对页岩气成因及工业前景的思考

页岩本身并不生气。以页岩为储层的油气藏,以裂缝为主要储集空间,即传统的裂缝性泥页岩油气藏。北美页岩气在以硅质胶结和以硅岩为主的储层中,产量偏高。这一现象从硅质的来源上,指出页岩气与碱性地幔流体的必然联系。阿巴拉契亚盆地深度3000m以下的页岩气,甲烷同系物碳同位素值完全反序排列,从地球化学角度证明页岩气来自地幔。如果页岩仅仅是储层而非气源岩,我国"页岩气十二五规划"探明页岩气储量6000×108m3和2015年产量65×108m3的目标将失去地质依据。因巨大的环境隐患,页岩气开发所必需的水力压裂法已在英、美、法、德、瑞士、保加利亚、澳大利亚等国立法禁止,在南非推迟发放所有的水力压裂法开采许可证。页岩气开采带来的环保问题不仅仅是有害气体向大气泄露,还有超过260种有害化学物质随着每次10000m3压裂液返排到地表,不断重复地向页岩气开采地区排放,将造成空前的污染。同时造成工业和民用供水短缺。美国页岩气被市场分析师称为"伪商业产品",价格在成本区间内。我国计划到2020年页岩气产量达600 108～1000 108m3,根据美国的经验,起码需要2万口页岩气井,10年内所需投资将达到4000亿～6000亿元。显然,页岩气即将成为吞噬中国几十年经济发展成果的黑洞,即将成为破坏我们生息环境的"切尔诺贝利"。

ON THE SHALE GASORIG IN AND ITS INDUSTRIAL PROSPECTS

hale can not generate gas,and shale gas reservoir is just traditional fractured mud and shale gas reservoir with shale as its reservoir and fractures as its reservoir spaces.In North America,shale gas reservoirs containing mainly siliceous cementation and siliceous rock,with relatively high production.Consequent relationship between shale gas and alkali mantle fluid is pointed out from view of siliceous source.Shale gas in depth of >3000m in Appalachian Basin has completely inverted sequence of methane homolog carbon isotope value,geochemically proving its mantle source.If shale is only reservoir not source rock,Chinese 12th five-year-plan with a target of 6000×108m3 proved reserves and 65×108m3 production in 2015 will lose geological basis.Because of enormous environmental hazards,hydraulic fracturing for development of shale gas is prohibited by legislation in Britain,the United States,Germany,Switzerland,Bulgaria and Australia.All hydraulic fracturing licenses are deferred in South Africa.Issues caused by shale gas development is not only harmful gas revealed to atmosphere,but also 260 kinds of harmful chemicals flow back continuously to surface with 10000m3 fracturing fluid,causing much contamination to environment and water shortage of industrial and civil use.In America,shale gas is called "false-commercial product" by market analyst,with price within cost interval.China plans to 2020 shale gas production reached 60～100 billion cubic metres.According to American experience,at least 20000 shale gas well needed,within 10 years the investment required to reach 400～600 billion yuan.Apparently,shale gas will become the black hole that engulf the achievements of Chinese decades economic development,and might be a "Chernobyl" that destroying descendants living environment.