Carbon dioxide miscible flooding in oil reservoirs is a general method of enhancing oil recovery, nevertheless, not all reservoirs adapt to this method. Therefore, evaluating the adaptability of carbon dioxide flooding reservoirs becomes an important problem which is urged to be solved. Through the research of carbon dioxide flooding situation and displacement mechanism, twelve factors which influenced the oil displacement effect could be obtained. Compared factors with oil recovery by means of the advanced analysis of SPSS, and chose ten factors to be the evaluating indices which could apply in cluster analysis. Through building mathematical model and clustering reservoirs, the adaptability of carbon dioxide flooding could be evaluated comprehensively. Apply this method to cluster nine typical reservoirs which have adopted carbon dioxide flooding, the results show that, this method can evaluate the adaptability of carbon dioxide flooding reservoirs, which is corresponding to the real exploitation effect.

Abstract. Remaining oil description is the core of its research. Although many description methods are available, most of them are qualitative ones. So, this paper introduces a concise quantitative method -"remaining oil dynamic data analysis", which uses the production performance data to study remaining oil. This method includes five procedures: (1) establish an optimal fitting relationship between cumulative oil production and water cut; (2) determine recoverable reserves through the relationship; (3) determine cumulative oil production by production data; (4) determine remaining recoverable reserves of single wells; (5) draw remaining oil distribution graphs. This method is applied to Hua 201 oilfield remaining oil research, and the result shows good adaptability to high water cut oilfield in late development stage. This method has simple and convenient calculation process and results that are close to field practice, therefore having important application value.