NITROGEN COMPOSITE HUFF-PUFF METHOD FOR CLOSED FAULT BLOCK OIL RESERVOIR

摘要

An nitrogen composite huff-puff method for a closed fault block oil reservoir, comprising: selecting an oil reservoir to be developed: coarsely screening the oil reservoir to which a development method is applicable according to the following conditions: the oil reservoir being a closed fault block oil reservoir, the burial depth 5000 m, the remaining oil saturation 0.5, the reservoir thickness 10 m, the horizontal permeability 100 mD, the ratio of the vertical permeability and the horizontal permeability 0.35, the reservoir porosity 0.20, the dip angle 8°; and sequentially performing operations of the following huff-puff stages: a nitrogen huff-puff stage, a nitrogen and water composite huff-puff stage, a nitrogen and foaming agent composite huff-puff stage, and a nitrogen and carbon dioxide composite huff-puff stage. According to the method, from the perspective of improving the later-period effect of nitrogen huff-puff, slugs such as water, a foaming agent solution, and carbon dioxide are added to the nitrogen huff-puff, so that the sealing and yield increasing effect of the nitrogen huff-puff is effectively improved, and high-efficient and stable development of the closed fault block oil reservoir in the later-period of the nitrogen huff-puff is achieved.