expansion together with dissolution process could enhance particle detachment and increased pressure drop across the cores. Based on obtained results, Berea sandstone has higher potential for LSW effects due to higher amount of brine/rock interactions and respectively higher oil recovery. Higher amount of K and Si was found in effluent samples for Berea type in compare with Bentheimer. Oil recovery measurements for long cores also showed higher values than for short cores, which tell us about the dependency of the results on the core length

Suspended nanofluid droplet evaporation

The experimental research of suspended droplet evaporation process in air flow was conducted for distilled water (DW) with different silicon oxide (SiO2) nanoparticle concentration. The data obtained allowed comparing droplet volume and temperature alteration dynamics with that in pure DW at different temperatures and flow rates

Suspended nanofluid droplet evaporation

The experimental research of suspended droplet evaporation process in air flow was conducted for distilled water (DW) with different silicon oxide (SiO2) nanoparticle concentration. The data obtained allowed comparing droplet volume and temperature alteration dynamics with that in pure DW at different temperatures and flow rates

Adsorption of Crude Oil Components onto Carbonate and Sandstone Outcrop Rocks and Its Effect on Wettability

The processes of establishing and altering reservoir wettability are still subjects of discussion due to the complexity of the underlying crude oil–brine–rock interactions. This study was aimed at investigating the interrelationship between acidic and basic crude oil components and wetting tendencies on core samples of various mineralogies. Core flooding tests with light crude oils were performed to determine whether acidic or basic polar organic components (POC) showed the highest surface reactivity, adsorbing more readily onto the rock surfaces. The influence of this adsorption on wettability and capillary forces was then identified by performing spontaneous imbibition tests. The core materials used were a rather pure Stevns Klint outcrop chalk, a silica-containing Aalborg outcrop chalk, and an outcrop sandstone with silica minerals of quartz, clays, and feldspars. The results of this work showed a correlation between core mineralogy and the type of predominantly adsorbing POC. Pure chalk showed preference for organic acid adsorption over base adsorption, while the sandstone showed opposite preference. Because of the presence of negatively charged silica minerals, the silica-containing chalk showed increased affinity toward basic components and reduced affinity toward the acids compared to that observed for pure chalk. Oil recovery tests by spontaneous imbibition showed that for all cores, the adsorption of oil components significantly reduced water wetness. Thus, the types of minerals that make up the rock surface have a profound influence on the adsorption of POC and on the generation of wettability, and this should be kept in mind when using crude oil to restore core material wettability in the laboratory.publishedVersio

Experimental investigation of rotation resistance moment energy spectra in multicylindrical circular Couette system with independently rotating cylinders

The torque of the rotational resistance in the Ku-Etta multi-cylinder system rotating in the direction towards each other is measured. The experiments were carried out for three values of the kinematic viscosity of the working fluid that fills the multicylinder system: water at a temperature of 24 °C (viscosity 0.9 cSt), an aqueous solution of glycerol at 20 °C and 41 °C (2.5 cSt and 5.2 cSt). An attempt is made to investigate the features of a viscous flow in the multicolor Couette flow system from the analysis of the energy spectra of the moment of resistance to rotation of cylinders

Investigation of a new application for cellulose nanocrystals: a study of the enhanced oil recovery potential by use of a green additive

Cellulose nanocrystals (CNC) were investigated for use in a potential new application, enhanced oil recovery. Core flooding experiments were performed on outcrop sandstone cores using CNC particles dispersed in low salinity brine (CNC–LS). Core flooding experiments performed on fully water-saturated cores confirm that a majority of viscosity-generating CNC particles successfully traverse the cores at temperature conditions ranging from 60 to 120 °C. Oil recovery tests performed on crude oil saturated sandstone cores at 60 and 90 °C show that when CNC–LS is applied in tertiary mode, ultimate oil recovery increases. During tertiary CNC–LS injection, CNC particles exacerbate differential pressure fluctuations, a phenomenon attributable to log jamming in pore throats, causing remobilisation of oil trapped within pore space regions. Results from the current work indicate that CNC particles dispersed in low saline brine remain promising for implementation in enhanced oil recovery operations.acceptedVersio

Experimental investigation of rotation resistance moment energy spectra in multicylindrical circular Couette system with independently rotating cylinders

The torque of the rotational resistance in the Ku-Etta multi-cylinder system rotating in the direction towards each other is measured. The experiments were carried out for three values of the kinematic viscosity of the working fluid that fills the multicylinder system: water at a temperature of 24 °C (viscosity 0.9 cSt), an aqueous solution of glycerol at 20 °C and 41 °C (2.5 cSt and 5.2 cSt). An attempt is made to investigate the features of a viscous flow in the multicolor Couette flow system from the analysis of the energy spectra of the moment of resistance to rotation of cylinders