Fracture effectiveness plays a key role in gas productivity of ultra-deep tight sandstone reservoirs,Kuqa depression,Tarim Basin.Based on cores,thin sections,well logging,well testing and production data,the study eva...Fracture effectiveness plays a key role in gas productivity of ultra-deep tight sandstone reservoirs,Kuqa depression,Tarim Basin.Based on cores,thin sections,well logging,well testing and production data,the study evaluated fracture effectiveness and illustrated its impacts on gas productivity.High-angle and vertical shear fractures are the most important types.Distribution of effective fractures shows great heterogeneous.Fracture effectiveness is influenced by tectonism,diagenesis and in-situ stress.Earlier fractures or fractures in close to gypsum rock are easier to be filled.Completely filled fractures can be reopened under late tectonism.Dissolution improves local fracture effectiveness.Minerals spanning fracture surfaces protect fracture effectiveness from late compression.Fractures filled with calcite can be activated by acidification.Effective fractures parallel to maximum horizontal principal compressive stress direction show larger aperture.Overpressure can decrease the effective normal stress to maintain fracture effectiveness.With exploitation,decline in pore pressure reduces fracture effectiveness.Linear density,aperture,and strike of effective fractures influence gas productivity.Effective fractures greatly enhance matrix permeability.Therefore,more abundant and larger aperture fractures are always corresponded to higher productivity.However,effective fractures also facilitate late water invasion,especially,both mutually parallel.Intense water invasion leads to rapidly declines in productivity.展开更多
China has successfully launched six lunar probes so far.From Chang'E-1 to Chang'E-4,they completed the circling,landing and roving exploration,of which Chang'E-4 was the first landing on the far side of th...China has successfully launched six lunar probes so far.From Chang'E-1 to Chang'E-4,they completed the circling,landing and roving exploration,of which Chang'E-4 was the first landing on the far side of the Moon in human history.Chang'E-5 was launched in December 2020,bringing back 1731 g of lunar soil samples.Through the detailed analysis of the samples,the scientists understand the history of late lunar volcanism,specifically extending lunar volcanism by about 800 million to 1 billion years,and proposed possible mechanisms.In addition,there are many new understandings of space weathering such as meteorite impacts and solar wind radiation on the Moon.China's first Mars exploration mission Tianwen-1 was successfully launched in July 2021.Through the study of scientific data,a number of important scientific achievements have been made in the topography,water environment and shallow surface structure of Mars.This paper introduces the main scientific achievements of Chang'E-4,Chang'E-5 and Tianwen-1 in the past two years,excluding technical and engineering contents.Due to the large number of articles involved,this paper only introduces part of the results.展开更多
基金supported by the National Natural Science Foundation of China(No.U21B2062)。
文摘Fracture effectiveness plays a key role in gas productivity of ultra-deep tight sandstone reservoirs,Kuqa depression,Tarim Basin.Based on cores,thin sections,well logging,well testing and production data,the study evaluated fracture effectiveness and illustrated its impacts on gas productivity.High-angle and vertical shear fractures are the most important types.Distribution of effective fractures shows great heterogeneous.Fracture effectiveness is influenced by tectonism,diagenesis and in-situ stress.Earlier fractures or fractures in close to gypsum rock are easier to be filled.Completely filled fractures can be reopened under late tectonism.Dissolution improves local fracture effectiveness.Minerals spanning fracture surfaces protect fracture effectiveness from late compression.Fractures filled with calcite can be activated by acidification.Effective fractures parallel to maximum horizontal principal compressive stress direction show larger aperture.Overpressure can decrease the effective normal stress to maintain fracture effectiveness.With exploitation,decline in pore pressure reduces fracture effectiveness.Linear density,aperture,and strike of effective fractures influence gas productivity.Effective fractures greatly enhance matrix permeability.Therefore,more abundant and larger aperture fractures are always corresponded to higher productivity.However,effective fractures also facilitate late water invasion,especially,both mutually parallel.Intense water invasion leads to rapidly declines in productivity.
文摘China has successfully launched six lunar probes so far.From Chang'E-1 to Chang'E-4,they completed the circling,landing and roving exploration,of which Chang'E-4 was the first landing on the far side of the Moon in human history.Chang'E-5 was launched in December 2020,bringing back 1731 g of lunar soil samples.Through the detailed analysis of the samples,the scientists understand the history of late lunar volcanism,specifically extending lunar volcanism by about 800 million to 1 billion years,and proposed possible mechanisms.In addition,there are many new understandings of space weathering such as meteorite impacts and solar wind radiation on the Moon.China's first Mars exploration mission Tianwen-1 was successfully launched in July 2021.Through the study of scientific data,a number of important scientific achievements have been made in the topography,water environment and shallow surface structure of Mars.This paper introduces the main scientific achievements of Chang'E-4,Chang'E-5 and Tianwen-1 in the past two years,excluding technical and engineering contents.Due to the large number of articles involved,this paper only introduces part of the results.