Songliao Basin In Northern Shallow Hydrocarbon Accumulation System For Quantitative Research

In this paper, the hydrocarbon accumulation process of mid-shallow oil and gas pools in Binbei area will be analyzed quantitatively by studying the disadvantage factors of oil and gas accumulation based on the accumulation threshold theory. With the method of the hydrocarbon-generation potential, the hydrocarbon-expelled amount and the oil and gas discharge amount of the mid-shallow hydrocarbon resource rocks K₁n¹,K₁n²,K₁qn¹ and K₁qn²⁺³ have been calculated respectively that the total of hydrocarbon discharge is 38.6×10⁸ t, including 36.9×10⁸ t oil and 1696.87×10⁸ m³ gas. The arrange of hydrocarbon migration and accumulation in single oil and gas play has been identified with the methods of GOI and the hydrocarbon-controlling rule as well as the oil and gas display of the drilled wells. According to the principle of petroleum accumulation system, the middle and shallow oil and gas play can be divided into three petroleum accumulation systems respectively. Based on the comprehensive analyses of geological conditions of oil and gas accumulation as well as primary factors of oil and gas waste, some calculational functions of oil and gas waste have been established by the physical simulation experiment. The accumulation threshold of every petroleum accumulation system has also been calculated with the functions. So,the hydrocarbon amount of every petroleum accumulation system is available with the calculational results of hydrocarbon discharge. The results of the evaluation showed that every petroleum accumulation system has not achieved its natural gas accumulation thresholds and only Heiyupao-Keshan petroleum accumulation system(Ⅱ)and Shuihua-Mingshui petroleum accumulation system(Ⅲ)have achieved their oil accumulation thresholds. The offered oil accumulation of the shallow oil and gas play are 12×10⁸t and 6×10⁸t respectively, that of the middle oil and gas play are 5×10⁸t and 2×10⁸t respectively. Finally, the study of dominant pathways of oil and gas migration has been done with the single-factor comprehensive analysis method and the multi-information superposition method. The research showed that the favorable exploration zones are Heiyupao-Keshan petroleum accumulation system and Shuihua-Mingshui petroleum accumulation system near the Binzhou Railroad. And the favorable exploration targets are the traps near the effective hydrocarbon migration pathways in the favorable exploration zones.