【摘要】 文章通过对鄂尔多斯盆地上古生界致密砂岩储层的分布特征、物性特征以及天然气成藏条件等进行分析,提出了鄂尔多斯盆地上古生界深盆气成藏的新模式,认为其成藏过程是天然气在垂向上向上排驱地层水并就近聚集,而不是长距离侧向运移的结果;鄂尔多斯盆地上古生界的气水分布从严格的意义上讲并不属于气水倒置的范畴,而是大量各自独立的致密砂岩天然气藏在平面上投影叠合的表象。根据这些结论,不仅对鄂尔多斯盆地,而且对阿尔伯达盆地的经典深盆气藏的气水倒置分布的观点也应该重新认识。更多还原

【Abstract】 "Deep-basin gas" is different from conventional gas pools on the mechanism of gas migration and accumulation. Because of the tightness of reservoir rocks of deep basin gas, gas in these tight-sands can migrate forward and expulse formation water like a piston, and result in an up-down embedment of gas and water (water over gas) in a tight reservoir. However, the up-down gas-water embedment in a single reservoir can not be used to explain the mechanism of regional gas-water distribution in Ordos Basin. Through a comprehensive analysis of the distribution of tight sand-bodies, their poor petrophysical properties and conditions for tight-sand gas migration and accumulation, it is proposed a new modal for the mechanism on gas accumulation in the Upper Paleozoic in Ordos basin. It is also concluded that the gas pools in these strata are the result of vertically upward migration and in-place accumulation of gas expulsed from source rocks, rather than the result of long-distance lateral migration along the tight-sands. Strictly, the regional gas-water distribution in the Upper Paleozoic in Ordos Basin do not coincide with the concept of gas-water up-down contact, but a result of projection on a plane of a series of independent tight-sand gas pools. According to these conclusions, even the classical example of deep basin gas accumulation and its "water-over-gas" phenomena in Alberta basin (Western Canada) should be reexamined.更多还原