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本文用实验方法研究了裂缝对水驱和聚合物驱采收率的影响。在模拟油藏的温度和压力条件下,开展了4组驱替实验、1组基础实验。基础实验是用未压裂的岩心进行驱替,对比了实施压裂地层和未压裂地层水驱和聚合物驱特性。测量了不同温度下原油和不同浓度聚合物溶液的黏度。实验结果表明,水驱碳酸盐岩油藏未压裂地层采收率高于实施压裂后有单一裂缝的地层。在碳酸盐岩油藏中,裂缝与油流方向水平(0°倾角)时采收率最高;裂缝与油流方向垂直(90°倾角)时采收率最低。水驱采收率随地层裂缝倾角的增加而减小。水驱之后进行聚合物驱,结果表明,所有实施压裂的碳酸盐岩地层,无论裂缝方向如何,采收率均高于未压裂地层。裂缝与油流方向成30°倾角时,采收率最高;裂缝与油流方向成90°倾角时,采收率最低。水驱和聚合物驱联合作用碳酸盐岩油藏,水平裂缝地层最终采收率最高。
In this paper, the effect of fractures on waterflooding and polymer flooding recovery has been studied experimentally. Under the conditions of temperature and pressure of simulated oil reservoir, four displacement experiments and one basic experiment were carried out. The basic experiment is to use non-fractured core flooding, compared with the implementation of fracturing and non-fracturing formation water flooding and polymer flooding characteristics. The viscosity of crude oil and polymer solutions with different concentrations were measured at different temperatures. Experimental results show that the recovery rate of unconsolidated reservoirs in water-flooding carbonate reservoirs is higher than that of fractures with single fractures. In carbonate reservoirs, fractures have the highest oil recovery in the direction of oil flow (0 ° dip), and the fractures have the lowest oil recovery at vertical (90 ° dip) to oil flow. Waterflood recovery decreases with the dip of formation fractures. Polymer flooding after waterflooding showed that all fractured carbonate formations, regardless of fracture orientation, had a higher recovery than uncracked formations. The fractures have the highest oil recovery when the fractures are at an angle of 30 ° to the oil flow direction. The fractures have the lowest oil recovery at a 90 ° dip angle to the oil flow direction. In combination with water flooding and polymer flooding, carbonate reservoirs have the highest ultimate recovery of fractured horizontal fractures.