松辽盆地青一段常规与非常规油气资源评价

Evaluation on the conventional and unconventional oil and gas resources in K1qn1of Songliao basin

计算源外排烃量和源内残留烃量是油气资源评价中不可缺少的工作,而据此获得的常规和非常规油气烃量是评价2种油气资源的指标。分析了松辽盆地青一段烃源岩基本特征,并根据排烃门限理论利用生烃潜力法确定了烃源岩生排烃特征,结合烃源岩的面积、厚度、密度等进行积分计算得到了源外排烃量和源内残留烃量,结果表明:松辽盆地青一段烃源岩排烃门限为0.7%,最大生烃潜力指数为2 000 mg/g,最大排烃率为1 525 mg/g,源外排烃量为2 165×10~8 t,源内残留烃量为1 102×10~8 t。再根据松辽盆地浮力成藏下限理论,确定松辽盆地青一段源外常规油气排烃量为618×10~8 t,源外非常规致密油气排烃量1 547×10~8 t,源内非常规残留烃量为1 102×10~8 t。综合分析认为,松辽盆地青一段常规与非常规油气资源较为丰富,2种类型油气烃量占比约为1:5,因此非常规油气资源更为丰富。

The calculation on the expulsion amount of hydrocarbon and the amount of residual hydrocarbon is an indispensable task in the evaluation of oil and gas resources.The amount of conventional and unconventional hydrocarbon obtained from this method is the key indicator for evaluating both oil and gas resources.By means of analyzing the basic characteristics of K1 qn1 source rocks of Songliao basin,and according to the theory of hydrocarbon expulsion threshold,the hydrocarbon generation and expulsion characteristics of the source rocks were determined by using the hydrocarbon generation potential method.Through integral calculation on the area,thickness and density of the source rocks,the expulsion amount of hydrocarbon and the amount of residual hydrocarbon were obtained,which indicate that the hydrocarbon expulsion threshold of K1 qn1 source rock is 0.7%,the maximum hydrocarbon generation potential index is 2 000 mg/g,the maximum hydrocarbon expulsion rate is 1 525 mg/g,the expulsion amount of hydrocarbon is 2 165×10^8t,and the amount of residual hydrocarbon is 1 102×10^8t.According to the lower limit theory of buoyancy accumulation in Songliao basin,it is determined that the expulsion amount of conventional hydrocarbon in K1 qn1 is 618×10^8t,the expulsion amount of unconventional tight hydrocarbon is 1 547×10^8t,and the amount of unconventional residual hydrocarbon is 1 102×10^8t.Through comprehensive analysis,it is considered that the conventional and unconventional oil and gas resources in K1 qn1 of Songliao basin are abundant,and the proportion of two types of hydrocarbon is about 1∶5.The unconventional oil and gas resources are more abundant in this region.