0 INTRODUCTION Pressure-stress coupling(PSC)refers to the bidirectional mechanical interaction between pore pressure and in-situ stress within subsurface formations(Hillis,2000).Variations in pore pressure redistribut...0 INTRODUCTION Pressure-stress coupling(PSC)refers to the bidirectional mechanical interaction between pore pressure and in-situ stress within subsurface formations(Hillis,2000).Variations in pore pressure redistribute the stress field,while evolving stress states in turn alter pore pressure.This reciprocity,governed by poroelasticity and multiphysics interactions,underlies a wide spectrum of geomechanical processes,including fracture initiation,fluid migration,reservoir evolution,and fault slip or seismicity(Xu et al.,2020).Conventional theories often treat pressure and stress as independent variables.展开更多
Transit Timing Variation(TTV)of hot Jupiters provides direct observational evidence of planet tidal dissipation.Detecting tidal dissipation through TTV needs high precision transit timings and long timing baselines.In...Transit Timing Variation(TTV)of hot Jupiters provides direct observational evidence of planet tidal dissipation.Detecting tidal dissipation through TTV needs high precision transit timings and long timing baselines.In this work,we predict and discuss the potential scientific contribution of the SiTian Survey in detecting and analyzing exoplanet TTV.We develop a tidal dissipation detection pipeline for the SiTian Survey that aims at time-domain astronomy with 721 m optical telescopes.The pipeline includes the modules of light curve deblending,transit timing acquisition and TTV modeling.SiTian is capable of detecting more than 25,000 exoplanets among which we expect~50 sources to show evidence of tidal dissipation.We present detection and analysis of tidal dissipating targets,based on simulated SiTian light curves of XO-3b and WASP-161 b.The transit light curve modeling gives consistent results within 1σto input values of simulated light curves.Also,the parameter uncertainties predicted by Markov Chain Monte Carlo are consistent with the distribution obtained from simulating and modeling the light curve 1000 times.The timing precision of SiTian observations is~0.5 minutes with one transit visit.We show that differences between TTV origins,e.g.,tidal dissipation,apsidal precession and multiple planets,would be significant,considering the timing precision and baseline.The detection rate of tidal dissipating hot Jupiters would answer a crucial question of whether the planet migrates at an early formation stage or random stages due to perturbations,e.g.,planet scattering or secular interaction.SiTian identified targets would be constructive given that the sample would extend tenfold.展开更多
High-quality reservoirs with sufficient physical properties of ultra-deep tight gas reservoirs in the Lower Cretaceous Bashijiqike Formation exhibit significant relationship with gas production across the Dabei Gas Fi...High-quality reservoirs with sufficient physical properties of ultra-deep tight gas reservoirs in the Lower Cretaceous Bashijiqike Formation exhibit significant relationship with gas production across the Dabei Gas Field.Clarifying the characteristics,controlling factors,evolution and distribution of the high-quality reservoirs is important for the deployment of"sweet spots".An integrated approach of petrography,SEM,cathode luminescence,XRD,physical property,NMR experiment,well logs and 3D pre-stack depth migration data was carried out.This study examined the sedimentation,diagenesis,tectonism,gypsumrock and overpressure to reveal the formation and distribution of the high-quality reservoirs.The sandstones are very fine-to coarse-grained lithic arkose.The variation in detrital grains texture and mineralogical composition affects diagenetic evolution,pore structure and gas-bearing characteristic.Three diagenetic facies(diagenetic facies A to C)are classified.Different diagenetic facies underwent different evolution of reservoir quality.The medium-fine to medium-grained lithic arkose(diagenetic facies A)underwent medium vertical compaction,tectonic compression and cementation,and exhibited relatively porous,which makes partial primary pores preserved with the occurrence and persistence of overpressure.Conversely,the very fine to fine-grained and mud gravel-rich medium-grained lithic arkose(diagenetic facies B)and diagenetic facies C appeared premature densification by strong compaction and tight carbonate cementation,respectively,which makes them free from overpressure effects.Natural fractures increased the permeability by several orders of magnitude.Gypsum-rock weakened the vertical compaction and tectonic compression,and delayed cementation,promoted and preserved overpressure.With the injection of internal high alkaline fluids,anhydrite/dolomite cements/veins and dissolution of siliceous developed.Diagenetic facies A exhibited sufficient physical properties and gas volume,making it the high-quality reservoir in tight gas sandstone.Diagenetic facies B and C mainly were used as barriers for hydrocarbon charging.Diagenetic facies A was mainly distributed in the middle-lower part of distributary channel or the middle-upper part of mouth bar.This distribution model provides guidance for exploration in ultra-deep tight sandstone gas reservoir.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U24B6002,42488101)the Key R&D Program of Shandong Province,China(No.2024CXPT076)the Independent innovation research program of China University of Petroleum(East China)(No.21CX06001A)。
文摘0 INTRODUCTION Pressure-stress coupling(PSC)refers to the bidirectional mechanical interaction between pore pressure and in-situ stress within subsurface formations(Hillis,2000).Variations in pore pressure redistribute the stress field,while evolving stress states in turn alter pore pressure.This reciprocity,governed by poroelasticity and multiphysics interactions,underlies a wide spectrum of geomechanical processes,including fracture initiation,fluid migration,reservoir evolution,and fault slip or seismicity(Xu et al.,2020).Conventional theories often treat pressure and stress as independent variables.
基金supported by funding from the Cultivation Project for LAMOST Scientific Payoff and Research Achievement of CAMS-CASthe National Natural Science Foundation of China(NSFC+4 种基金No.11872246,12041301)the Beijing Natural Science Foundation(No.1202015)supported by the National Natural Science Foundation of China(NSFC,Grant Nos.11988101 and 42075123)the National Key RD Program of China No.2019YFA0405102the science research grants from the China Manned Space Project with NO.CMS-CSST-2021-B12。
文摘Transit Timing Variation(TTV)of hot Jupiters provides direct observational evidence of planet tidal dissipation.Detecting tidal dissipation through TTV needs high precision transit timings and long timing baselines.In this work,we predict and discuss the potential scientific contribution of the SiTian Survey in detecting and analyzing exoplanet TTV.We develop a tidal dissipation detection pipeline for the SiTian Survey that aims at time-domain astronomy with 721 m optical telescopes.The pipeline includes the modules of light curve deblending,transit timing acquisition and TTV modeling.SiTian is capable of detecting more than 25,000 exoplanets among which we expect~50 sources to show evidence of tidal dissipation.We present detection and analysis of tidal dissipating targets,based on simulated SiTian light curves of XO-3b and WASP-161 b.The transit light curve modeling gives consistent results within 1σto input values of simulated light curves.Also,the parameter uncertainties predicted by Markov Chain Monte Carlo are consistent with the distribution obtained from simulating and modeling the light curve 1000 times.The timing precision of SiTian observations is~0.5 minutes with one transit visit.We show that differences between TTV origins,e.g.,tidal dissipation,apsidal precession and multiple planets,would be significant,considering the timing precision and baseline.The detection rate of tidal dissipating hot Jupiters would answer a crucial question of whether the planet migrates at an early formation stage or random stages due to perturbations,e.g.,planet scattering or secular interaction.SiTian identified targets would be constructive given that the sample would extend tenfold.
基金supported by the National Natural Science Foundation of China,China(No.U21B2062).
文摘High-quality reservoirs with sufficient physical properties of ultra-deep tight gas reservoirs in the Lower Cretaceous Bashijiqike Formation exhibit significant relationship with gas production across the Dabei Gas Field.Clarifying the characteristics,controlling factors,evolution and distribution of the high-quality reservoirs is important for the deployment of"sweet spots".An integrated approach of petrography,SEM,cathode luminescence,XRD,physical property,NMR experiment,well logs and 3D pre-stack depth migration data was carried out.This study examined the sedimentation,diagenesis,tectonism,gypsumrock and overpressure to reveal the formation and distribution of the high-quality reservoirs.The sandstones are very fine-to coarse-grained lithic arkose.The variation in detrital grains texture and mineralogical composition affects diagenetic evolution,pore structure and gas-bearing characteristic.Three diagenetic facies(diagenetic facies A to C)are classified.Different diagenetic facies underwent different evolution of reservoir quality.The medium-fine to medium-grained lithic arkose(diagenetic facies A)underwent medium vertical compaction,tectonic compression and cementation,and exhibited relatively porous,which makes partial primary pores preserved with the occurrence and persistence of overpressure.Conversely,the very fine to fine-grained and mud gravel-rich medium-grained lithic arkose(diagenetic facies B)and diagenetic facies C appeared premature densification by strong compaction and tight carbonate cementation,respectively,which makes them free from overpressure effects.Natural fractures increased the permeability by several orders of magnitude.Gypsum-rock weakened the vertical compaction and tectonic compression,and delayed cementation,promoted and preserved overpressure.With the injection of internal high alkaline fluids,anhydrite/dolomite cements/veins and dissolution of siliceous developed.Diagenetic facies A exhibited sufficient physical properties and gas volume,making it the high-quality reservoir in tight gas sandstone.Diagenetic facies B and C mainly were used as barriers for hydrocarbon charging.Diagenetic facies A was mainly distributed in the middle-lower part of distributary channel or the middle-upper part of mouth bar.This distribution model provides guidance for exploration in ultra-deep tight sandstone gas reservoir.
