Coevolutionary Diagenesis in Tight Sandstone and Shale Reservoirs within Lacustrine-Delta Systems: A Case Study from the Lianggaoshan Formation in the Eastern Sichuan Basin, Southwest China

Tight sandstone and shale oil and gas are the key targets of unconventional oil and gas exploration in the lake-delta sedimentary systems of China. Understanding the coevolutionary diagenesis of sandstone and shale reservoirs is crucial for the prediction of reservoir quality, ahead of drilling, in such systems. Thin-section description, scanning electron microscopy (SEM), X-ray diffraction (XRD), fluid inclusion analysis, porosity and permeability tests, high-pressure mercury intrusion (HPMI) measurements and nuclear magnetic resonance tests (NMR) were used to reveal the coevolutionary diagenetic mechanisms of a sandstone and shale reservoir in the Lianggaoshan Formation of the Eastern Sichuan Basin, China. The thermally mature, organic-matter-rich, dark shale of layer3 is the most important source rock within the Lianggaoshan Formation. It started to generate abundant organic acids at the early stage of mesodiagenesis and produced abundant hydrocarbons in the early Cretaceous. Porewater with high concentrations of Ca2+ and CO32− entered the sandstone reservoir from dark shale as the shale was compacted during burial. Potassium feldspar dissolution at the boundary of the sandstone was more pervasive than at the center of the sandstone. The K+ released by potassium feldspar dissolution migrated from the sandstone into mudstone. Grain-rimming chlorite coats occurred mainly in the center of the sandstone. Some silica exported from the shale was imported by the sandstone boundary and precipitated close to the shale/sandstone boundary. Some intergranular dissolution pores and intercrystal pores were formed in the shale due to dissolution during the early stages of mesodiagenesis. Chlorite coats, which precipitated during eodiagenesis, were beneficial to the protection of primary pore space in the sandstone. Calcite cement, which preferentially precipitated at the boundary of sandstone, was not conducive to reservoir development. Dissolution mainly occurred at the early stage of mesodiagenesis due to organic acids derived from the dark shale. Calcite cement could also protect some primary pores from compaction and release pore space following dissolution. The porosity of sandstone and shale was mainly controlled by the thickness of sandstone and dark shale

Research on the Role of Design Aesthetics in Modern Designxs

The essence of design is "to create things according to the laws of beauty". The factor of beauty is one of the most important criteria to evaluate the quality of design, and consumers will recognize those products with perfect combination of technology and form. With the expansion of the consumer society and the spread of the aesthetics of everyday life, the social status of design is increasingly prominent. Whether or not the design can be accepted or recognized by consumers in the end, aesthetics is one of the most important factors

Sulfur Isotopic Analysis and Sulfur Source Study of Phosphorite-associated Sulfate from the Ediacaran Doushantuo Formation in Guizhou Province

BACKGROUND： Phosphate deposit of the Ediacaran Doushantuo Formation in Guizhou province is a typical representative of the global phosphorite formation event in the late Neoproterozoic, which is closely related to climate change and evolution of life. However, the current research on the deposition of phosphorus deposits is limited to the mechanism of phosphorus formation and the source of phosphorus, and research on the phosphorus formation process of this deposit and its correlation with the paleo-ocean environment of the same period by isotopic geochemical indicators is relatively weak. OBJECTIVES： In order to determine the sulfur source of phosphorite-associated sulfate. METHODS: Based on the field section observation and the study of petrological characteristics under the microscope, elemental analyzer-isotope ratio mass spectrometry (EA-IRMS) was used to measure the sulfur isotopic composition of phosphorite-associated sulfate from the Ediacaran Doushantuo Formation. RESULTS: The sulfur isotopic composition of phosphorite-associated sulfate ranged from 32.7‰ to 36.9‰ (n=32, mean=34.1‰), which was 11‰ lower than that of the seawater of the same period, indicating that the phosphorite-associated sulfate was not all from the surface seawater. CONCLUSIONS: The idealized early ocean (>520Ma) chemical zoning model indicates that there is a relatively 34S-depleted H2S zone in the seawater at the same time. Combined with the understanding that the source of phosphorus in the phosphorite is closely related to the upwelling, it can be considered that the sulfur isotopic composition of phosphorite-associated sulfate of the Doushantuo Formation represents the mixed signal of surface seawater and upwelling

Sex-Specific Differences in the Toxic Effects of Heavy Fuel Oil on Sea Urchin (Strongylocentrotus intermedius)

The purpose of this study was to explore and compare the sex-specific differences in the toxic effects of water-accommodated fractions of 380# heavy fuel oil (HFO WAF) on the sea urchin Strongylocentrotus intermedius. Sea urchins were acutely exposed to HFO WAF at different nominal concentrations (0%, 10% and 20%) for seven days. The results showed that females had a higher polycyclic aromatic hydrocarbons (PAHs) bioaccumulation in gonad tissues and that both the total antioxidant capacity (TAC) and lipid peroxidation (LPO) levels in the gonad tissues of females were much higher than those of males. The PAHs bioaccumulation in gametes indicated that parents’ exposure could lead to a transfer of PAHs to their offspring, and eggs had higher TAC and LPO than sperms. After maternal and paternal exposure to HFO WAF, the frequency of morphological abnormalities of the offspring was increased when compared to the control. Overall, these results indicated that maternal exposure to HFO WAF could cause more significantly toxic effects on sea urchins than paternal exposure could, which could lead to more significantly negative effects on their offspring

Generation and Identification of the Number of Copies of Exogenous Genes and the T-DNA Insertion Site in SCN-Resistance Transformation Event ZHs1-2

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) causes an estimated economic loss of about USD 3 billion each year in soybean (Glycine max L.) production worldwide. Overexpression of resistance genes against SCN provides a powerful approach to develop SCN resistance cultivars in soybean. The clarification of molecular characterization in transformation events is a prerequisite for ecological risk assessment, food safety, and commercial release of genetically modified crops. Here, we generated transgenic events harboring the BCN (beet cyst nematode) resistance Hs1pro−1 gene using the Agrobacterium-mediated method in soybean, evaluated their resistance to SCN infection, and clarified the molecular characterization of one of the transformation events. Five independent and stable inheritable transformation events were generated by an Agrobacterium-mediated transformation method. SCN resistance tests showed the average number of developed females per plant and female index (FI) in T4 ZHs1-1, ZHs1-2, ZHs1-3, ZHs1-4, and ZHs1-5 transformation events were significantly lower than that in the nontransgenic control. Among these, the ZHs1-2 transformation event had the lowest number of developed females per plant and FI. Southern hybridization showed the exogenous target Hs1pro−1 gene was inserted in one copy and the Bar gene was inserted two copies in the ZHs1-2 transformation event. The exogenous T-DNA fragment was integrated in the reverse position of Chr02: 5351566–5231578 (mainly the Bar gene expression cassette) and in the forward position of Chr03: 17083358–17083400 (intact T-DNA, including Hs1pro−1 and Bar gene expression cassette) using a whole genome sequencing method (WGS). The results of WGS method and Southern hybridization were consistent. All the functional elements of exogenous T-DNA fragments were verified by PCR using specific primer pairs in the T5 and T6 ZHs1-2 transformation events. These results demonstrated that the overexpression of Hs1pro−1 gene enhanced SCN resistance, and provide an important reference for the biosafety assessment and the labeling detection in transformation event ZHs1-2