渤海窄河道型油藏注水能力分析

Analysis of Water Injection Capacity in Narrow Channel Reservoirs of Bohai Area

BZ油田是典型的窄河道型注水开发油田,目前油田部分注水井的井口压力非常高,对油田开发产生不利的影响。结合窄河道地质油藏特征分析油田注入压力高的原因和注水井的注入能力很有必要。应用渗流力学理论,考虑窄河道油藏横向上厚度和渗透率的变化,推导出窄河道油藏注水井注入压力的计算公式,并通过数值模拟进行验证。公式分析表明:注水井井口压力高的原因是窄河道油藏薄注厚采模式的影响;利用该公式获得窄河道油藏极限注水量的理论图版,用来指导酸化措施的提出,取得了比较好的应用效果。

The BZ Oilfield in Bohai area is a typical narrow channel sand oilfield developed by water injection. At present, there is a very high wellhead pressure in part of the injection wells. It is urgently necessary to analyze the cause of high wellhead pressure and the injection capacity of the injection wells in the oilfield. The authors, by adopting the theory of percolation mechanics and taking consideration of the variation of the thickness and permeability of the narrow channel reservoirs, derived the calculation formula of the injection pressure in the narrow channel reservoirs. The results are very close to the numerical simulation. The formula analysis demonstrated that the high wellhead pressure was caused by the development mode of thin layer injection and thick layer production in the narrow channel reservoirs. A theory plate of maximum water injection capacity was plotted by the formula of narrow channel reservoirs, which can be used to guide the proposing of acidizing measures and has achieved good application effect.