高含水期砂岩油田优势流场调整研究

Predominant flow field adjustment of sandstone reservoir in high water cut stage

高含水期油田存在的主要问题为:注水井注入水沿储层渗流阻力小的优势流场区域无效循环,采油井含水率高,储层剩余油零散分布,油田开发初期的配产配注参数对于高含水期已经不再适用。因此,本文以双河油田某高含水期区块为例,通过油藏数值模拟的方法,对该区块高含水期的合理注采参数进行了研究,确定在高含水期该区块最优的注采参数,通过模糊综合评价以及归一化处理方法对该区块进行了基于小层的优势流场模糊综合评价,得出高含水期该区块的流场分布图,确定了优势流场区域。最后通过对存在于优势流场中的注水井封堵无效循环层后,进行注水井以及采油井的注采参数优化调整,数值模型预测5年,该区块采收率累计提高1.59个百分点,累产油增量12.1×10~4t。

The main problem of high water cut oilfield is that water from injection wells ineffective circle along advantaged flow field area where the flow resistance is small, in addition, water content is high and remaining oil scatters, accordingly, production allocation and injection allocation parameters of high water-cut stage are no longer applicable in initial stage of oilfield development. Take high water-cut stage block of Shuanghe oilfield for example, by the adoption of reservoir numerical simulation, this paper studies reasonable injection and production parameters of high water cut stage in this area and determines the optimal parameters, moreover, by adopting fuzzy comprehensive evaluation method and normalized processing method, fuzzy comprehensive evaluation method of predominant flow field based on subzone is conducted, accordingly, flow field distributing graph of this area is obtained, and the predominant flow field area is determined. Finally, the cumulative recovery increases 1.59 percentage points and oil production rises up to 12.1 × 10^4t after injection well plugging which exists in advantaged flow field with optimal production wells and injection well parameters adjustment after five years of numerical model predict.