Application of basin simulation technology on the assessment of hydrocarbon resources potential of the Lunpola Basin in Tibet

The Lunpola Basin is the only petroliferous basin in Tibet that has obtained industrial oil flows. Due to the complicated geologic conditions and the oil is relatively thick, the progress of its oil-gas exploration is slow. In order to analyze the potentiality of hydrocarbon resources and effectively guide the oil exploration in the future, the basin simulation technology was applied to study geologic history, thermal history, hydrocarbon-generation history and the resources amount of Paleogene in this basin was calculated by combining new drilling and seismic data. The results show that the hydrocarbon-generation quantity and oil-gas resource amount of Paleogene in the Lunpola Basin are 49.80×10⁸ t and 1.507×10⁸ t respectively. The Jiangriacuo Sag is the largest hydrocarbon-generation center in this basin, which has hydrocarbon-generation quantity as 20.93×10⁸ t and the oil and gas resource amount as 1.05×10⁸ t. The Jiangjiacuo Sag and the north part of the Pacuo Sag are the second most important hydrocarbon generation centers, which have hydrocarbon generation quantity as 8.83×10⁸ t and 14.76×10⁸ t, and the resources amount as 0.41×10⁸ t and 0.71×10⁸ t respectively. From the simulation results, considering the hydrocarbon-generation intensity, the Jiangriacuo Sag and the Jiangjiacuo Sag are the favorable areas for hydrocarbon accumulation. Because of the poor hydrocarbon source and trap conditions, only the Luomadiku structural trap has been found, and the resource abundance in the Pacuo Sag is low. By using basin simulation technology, the hydrocarbon resources composition and the favorable zones of hydrocarbon resources distribution in the Lumpola Basin are defined, which points out the direction for further exploration.