Mechanical cutting provides one of the most flexible and environmentally friendly excavation methods.It has attracted numerous efforts to model the rock chipping and fragmentation process,especially using the explicit...Mechanical cutting provides one of the most flexible and environmentally friendly excavation methods.It has attracted numerous efforts to model the rock chipping and fragmentation process,especially using the explicit finite element method(FEM) and bonded particle model(BPM),in order to improve cutting efficiency.This study investigates the application of a general-purpose graphic-processing-unit parallelised hybrid finite-discrete element method(FDEM) which enjoys the advantages of both explicit FEM and BPM,in modelling the rock chipping and fragmentation process in the rock scratch test of mechanical rock cutting.The input parameters of FDEM are determined through a calibration procedure of modelling conventional Brazilian tensile and uniaxial compressive tests of limestone,A series of scratch tests with various cutting velocities,cutter rake angles and cutting depths is then modelled using FDEM with calibrated input parameters.A few cycles of cutter/rock interactions,including their engagement and detachment process,are modelled for each case,which is conducted for the first time to the best knowledge of the authors,thanks to the general purpose graphic processing units(GPGPU) parallelisation.The failure mechanism,cutting force,chipping morphology and effect of various factors on them are discussed on the basis of the modelled results.Finally,it is concluded that GPGPU-parallelised FDEM provides a powerful tool to further study rock cutting and improve cutting efficiencies since it can explicitly capture different fracture mechanisms contributing to the rock chipping as well as chip formation and the separation process in mechanical cutting.Moreover,it is concluded that chipping is mostly owed to the mix-mode Ⅰ-Ⅱ fracture in all cases although mode Ⅱ cracks and mode Ⅰ cracks are the dominant failures in rock cutting with shallow and deep cutting depths,respectively.The chip morphology is found to be a function of cutter velocdty,cutting depth and cutter rake angle.展开更多
Petroleum was generated from sedimentary rocks. The world＇s oldest oil source rock so far was found in Proterozoic rocks. Since then, 73% to 81% of the earth＇s surface has been covered with sedimentary rocks. Howeve...Petroleum was generated from sedimentary rocks. The world＇s oldest oil source rock so far was found in Proterozoic rocks. Since then, 73% to 81% of the earth＇s surface has been covered with sedimentary rocks. However, only quite a limited area is rich in oil and gas. It is found that source rocks have controlled oil and gas distribution, and they are mainly formed in two systems： （1） river-lake systems and （2） river-gulf systems. Phytoplankton is an important source of kerogen, the blooming of which is strongly dependent on nutrients. Rivers are the major nutrient provider for basins. Rivers around lakes and an undercompensation （where the sedimentation rate is less than the rate of basin subsidence） environment provide favorable conditions for phytoplankton blooming in lakes. Gulfs are usually located at the estuary of big rivers, characterized by restricted current circulation and exchange with the open sea, which benefit maintaining the nutrient density, phytoplankton levels and organic matter preservation. The river-gulf system is the most favorable place for marine source rock development. Most of the world famous marine petroleum-rich provinces are developed from river-gulf systems in geological history, such as the Persian Gulf Basin, Siberian Basin, Caspian Basin, North Sea, Sirte Basin, Nigerian Basin, Kwanza Basin, Gulf of Mexico, Maracaibo Basin and the Eastern Venezuelan Basin.展开更多
The values of the helium isotopes in the inclusions of the Ordovician reservoir rocks in the Kongxi buried hill belt in the Huanghua depression were first measured and the source of helium and its geological significa...The values of the helium isotopes in the inclusions of the Ordovician reservoir rocks in the Kongxi buried hill belt in the Huanghua depression were first measured and the source of helium and its geological significance were investigated in comparison with those of the helium isotopes in the conclusions in the Ordovician rocks in the Ordos basin and the Tarim basin. The input of the mantle-derived helium into the inclusions in the carbonate reservoir rocks was found from the Konggu 3 well, the Konggu 4 well, and the Konggu 7 well in the Kongxi buried hill belt. The 3He/4He and R/Ra in the conclusions in the Ordovician oil-bearing reservoir rocks in the Konggu 7 well average 2.54×10-6(3) (sample quantity, the same below) and 1.82(3), respectively. The percent of the mantle-derived helium in the inclusions of the reservoir rocks in the Konggu 7 well reaches up to an average of 23.0%(3). The age of the contribution of the mantle-derived helium to the inclusions in the Kongxi buried hill belt is in the Late Triassic or the Early Tertiary. The finding of the mantle-derived helium shows that the interaction of the deep crust with mantle and the activity of deep faults occurred, the terrestrial heat flow value was high, and mantle-derived inorganic gas pools might be formed in the Kongxi buried hill belt. The finding of the mantle-derived helium in the inclusions of oil-bearing reservoir rocks also provides a new way for researching the activity of mantle-derived matter and its associated geological problems.展开更多
基金the support of CSIRO and the Australia-Japan Foundation(Grant No.17/20470)supported by the Japan Society for the Promotion of Science KAKENHI(Grant No.JP18K14165)for Grant-in-Aid for Young Scientists。
文摘Mechanical cutting provides one of the most flexible and environmentally friendly excavation methods.It has attracted numerous efforts to model the rock chipping and fragmentation process,especially using the explicit finite element method(FEM) and bonded particle model(BPM),in order to improve cutting efficiency.This study investigates the application of a general-purpose graphic-processing-unit parallelised hybrid finite-discrete element method(FDEM) which enjoys the advantages of both explicit FEM and BPM,in modelling the rock chipping and fragmentation process in the rock scratch test of mechanical rock cutting.The input parameters of FDEM are determined through a calibration procedure of modelling conventional Brazilian tensile and uniaxial compressive tests of limestone,A series of scratch tests with various cutting velocities,cutter rake angles and cutting depths is then modelled using FDEM with calibrated input parameters.A few cycles of cutter/rock interactions,including their engagement and detachment process,are modelled for each case,which is conducted for the first time to the best knowledge of the authors,thanks to the general purpose graphic processing units(GPGPU) parallelisation.The failure mechanism,cutting force,chipping morphology and effect of various factors on them are discussed on the basis of the modelled results.Finally,it is concluded that GPGPU-parallelised FDEM provides a powerful tool to further study rock cutting and improve cutting efficiencies since it can explicitly capture different fracture mechanisms contributing to the rock chipping as well as chip formation and the separation process in mechanical cutting.Moreover,it is concluded that chipping is mostly owed to the mix-mode Ⅰ-Ⅱ fracture in all cases although mode Ⅱ cracks and mode Ⅰ cracks are the dominant failures in rock cutting with shallow and deep cutting depths,respectively.The chip morphology is found to be a function of cutter velocdty,cutting depth and cutter rake angle.
文摘Petroleum was generated from sedimentary rocks. The world＇s oldest oil source rock so far was found in Proterozoic rocks. Since then, 73% to 81% of the earth＇s surface has been covered with sedimentary rocks. However, only quite a limited area is rich in oil and gas. It is found that source rocks have controlled oil and gas distribution, and they are mainly formed in two systems： （1） river-lake systems and （2） river-gulf systems. Phytoplankton is an important source of kerogen, the blooming of which is strongly dependent on nutrients. Rivers are the major nutrient provider for basins. Rivers around lakes and an undercompensation （where the sedimentation rate is less than the rate of basin subsidence） environment provide favorable conditions for phytoplankton blooming in lakes. Gulfs are usually located at the estuary of big rivers, characterized by restricted current circulation and exchange with the open sea, which benefit maintaining the nutrient density, phytoplankton levels and organic matter preservation. The river-gulf system is the most favorable place for marine source rock development. Most of the world famous marine petroleum-rich provinces are developed from river-gulf systems in geological history, such as the Persian Gulf Basin, Siberian Basin, Caspian Basin, North Sea, Sirte Basin, Nigerian Basin, Kwanza Basin, Gulf of Mexico, Maracaibo Basin and the Eastern Venezuelan Basin.
基金the National Natural Science Foundation of China (Grant Nos. 40172053 , 49972051) the Important Direction Project of Knowledge Innovation in Resource and Environment Fields of the Chinese Academy of Sciences (Grant No. KZCX3-SW-128) the 2002 Foundation of State Key Laboratory of Gas Geochemistry.
文摘The values of the helium isotopes in the inclusions of the Ordovician reservoir rocks in the Kongxi buried hill belt in the Huanghua depression were first measured and the source of helium and its geological significance were investigated in comparison with those of the helium isotopes in the conclusions in the Ordovician rocks in the Ordos basin and the Tarim basin. The input of the mantle-derived helium into the inclusions in the carbonate reservoir rocks was found from the Konggu 3 well, the Konggu 4 well, and the Konggu 7 well in the Kongxi buried hill belt. The 3He/4He and R/Ra in the conclusions in the Ordovician oil-bearing reservoir rocks in the Konggu 7 well average 2.54×10-6(3) (sample quantity, the same below) and 1.82(3), respectively. The percent of the mantle-derived helium in the inclusions of the reservoir rocks in the Konggu 7 well reaches up to an average of 23.0%(3). The age of the contribution of the mantle-derived helium to the inclusions in the Kongxi buried hill belt is in the Late Triassic or the Early Tertiary. The finding of the mantle-derived helium shows that the interaction of the deep crust with mantle and the activity of deep faults occurred, the terrestrial heat flow value was high, and mantle-derived inorganic gas pools might be formed in the Kongxi buried hill belt. The finding of the mantle-derived helium in the inclusions of oil-bearing reservoir rocks also provides a new way for researching the activity of mantle-derived matter and its associated geological problems.
