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This study investigates the characteristics of the heterogeneous carbonate reservoir of Majiagou Formation in Jingxi area, Ordos Basin, China, to explain the diagenetic control and distribution of high‐quality reservoir intervals. The carbonates of the study area mainly consist of silt‐sized crystalline dolomite, microcrystalline dolomite, and microcrystalline limey dolomite. Both dolomite content and dolomite size gradually decrease both from top to bottom and from slope to basin. Intercrystalline pores exist in the silt‐sized crystalline dolomite, and vuggy pores and fractures mainly developed in microcrystalline (limey) dolomite. Furthermore, typical geopetal infills and three stages of calcite cements could be differentiated. Based on petrographical and geochemical analysis, the reservoir is dominantly controlled by seepage reflux dolomitization and telogenetic karstification. Four reservoir evolutions could be differentiated. The reservoir in the first model is dominated by intercrystal porosity occurring in silt‐sized crystalline dolostone. It experienced strong dolomitization, telogenetic karstification, and shallow as well as deep burial cementation. The reservoir in the second model consists of only a small amount of high‐angle dissolution fissures and vertical dissolution cavities in microcrystalline (limey) dolostone. It experienced relatively weak dolomitization, strong telogenetic karstification, and two important calcite cementation events. The reservoir in the third model is marked by many vuggy pores and dissolution fractures, occurring in microcrystalline (limey) dolostone. The strata experienced relatively weak dolomitization, strong telogenetic karstification, and two weak calcite cementation episodes. The reservoir in the fourth model is dominated by fractures and their related dissolution pores, which developed in microcrystalline (limey) dolostone. These dolostones experienced relatively weak dolomitization, telogenetic karstification, and calcite cementation. From a reservoir point of view, the reservoirs represented by the first and third models, which respectively are composed of silt‐sized crystalline dolomite occurring in the top of the whole dolostone succession and the dolomite affected by telogenetic karstification, are the most vital exploration targets. [ABSTRACT FROM AUTHOR]

The meteoric diagenetic environment has multiphase characteristic, but the scales of the reservoirs in different meteoric diagenetic environments have been rarely considered. On the basis of geological and well-logging analyses, three distinct phases of the meteoric diagenetic process were observed in the Ordovician of the Jingxi area in Ordos Basin, China. The phreatic zone formed in the first phase is partially preserved, whereas those formed in the second and third phases are completely retained. Strata in the western (close to the Central Uplift Belt) and eastern parts underwent bedding-parallel meteoric dissolution and cross-layer meteoric dissolution, respectively. The distributions of the dissolution formation thicknesses in two successive phases of the meteoric diagenetic process exhibit complementarity at the same positions in the plane. The favorable reservoirs at the top of the Ordovician are mainly distributed in the western parts. The second phase of the meteoric diagenetic process is most conducive to the formation of carbonate reservoirs. By dividing and comparing the multiphases of the meteoric diagenetic environment of carbonates, the favorable karst reservoirs can be predicted in each phase. [ABSTRACT FROM AUTHOR]

We clarified three stages of dolomitization and secondary changes by studying the petrology and geochemistry characteristics of dolomite from the Ma55-Ma510 sub-members of the Ordovician Majiagou Formation in the Jingxi area in the Ordos Basin: (1) Syngenetic microbial dolomitization is characterized by formation of dolomite with a mainly micrite structure and horse tooth-shape dolomite cements. (2) Seepage reflux dolomitization during the penecontemporaneous period superposed adjustment functions such as recrystallization and stabilization in the middle-deep burial stage, forming dolomites mainly consisting of micro crystal and powder crystal structure. (3) Powder dolomite, fine dolomite, and medium-coarse crystalline dolomite formed in pores and fractures in the middle-deep burial stage. The secondary concussive transgression-regression under a regressive background is an important condition for the occurrence of many stages of dolomitization in the study area. The basin was an occlusive epicontinental sea environment in the Ma5 member of the Ordovician Majiagou Formation sedimentary period. In the sediments, sulfate content was high, which is conducive to the preservation of microbial activity and microbial dolomitization. Micritic dolomite formed by microbial dolomitization provides good migration pathways for seepage reflux dolomitization. Affected by evaporation seawater with increased Mg/Ca ratio, seepage reflux dolomitization was widely developed and formed large-scale dolomite, and underwater uplifts and slopes are favorable areas for dolomite. In the middle-deep burial stage, dolomitizing fluid in the stratum recrystallized or stabilized the previous dolomite and formed a small amount of euhedral dolomite in the pores and fractures. [ABSTRACT FROM AUTHOR]

Pore structure is the key factor to control the quality and fluid flow of ultra-tight reservoir. The relationship between rock types, pore types, and pore sizes of ultra-tight sandstone reservoirs was identified by observing microscopic characteristics under a polarizing microscope and scanning electron microscope (SEM) and quantitively assessed using high-pressure mercury intrusion (HPMI) and fractal theory. By a comparative analysis of lithic sandstone and feldspar lithic sandstone reservoirs of Upper Triassic Xujiahe Formation of the Northern Sichuan Basin, we found that the pore type of the ultra-tight sandstone reservoir was linked to the rock type. Argillaceous lithic sandstone minly generates fracture pores, while fine-grained lithic sandstone and feldspar lithic sandstone formed dissolved pores by dissolution of carbonate cement, rock debris, and feldspar particles. Meanwhile, clay minerals such as kaolinite and chlorite in the reservoir possess pores between clay platelets and intraplatelet pores within clay aggregates, which are important pore types for ultra–tight sandstone reservoirs. A method to divided intervals of pore size distribution was proposed using high-pressure mercury intrusion (HPMI), and three intervals of pore diameter distribution were observed: 10–40 nm, 40 nm–1 μm, and 1–100 μm, which is largely controlled by pore type. The reservoir with only fracture pores is a one–interval reservoir with pore diameter in the range of 1–100 μm, while the reservoirs with dissolved pores and clay mineral-related pores have the above three intervals. Meanwhile, the fractal of pores in different scale range is different, and the larger the pore size, the stronger is the reservoir heterogeneity. A treelike pore structure model can be utilized to define pore development features in ultra–tight sandstone reservoirs. Micron–scale pores with diameters of 1–100 μm is mostly made up of fractures, cement and particle dissolution pores. However, nano–scale pores in the range of 40 nm–1 μm and 10–40 nm are predominantly pores formed between clay platelets and intraplatelet pores within clay aggregates, respectively. • Rock type, pore type, and pore size of ultra-tight sandstone reservoirs have a close relationship. • Pores between clay platelets and pores within clay aggregates are essential pore types in ultra-tight sandstones. • Three intervals of pore distribution were divided using high-pressure mercury intrusion (HPMI). • The heterogeneity of pores in ultra-tight reservoirs is mostly dictated by pore size and fractures. [ABSTRACT FROM AUTHOR]

The current study presents the development process and initial validation of a measure designed for assessing psychological needs satisfaction in a secondary school physical education context (Psychological Needs Satisfaction Scale in Physical Education, PNSSPE). Junior secondary school (grades 7 to 9) students (N = 1,258) were invited to participate in three studies. In Study 1, item generation (34 items) and initial content validity of the PNSSPE were achieved. In Study 2, the factorial structure of the PNSSPE was tested using exploratory and confirmatory factor analyses. Internal consistency reliabilities of the subscales were also examined. In Study 3, the reliability and validity of the scores derived from the PNSSPE were further examined in an independent sample. Overall, the PNSSPE demonstrated good content, factorial, discriminant, and nomological validities. It also demonstrated acceptable internal consistency and test–retest reliability. The measurement model was proven invariant across gender and samples. Psychometric evidence from a series of studies suggests that the PNSSPE could be used as a reliable and valid measure to assess Hong Kong secondary school students’ satisfaction of psychological needs in physical education. [ABSTRACT FROM AUTHOR]

The distribution, origin, and evolution of overpressure in the petroliferous basin are important problems that need to be addressed for oil and gas exploration. The distribution and origin of overpressure in the Shahejie Formation in the northern Dongpu Depression are analyzed based on geological studies, logs, and pressure data. The contribution ratios of different overpressure origins are quantified, and the evolutionary stages of overpressures of different origins are further divided. The results show that the formation pressure coefficients of Shahejie Formation in the Dongpu Depression are mainly within the range of 0.9–1.5. The overpressures are mainly distributed in the Sha-3 and Sha-4 Members of the Haitongji sag, the Central uplift belt and the Qianliyuan sag. From the sag to its surrounding area, the formation pressure coefficient gradually decreases. The high deposition rate and strong hydrocarbon generation are the main causes of overpressure formation in the Shahejie Formation in the Dongpu Depression. Based on the stress–strain characteristics of different origin overpressures and the log response parameters, two models, acoustic travel time-effective vertical stress and electrical resistivity-effective vertical stress, are established to identify and quantify the different origin overpressures. The calculation results for the area from the Haitongji sag and Qianliyuan sag to the Central uplift belt show that the main cause of overpressure gradually changes from both disequilibrium compaction and hydrocarbon generation to disequilibrium compaction as the main factor, with the contribution of disequilibrium compaction to overpressure in the Central uplift belt at about 87%. The Sha-3 Members of the Shahejie Formation in the Haitongji sag and the Qianliyuan sag are more strongly affected by hydrocarbon generation, which accounts for 42% and 47.5% of overpressure origin, respectively. There are five stages in the evolution of overpressure in the Shahejie Formation in the northern Dongpu Depression: normal compaction (before 35 Ma), mixed pressurization (35-27 Ma), uplift and pressure release (27-17 Ma), disequilibrium compaction (17-11 Ma), and secondary mixed pressurization (12 Ma-present). • Overpressure mainly distributes in the Sha-3 and Sha-4 Members of the Dongpu Depression. • Disequilibrium compaction and hydrocarbon generation are main overpressure origins. • Two models to identify and quantify different origins' overpressure were came up. • Overpressure origin changes in different tectonic units and evolution stages. [ABSTRACT FROM AUTHOR]

The Dongpu Depression, containing huge amounts of hydrocarbons, is a typical petroliferous province in the Bohai Bay Basin, east China. As one set of the main source rocks, the first member of Shahejie Formation (E2s1) shows huge exploration potential with approximately 0.83 × 108 t resources remaining to be discovered. However, the geochemical characteristics and thermal evolution history of E2s1 source rocks have still not been determined. In this study, the sedimentary features were firstly analysed based on the geological data. Then the organic matter abundance, kerogen type, and thermal maturity of E2s1 source rocks in the present day were evaluated according to the Rock‐Eval pyrolysis, micro‐components of kerogen, total organic carbon (TOC), and vitrinite reflectance analysis. Furthermore, the evolution of thermal history and hydrocarbon generation was determined using the PetroMod procedure. The results show that dark mudstones and salt rocks were well developed in E2s1, which are propitious for organic matter to grow and preserve. E2s1 source rocks contain abundant organic matter and moderate to good generative source rock potential. E2s1 source rocks mainly consist of Type II kerogen and have entered early to maturation stage for hydrocarbon generation. Due to the limited buried depth, E2s1 source rocks only attained lower thermal maturity and generated finite hydrocarbons. The initial rapid subsidence and the second rift after uplift erosion resulted in the higher geo‐temperature at the end of E3d and the present day. Corresponding to the geo‐temperature evolution, there are two stages of hydrocarbon generation for E2s1 source rocks: The first stage was in the late E3d period, and the late stage was from the late Neogene to the present day. Moreover, the hydrocarbon generation rate and quantity of the late stage are much higher than the first stage, indicating the major hydrocarbon generation stage. Due to the limited hydrocarbon generation capacity, oils generated from E2s1 source rocks are low maturity; thus, it cannot migrate for a long distance and only accumulated around the sag belts. [ABSTRACT FROM AUTHOR]

The southwest vortex (SWV) is a critical weather system in China, but our knowledge of this system remains incomplete. Here, we investigate the cloud properties in the SWV. First, we search for the SWVs with time steps and center locations that are consistent between the SWV yearbook and ERA-Interim reanalysis data. Second, we supplement these SWVs' life spans and movement paths. Third, we relocate the Fengyun (FY) satellite FY-4A cloud retrievals in the 10° × 10° region centered on each SWV and analyze the cloud occurrence frequency (COF), cloud-top height (CTH), and cloud optical thickness (COT). A distribution mode of cloud types is summarized from the COFs, with water clouds, supercooled clouds, mixed clouds, ice clouds, cirrus clouds, and overlap clouds occurring sequentially from west to east. The CTH probability density (PD) distribution features a significant north–south difference. In addition, the COT PD distributions exhibit a common trend: with increasing COT, the PD increases rapidly and then slowly before peaking, whereupon the PD decreases abruptly. From spring to summer, the region with the highest convective COF shifts from the northeast to the northwest, and an east–west gradient of the convective COF appears in autumn and winter. Furthermore, we investigate the cloud properties during SWV-related heavy rainfall. Heavy rain occurs mainly in the west of the SWV, and convective clouds are mainly in the northwest, partly in the southwest and near the SWV center. The average CTH in heavy rainfall is generally higher than 6 km, and the average COT is greater than 20. Significance Statement: The southwest vortex (SWV) is an important weather system in China. However, we do not yet comprehensively know this weather system. The cloud properties can indicate the structures of weather systems and are key parameters in numerical weather prediction (NWP) models. Thus, investigating cloud properties is necessary and meaningful to understand the SWV and accurately predict SWV-related precipitation in NWP models. In this paper, a typical distribution mode of six cloud types in the SWV is summarized from the cloud occurrence frequency, and the distribution features of convective clouds, cloud-top height, and cloud optical thickness in the SWV are analyzed. Furthermore, the cloud properties in SWV-related heavy rain are also studied. [ABSTRACT FROM AUTHOR]

Chlorite is beneficial to the preservation of primary pores, and its formation mechanism in marine sandstone has been widely reported. However, few studies have focused on the genetic mechanism of various types of chlorite in lacustrine deltaic sandstone. Therefore, the occurrence, diagenetic time and origin of chlorite in Xujiahe tight sandstone were investigated using microscopic images and mineralogical chemical analysis, and three stages of chlorite were identified, namely, grain-coating (Ch1), pore-lining (Ch2), and pore-filling (Ch3) chlorite, which belong to the Fe chlorite, Al chlorite and transitional types, respectively. The variations in morphology and chemical composition reflect differences in the sources and formation mechanisms. Chlorite sandstones are mainly distributed in the underwater distributary channel, which has strong hydrodynamic conditions. The formation of Ch1 is controlled by the sedimentary environment and flocculation. Salinity differences resulted in a larger amount of flocculation deposits in the estuaries during the syngenetic period. In the shallow burial stage, the clay coating underwent in situ transformation under thermal impacts and formed the Ch1. Xujiahe sandstones experienced complex diagenetic processes, which include early compaction, three stages of chlorite cementation, two stages of quartz precipitation, dissolution and two stages of carbonate cementation. Organic acid dissolution of volcanic rock fragments, phyllite, and biotite likely supplied sufficient Fe2+ for the growth of Ch2 in a relatively closed diagenetic system. As the pore water became weakly alkaline, diagenetic fluid migration originating from the clay mineral transformation in mudstone mainly provided Fe2+ and Mg2+ for Ch3 growth in sandstones. Chlorite is considered to have "composite" impacts on deep tight sandstones, with grain-coating and pore-lining chlorites protecting the primary pores by restricting the silica supply and occupying potential quartz nucleation sites; however, grain-coating chlorite caused throat obstruction or even closure under strong mechanical compaction, which reduced the permeability of the reservoir. • Three different types of chlorite have been found in the Xujiahe tight sandstones. • It has been clear that the formation time of chlorite and the paragenetic sequence of authigenic minerals. • The origin and formation mechanism of authigenic chlorite in three types have been investigated. • We considerd that authigenic chlorite has a "composite" impact on deep tight sandstone: preserve primary porosity but reduce the permeability. [ABSTRACT FROM AUTHOR]

Aims/Introduction: Although the efficacy of teneligliptin, a highly selective dipeptidyl peptidase‐4 inhibitor, has been amply studied for the treatment of type 2 diabetes, no clinical trials of teneligliptin have been carried out in China. We evaluated the efficacy and safety of teneligliptin monotherapy compared with a placebo in Chinese patients with type 2 diabetes mellitus inadequately controlled with diet and exercise. Materials and Methods: This multicenter, randomized, double‐blind, placebo‐controlled, parallel‐group study, carried out at 42 sites, enrolled type 2 diabetes patients with glycosylated hemoglobin 7.0 to <10.0% and fasting blood glucose <270 mg/dL. Patients were randomly assigned, in a 1:1 ratio, to treatment with 20 mg teneligliptin or a placebo (n = 127, each) administered orally once daily before breakfast for 24 weeks. Change in glycosylated hemoglobin from baseline to week 24 was the primary efficacy end‐point. Safety was assessed by the incidence of adverse events and adverse drug reactions. Results: The least square mean (LSM) change in glycosylated hemoglobin from baseline to week 24 was −0.95% with teneligliptin versus −0.14% with a placebo, yielding an LSM difference (teneligliptin vs placebo) of −0.80% (P < 0.0001). For the secondary end‐point, from baseline to week 24, the LSM change in fasting blood glucose was −21.9 mg/dL with teneligliptin versus −1.4 mg/dL with a placebo, yielding an LSM difference (teneligliptin vs placebo) of −20.5 mg/dL (P < 0.0001). The adverse event and adverse drug reaction incidence rates, including hypoglycemia, were similar in both groups. Conclusions: At 24 weeks, teneligliptin was generally well tolerated and effective in Chinese patients with type 2 diabetes mellitus inadequately controlled with diet and exercise. [ABSTRACT FROM AUTHOR]

The physical properties, group compositions, carbon isotopes and biomarkers of the Upper Paleozoic crude oil in the Shiguhao area in northern Ordos Basin were investigated to study geochemical characteristics and source of the crude oil. The Upper Paleozoic crude oil in the Shiguhao area belongs to the medium oil with high viscosity, high wax content, low sulfur content and low freezing point, and it displays the group composition of high saturated hydrocarbons/aromatics. The carbon isotopic compositions and biomarkers of crude oil indicated that the Upper Paleozoic crude oil was coal-derived oil and at the mature stage. The physical properties, carbon isotopes and GC-MS parameters of saturated hydrocarbons indicated that, the crude oil displayed a good affinity with the Upper Paleozoic coal rocks in the Shanxi Formation. Therefore, the Upper Paleozoic coal rocks in the Shanxi Formation were the important source of the Upper Paleozoic crude oil, and this provided valuable direction for the petroleum exploration in northern Ordos Basin. [ABSTRACT FROM AUTHOR]