A PRELIMINARY ANALYSIS OF OIL-POOL FORMING CONDITIONS IN THE LATE PERIOD IN THE NORTHERN TARIM AREA

A whole process including oil-gas source,migration-accumulation and trap-preservation has been emphasized in the modern petroleum geology. From the Paleozoic to the Cenozoic Erathem there were rich oilgas sources and a well developed reservoir system;and various kinds of oil-gas pools have been discovered in the northern Tarim area. But up to now no oil-gas pools sourced from the Paleozoic in Cenozoic Erathem reservoirs are found in this area. According to numerous determinations of samples selected from the field,comprehensive comparision of collected data, and the observation and ahalyses of tectonic evolution,specially,the neotectonic movement and inversion tectonics,etc.,the oil pool forming condition in the late period in the northern Tarim area has been explained from three aspects: the oil-gas source,migration-accumulation and the Paleozoic sourced Cenozoic reservoir. Finally it is shown that the forward thrust fault block sequence of piggy-back pushing from the Tianshan Mountain to the Tarim basin,tensile structures with graben-horsts and strike slip transfer tectonics could become the oil-gas bearing local structures with oil pools formed in the late period.