With the rapid expansion and extension of natural gas exploration and development,it is more and more difficult to discover large-scale reserves in China.To intensify the research on new natural gas exploration domain...With the rapid expansion and extension of natural gas exploration and development,it is more and more difficult to discover large-scale reserves in China.To intensify the research on new natural gas exploration domains,we reviewed the progress and trend of natural gas exploration and analyzed the main areas with large-scale proved gas in place(GIP).Then,based on a statistic analysis of large gas fields in China as well as their hydrocarbon accumulation characteristics,their genetic systems were classified and each system's distribution law was also identified.Some research results were obtained.First,carbonate paleo-uplifts of cratonic basins,tight sandstones of extensive gentle slopes and thrust structures of foreland basins are the main areas with large-scale proved GIP in China.Second,there are five genetic systems for large gas fields,i.e.cratonic rift and paleo-uplift(A),stable slope of low-angle open lake(B),thrust structure of piedmont fault depression(C),faulted uplift and igneous rock of intracontinental pull-apart fault depression(D),and anticline structure of epicontinental strikeeslip fault depression(E),and one genetic system(F)for unconventional gas,i.e.adsorption and accumulation in nano-scale space.Third,there is one core genetic system for large conventional gas fields in each geologic cycle.Fourth,two-level accumulation,i.e.no migration inside the source and large scale transportation termination,exists in each single genetic system,and sequential accumulation is formed under the control of multiple factors in the areas where multiple genetic systems are superimposed.Fifth,the multi-system superimposed area is rich in large gas fields and the multistress hinge zone in the central area is the natural gas convergence zone.Finally,the future orientation and targets of natural gas exploration in China were pointed out.First,the system A includes SinianeLower Paleozoic in the Sichuan Basin,Cambrian in the Tarim Basin and CambrianeOrdovician in the Ordos Basin.Second,the system C includes the transform zone of Kuqa thrust structure,the northwestern Sichuan Basin and the southwestern Tarim Basin.Third,the system E includes the basins in the eastern China seas.Fourth,the system F includes organic-rich shales in South China and deep coal beds in the Ordos Basin in central China.展开更多
The shapes and geometrical parameters of nozzles are key factors for fluidics. The relationship among the reaction thrust, flow rate pressure, diameter do and length L of a cylinder nozzle is analyzed theoretically. T...The shapes and geometrical parameters of nozzles are key factors for fluidics. The relationship among the reaction thrust, flow rate pressure, diameter do and length L of a cylinder nozzle is analyzed theoretically. The simulation of the flow field characteristics was conducted via the FLUENT computational fluid dynamics package. Effects of the inlet conditions and the nozzle dimensions on the reaction thrust of a water jet were addressed particularly. The reaction thrust experiments were performed on a custom-designed test apparatus. The experimental results reveal that a） the nozzle diameter and the inlet conditions exert great influence on the water jet reaction thrust; and b） for L≤4d0, where the nozzle is treated as a thin plate-orifice, the reaction thrust is independent of nozzle length; for L〉4d0, where the nozzle is treated as a long orifice, the reaction thrust can reach maximum under the condition of a certain flow rate. These findings lay a theoretical foundation for the design of nozzles and have significant value, especially for the future development of high-oressure water-let orooulsion technology.展开更多
基金supported by the National Major Science and Technology Project“Accumulation Mechanism,Enrichment Law,and New Exploration Fields of Large Gas Fields(No.2016ZX05007-003)”“Enrichment Law and Key Technologies of Exploration and Development of Tight Gas(No.2016ZX05047)”。
文摘With the rapid expansion and extension of natural gas exploration and development,it is more and more difficult to discover large-scale reserves in China.To intensify the research on new natural gas exploration domains,we reviewed the progress and trend of natural gas exploration and analyzed the main areas with large-scale proved gas in place(GIP).Then,based on a statistic analysis of large gas fields in China as well as their hydrocarbon accumulation characteristics,their genetic systems were classified and each system's distribution law was also identified.Some research results were obtained.First,carbonate paleo-uplifts of cratonic basins,tight sandstones of extensive gentle slopes and thrust structures of foreland basins are the main areas with large-scale proved GIP in China.Second,there are five genetic systems for large gas fields,i.e.cratonic rift and paleo-uplift(A),stable slope of low-angle open lake(B),thrust structure of piedmont fault depression(C),faulted uplift and igneous rock of intracontinental pull-apart fault depression(D),and anticline structure of epicontinental strikeeslip fault depression(E),and one genetic system(F)for unconventional gas,i.e.adsorption and accumulation in nano-scale space.Third,there is one core genetic system for large conventional gas fields in each geologic cycle.Fourth,two-level accumulation,i.e.no migration inside the source and large scale transportation termination,exists in each single genetic system,and sequential accumulation is formed under the control of multiple factors in the areas where multiple genetic systems are superimposed.Fifth,the multi-system superimposed area is rich in large gas fields and the multistress hinge zone in the central area is the natural gas convergence zone.Finally,the future orientation and targets of natural gas exploration in China were pointed out.First,the system A includes SinianeLower Paleozoic in the Sichuan Basin,Cambrian in the Tarim Basin and CambrianeOrdovician in the Ordos Basin.Second,the system C includes the transform zone of Kuqa thrust structure,the northwestern Sichuan Basin and the southwestern Tarim Basin.Third,the system E includes the basins in the eastern China seas.Fourth,the system F includes organic-rich shales in South China and deep coal beds in the Ordos Basin in central China.
基金Funded by the Natural Science Foundation of China (No. 50775081)the National High-tech R&D (863) Program No. 2006AA09Z238)the NCET-07-0330, State Education Ministry.
文摘The shapes and geometrical parameters of nozzles are key factors for fluidics. The relationship among the reaction thrust, flow rate pressure, diameter do and length L of a cylinder nozzle is analyzed theoretically. The simulation of the flow field characteristics was conducted via the FLUENT computational fluid dynamics package. Effects of the inlet conditions and the nozzle dimensions on the reaction thrust of a water jet were addressed particularly. The reaction thrust experiments were performed on a custom-designed test apparatus. The experimental results reveal that a） the nozzle diameter and the inlet conditions exert great influence on the water jet reaction thrust; and b） for L≤4d0, where the nozzle is treated as a thin plate-orifice, the reaction thrust is independent of nozzle length; for L〉4d0, where the nozzle is treated as a long orifice, the reaction thrust can reach maximum under the condition of a certain flow rate. These findings lay a theoretical foundation for the design of nozzles and have significant value, especially for the future development of high-oressure water-let orooulsion technology.
