中高渗透砂岩油田优势流场识别与调整

Identification and adjustment of streamline field in middle-high permeability sandstone oilfield

对于非均质性较强的中高渗透砂岩油田,由于开发及地质原因,在高含水开发阶段注入水沿天然高渗透条带形成无效循环,导致制定的剩余油挖潜措施实施效果较差。因此,准确识别该阶段的优势流场,对于有效控制优势流场和制定挖潜剩余油措施至关重要。以高含水开发阶段的双河油田某区块为研究对象,通过模糊综合评判,结合流线数值模拟技术,制定优势流场的判别标准;通过各小层油水井间的流线分布、注采分配因子和注水效率,确定单井组注水井向该井组不同受效井方向的分水量及注水效率。定性、定量判别研究区油水井间优势流场的平面分布规律。自2013年6月现场进行变流线矢量化调整,截至2015年10月,研究区综合含水率下降1.5%,累积增产原油3.15×10~4t,采收率提高1.2%,取得了较好的稳油控水效果。

In the middle-high permeability sandstone oilfield with strong heterogeneity,invalid recycling of the injected water is formed along the natural high permeability belt at high water cut stage due to the development and geological reasons,which results in poor implementation of tapping the potential of remaining oil. Therefore,identifying the predominant streamline field accurately at this stage is very important for taking effective measures to control the predominant streamline field and tap the potential of remaining oil. A certain block in Shuanghe oilfield at high water cut stage was researched.Judging criterion for predominant streamline field was made through fuzzy comprehensive evaluation and streamline numerical simulation technology. Injected water volume and efficiency of the injection wells in single well group were determined in different affected directions to response well through streamline distribution,injection-production allocation factor and injection efficiency between oil well and injection well in each layer. Rule of plane distribution of the predominant streamline field between oil well and injection well in the studied area was studied qualitatively and quantitatively. Until October 2015,composite water cut of the studied area had dropped by 1.5% and the cumulative incremental oil had been 3.15×10~4t and the recovery had been improved by 1.2%. Good effect of stabilizing oil and controlling water cut had been achieved since vectorization adjustment of variable streamline was made in the field in June 2013.