低盐度水驱提高采收率实验研究

为了研究低盐度水驱时不同盐度条件下注水速度对开发的影响,通过室内岩芯驱替实验开展了注水速度对低盐度水驱提高采收率的影响研究。研究结果表明：当注水速度小于0.4 mL/min时,在相同注入体积情况下,与较高盐度水驱相比,低盐度水驱的采出程度更高,达到最大采出程度所需要的时间也更长;而在注水速度大于0.4 mL/min时,在相同注入体积情况下,低盐度水驱时的采出程度相对更低,达到最大采出程度所需的时间也更短;就提高采收率而言,高盐度水驱与低盐度水驱均存在最佳注水速度,且低盐度水驱的最佳注水速度要小于高盐度水驱的最佳注水速度。

An Experimental Study on Improving Recovery Rate Using Low-salinity Water Drive

The effects of water-injection speed on the recovery rate using low-salinity water drive were studied through an indoor rock core displacement experiment. This experimental study was performed to investigate the effects of water-injection speed on recovery using water drive of different degrees of salinity. The research results showed that, with the same volume of water injected at a speed below 0.4 mL/min, low-salinity water drive resulted in a higher recovery rate but longer time to reach the maximum recovery rate compared to high-salinity water drive; and with the same volume of water injected at a speed above 0.4 mL/min, low-salinity water drive resulted in a lower recovery rate but shorter time to reach the maximum recovery rate, compared to high-salinity water drive. In other words, the maximum recovery rate corresponded to an optimum water-injection speed, irrespective of whether low-salinity or high-salinity water drive was used. Thus, the results also showed that the optimum water-injection speed for low-salinity water drive was lower than that for the high-salinity water drive.