Analysis about the Characteristics of Shallow Oil and Gas and Favorable Exploration Area in Beisantai Uplift

It is revealed by the data of single-well testing, logging and production testing from the shallow layers (Paleogene and Neogene) of Beisantai Uplift that, oil and gas shows are mainly found in the wells penetrated Paleogene in the east of Beisantai Uplift. The oils were mainly heavy oil, and no commercial oil flowing had been found. The logging results indicated that the oil bearing sands have the characteristics of oil layers in the east. Proximal in the west, oil and gas shows have been seen only in three wells, North-27, Xiquan-4 and Xiquan-011. The sedimentary facies is alluvial fan. A large set of thick transgressive mudstone was deposited after sedimentation of sandstones, which provides good condition for trap formation. The evaluation results through radioactive radon, spectrometry uranium, thorium, uranium, grass Gamma and comprehensive show that the areas along up dip and down dip direction of well block-north 27 are favorable oil and gas zones, and the areas along the down dip direction are the most favorable area for oil and gas accumulation. Finally, it is pointed out that in order to reduce the exploration risk in this region, the deep oil layers should be also exploration targets when conducting exploration along the down dip direction in the west of Beisantai Uplift.