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The nondestructive technology for analyzing the in-situ brine and oil distribution is of great significance for laboratory characterization of the sealed core samples. In this paper, a novel method is proposed for quantitative analysis of brine and thin oil saturation in a sealed low permeable core based on one dimensional (1D) NMR technique. Based on the difference of critical phase transition temperature of the two components, the variation of 1H proton spin relaxation signal for oil and water phase could be distinguished and therefore the oil and water saturation could be measured in the nondestructive manner. The proposed method, including the experimental and data analysis procedure was demonstrated and validated in the case on determination of oil/brine composition in a sealed low permeable sandy conglomerate sample. Through comparison of the T2 spectrum at temperature of 25 °C where both brine and oil are in liquid phase and at temperature of −15 °C where the brine freezes to solid phase, the brine and oil saturation in the low permeable core are successfully obtained. It is expected the proposed method could essentially support the laboratory analysis of the in-situ component compositions. [ABSTRACT FROM AUTHOR]

CO2 sequestration in deep saline aquifers is a promising method to reduce atmospheric CO2. The on‐going CO2CRC Otway project aims to demonstrate the effectiveness of large‐scale CO2 storage in deep saline formations and to develop new monitoring technologies in Australia. The relative permeability curves are essential for predicting the movements of CO2 and estimate residual trapping in the aquifer during and after injection through numerical simulations. However, studies of relative permeability curves for the Paaratte sandstone at the in situ conditions are limited. In addition, different rock types in the Paaratte formation can behave differently when CO2 displaces brine. This work reports four relative permeability experiments of CO2/brine systems using the unsteady‐state core flooding method for different types of rock collected from various depths of Paaratte formations at near‐reservoir conditions. The relative permeability results calculated from the analytical Johnson, Bossler, and Naumann (JBN) method and the numerical history matching method are compared. The JBN method does not calculate the relative permeability accurately for CO2/brine systems due to the assumptions of incompressible flow, since the CO2 relative permeability results calculated from the JBN method are similar for all the cases. The history matching results show that the brine (water) relative permeability of the core samples with a high fraction of macropores is similar to the measurements for Paaratte formation reported in the literature over a large range of brine (water) saturation. In contrast, the brine relative permeability of the core samples with a high fraction of micropores is considerably higher than that of the core samples with macropores, suggesting better connectivity for the samples with a high fraction of micropores. The new findings will be useful in reservoir‐scale numerical modelings of the Paaratte formation to more accurately predict the movement of CO2 during and after the injection. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The formation of stratigraphy in shallow marine environments has long been an important topic within the geologic community. Although many advances have been made in the field of forward stratigraphic modeling (FSM), there are still some areas that can be improved in the existing models. In this work, the authors present our recent development and application of Sedapp, which is a new nonlinear open-source R code for FSM. This code uses an integrated depth–distance related function as the expression of the transport coefficient to underpin the FSM with more alongshore details. In addition to conventional parameters, a negative-feedback sediment supply rate and a differentiated deposition–erosion ratio were also introduced. All parameters were implemented in a nonlinear manner. Sedapp is a 2DH tool that is also capable of running 1DH scenarios. Two simplified case studies were conducted. The results showed that Sedapp not only assists in geologic interpretation but is also an efficient tool for internal architecture predictions. [ABSTRACT FROM AUTHOR]

Low wear resistance and high sensitivity to fretting fatigue (FF) damage limit the application of titanium alloys. In order to improve its wear resistance, surface plasma Zirconium (Zr) alloying is a candidate through solution strengthening with its property of infinite solid solution with α –Ti and β –Ti. In this work, the plasma Zr metallurgy technique was used to improve the FF resistance of Ti6Al4V alloy combined with shot peening (SP), which is different from the combined treatments of the surface modification with high hardness and SP, and may explain the impacts of ductility and strength in improving FF resistance. The results indicate that the Zr metallurgy layer is composed of a Zr–Ti solid solution with low surface hardness and density, which induce the reduction of the fretting wear (FW) resistance and FF resistance of the Ti6Al4V alloy. Instead, when SP was used as the post treatment, the FW and FF behavior of the titanium alloy were increased obviously after prior plasma Zr metallurgy, especially to high cycle fatigue. This indicates that residual stress introduced by SP is beneficial for improving both FW and resistance. [ABSTRACT FROM AUTHOR]

Highlights • Dual energy CT measurements are performed. • Three phase distributions in the foam displacement process are obtained. • Obvious entrance effect is observed in CO 2 foam flooding process. • Parameter studies are performed on foam quality, comparison with N 2 foam, system back pressure and the rock permeability. • Mechanisms for the foam flow inlet behavior are investigated based on stochastic bubble population balance model. Abstract In relation with the potential applications of CO 2 foam technology on Enhanced Oil Recovery and CO 2 geological storage, the foam assisted CO 2 displacement process in a surfactant solution and oil pre-saturated porous medium is experimentally investigated with special attention on the dynamic foam propagation behavior in the entrance region of porous media. Computational Tomography (CT) imaging is employed to visualize the transient CO 2 foam sweep process and the dual-energy CT measurement is performed to obtain the dynamic three phase saturation distributions along the sample core. Studying parameters include the comparison with N 2 foam, system backpressure and the porous medium permeability. It is found foam could push most of the liquid phase in the latter part of the porous media but leaves the forepart of the sample less flooded, showing a clear entrance effect of foam flooding process. Compared to CO 2 foam, N 2 foam displacement process shows higher liquid phase saturation in the entrance section and presents less oil recovery rate. Elevating system backpressure to 1.0 MPa leads to less pressure drop for CO 2 foam flooding process without compromising the oil phase sweep efficiency. The CO 2 foam flooding process in lower permeable medium shows higher pressure drop and higher oil recovery rate. The mechanisms for the inlet behavior of the foam displacement processes have been scrutinized based on good qualitative and quantitative agreement of the experimental and numerical results with the stochastic bubble population balance model. [ABSTRACT FROM AUTHOR]