强底水稠油油藏水平井三维水驱物理模拟实验

珠江口盆地海相砂岩稠油油藏底水活跃，夹层分布复杂，开发难度较大，现有的常规实验规范无法准确地描述此类油藏的波及规律。基于南海东部X稠油油藏特征，设计了水平井三维水驱物理模拟实验，抽提出原油黏度和夹层分布范围作为影响水驱开发效果的主控因素，分析了强底水稠油油藏水驱开发中的水脊形态与波及规律。结果表明：稠油油藏水脊变化过程为局部锥进—局部见水—局部上托—围绕见水点拓展；稠油油藏水驱存在明显的油水过渡带，在开发后期波及范围增大有限，可采用大排量提液措施，重点挖潜在波及区油水过渡带中的剩余油；稠油油藏水驱应关注水平井沿程非均质性；对于含夹层稠油油藏，小范围夹层底部剩余油较少，大范围夹层易发生底水绕流形成次生边水，沿井筒方向波及范围增大幅度较大，在夹层下部残存大量剩余油，表现为“屋檐油”。该成果可为强底水稠油油藏治水防水及剩余油挖潜提供方案。

Three-dimensional water flooding physical simulation experiment of horizontal well in heavy oil reservoir with strong bottom water

The marine sandstone heavy oil reservoirs in the Pearl River Mouth Basin in the South China Sea are characterized by strong energy of bottom water,non-uniformed distribution of interlayers,and difficult development.Conventional experimental standards barely reveal reservoir sweep feature under high-intensity water flooding.A three-dimensional water flooding physical simulation experiment of horizontal well was designed based on the characteristics of the heavy oil reservoir named X in Pearl River Mouth Basin.The oil viscosity and interlayer distribution range were proposed as the main controlling factors affecting water flooding effect,and the characteristics of water cresting and sweep feature in water flooding development of heavy oil reservoirs with strong bottom water were analyzed.The results show that the changing process of water cresting in heavy oil reservoir is local coning-local water breakthrough-local upper support-expansion around water breakthrough point.There exists obvious oil-water transitional zone in heavy oil reservoir water flooding,and the sweep region is limited in the late stage of development,so large displacement measures can be used.The remaining oil in the oil-water transitional zone of flood sweep zone is a potential tapping target.The problem of heterogeneity along horizontal wells should be focused on the development of heavy oil reservoirs water flooding.For heavy oil reservoirs with interlayer,there is a small amount of residual oil at the bottom of the small range interlayer.Since the secondary edge water is easily formed when the bottom water flows around the large interlayer so that the sweep region along the wellbore direction increases greatly,and there is a large amount of residual oil at the bottom of the interlayer called"eaves oil".This study can provide research direction for waterproofing and tapping potential of remaining oil of heavy oil reservoirs with strong bottom water.