A study on the Identification of Jurassic paleo-oil reservoirs in the Mosuowan uplift, Junggar Basin

Abstract

At present, some small to medium-sized oil and gas reservoirs have been discovered in Jurassic Lower Sangonghe Formation (J1s). Previous studies speculated that the Mosuowan uplift was an important gathering area for oil and gas migration during the middle and late Jurassic, and it had a large-scale oil accumulation. Due to the southern dipping of the basin during the Himalayan Period, the paleo-oil and gas reservoirs formed in the Mosuowan uplift in the early stage migrated from the south to the north and re-accumulated. In this paper, the grain fluorescence technique was used to measure the fluorescence intensity of hydrocarbons and free hydrocarbons in the particles of the reservoir by laser scanning analysis. The fluid stratigraphy analysis technique was used to remove the free natural gas and light hydrocarbons in the reservoir sandstone by vacuum desorption. The two techniques combined with gas measurement of total hydrocarbons, geochemical parameters and oil test results, identify the height of the ancient oil column, and clarify that most of the wells exist in the exploration layer. But the height of the column is generally small, and most of the single layers are less than 20m, indicating that the Mosuowan uplift does not form a broad-cover type of oil and gas reservoir. Most wells don’t have obvious ancient oil columns.