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Evolution features of in-situ permeability of low-maturity shale with the increasing temperature,Cretaceous Nenjiang Formation,northern Songliao Basin,NE China

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Petroleum Exploration and Development 2022年第3期49卷 516-529页

作者： HE Wenyuan MENG Qi'an LIN Tiefeng WANG Rui LIU Xin MA Shengming LI Xin YANG Fan SUN Guoxin Daqing Oilfield Co.Ltd. PetroChinaDaqing 163712China Exploration and Development research Institute of Daqing Oilfield Co.Ltd. Daqing 163712China Heilongjiang Provincial Key Laboratory of Shale Oil&Tight Oil Accumulation Daqing 163712China

Temperature-triaxial pressure permeability testing at the axial pressure of 8 MPa and confining pressure of 10 MPa,closed shale system pyrolysis experiment by electrical heating and scanning electron microscopy analysis are used to study the evolution mechanism of in-situ permeability in the direction parallel to bedding of low-maturity shale from Member 2(K_(2)n_(2))of Cretaceous Nenjiang Formation in northern Songliao Basin with mainly Type I kerogen under the effect of *** the increasing temperature,the in-situ permeability presents a peak-valley-peak *** lowest value of in-situ permeability occurs at 375℃.Under the same temperature,the in-situ permeability decreases with the increase of pore *** in-situ permeability evolution of low-maturity shale can be divided into 5 stages:(1)From 25℃to 300℃,thermal cracking and dehydration of clay minerals improve the ***,the value of permeability is less than 0.01×10^(-3)μm^(2).(2)From 300℃to 350℃,organic matter pyrolysis and hydrocarbon expulsion result in mineral intergranular pores and micron pore-fractures,these pores and fractures form an interconnected pore network at limited scale,improving the *** the liquid hydrocarbon,with high content of viscous asphaltene,is more difficult to move under stress and more likely to retain in pores,causing slow rise of the permeability.(3)From 350℃to 375℃,pores are formed by organic matter pyrolysis,but the adsorption swelling of liquid hydrocarbon and additional expansion thermal stress constrained by surrounding stress compress the pore-fracture space,making liquid hydrocarbon difficult to expel and permeability reduce rapidly.(4)From 375℃to 450℃,the interconnected pore network between different mineral particles after organic matter conversion,enlarged pores and transformation of clay minerals promote the permeability to increase constantly even under stress constraints.(5)From 450℃to 500℃,the stable pore system and cro

关键词： Songliao Basin Cretaceous Nenjiang Formation low-maturity shale in-situ conversion pore-fracture structure in-situ permeability shale oil

Properties of Continental Margin and its Hydrocarbon Exploration Significance in Cambrian in the Southern Ordos Kratogen of North China

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Acta Geologica Sinica(English Edition) 2013年第3期87卷 777-803页

作者： BAI Yunlai MA Yuhu HUANG Yong LIAO Jianbo LIU Xiaoguang Northwest Branch of research Institute of Petroleum Exploration and Development (NWGI) PetroChina School of Earth-Sciences and Resources China University of Geosciences (Beijing) The 107 Geological Team Bureau of Geology and Mineral Resources of Chongqing City

It is important to determine the properties of the tectonics in Cambrian period for the sake of prospecting deep hydrocarbon in the near future in the southern Ordos Kratogen of North China. Authors chose the marginal areas of the southern Ordos basin as the object of research, avoided the effects of both the Qinling Orogenic Belts （QOB） and Weihe River Graben （WRG） whose geological structures are too complicated. By surveying typical Cambrian outcrops and profdes in the basin edges and based on the cores of 57 wells which penetrated the Cambrian in the basin, combined with the seismic profiles, the field gammaray measuement results and the carbon isotope analysis, Authors conclude that the southern margin of the Ordos Kratogen during Cambrian was a passive continental margin which resulted from sea-floor spreading of the Ancient Qinling Ocean. Epicontinental sea carbonate sediments formed in the south Ordos continental margin during Cambrian, and were predominant as tidal flat and o61itic shoal. Both transgression-regression process and the change in palaeostructure have the obvious cyclicity. Using the junction between the late Nangao age of Qiandong epoch and the early Duyun age of Qiandong epoch as a boundary, each had a full transgression cycle at the upper and lower stages. The early cycle is characterized by high energy clastic littoral facies while the late cycle is characterized by carbonate ramp on which clear water and muddy water developed alternately changing to carbonate platform last. During the early stages, An aulacogen was formed in the middle section of the southern margin. The southern Ordos margin was uplifted and denudated by the Huaiyuan Movement which occurred from the late Furongian age to the middle Flolan age and the history of the passive continental margin ended and entering into a new tectonic cycle. The unconformity surface caused by the Huaiyuan Movement, along with its neighborhood areas where dissolved pores and cavities are develop

关键词： the Southern Ordos Kratogen Passive continental margin Cambrian deep hydrocarbon exploration

Characteristics and genesis of the Feixianguan Formation oolitic shoal reservoir, Puguang gas field, Sichuan Basin, China

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Frontiers of Earth Science 2015年第1期9卷 26-39页

作者： Peiyuan CHEN Xiucheng TAN Huiting YANG Ming TANG Yiwei JIANG Xiuju JIN Yang YU State Key Laboratory of Oil and Gas Geology and Exploration Southwest Petroleum University Chengdu 610500 China School of Geoscience and Technology Southwest Petroleum University Chengdu 610500 China research Institute of Petroleum Exploration and Development SINOPEC Zhongyuan Oilfield Company Puyang 457001 China

The Lower Triassic Feixianguan Formation at the well-known Puguang gasfield in the northeastern Sichuan Basin of southwest China produces a representa- tive oolitic reservoir, which has been the biggest marinesourced gasfield so far in China （discovered in 2003 with proven gas reserves greater than 350× 10^8 m3）. This study combines core, thin section, and scanning electron microscopy observations, and geochemical analysis （C, O, and Sr isotopes） in order to investigate the basic characteristics and formation mechanisms of the reservoir. Observations indicate that platform margin oolitic dolomites are the most important reservoir rocks. Porosity is dominated by intergranular and intragranular solution, and moldic pore. The dolomites are characterized by medium porosity and permeability, averaging at approximately 9% and 29.7 mD, respectively. ^87Sr/^86Sr （0.707536-0.707934） and δ^13CpDB （1.8 ‰--3.5 ‰） isotopic values indicate that the dolomitization fluid is predominantly concentrated seawater by evaporation, and the main mechanism for the oolitic dolomite formation is seepage reflux at an early stage of eodiagenesis. Both sedimentation and diagenesis （e.g., dolomitization and dissolution） have led to the formation of high-quality rocks to different degrees. Dolomite formation may have little contribution, karst may have had both positive and negative influences, and burial dissolution-TSR （thermochemical sulfate reduction） may not impact widely. The preservation of primary intergranular pores and dissolution by meteoric or mixed waters at the early stage of eogenesis are the main influences. This study may assist oil and gas explorationactivities in the Puguang area and in other areas withdolomitic reservoirs.

关键词： oolite shoal reservoir carbonate diagenesis,Triassic Feixianguan Formation Puguang gas field Sichuan Basin

Formation condition of deep gas reservoirs in tight sandstones in Kuqa Foreland Basin

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Petroleum research 2018年第4期3卷 346-358页

作者： Xuesong Lu Mengjun Zhao Keyu Liu Qingong Zhuo Junjia Fan Zhichao Yu Yanjie Gong petrochina research Institute of Petroleum Exploration and Development Beijing 100083China CNPC Key Laboratory of Basin Structure and Hydrocarbon Accumulation Beijing 100083China School of Geosciences China University of PetroleumShandong 266580China

Due to the high expense of deep oil and gas exploration,prediction of gas-bearing properties before drilling is crucial for deep gas reservoir of tight *** tight sandstone gas fields in Kuqa Foreland Basin are characterized by high abundance,high gas saturation,high pressure,high and stable yield,which belong to high-efficiency tight gas *** on theoretical analysis of controlling factors and mechanisms of gas-bearing properties for tight sandstone gas reservoir,and taking tight sandstone gas fields with high effectiveness such as Dibei,Keshen and Dibei gas fields in Kuqa Foreland Basin as examples,formation condition and mechanism of high-efficiency tight sandstone gas reservoir in Kuqa area are studied through a comparative analysis of typical tight sandstone gas reservoir in Sichuan Basin and Ordos *** results show that the formation condition of deep gas reservoir of tight sandstone in Kuqa foreland basin includes four factors:i.e.,overpressure gas charging,fracture development,“early-oil and late-gas”accumulation process and favorable preservation *** overpressure gas charging and fracture development are the most important factors for formation of high-efficiency tight gas reservoirs in Kuqa Foreland ***-quality source rocks,high sourcereservoir pressure difference,and overpressure filling induced thereby are preconditions for formation of tight sandstone with high gas *** fracture development controls gas migration,accumulation,and high yield of tight sandstone gas *** reservoir wettability changed by the early oil charging is beneficial to late natural gas charging,and the preservation condition of high-quality gypsum cap rocks is the key factor for gas reservoirs to maintain overpressure and high gas *** of above four favorable factors leads to the tight sandstone gas reservoir with high abundance,high gas saturation and high gas production in Kuqa Foreland Basin,which is very

关键词： Deep gas reservoir Tight sandstone Overpressure Fracture “Early-oil and late-gas”accumulation process Preservation condition Kuqa foreland basin

Formation mechanism of reservoir oolitic dolomite in Lower Triassic Feixianguan formation, northeastern Sichuan Basin, southwest China

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Journal of Central South University 2014年第8期21卷 3263-3274页

作者：陈培元谭秀成刘宏马腾罗冰姜兴福于洋靳秀菊 State Key Laboratory of Oil and Gas Geology and Exploration (Southwest Petroleum University) School of Geoscience and Technology Southwest Petroleum University research Institute of Petroleum Exploration and Development Post-doctoral Workstation of PetroChina Southwest Oil and Gas Field Company Department of Exploration Industry PetroChina Southwest Oil and Gas Field Company research Institute of Petroleum Exploration and Development SINOPECZhongyuan Oilfield Company

A series of marine natural gas fields were recently discovered in oolitic dolomites of the Lower Triassic Feixianguan formation, northeastern Sichuan Basin, southwest China. The mechanism forming these reservoir dolomites is debatable, limiting the ability to characterize these reservoir successfully. Based on the investigation of the representative Dukouhe, Luojiazhai, and Puguang areas, this issue was addressed by examining the distribution, petrology, and geochemistry of the dolomites, the most comprehensive study to date was provided. Dolomitization occurred at a very early stage of diagenesis, as shown by the petrological features of the rock fabric. Vadose silt, which is composed primarily of dolomitic clasts, is found in the primary and secondary pores of the oolitic dolomite. This indicates that the overlying strata were subjected to dolomitization when the Feixianguan formation was located in the vadose zone. Therefore, it may be inferred that the dolomitization which occurred before the formation was exposed to meteoric conditions. The spatial distribution and geochemical characteristics of the dolomite indicate that dolomitization occurred as a result of seepage reflux. The degree of dolomitization decreases with increasing distance from the evaporative lagoon. Furthermore, the type and porosity of the dolomite vary in different zones of the upward-shoaling sequence, with the porosity gradually decreasing from the highest layer to the lowest layer. This reflects a close relationship between dolomitization and seawater evaporation during the formation of the dolomite. Geochemical analysis provided further evidence for the relationship between the dolomitization fluid and the coeval seawater. The 87Sr/86Sr and 813C isotopes, as well as the abundances of trace elements, Fe and Mn, indicate that seawater concentrated by evaporation acted as the dolomitization fluid. These results also show that dolomitization most likely occurred in a semi-closed diagenetic e

关键词： Lower Triassic Feixianguan formation early exposure seepage reflux dolomitization Sichuan Basin northeastern Sichuan

Effects of Sealing Flow Supply Configuration with Holes on Sealing Effectiveness of Turbine Rim Seal

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Journal of Thermal Science 2023年第1期32卷 366-386页

作者： GAI Zepeng ZHU Pengfei HU Jianping LIU Zhenxia YIN Hang School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China

This paper proposes a new-designed rim seal configuration with sealing holes based on the conventional radial rim seal,and presents a numerical comparison of the sealing performance between the conventional sealing flow supply configuration and the new sealing flow supply configuration with holes at different sealing flow *** sealing effectiveness and unsteady flow yields at the rim seal are numerically simulated by using the URANS method and SST turbulent model from ANSYS *** influence of the new sealing flow supply configuration on the sealing effectiveness at different sealing flow rates is *** effectiveness of different sealing flow rates in the conventional rim seal is also *** to the conventional rim seal,the increase in the sealing flow rate reduces the degree of gas ingestion induced by the effect of mainstream ingress at the rim clearance,while the unsteady flow characteristics are enhanced,and the number and amplitude of the low-frequency signals *** position of the Kelvin-Helmholtz instabilities vortex structures is left by the increased sealing flow rate,and its strength is *** with the conventional rim seal configuration,the new sealing flow supply configuration with holes could reduce the sealing efficiency by 5.06%at most at sealing flow distribution m_(1):m_(2)=3:1 when Cw=2000,and improve the sealing efficiency by 11.71%at most at sealing flow distribution m_(1):m_(2)=1:1 when Cw=*** shows that the lateral jet from the holes induces a larger-scale Kelvin-Helmholtz vortex structure at Cw=2000,thus the sealing efficiency in the wheel space is also ***,the size of the Kelvin-Helmholtz vortex structures is significantly suppressed by the new sealing flow supply configuration at Cw=7500,which is beneficial to improving the sealing effectiveness of the conventional rim seal.

关键词： secondary air system rim seal ingestion and seal unsteady flow discrete sealing holes

The short and long-term effect of polystyrene nanoplastics on nitrifying sludge at high nitrite concentrations

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Journal of Environmental Sciences 2024年第1期135卷 222-231页

作者： Xiaolong Wang Jialu Huang Zhiqiang Qi Ruiqin Kang Chao Du Da Li School of Chemical and Environmental Engineering Anyang Institute of TechnologyAnyang 455000China Henan Licheng Environmental Technology Co. Ltd.Anyang 455000China State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China

The effect of nanoplastics(NPs)on nitrite oxidation bacteria(NOB)community in treating high-strength wastewater remains unclear,which seriously affects the stability of nitrogen removal *** this study,highly active nitrifying sludge was enriched and exposed to 50nm polystyrene NPs(PS-NPs)for short-term(1,100,500,and 1000 mg/L,1.5 hr)and long-term(1,10,100 mg/L,40 days)at high nitrite *** contrast to previous studies,our results showed that the exposures to PS-NPs had little effect on nitrifying *** long-term exposure,the protein/polysaccharide ratios in extracellular polymeric substances(EPS)were positively correlated with PS-NPs concentrations(0.78–0.99).The produced reactive oxygen species(ROS)were gradually removed,and PS-NPs higher than 10 mg/L caused damage to membrane ***-term exposure for 40 days increased the community diversity and caused significant differences between the control and exposed *** control group were dominated by Nitrobacter and Exiguobacterium,while the exposure group was dominated by Bacillus,Mycobacterium,and Nitrospira.A noticeable shift in the NOB community from Nitrobacter(26.5%to 3.4%)to Nitrospira(1.61%to 14.27%)was observed.A KEGG analysis indicated a decrease in cell growth and death,cell motility and energy *** appeared that NOB could adapt to PS-NPs stress through enhanced secretion and removal of oxidative ***,this study provided new insights into the response mechanism of NOB to PS-NPs exposure.

关键词： Nanoplastics Nitrifying activity Extracellular polymeric substance(EPS) Exposure Community analysis

Acoustic emission detection of 316L stainless steel welded joints during intergranular corrosion

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International Journal of Minerals,Metallurgy and Materials 2015年第9期22卷 942-949页

作者： Meng-yu Chai Quan Duan Wen-jie Bai Zao-xiao Zhang Xu-meng Xie School of Chemical Engineering and Technology Xi'an Jiaotong University Zhejiang Provincial special Equipment Inspection Institute

This study analyzes acoustic emission （AE） signals during the intergranular corrosion （IGC） process of 316L stainless steel welded joints under different welding currents in boiling nitric acid. IGC generates several AE signals with high AE activity. The AE technique could hardly distinguish IGC in stainless steel welded joints with different welding heat inputs. However, AE signals can effectively distinguish IGC characteristics in different corrosion stages. The IGC resistance of a heat-affected zone is lower than that of a weld zone. The initiation and rapid corrosion stages can be distinguished using AE results and microstructural analysis. Moreover, energy count rate and amplitude are considered to be ideal parameters for characterizing different IGC processes. Two types of signals are detected in the rapid corrosion stage. It can be concluded that grain boundary corrosion and grain separation are the AE sources of type 1 and type 2, respectively.

关键词： stainless steel intergranular corrosion acoustic emission microstructure weight loss

The continuous wavelet projections algorithm: A practical spectral-feature-mining approach for crop detection

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The Crop Journal 2022年第5期10卷 1264-1273页

作者： Xiaohu Zhao Jingcheng Zhang Ruiliang Pu Zaifa Shu Weizhong He Kaihua Wu College of Artificial Intelligence Hangzhou Dianzi UniversityHangzhou 310018ZhejiangChina School of Geosciences University of South FloridaTampaFL 33620USA Lishui Institute of Agriculture and Forestry Sciences Lishui 323000ZhejiangChina

Spectroscopy can be used for detecting crop characteristics. A goal of crop spectrum analysis is to extract effective features from spectral data for establishing a detection model. An ideal spectral feature set should have high sensitivity to target parameters but low information redundancy among ***, feature-selection methods that satisfy both requirements are lacking. To address this issue,in this study, a novel method, the continuous wavelet projections algorithm(CWPA), was developed,which has advantages of both continuous wavelet analysis(CWA) and the successive projections algorithm(SPA) for generating optimal spectral feature set for crop detection. Three datasets collected for crop stress detection and retrieval of biochemical properties were used to validate the CWPA under both classification and regression scenarios. The CWPA generated a feature set with fewer features yet achieving accuracy comparable to or even higher than those of CWA and SPA. With only two to three features identified by CWPA, an overall accuracy of 98% in classifying tea plant stresses was achieved, and high coefficients of determination were obtained in retrieving corn leaf chlorophyll content(R^(2)= 0.8521)and equivalent water thickness(R^(2)= 0.9508). The mechanism of the CWPA ensures that the novel algorithm discovers the most sensitive features while retaining complementarity among features. Its ability to reduce the data dimension suggests its potential for crop monitoring and phenotyping with hyperspectral data.

关键词： Hyperspectral Crop parameters Crop phenotyping Continuous wavelet analysis Successive projections algorithm