In this work, we adopted the adjustment and control technology of fire flooding in block S which is a common heavy oil multi-layer reservoir. We aim to tackle the problems of large inter-layer utilization differences and uneven advance of plane fire line after areal fire flooding in block S which has been implemented for about 12 years.
Block S contains roughly 30 oil layers longitudinally, with an average single layer thickness of 2.2 meters. The interlayers are well developed with a thickness of about 4 meters, which is in line with the basic conditions of layered fire flooding development. Based on the characteristics of geological body development, we comprehensively analyzed the development bottleneck problems and potential conditions of subsequent development in this area by means of the identification method of combustion state, analysis of field monitoring data, numerical simulation research and dynamic production rule research.
Based on the principle of increasing the using degree of fire flooding and improving the combustion effect, we put forward the adjustment and control technology of fire flooding suitable for this kind of reservoir. First of all, based on the characteristics of reservoir development, we reasonably combined the displacement interval to effectively strengthen the longitudinal use of the fire line. Secondly, through the reasonable configuration of areal pattern and linear pattern, the spread range of the plane fire line can be expanded. At last, the optimum combustion condition of fire drive is created by reasonably optimizing ignition temperature and gas injection intensity. Field practice has preliminarily demonstrated that the combustion state of typical well groups can be improved by such adjustment and control techniques. We believe that the recovery rate can reach 55% by gradually implementing regulatory measures.
In summary, we demonstrate the adjustment and control techniques for multi-layer fire flooding in medium and deep common heavy oil reservoirs. As a replacement technology for conventional areal pattern fire flooding, it can further improve the development effect and improve recovery.