页岩气成藏的关键因素
KEY FACTORS IN SHALE GAS ACCUMULATION
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摘要: 为了了解页岩气成藏的主控因素,对国内外页岩气的成藏条件进行了梳理,经综合分析认为,稳定的区域构造环境为泥、页岩的持续沉降提供了可容空间,奠定了页岩气成藏的物质基础;持续的沉降作用为泥、页岩的不间断受热和生烃提供了热力学条件;构造隆升幅度小为页岩气的保存提供了的保障,因此,区域构造稳定可能是页岩气成藏的关键。以美国福特沃斯盆地Barnett页岩的埋藏史为基础,通过四川盆地和鄂尔多斯盆地古生界泥页岩的埋藏史对比分析认为,鄂尔多斯盆地页岩气的成藏条件可能好于四川盆地,实现页岩气突破的可能性更大。Abstract: In order to identify the main controlling factors in shale gas accumulation,this paper made a review on the conditions for shale gas accumulation with the data from both at home and abroad. Stable tectonic environments provide the accommodation space for deposition of mudstone and shale and laid the material foundation for shale gas accumulation;Continuous sedimentation offers the thermodynamic condition for mudstone and shale to generate heat and hydrocarbon;Relatively weak tectonic uplifting is favorable for the preservation of shale gas. Therefore,stable tectonic environments may be the key factor to shale gas accumulation. The comparing of the buried history of the Paleozoic argillutite between Sichuan Basin and Erdos Basin with reference to the Barnett shale in the Fort Worth Basin of the US. it is inferred that conditions of shale gas accumulation in Erdos Basin maybe is better than those in Sichuan basin, and may be a better target for commercial exploration.