泡沫体系对油井堵水物理模拟实验研究

Physical simulation experiment of foam system for water plugging in oil wells

随着海上油田的持续开采,部分油井将进入高含水阶段,控水稳油成为改善海上油田开发效果的关键。针对渤海油田堵水技术需求,以渤海典型油藏地质特征和流体为研究对象,采用三维物理模型,开展了泡沫堵水体系封堵效果影响因素及注入轮次优化实验研究。结果表明,SD型泡沫堵水体系具有较好的堵水效果。随着注入轮次的增加,油井的采出程度增加;储层的非均质性越强,采用泡沫堵水措施效果越差;在均质岩心中开展两轮次堵水,采出程度分别提高了15.1%和6.5%,且不同区域石英砂剩余油分布较少,驱替效果均匀;在非均质岩心中开展两轮次堵水,产出液含水率变化较差,下降漏斗的深度和宽度均降低,采出程度分别提高了9.4%和8.1%,岩心颜色出现分层现象,低渗层动用较差,驱替效果不理想。

With the continuous development of offshore oilfield,some oil wells will enter the stage of high water cut,so water control and oil stabilization become the key to improve the development effect of offshore oilfield.Aiming at the demand of water plugging technology in Bohai oilfield,taking the geological characteristics and fluid of typical reservoirs in Bohai as the research object,the three-dimensional physical model was used to carry out the experimental study on the plugging effect of foam water plugging system and the optimization of injection cycle.The results showed that the SD type foam water plugging system has a good effect of water shutoff.With the increase of injection times,the recovery degree of the oil well increased.The stronger the heterogeneity of the reservoir was,the worse the effect of foam plugging was.In the homogeneous rock core,the degree of recovery was increased by 15.1% and 6.5% respectively.After two rounds of water plugging in heterogeneous rock core,the water content of the produced liquid changes poorly,the depth and width of the downcomer were reduced,the recovery degree was increased by 9.4% and 8.1%,the core color was stratified,the low permeability layer was poor in production,and the displacement effect was not ideal.