������Ȼ�� (CH 4 ) ���͡�ԭ����ˮԭ���������Դ CO 2 ����ij�ע����ģ�ͣ���ģ���� CO 2 �ܷ��γ��㹻�����������͵Ĺؼ�����������ϲ����밼��Ȫ�Ķδ������ģ������ϣ��ڴ����з����Դ CO 2 ������������󣬲��� CO 2 ��עʱ����������ע��ʱ�䡣�����о����������������Դ CO 2 ���Ͷ����������Լ�Ӱ�����С�IJ��� (CO 2 ��ԭ�͵��ܶȡ������������׺�뾶�� CO 2 ���߶�) ���з������ó��Դ CO 2 ��ԭ���������ĸ��������ͻ�������������� (ëϸ������)�����������ѧ�ĽǶ�֤���Դ���� CO 2 �ܹ��������������ƶ����á�

Through the analysis on the theory of natural gas (CH 4 ) displacement and oil driving water��we established the model of mantle- derived CO 2 - bearing fluid infilling and displacement�� The key of the model is whether CO 2 could form sufficient driving force�� The fourth- member of Quantou Formation reservoir in Changling sag of southern Songliao basin is matched with the model�� and we found the mixed layers of mantle- derived CO 2 and oil-gas��moreover��the infilling of oil and gas was earlier than that of CO 2 �� According to the geological conditions of the studied area��we analyzed the driving and resistant force as well as the parameters which related to them��such as original CO 2 density��interfacial tension��pore throat radius and CO 2 column height�� We concluded that the buoyancy created by mantle- derived CO 2 and crude oil is enough to break through the migration resistance (i. e�� �� capillary resistance)�� It can be proved that mantle- derived CO 2 plays a promoting role in the migration of oil and gas in perspectives of physics and mathematics��