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受加拿大阿尔伯达和北美其它一些含煤盆地勘探开发深盆气经验的启发，分析研究了鄂尔多斯盆地上古生界后发现，该盆地同样具备深盆气存在的基本石油地质条件和主要特征，是一个极其巨大的深盆气田。３项基本条件是：①有足够的、优质的、现今仍能生气生烃的烃源岩—煤系地层；②致密的储集层与烃源岩紧密配置，本区储层孔隙度绝大部分为５％～１０％，渗透率绝大部分小于１×１０－３μｍ２；③较好的区域性盖层。６个特征是：①下倾区大面积含气，上倾区含水，区域性气水倒置；②负压异常；③上古生界区域盖层以下整段厚４００ｍ地层饱含气（普遍含气）；④没有底水或边水，含气与构造无关；⑤盆地北部上倾水区内的中、小构造含气；⑥可能存在天然气泄漏区。采用类比法预测，上古生界天然气资源量为５０×１０１２ｍ３左右，多套透镜状砂体叠置连片，含气面积１０×１０４ｋｍ２，潜在可探明储量２×１０１２ｍ３，可能建成２００×１０８ｍ３／ａ产能。预测出４个有利区势带，其中Ｉ号区和Ｉ号区面积之和近２．５×１０４ｋｍ２，应作为近期主攻方向。

A STUDY OF THE DEEP BASIN GAS IN THE UPPER PALEOZOIC IN EERDUOSI BASIN

??Derived inspiration from the experiences in exploring and developing the deep basin gas in Alberta,Canada,and in other coal bearing basins in North America,through the analysis and research on the Upper Paleozoic in Eerduosi Basin,it is found that this basin in similarly provided with the fundamental petroleum geological conditions and major properties of the existence of deep basin gas,being a very giant deep basin gas field.Three fundamental conditions are:??having sufficient and high quality source rocks??coal measure strata being able to generate gas and other hydrocarbons at present;??having close deployment of tight reservoirs with source beds,the porosities are mostly 5??10% and permeabilities less than 1×10^-3??m² in the region;??having quite good regional cap rocks.Six properties include:??the downdip region is occupied in a large area by gas,while the updip region by water,forming a regional gas water inversion;??negative pressure anomaly;??the whole strata with a depth of 400m under the regional cap rocks of the Upper Paleozoic are saturated by gas (generally contain gas);??having no bottom or edge water and the gas bearing area is irrelative to the structure;??the medium small structures within the updip water region in the north of the basin are occupied by gas;??natural gas discharge area may be in existence.Through prediction by analogy method,it is concluded that the natural gas resource extent is about 50×10¹²m³,the gas bearing area being composed of many sets of the superimposed and continuous lenticular sand bodies is 10×10⁴km²,the potential proved reserves are 2×10¹²m³ and a productivity of 200×10⁸m³/a may be built up.Four advantageous zones are forecasted,in which the No.1 and No.2 zones with an area of near 2.5×10⁴km² should be taken as the major exploration region in the near future.