关键词: 定量颗粒荧光技术, 古油藏, 志留系, 塔里木盆地, 塔中地区

Abstract: Quantitative grain fluorescence technique is for the first time applied in study of Silurian palaeo-oil pools distribution in the Central Tarim Basin. Much attention was put on discussion of possibility of vertical superposition and horizontal continuity of small pools to form a large-scale palaeo-oil pool. The results show that there weren’t large-scale moveable oil pools superposed and connected with same palaeo-oil-water contact, while all the small oil pools distributed separately in the single local structures. In geological periods, oil pools were formed in the 1st sub-member of upper member of Kepingtage Formation in well-Tazhong 4 and well-Tazhong 17 areas, but they were destroyed later on. In the 3rd sub-member of this upper member in well-Tazhong 117 area and the 1st sub-member in well-Tazhong 31 area, oil pools were only formed in the later oil accumulation stage. In the 1st sub-member in Tacan 1 well area, a large pool came into being in the first oil accumulation stage, but without oil charging in later stages. The results also indicate that Silurian reservoirs are good for oil & gas migration so that plenty hydrocarbons migrated through them in geological stages. The central fault belt in the Tazhong uplift are thought to be the favorable locations for oil accumulation, so it should be taken into consideration in future Silurian exploration.

Key words: quantitative grain fluorescence technique, palaeo-oil pool, Silurian, Tarim Basin, Tazhong area