Investigating rock properties and fracture propagation pattern during supercritical CO₂ pre-fracturing in conglomerate reservoir

Carbon dioxide pre-fracturing has shown high application potential in improving oil recovery in conglomerate reservoirs. However, the influence of CO₂ on the physical properties of reservoir rock and its diffusion behavior within the reservoir matrix have not been systematically studied. This paper integrates CO₂-saturated water soaking experiments, true triaxial fracturing experiments and field-scale tests to demonstrate that CO₂ soaking induces quartz reduction and clay mineral increase, leading to a decrease in porosity and mechanical strength. Clay-cemented conglomerates experience a greater loss in compressive strength and a higher reduction in permeability compared to calcareous-cemented counterparts under identical CO₂ soaking. In the horizontal principal stress direction, CO₂ fracturing achieves a greater fracture penetration depth than slickwater fracturing or CO₂ pre-injection followed by slickwater fracturing. CO₂ pre-fracturing reduces breakdown pressure by 15%-5% and increases fracture complexity. Field tests confirm a reduction in injection pressure and improved effective stimulation. However, dnarrower fracture width and higher tortuosity may limit proppant transportation.Document Type: Original articleCited as: Zhou, H., Yan, T., Trivedi, J., Wang, B., Zhou, F. Investigating rock properties and fracture propagation pattern during supercritical CO₂ pre-fracturing in conglomerate reservoir. Advances in Geo-Energy Research, 2025, 17(2): 95-106. https://doi.org/10.46690/ager.2025.08.0

Overexpression of ERBB-2 was more frequently detected in malignant than benign pheochromocytomas by multiplex ligation-dependent probe amplification and immunohistochemistry

To analyze the genetic alterations of pheochromocytomas and evaluate the difference among malignant, extra-adrenal, and benign pheochromocytomas. Forty-three tumor samples were tested for genetic changes using multiplex ligation-dependent probe amplification. Among them, 39 samples were available for protein expression analysis by immunohistochemistry (IHC). All 43 patients (24 women and 19 men; mean age 44.6±13.6 years; range 18–75 years; 9 with malignant, 7 extra-adrenal, and 27 benign) showed multiple copy number losses or gains. The average copy number change was 13.10 in malignant, 13.93 in benign, and 13.47 in paraganglioma patients. There is no significant difference among the three groups of pheochromocytomas. However, we discovered that in the malignant pheochromocytomas, 6 of the 9 patients (67%) showed erythroblastic leukemia viral oncogene homolog 2 (ERBB-2) oncogene gain, whereas only 12 of the 34 (35%) identified change in the benign and extra-adrenal pheochromocytomas. Further, IHC confirmed that ERBB-2-positive staining was more frequent and stronger in malignant pheochromocytomas than in benign and extra-adrenal pheochromocytomas. Our study illustrates the chromosomal changes of the whole genome of Chinese pheochromocytoma patients. The results suggest that there may be certain progression of genetic events that involves chromosomes 1p, 3p, 6p, 11q, 12q, 17q, and 19q in the development of pheochromocytomas, and the activation of ERBB-2 located on chromosome 17q is an important and early event in the malignancy development of these tumor types. The overexpression of ERBB-2 identified by IHC suggested that this oncogene could be associated with the malignancy of pheochromocytomas and paragangliomas

Examining how internet use and non-farm employment affect rural households’ income gap? Evidence from China

The objective of this study is to assess the effect of Internet use on the income disparity between rural households and to determine how Internet usage can be used to reduce this income gap. We use the Recentered Influence Function Regression (RIF) and data from the China Family Panel Studies (CFPS) conducted by the China Social Science Survey (CSSS) center at Peking University to make the results of regression estimation more reliable. The results reveal that Internet use can make rural households’ income gap shrink considerably, and that the degree of non-farm employment among rural families has a mediating effect between Internet use and the income disparity of farm households. In addition, the Eastern region experiences a stronger mitigating effect from Internet use, whereas ethnic minorities find out no such mitigating effect. This study expands the scope of income disparity theory, provides new ideas for the construction of digital villages, and identifies new empirical evidence and decision-making grounds for improving the livelihoods of rural households and narrowing the income gap between rural households

Towards Exascale Computation for Turbomachinery Flows

A state-of-the-art large eddy simulation code has been developed to solve compressible flows in turbomachinery. The code has been engineered with a high degree of scalability, enabling it to effectively leverage the many-core architecture of the new Sunway system. A consistent performance of 115.8 DP-PFLOPs has been achieved on a high-pressure turbine cascade consisting of over 1.69 billion mesh elements and 865 billion Degree of Freedoms (DOFs). By leveraging a high-order unstructured solver and its portability to large heterogeneous parallel systems, we have progressed towards solving the grand challenge problem outlined by NASA, which involves a time-dependent simulation of a complete engine, incorporating all the aerodynamic and heat transfer components.Comment: SC23, November, 2023, Denver, CO., US

Early career ocean professionals declaration on Ocean Negative Carbon Emissions for our ocean and future

This paper highlights the urgent need to accelerate research and action on ocean carbon sinks through human intervention, known as Global Ocean Negative Carbon Emissions (Global-ONCE) Programme, as a vital strategy in global efforts to mitigate climate change. Achieving 'net zero' by 2050 cannot rely on emission reductions alone, emphasising the necessity of complementary approaches. Global-ONCE's mission extends beyond scientific exploration. It embodies a profound commitment to protecting and restoring blue carbon ecosystems, as well as implementing ocean-based solutions that are sustainable, equitable, and inclusive. Early Career Ocean Professionals (ECOPs) are at the heart of these efforts, and their innovative approaches, technical expertise, and passion make them indispensable leaders in advancing ONCE initiatives. ECOPs bridge the gap between science and society, playing a relevant role in integrating cutting-edge research, technological advancements, and community-driven action to address climate threats. By bringing together diverse perspectives and leveraging their interdisciplinary expertise, ECOPs ensure ONCE strategies are grounded in scientific rigour and practical feasibility. Through advocacy, education, and collaboration, ECOPs not only spearhead research and innovation but also inspire collective action to safeguard our oceans. This paper amplifies the critical role of ECOPs as agents of change and calls for a unified global commitment to harness the ocean's potential for a climate-resilient future

Polarization switching of sodium guide star laser for brightness enhancement

The efficiency of optical pumping that enhances the brightness of sodium laser guide star with circularly polarized light is reduced substantially due to the precession of sodium atoms in geomagnetic field. Switching the laser between left and right circular polarization at the Larmor frequency is proposed to improve the photon return. With ESO's cw laser guide star system at Paranal as example, numerical simulation for both square-wave and sine-wave polarization modulation is conducted. For the square-wave switching case, the return flux is increased when the angle between geomagnetic field and laser beam is larger than 60 degrees, as much as 40% at 90 degrees. The method can also be applied for remote measurement of magnetic field with available cw guide star laser