Natural gas hydrates have been hailed as a new and promising unconventional alternative energy,especially as fossil fuels approach depletion,energy consumption soars,and fossil fuel prices rise,owing to their extensiv...Natural gas hydrates have been hailed as a new and promising unconventional alternative energy,especially as fossil fuels approach depletion,energy consumption soars,and fossil fuel prices rise,owing to their extensive distribution,abundance,and high fuel efficiency.Gas hydrate reservoirs are similar to a storage cupboard in the global carbon cycle,containing most of the world's methane and accounting for a third of Earth's mobile organic carbon.We investigated gas hydrate stability zone burial depths from the viewpoint of conditions associated with stable existence of gas hydrates,such as temperature,pressure,and heat flow,based on related data collected by the global drilling programs.Hydrate-related areas are estimated using various biological,geochemical and geophysical tools.Based on a series of previous investigations,we cover the history and status of gas hydrate exploration in the USA,Japan,South Korea,India,Germany,the polar areas,and China.Then,we review the current techniques for hydrate exploration in a global scale.Additionally,we briefly review existing techniques for recovering methane from gas hydrates,including thermal stimulation,depressurization,chemical injection,and CH4-CO2 exchange,as well as corresponding global field trials in Russia,Japan,United States,Canada and China.In particular,unlike diagenetic gas hydrates in coarse sandy sediments in Japan and gravel sediments in the United States and Canada,most gas hydrates in the northem South China Sea are non-diagenetic and exist in fine-grained sediments with a vein-like morphology.Therefore,especially in terms of the offshore production test in gas hydrate reservoirs in the Shenhu area in the north slope of the South China Sea,Chinese scientists have proposed two unprecedented techniques that have been verified during the field trials:solid fluidization and formation fluid extraction.Herein,we introduce the two production techniques,as well as the so-called"fbur-in-one"environmental monitoring system employed during the Shenhu production te展开更多
基金supported by Natural Science Foundation of China (91858208)National Key Basic Research and Development Program of China 2018YFC0310003 and 2017YFC0307704)+2 种基金Taishan scholar Special Experts Project (ts201712079)the Foundation of Key Laboratory of Marine Geology and Environment, Institute of Oceanology, CAS (MGE2017KG05)the Marine Geological Survey Program of China Geological Survey (DD20190819)
文摘Natural gas hydrates have been hailed as a new and promising unconventional alternative energy,especially as fossil fuels approach depletion,energy consumption soars,and fossil fuel prices rise,owing to their extensive distribution,abundance,and high fuel efficiency.Gas hydrate reservoirs are similar to a storage cupboard in the global carbon cycle,containing most of the world's methane and accounting for a third of Earth's mobile organic carbon.We investigated gas hydrate stability zone burial depths from the viewpoint of conditions associated with stable existence of gas hydrates,such as temperature,pressure,and heat flow,based on related data collected by the global drilling programs.Hydrate-related areas are estimated using various biological,geochemical and geophysical tools.Based on a series of previous investigations,we cover the history and status of gas hydrate exploration in the USA,Japan,South Korea,India,Germany,the polar areas,and China.Then,we review the current techniques for hydrate exploration in a global scale.Additionally,we briefly review existing techniques for recovering methane from gas hydrates,including thermal stimulation,depressurization,chemical injection,and CH4-CO2 exchange,as well as corresponding global field trials in Russia,Japan,United States,Canada and China.In particular,unlike diagenetic gas hydrates in coarse sandy sediments in Japan and gravel sediments in the United States and Canada,most gas hydrates in the northem South China Sea are non-diagenetic and exist in fine-grained sediments with a vein-like morphology.Therefore,especially in terms of the offshore production test in gas hydrate reservoirs in the Shenhu area in the north slope of the South China Sea,Chinese scientists have proposed two unprecedented techniques that have been verified during the field trials:solid fluidization and formation fluid extraction.Herein,we introduce the two production techniques,as well as the so-called"fbur-in-one"environmental monitoring system employed during the Shenhu production te
